Supreem Circuits Diagram and Projects: SWITCHS

Simple Sound-Activated Lamp (Relay/Switch)

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This simple <b>Sound-Activated Lamp</b> circuit shown int the schematic diagram actives the switch  using sound. We can use this circuit for various applications, such as  automatic (sound-controlled) disco light or car’s LED light show.  The  Q1 amplify the audio from mic. The R1 is used to adjust the peak of  signal to greater than about 0.7 volts, act as sensitivity adjuster. A  certain level, the signal coming from microphone, after amplification by  Q1, will trigger the SCR and light lamp I1. If we change the lamp with a  relay, then we can get a sound-activated relay/switch, which can be  used to control more powerful / high wattage high voltage lamps. If we  use a relay, place a 1N4007 diode in parallel with the relay coil to  prevent the back-emf from  relay coil destroying the SCR. </div>
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<b> Sound-Activated Lamp Circuit Diagram</b></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEidqrniTv-jFWhjYIEHAA-V39i70nFWC8zt_j6YdxZvgUBAeChSxlnqifFU0UCzRvn7lU52Mi4sjKkNeYeU27a5YVJ3iQsZRFIv_gd8VeXBjTo6RVwVFZRmZeR8bsLB9TEuUApUyLGuFZ66/s401/Sound-Activated+Lamp.gif" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt=" Sound-Activated Lamp Circuit Diagram" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEidqrniTv-jFWhjYIEHAA-V39i70nFWC8zt_j6YdxZvgUBAeChSxlnqifFU0UCzRvn7lU52Mi4sjKkNeYeU27a5YVJ3iQsZRFIv_gd8VeXBjTo6RVwVFZRmZeR8bsLB9TEuUApUyLGuFZ66/s1600/Sound-Activated+Lamp.gif" title=" Sound-Activated Lamp Circuit Diagram" /></a></div>
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Simple Sound-Activated Lamp (Relay/Switch)

This simple Sound-Activated Lamp circuit shown int the schematic diagram actives the switch using sound. We can use this circuit for var...

Using 555 Timer - Voltage Controlled Switch

555, SWITCHS 05:39

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In this circuit the 555 timer is used in a novel way, as a voltage  controlled switch.The old and omnipresent NE555 can be very good at  something it was not meant for: driving relays or other loads up to 200  mA. The picture shows an example circuit: if the input level rises over  2/3 of the supply voltage - it will turn on the relay, and the relay  will stay on until the level at the input drops below one third of the  supply voltage.<br />
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If the relay and D1 were connected between pin 3 and ground, the relay  would be activated when the input voltage drops below one third, and  deactivated when the input voltage goes over two thirds of the supply  voltage. It is also a nice advantage that the input requires only about 1  uA, which is something bipolar transistors can't compete with. (This  high impedance input must not be left open.) A large hysteresis makes  the circuit immune to noise. The output (pin 3) can only be either high  or low (voltage-wise), and it changes its state almost instantenously,  regardless of the input signal shape.<br />
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The voltage drop across the NE555's output stage (at 35-100 mA) is  0.3-2.0 V, depending on the way the relay is connected and the exact  current it draws. D1 is absolutely vital to the safety of the integrated  circuit.</div>
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Using 555 Timer - Voltage Controlled Switch

In this circuit the 555 timer is used in a novel way, as a voltage controlled switch.The old and omnipresent NE555 can be very good at s...

High and Low Mains Voltage Cut Off Circuit Diagram

SWITCHS 05:21

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<img border="0" height="229" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgAuk1lS8EORwaW9rUCYQdNfhyphenhyphenYAPZeEIrypmNcBR6PbmjiIdvbl7NZ_di0srnk5q2Izzx0YtBzOuO7M8LKoGt3XLyEI8-z1YQHeaZfOoZ9wGeyjgsEoDSZzi-w1X4Urc-ctRfiqW0A4TI/s320/OVER+VOLTAGE+UNDER+VOLTAGE.png" width="320" /></div>
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Are you having problems with your input Mains supply? That’s common  problem associated with our input mains AC line, where a high and a low  voltage conditions are quite frequently encountered by us. The simple  circuit shown here can be built and installed in you house electrical  board for getting a 24/7 safety from the possible dangerous AC voltage  conditions. The circuit keeps the relay and the wired appliances as long  as the mains input stays within a safe tolerable level and switches the  load OFF the moment a dangerous or unfavorable voltage condition is  sensed by the circuit.<br />
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<b>Parts List</b></div>
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R1, R2 = 1K,</div>
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P1, P2 = 10K Preset,</div>
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T1, T2 = BC547B,</div>
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C1 = 100uF/25V,</div>
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D1 = 1N4007</div>
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RL1 = 12V, SPDT,</div>
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TR1 = 0-12V, 500mA<br />
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Sourced By: Homemadecircuits </div>
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High and Low Mains Voltage Cut Off Circuit Diagram

Are you having problems with your input Mains supply? That’s common problem associated with our input mains AC line, where a high and ...

Simple Timer Circuit with Independent On and OFF Delay Adjust Facility

SWITCHS 07:38

Simple Timer Circuit with Independent On and OFF Delay Adjust Facility

The circuit can be used for generating delays at a desired rate. The On time of the relay can be controlled by adjusting the Pot VR...

TOUCH SWITCHS

SWITCHS 05:58

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<b>TOUCH SWITCH 1</b><br />
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This circuit detects the skin resistance of a finger to deliver a  awfully tiny current to the super-alpha try of transistors to show the  circuit ON. The output of the "super transistor" activates the BC 557  transistor. The voltage on the highest of the world is passed to the  front of the circuit via the 4M7 to require the place of your finger and  also the circuit remains ON.</div>
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 To turn the circuit OFF, a finger on the OFF pads can activate the primary transistor and this may rob the <br />
"super transistor" of voltage and also the circuit can close up. </div>
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<b>TOUCH SWITCH-2</b><br />
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This circuit detects the skin resistance of a finger to show the circuit  ON for concerning one second. The output are often taken to a counting  circuit. The circuit consumes no current when in quiescent mode:<br />
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<a href="http://streampowers.blogspot.com/2012/07/touch-switchs.html" target="_blank">http://streampowers.blogspot.com/2012/07/touch-switchs.html</a> </div>
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TOUCH SWITCHS

TOUCH SWITCH 1 This circuit detects the skin resistance of a finger to deliver a awfully tiny current to the super-alpha try of t...

The Gentle Touch Circuit Diagram

SWITCHS 11:33

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Consumer  appliances these days hardly ever have a proper mains switch. Instead,  appliances are turned on and off at the touch of a button on the remote  control, just like any other function. This circuit shows how a device  (as long as it does not draw too high a current) can be switched on and  off using a pushbutton. The approach requires that a microcontroller is  already available in the circuit, and a spare input port pin and a spare  output port pin are required, along with a little software. When power  is applied T1 initially remains turned off. When the button is pressed  the gate of T1 is taken to ground and the p-channel power MOSFET  conducts. The microcontroller circuit is now supplied with power. Within  a short period the microcontroller must take output PB1 high. This  turns on n-channel MOSFET T1 which in turn keeps T1 turned on after the  push-button is released.</div>
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Now the microcontroller must poll the state  of the push-button on its input port (PB0) at regular intervals.  Immediately after switch-on it will detect that the button is pressed (a  low level on the input port pin), and it must wait for the button to be  released. When the button is next pressed the device must switch itself  of f: to do this the firmware running in the microcontroller must set  the output port pin to a low level. When the button is subsequently  released T1 will now turn off and the supply voltage will be removed  from the circuit.</div>
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The circuit itself draws no current in the  off state, and for (rechargeable) battery-powered appliances it is  therefore best to put the switch before the voltage regulator. For  mains-powered devices the switch can also be fitted before the voltage  regulator (after the rectifier and smoothing capacitor). Since there is  no mains switch there will still be a small standby current draw in this  case due to the transformer. Be careful not to exceed the maximum  gate-source voltage specification for T1: the IRFD9024 device suggested  can withstand up to 20 V. At lower voltages R2 can be replaced by a wire  link; otherwise suitable values for the voltage divider formed by R1  and R2 must be selected.<br />
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<b>Circuit diagram:</b><br />
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 The Gentle Touch Circuit Diagram</div>
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The author has set up a small website for  this project at http://reweb.fh-weingarten.de/elektor, which gives  source code examples (which include dealing with pushbutton contact  bounce) for AVR microcontrollers suitable for use with AVR Studio and  GNU C. Downloads are also available at http://www.elektor.com.</div>
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Source by : <span style="color: black;"><a href="http://streampowers.blogspot.com/2012/06/gentle-touch-circuit-diagram.html" target="_blank">Streampowers </a></span></div>
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The Gentle Touch Circuit Diagram

Consumer appliances these days hardly ever have a proper mains switch. Instead, appliances are turned on and off at the touch of ...

Touch Switch II

555, SWITCHS 02:56

Touch Switch II

This circuit uses a 555 timer as the bases of the touch switch. You can learn more about 555 timers in the Learning section on my site. ...

Mini RS232 Data Switch

SWITCHS 11:59

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Only  simple materials and a little bit of skill are  needed to build an  RS232 switch. All that you need are two 9-way sub-D  plugs with solder  pins, a small piece of sheet aluminium, two sets of  screw retainer  posts, a 4-pole double-throw switch, a strain relief  sleeve and a  suitable plastic connector shell for a 25-way sub-D  connector, with  both in-line and right-angle cable entries (such as  Conrad Electronics  #711322). What is important is that the side cable  entry together with  its associated strain relief leaves enough room for  the switch. If  necessary, you may have to cut away a few square  millimetres of the  sidewall or a few ribs of the plastic shell.</div>
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<b>Project image :</b></div>
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 <span style="color: black;"><a href="http://www.ecircuitslab.com/" target="_blank"><img alt="Mini RS232 Data Switch Image" border="0" height="257" src="http://lh5.ggpht.com/-ooxAFpG5_HQ/T2zRwkZW1ZI/AAAAAAAAE3Q/-g7ZavHanm8/Mini%252520RS232%252520Data%252520Switch%252520Image%25255B6%25255D.png?imgmax=800" style="border-bottom: 0px; border-left: 0px; border-right: 0px; border-top: 0px; display: block; float: none; margin-left: auto; margin-right: auto;" title="Mini RS232 Data Switch Image" width="399" /></a></span> </div>
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Mini RS232 Data Switch Image</div>
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The  switch is operated via the in-line cable  opening, as can be seen from  the photo. A suitable switch with an  overall length of 29 mm can be  found in the Conrad catalogue under  order number 708232. The only  modification that must be made to the  connector shell is to drill two  holes for the retaining screws for the  switch (M2.6 screws) at a spacing  of 24 mm. </div>
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<b>Circuit diagram :</b></div>
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<span style="color: black;"><a href="http://lh6.ggpht.com/-mH2xS0nHRkA/T2zRx4-yIAI/AAAAAAAAE3Y/iaTzg6J1a5Q/s1600-h/Mini%252520RS232%252520Data%252520Switch%252520Circuit-Diagram%25255B7%25255D.png" target="_blank"><img alt="Mini RS232 Data Switch Circuit-Diagram" border="0" height="398" src="http://lh3.ggpht.com/-80Fo9d4rDRU/T2zRzenJtGI/AAAAAAAAE3g/1iLpdnhqPwU/Mini%252520RS232%252520Data%252520Switch%252520Circuit-Diagram_thumb%25255B5%25255D.png?imgmax=800" style="border-bottom: 0px; border-left: 0px; border-right: 0px; border-top: 0px; display: block; float: none; margin-left: auto; margin-right: auto;" title="Mini RS232 Data Switch Circuit-Diagram" width="450" /></a></span></div>
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<b>Mini RS232 Data Switch Circuit Diagram </b></div>
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Connect  the two sub-D connectors together  using the piece of aluminium and the  screw retainer posts. Then solder  the cable to the connectors and the  switch as indicated. The two  connectors are wired somewhat differently.  While the upper sub-D plug  is connected 1:1 with the input cable (with  the switch in the  appropriate position), the DCD, DTR, DSR and RI pins  of the lower  connector are left open. This is because RTS and CTS are  fully  sufficient for handshaking, as long as DTR and DSR are connected  to  each other. The only leads that are switched are RXD, RTS, TSD and  CTS.  The ground potential is fed from the cable to both connectors.  After  everything has been properly soldered together, you can fit  everything  into the cable shell as shown.</div>
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<span style="color: black;"><a href="http://streampowers.blogspot.com/2012/06/mini-rs232-data-switch.html" target="_blank">http://streampowers.blogspot.com/2012/06/mini-rs232-data-switch.html </a></span></div>
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Mini RS232 Data Switch

Only simple materials and a little bit of skill are needed to build an RS232 switch. All that you need are two 9-way sub-D plugs with ...

Automatic TV Lighting Switch

SWITCHS 03:29

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The  author is the happy owner of a television set  with built-in Ambilight  lighting in the living room. Unfortunately, the  television set in  the  bedroom lacks this feature. To make up for this,  the author attached a  small lamp to the wall to provide background  lighting, This makes   watching television a good deal more enjoyable,  but it ’s  not the  ideal solution. Although the TV set can be  switched  off with the  remote  control, you still have to get out of bed to switch  off the  lamp.</div>
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<b>Circuit diagram :</b></div>
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<b><a href="http://lh6.ggpht.com/-ddiNEhTd4rc/T2Dv6DLhAjI/AAAAAAAAEz8/GnjNmowziDw/s1600-h/Automatic%252520TV%252520Lighting%252520Switch-Circuit-Diagram%25255B6%25255D.png" target="_blank"><img alt="Automatic TV Lighting Switch-Circuit-Diagram" border="0" height="367" src="http://lh5.ggpht.com/-WViTqh-cPZk/T2Dv7nv66EI/AAAAAAAAE0E/qf-SNXMuzzI/Automatic%252520TV%252520Lighting%252520Switch-Circuit-Diagram_thumb%25255B4%25255D.png?imgmax=800" style="border-color: -moz-use-text-color; border-style: none; border-width: 0px; display: block; float: none; margin-left: auto; margin-right: auto;" title="Automatic TV Lighting Switch-Circuit-Diagram" width="500" /></a> </b></div>
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<b>Automatic TV Lighting Switch Circuit Diagram</b></div>
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Consequently,  the author devised this  automatic lighting switch that switches the  background light on and off  along with the T V set. The entire circuit  is fitted in series with  the mains cable of the TV set, so there’s no  need to tinker with the  set. It works as follows: R1 senses  the current  drawn by the TV  set.  It has a maximum value  of 50 mA in standby  mode,  rising  to around    500 m A  when  the  set  is  operating. The  voltage across R1 is  limited by D5 during negative  half- cycles  and   by  D1– D4  during  positive half-cycles.  T he  voltage  across  these   four diodes  charges capacitor C1 via D6 during positive  half-cycles.  This voltage  drives the internal LED of solid-state switch TRI1 via R2,  which causes  the internal triac to conduct and pass the mains voltage to  the  lamp.   Diode D7 is not absolutely necessary, but  it is  recommended  because the LED in the  solid-state switch is not especially  robust   and cannot handle reverse polarisation. Fuse  F1 protects the   solid-state switch against  overloads. T he  value  of  use d  here  (10   Ω)  for  resistor R1 works nicely with an 82-cm (32 inch)  LCD screen.  </div>
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With  smaller sets having lower  power  consumption, the value of R1 can be   increased to 22 or 33 Ω, in which  case you  should use a 3-watt type.  Avoid using an  excessively high  resistance, as otherwise TRI1 will  switch on when the TV set is in  standby mode.  Some TV sets have a  half-wave rectifier in the  power  supply, which places an unbalanced   load on the AC power outlet. If the  set only  draws current on negative  half-cycles, the cir-cuit won’t  work properly. In countries with   reversible AC power plugs you can  correct  the problem by simply  reversing the plug. Compared with normal  triacs, optically cou-pled  solid-state relays have poor resistance  to  high switch-on currents  (inrush currents). </div>
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For  this reason, you should be careful with   older-model TV sets with  picture tubes (due  to demagnetisation  circuits). If the relay fails,   it usually fails shorted, with the  result that the TV background light  remains on all the time. If you  build this circuit on a piece of  perf-board, you must remove all the  copper next  to conductors and  components carrying  mains voltage. Use  PCB terminal blocks with a  spacing of 7.5 mm. This way the separation  between the connections on  the solder  side will also be 3 mm. If you  fit the entire  arrangement  as a Class II device, all parts of  the  circuit at mains potential must  have a  separation of at least 6 mm  from any metal  enclosure or  electrically conductive exterior  parts  that can be touched. </div>
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<span style="color: black;"><a href="http://streampowers.blogspot.com/2012/06/automatic-tv-lighting-switch_11.html" target="_blank">http://streampowers.blogspot.com/2012/06/automatic-tv-lighting-switch_11.html</a> </span></div>
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Automatic TV Lighting Switch

The author is the happy owner of a television set with built-in Ambilight lighting in the living room. Unfortunately, the television s...

Simple Electronic Quiz Switch

SWITCHS 03:54

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One  of the common  rounds in the  quizzes is the  buzzer round. We are  describing here a simple electronic circuit that  can be used in any  test or quiz competition. In this circuit, only four  persons can  participate,  and  every  participant is assigned a certain  number.  Whenever a switch is pressed, the circuit locks the remaining  three  entries. At the same time, an alarm sounds and the designated  switch  number is displayed on the seven segment LED display.When a  player  presses his switch, the corresponding output of IC1 goes high.  Let us  suppose, when switch S1 is pressed, D1 input of IC1 goes low and  its  corresponding output Q1 goes high. As a result, current passes  through  D5 to piezo buzzer PZ1, which creates a beep. At the same time,  current  also passes through diodes D6-D7 to show the number on the LED   display.<br />
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<b>Circuit diagram:</b></div>
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<b><a href="http://lh4.ggpht.com/-__4rW2nnWHc/TtUtNKGW4iI/AAAAAAAAEMA/juaYFFZT48o/s1600-h/Simple%252520Electronic%252520Quiz%252520Switch%252520Circuit%252520Diagram%25255B7%25255D.png" target="_blank"><img alt="Simple Electronic Quiz Switch Circuit Diagram" border="0" height="300" src="http://lh5.ggpht.com/-Tv_UyG_M-KE/TtUtOR1WcnI/AAAAAAAAEMI/OA240SA0suM/Simple%252520Electronic%252520Quiz%252520Switch%252520Circuit%252520Diagram_thumb%25255B5%25255D.png?imgmax=800" style="border-bottom-width: 0px; border-left-width: 0px; border-right-width: 0px; border-top-width: 0px; display: block; float: none; margin-left: auto; margin-right: auto;" title="Simple Electronic Quiz Switch Circuit Diagram" width="500" /></a> </b></div>
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<b>Simple Electronic Quiz Switch Circuit Diagram</b></div>
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Similarly,  when any other switch (S2-S4) is pressed, the corresponding   number   gets  displayed  on  seven segment displaying DIS1 and buzzer  sounds.  Switch S5 is used to reset the display exclusively. Switch S5  is a push  to on switch. The circuit is powered by 9V battery. Assemble  the circuit  on a general purpose PCB and enclose it in a suitable  case  along with  seven segment display and piezo buzzer. The assembled  circuit can be  kept near the host and the switches connected through  the external can  be assigned to the players. </div>
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<span style="color: black;"><a href="http://streampowers.blogspot.com/2012/06/simple-electronic-quiz-switch.html" target="_blank">http://streampowers.blogspot.com/2012/06/simple-electronic-quiz-switch.html</a></span></div>
</div>

Simple Electronic Quiz Switch

One of the common rounds in the quizzes is the buzzer round. We are describing here a simple electronic circuit that can be used in ...

Simple Electronic Lock

SWITCHS 00:36

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There  are six (or more) push switches. To 'unlock'  you must press all the  correct ones at the same time, but not press any  of the cancel  switches. Pressing just one cancel switch will prevent the  circuit  unlocking. When the circuit unlocks it actually just turns on  an LED  for about one second, but it is intended to be adapted to turn on  a  relay which could be used to switch on another circuit. Please Note:   This circuit just turns on an LED for about one second when the correct   switches are pressed. It does not actually lock or unlock anything!</div>
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<b>Circuit diagram :</b></div>
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<b> <a href="http://lh3.ggpht.com/-Zwm2kMHU098/TmkAm0ea6sI/AAAAAAAADm0/eS-MFU4oTio/s1600-h/Simple%252520Electronic%252520Lock%252520Circuit%252520Diagram%25255B7%25255D.png" target="_blank"><img alt="Simple Electronic Lock Circuit Diagram" border="0" height="266" src="http://lh5.ggpht.com/-SGRiPIv87fo/TmkA1dpigTI/AAAAAAAADm4/dntx0jWqfNw/Simple%252520Electronic%252520Lock%252520Circuit%252520Diagram_thumb%25255B5%25255D.png?imgmax=800" style="border-bottom: 0px; border-left: 0px; border-right: 0px; border-top: 0px; display: block; float: none; margin-left: auto; margin-right: auto;" title="Simple Electronic Lock Circuit Diagram" width="500" /></a></b></div>
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Simple Electronic Lock Circuit Diagram</div>
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<b>Stripboard Layout :</b></div>
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<b><a href="http://lh4.ggpht.com/-IwjsuG8IEqQ/TmkA8cgJU-I/AAAAAAAADm8/xeJtoRMBHkE/s1600-h/Stripboard%252520Layout%25255B7%25255D.png" target="_blank"><img alt="Stripboard Layout" border="0" height="251" src="http://lh3.ggpht.com/-f2O2FWwgZy0/TmkBCsY_P5I/AAAAAAAADnA/cAWTosTaVAM/Stripboard%252520Layout_thumb%25255B5%25255D.png?imgmax=800" style="border-bottom: 0px; border-left: 0px; border-right: 0px; border-top: 0px; display: block; float: none; margin-left: auto; margin-right: auto;" title="Stripboard Layout" width="500" /></a></b></div>
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<b>Parts :</b></div>
<ul>
<li>resistors: 470, 100k ×2, 1M</li>
<li>capacitors: 0.1μF, 1μF 16V radial</li>
<li>on/off switch</li>
<li>push-switch ×6 (or more)</li>
<li>stripboard 12 rows × 25 holes</li>
<li>red LED</li>
<li>555 timer IC</li>
<li>8-pin DIL socket for IC</li>
<li>battery clip for 9V PP3</li>
<li> </li>
</ul>
A kit for this project is available from RSH Electronics: <span style="color: black;">www.kpsec.freeuk.com</span><br />
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<span style="color: black;"><a href="http://streampowers.blogspot.com/2012/06/simple-electronic-lock.html" target="_blank">http://streampowers.blogspot.com/2012/06/simple-electronic-lock.html </a></span></div>
</div>

Simple Electronic Lock

There are six (or more) push switches. To 'unlock' you must press all the correct ones at the same time, but not press any ...

12v Light / Dark Switch

SWITCHS 10:26

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Often,  for certain low voltage lighting systems; you would like to turn  off  the lights during the bright light of the day.  Most commercial   day/night switches are designed for AC lighting.  This hobby circuit   below was designed for a 12v DC system.  But, it could be modified for   other voltage as well.  It uses an inexpensive photo-transistor as the   light detector.  An n-channel FET is used to switch power to the   lights.  A transistor circuit is included to provide some hysteresis.  </div>
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This keeps the circuit from  fluttering the light during the transition  from day to night and night  to day.  It is recommended that a plastic  tube be placed over the  transistor to prevent it from being illuminated  by the lights it is  controlling.  By selecting the appropriate power  FET, the circuit could  control over 100 watts worth of 12v lighting.    (July 22, 2008)</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh15yBWB_LzVfTYgD3baBhp5cFaP7GWBIeef1WvH52NzxfVzsR6DuOKqSQMNp8y2Kg_72L6pxen1Q-7zXUMQhVhbvvzF0xsKfQg-X5azv_sqd79shCHlYu-77KC4_t54f5UML1LhuwoBes/s1600/12v+LightDark+Switch.gif" style="margin-left: 1em; margin-right: 1em;"><img alt="Circuit Project:12v LightDark Switch" border="0" height="245" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh15yBWB_LzVfTYgD3baBhp5cFaP7GWBIeef1WvH52NzxfVzsR6DuOKqSQMNp8y2Kg_72L6pxen1Q-7zXUMQhVhbvvzF0xsKfQg-X5azv_sqd79shCHlYu-77KC4_t54f5UML1LhuwoBes/s400/12v+LightDark+Switch.gif" title="Circuit Project:12v LightDark Switch" width="400" /></a></div>
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Source: DiscoverCircuits</div>
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12v Light / Dark Switch

Often, for certain low voltage lighting systems; you would like to turn off the lights during the bright light of the day. Most co...

Simple Automatic Headlight Brightness Switch Circuit Diagram

LED, SWITCHS 11:15

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Going by car the highway with your high-beam headlights can actually increase your visibility, but can be a blinding hazard for other drivers. This easy circuit can be connected into your headlight swap to provide automatic swaping between high and reduced beam headlights when there is oncoming traffic. It does this by feeling the lights of that traffic. In this way, you can propel securely with your high-beams on without blinding other drivers. </div>
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 <b>Automatic Headlight Brightness Switch Circuit Diagram</b></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg5-hWzqETGcRYxaqdW-ZLw0XcbpCGYzh0hvCKLVqT3hmYMTpcnYEhxCDgbAyV0w4c7xRIPq_PWTUhadpliQ_0fem82B9KVYApe-HAPe74FD24NLwPqmOxU76Bs-eOBMAb5hLOxAsFSQJ-4/s1600/Automatic+Headlight+Brightness+Switch+Circuit+Diagram.gif" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="Automatic Headlight Brightness Switch Circuit Diagram" border="0" height="382" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg5-hWzqETGcRYxaqdW-ZLw0XcbpCGYzh0hvCKLVqT3hmYMTpcnYEhxCDgbAyV0w4c7xRIPq_PWTUhadpliQ_0fem82B9KVYApe-HAPe74FD24NLwPqmOxU76Bs-eOBMAb5hLOxAsFSQJ-4/s400/Automatic+Headlight+Brightness+Switch+Circuit+Diagram.gif" title="Automatic Headlight Brightness Switch Circuit Diagram" width="400" /></a></div>
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<li>Q1 should me mounted in such a way so it points toward the front of the car with a clear line of site. </li>
<li>Suitable places are on the dashboard, in the front grill, etc.</li>
<li>Adjust all the pots for proper response by testing on a deserted road.</li>
<li>S1 enables and disables the circuit.B1 is, obviously, in the car already.</li>
<li>Before you try to connect this circuit, get a wiring diagram for your car. </li>
<li>Some auto manufacturers do weird things with wiring.</li>
<li>Connection A goes to the high beam circuit, B goes to the headlight switch common and C connects to the low beam circuit.</li>
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<span style="color: #eeeeee;"><b><span style="font-family: Arial;">Part</span></b></span></center>
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<span style="color: #eeeeee;"><b><span style="font-family: Arial;">Total Qty.</span></b></span></center>
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<span style="color: #eeeeee;"><b><span style="font-family: Arial;">Description</span></b></span></center>
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<span style="color: #eeeeee;"><b><span style="font-family: Arial;">Substitutions</span></b></span></center>
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<tr bgcolor="#072653"><td><span style="color: #eeeeee;">R1</span></td><td><span style="color: #eeeeee;">1</span></td><td><span style="color: #eeeeee;">5K 1/4W Resistor</span></td><td><span style="color: #eeeeee;"><br /></span></td></tr>
<tr bgcolor="#072653"><td><span style="color: #eeeeee;">R2, R3, R4</span></td><td><span style="color: #eeeeee;">3</span></td><td><span style="color: #eeeeee;">5K Pot</span></td><td><span style="color: #eeeeee;"><br /></span></td></tr>
<tr bgcolor="#072653"><td><span style="color: #eeeeee;">Q1</span></td><td><span style="color: #eeeeee;">1</span></td><td><span style="color: #eeeeee;">NPN Phototransistor</span></td><td><span style="color: #eeeeee;"><br /></span></td></tr>
<tr bgcolor="#072653"><td><span style="color: #eeeeee;">Q2</span></td><td><span style="color: #eeeeee;">1</span></td><td><span style="color: #eeeeee;">2N3906 PNP Transistor</span></td><td><span style="color: #eeeeee;"><br /></span></td></tr>
<tr bgcolor="#072653"><td><span style="color: #eeeeee;">K1</span></td><td><span style="color: #eeeeee;">1</span></td><td><span style="color: #eeeeee;">Low Current 12V SPST Relay</span></td><td><span style="color: #eeeeee;"><br /></span></td></tr>
<tr bgcolor="#072653"><td><span style="color: #eeeeee;">K2</span></td><td><span style="color: #eeeeee;">1</span></td><td><span style="color: #eeeeee;">High Current 12V SPDT Relay</span></td><td><span style="background-color: red;"><span style="color: #eeeeee;"><br /></span></span></td></tr>
<tr bgcolor="#072653"><td><span style="color: #eeeeee;">S1</span></td><td><span style="color: #eeeeee;">1</span></td><td><span style="color: #eeeeee;">SPST Switch</span></td><td><span style="background-color: red;"><span style="color: #eeeeee;"><br /></span></span></td></tr>
<tr bgcolor="#072653"><td><span style="color: #eeeeee;">B1</span></td><td><span style="color: #eeeeee;">1</span></td><td><span style="color: #eeeeee;">Car Battery</span></td><td><span style="background-color: red;"><span style="color: #eeeeee;"><br /></span></span></td></tr>
<tr bgcolor="#072653"><td><span style="color: #eeeeee;">MISC</span></td><td><span style="color: #eeeeee;">1</span></td><td><span style="color: #eeeeee;">Case, wire, board, knobs for pots</span></td><td><span style="background-color: red;"><span style="color: #eeeeee;"><br /></span></span></td></tr>
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Simple Automatic Headlight Brightness Switch Circuit Diagram

Going by car the highway with your high-beam headlights can actually increase your visibility, but can be a blinding hazard for other driv...

Alternating ON-OFF Control

SWITCHS 01:58

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Use this circuit instead of a standard on-off switch. Switching is very gentle. Connect unused input pins to an appropriate logic level. Unused output pins *MUST* be left open!. First 'push' switches ON, another 'push' switches OFF. You can use 1/4 watt resistors if they are metal-film type. Any proper substitute will work for Q1, including the european TUN's. For C2, if you find the relay acts not fast enough, leave it out or change to a ceramic cap between 10 and 100nF.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZLfpO-zzKdpQqFZSPXOgHlMICcrSCOYcogten7VPdF6WnXgvBtD-lFYRRymKzV0GCCdpBUVB2fcQLNw0DCSQXIztgbODX4rZkqit74EuhZfqZcXJ31HfxCwcxCP_leucL68V-1t5CFN5X/s1600/on+off.PNG" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZLfpO-zzKdpQqFZSPXOgHlMICcrSCOYcogten7VPdF6WnXgvBtD-lFYRRymKzV0GCCdpBUVB2fcQLNw0DCSQXIztgbODX4rZkqit74EuhZfqZcXJ31HfxCwcxCP_leucL68V-1t5CFN5X/s1600/on+off.PNG" /></a></div>
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<b>Parts List</b><br />
All resistors are 1/2 Watt and 5% tolerance.<br />
R1 = 10K<br />
R2 = 100K<br />
R3 = 10K<br />
C1 = 0.1µF, Ceramic<br />
C2 = 1µF/16V, Electrolytic<br />
D1= 1N4001<br />
Q1 = 2N4401 (ECG123AP, NTE123AP, etc.)<br />
IC1 = 4069, CMOS, Hex Inverter (14069), or equivalent<br />
S1 = Momentary on-switch<br />
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Source by : <a href="http://streampowers.blogspot.com/2011/08/alternating-on-off-control.html" target="_blank">Streampowers </a></div>
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Alternating ON-OFF Control

Use this circuit instead of a standard on-off switch. Switching is very gentle. Connect unused input pins to an appropriate logic level. U...

Video Switch for Intercom System

SWITCHS 00:07

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Nowadays  a lot of intercom units are  equipped with  video cameras so that you  can  see as well as hear who is at the door.  Unfortunately, the camera  lens is perfectly placed to serve as a sort  of support point for  people  during the conversation, with the result  that  there’s hardly  anything left see in the video  imagery.  One way  to solve this problem  is to install two cameras on the street side  instead only  one,  preferably some distance apart. If you  display the  imagery from the  two cameras  alternately, then at least half of the  time you  will be  able to see what is happening in front  of the door.  Thanks to the  video switch module described  here, which should be  installed on the  street  side not too far away from the two cameras,   you need only one  monitor inside the house and you don’t need to install  any additional  video cables.  </div>
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<b>Video Switch for Intercom System Circuit Diagram</b></div>
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Along  with a video switch, the circuit  includes  a video amplifier that has  been used with  good results in  many other Elektor projects,  which  allows the brightness and the  contrast  to be adjusted separately. This  amplifier is  included  because the distance between the  street and the  house may be rather  large, so it is helpful to be able to compensate for  cable attenuation  in this manner.  The switch stage is built around the  well  known 4060  IC, in which switches IC2a and  IC2d alternately pass  one of the two  signals to  the output. They are driven by switches IC2b  and IC2c,  which generate control signals that  are 180 degrees out of  phase. The  switching rate for the video signals is  determined by a  clock signal  from an ‘old  standby’ 555 IC, which causes the signals to   swap every 2  seconds with the speciﬁed com ponent values.  </div>
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Naturally,   this circuit can also used in many other situations, such as where two   cameras are needed for surveillance but only one video cable is   available. </div>
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 <a href="http://streampowers.blogspot.com/2012/06/video-switch-for-intercom-system_11.html" target="_blank">http://streampowers.blogspot.com/2012/06/video-switch-for-intercom-system_11.html</a></div>
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Video Switch for Intercom System

Nowadays a lot of intercom units are equipped with video cameras so that you can see as well as hear who is at the door. Unfortunate...

Solid-State Switch For Dc-Operated Gadgets

SWITCHS 00:41

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This  solid state DC switch can be assembled using just three  transistors  and some passive components. It can be used to switch on one  gadget  while switching off the second gadget with momentary operation  of  switch. To reverse the operation, you just have to momentarily  depress  another switch. </div>
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The circuit operates over 6V-15V  DC  supply voltage. It uses positive feedback from transistor T2 to   transistor T1 to keep this transistor pair in latched state (on/ off),   while the state of the third transistor stage is the complement of   transistor T2’s conduction state. </div>
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Initially when switch S3 is   closed, both transistors T1 and T2 are off, as no forward bias is   available to these, while the base of transistor T3 is effectively   grounded via resistors R8 and R6 (shunted by the load of the first   gadget). As a result, transistor T3 is forward biased and gadget 2 gets   the supply. This is indicated by glowing of LED2. </div>
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<b><span style="color: blue;"><a href="http://lh5.ggpht.com/-7wm6GjBOSOk/UBbb09MHANI/AAAAAAAAHPo/m0Pk5cXK-vk/s1600-h/Solid-State%252520Switch%252520For%252520Dc-Operated%252520Gadgets-Circuit%252520Diagram%25255B7%25255D.png" target="_blank"><img alt="Solid-State Switch For Dc-Operated Gadgets-Circuit Diagram" border="0" height="293" src="http://lh4.ggpht.com/-ohBynY7qcdA/UBbb29oqd5I/AAAAAAAAHPw/mvn_koUjj9U/Solid-State%252520Switch%252520For%252520Dc-Operated%252520Gadgets-Circuit%252520Diagram_thumb%25255B5%25255D.png?imgmax=800" style="border-color: -moz-use-text-color; border-style: none; border-width: 0px; display: block; float: none; margin-left: auto; margin-right: auto;" title="Solid-State Switch For Dc-Operated Gadgets-Circuit Diagram" width="450" /></a> </span></b><br />
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<b>Solid-State Switch For Dc-Operated Gadgets Circuit Diagram</b></div>
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When  switch S1 is momentarily  depressed, T1 gets the base drive and it  grounds the base of transistor  T2 via resistor R4. Hence transistor T2  (pnp) also conducts. The  positive voltage available at the collector of  transistor T2 is fed  back to the base of transistor T1 via resistor R3.  Hence a latch is  formed and transistor T2 (as also transistor T1)  continues to conduct,  which activates gadget 1 and LED1 glows. </div>
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Conduction  of transistor T2  causes its collector to be pulled towards positive  rail. Since the  collector of T2 is connected to the base of pnp  transistor T3, it  causes transistor T3 to cut off, switching off the  supply to gadget 2)  as well as extinguishing LED2. This status is  maintained until switch  S2 is momentarily pressed. Depression of switch  S2 effectively grounds  the base of transistor T1, which cuts off and  thus virtually opens the  base-emitter circuit of transistor T2 and thus  cutting it off. This is  the same condition as was obtained initially.  This condition can be  reversed by momentarily pressing switch S1 as  explained earlier. </div>
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<b>EFY lab note.</b>  During  testing, it was noticed that for proper operation of the  circuit, gadget  1 must draw a current of more than 100 mA (i.e. the  resistance of  gadget 1 must be less than 220 ohms) to sustain the  latched ‘on’ state.  But this stipulation is not applicable for gadget  2. A maximum current  of 275 mA could be drawn by any gadget.</div>
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Author : Praveen Shanker - Copyright : EFY</div>
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Solid-State Switch For Dc-Operated Gadgets

This solid state DC switch can be assembled using just three transistors and some passive components. It can be used to switch on one ...

USB Switch Schematic Circuit

SWITCHS 04:24

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Anyone  experimenting or developing USB ported peripheral hardware soon be  comes irritated by the need to disconnect and connect the plug  in order  to reestablish communication with the PC. This process is necessary for  example each time the peripheral equipment is reset or a new version of  the firmware is installed. As well as tiresome it eventually leads to  excessive contact wear in the USB connector. The answer is to build this  electronic isolator which disconnects the peripheral device at the  touch of a button. This is guaranteed to reduce any physical wear and  tear and restore calm once again to the workplace. </div>
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<b>Circuit image :</b><br />
 <span style="color: black;"><a href="http://www.ecircuitslab.com/" target="_blank"><img alt="USB Switch-Image" border="0" height="259" src="http://lh6.ggpht.com/-NePqWB4Q4bs/T_c2CvpUPiI/AAAAAAAAHGI/6e004fcguHs/USB%252520Switch-Image%25255B6%25255D.png?imgmax=800" style="border: 0px none; display: block; float: none; margin-left: auto; margin-right: auto;" title="USB Switch-Image" width="374" /></a></span> <br />
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USB Switch Schematic Circuit Image</div>
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The circuit uses a  quad analogue switch type 74HC4066. Two of the switches in the package  are used to isolate the data path. The remaining two are used in a  classic bistable flip-flop configuration which is normally built using  transistors. A power MOSFET switches the power supply current to the USB  device.  Capacitor C2 ensures that the flip flop always  powers-up in a  defined state when plugged  into the USB socket (‘B’ in the diagram). </div>
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The  peripheral device connected  to USB socket ‘A’  will therefore always be ‘not connected’ until   pushbutton S2 is pressed. This flips the bistable, turning on both  analogue gates in the data lines and switching the MOSFET on. The  PC  now recognises the USB device. Pressing  S1 disconnects the device.</div>
<b>Circuit diagram :</b><br />
<span style="color: black;"><a href="http://lh5.ggpht.com/-ctwiB2pA6yk/T_c2EQMAhqI/AAAAAAAAHGQ/Xjt1LpiMpy0/s1600-h/USB%252520Switch-Circuit-daigram%25255B6%25255D.png"><img alt="USB Switch-Circuit-daigram" border="0" height="274" src="http://lh5.ggpht.com/-fG1Z7JyguV8/T_c2F-N6zqI/AAAAAAAAHGY/LIlwkA107Yc/USB%252520Switch-Circuit-daigram_thumb%25255B4%25255D.png?imgmax=800" style="border: 0px none; display: block; float: none; margin-left: auto; margin-right: auto;" title="USB Switch-Circuit-daigram" width="450" /></a></span><br />
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<b>USB Switch Schematic Circuit Diagram</b></div>
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The circuit does not sequence  the connections as a physical USB connector does; the power supply  connection strips are slightly longer than the two inner data carrying  strips to ensure the peripheral receives power before the data signals  are connected. The electronic switch does not suffer from the same  contact problems as the physical  connector so these measures are not  required in the circuit. The  simple circuit can quite easily be  constructed on a small  square of perforated strip-board. </div>
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The design uses the 74HC(T)4066  type analogue switch, these have  better characteristics compared to the  standard 4066 device. The USB switch is suitable for both low-speed  (1.5 MBit/ s) and full-speed (12 MBit/s) USB ports applications but the  proper ties of the analogue switches and perf-board construction  will  not support hi-speed (480 MBit/s) USB operation. </div>
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The IRFD9024 MOSFET can pass a current of  up to 500 mA to the peripheral device with-out any problem.</div>
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 <span style="color: black;"><a href="http://streampowers.blogspot.com/2012/07/touch-switchs.html" target="_blank">http://streampowers.blogspot.com/2012/07/touch-switchs.html</a></span></div>
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USB Switch Schematic Circuit

Anyone experimenting or developing USB ported peripheral hardware soon be comes irritated by the need to disconnect and connect the plu...

AC Mains Bistable Switch

SWITCHS 04:23

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This  AC mains-operated bistable  switch turns on or turns off a   device  using a miniature neon  lamp and a few discrete components.  This   switch can be used for control pan-els, appliances and lighting   controls.  A push-to-on switch is used to  light up the neon lamp. The   light emit-ted by the neon lamp, in turn, enables  the switching action   of the circuit. Use  of a 555 timer wired for bistable operation makes   the circuit act as a bistable  switch.<br />
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<b>Circuit diagram :</b><br />
<b><a href="http://lh4.ggpht.com/-dw28FIB31_o/T7P-pU0DgVI/AAAAAAAAFjc/wtPlggvGrxg/s1600-h/AC%252520Mains%252520Bistable%252520Switch-Circuit%252520Diagram%25255B3%25255D.png" target="_blank"><img alt="AC Mains Bistable Switch-Circuit Diagram" border="0" height="172" src="http://lh6.ggpht.com/-fwKXMOW1Q0k/T7P-rbOtvQI/AAAAAAAAFjk/62a6wRI3EnE/AC%252520Mains%252520Bistable%252520Switch-Circuit%252520Diagram_thumb%25255B3%25255D.png?imgmax=800" style="border-bottom: 0px; border-left: 0px; border-right: 0px; border-top: 0px; display: block; float: none; margin-left: auto; margin-right: auto;" title="AC Mains Bistable Switch-Circuit Diagram" width="450" /></a> </b><br />
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<b>AC Mains Bistable Switch Circuit Diagram</b></div>
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The   neon lamp (NL1) and the  push-to-on switch (S1) are directly connected   to 230V AC mains. The 12V DC  supply for timer 555 (IC1) is derived    from 230V AC mains through capacitive dropper C1, resistor R1 and a 12V    zener diode. IC1 works as a flip-flop  circuit, with the signal at its   output  pin 3 toggling every time it receives a  pulse at its pins 2  and  6. </div>
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The operation of the circuit is  simple. When you press  switch S1 momentarily, the neon lamp glows,  making  phototransistor T1  conduct to provide  a pulse at pins 2 and 6  of IC1.  When switch S1 is  pressed, the output of IC1  goes high and  LED1 glows. Pressing S1  again  makes the output of IC1 low and  LED1  stops glowing.</div>
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In place  of LED1, you can use  an  optodiac or suitable relay (not shown  in the  circuit) along with a  suitable  driver circuit to drive AC loads.  Assemble the circuit on a  general-purpose PCB with the neon lamp and   the phototransistor housed  in a small  black tube isolated from the  external  light source, and  enclose in a suitable  cabinet. Fix switch  S1 on the  front panel of  the cabinet,  and mains power cord at  the  rear. At the rear, also fix   a 3-pin socket to connect the  AC load. </div>
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<b>Caution.</b>    Take care  when operating this circuit  as it is directly connected  to   230V AC mains. Better still,  don’t attempt this circuit  if you  have  no experience  in handling high-voltage  circuits.<br />
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Sourced By: EFY </div>
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<span style="color: black;"><a href="http://streampowers.blogspot.com/2012/06/ac-mains-bistable-switch.html" target="_blank">http://streampowers.blogspot.com/2012/06/ac-mains-bistable-switch.html</a> </span></div>
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AC Mains Bistable Switch

This AC mains-operated bistable switch turns on or turns off a device using a miniature neon lamp and a few discrete components. Th...

Green USB switch

SWITCHS 04:22

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According  to the Energy Saving  Trust, if you add up  all the current drawn in  standby mode by items such as stereos, TVs,  VCRs and DVDs over a year  in the UK alone, it amounts to 3.1 million  tonnes of CO2 released into  the atmosphere.This is without factoring in  the current drawn by all  the PCs,laptops and their associated  peripherals left in standby mode. </div>
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<b>Circuit diagram :</b><br />
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<span style="color: black;"><a href="http://lh4.ggpht.com/-d9MJiZWGlKM/T5wxj6HkDVI/AAAAAAAAFPg/NTDZbt6twrk/s1600-h/Green%252520USB%252520switch-Circuit%252520Diagram%25255B5%25255D.png"><img alt="Green USB switch-Circuit Diagram" border="0" height="450" src="http://lh4.ggpht.com/-b9A56YELC8w/T5wxmm5pU9I/AAAAAAAAFPo/39NYnt6scDc/Green%252520USB%252520switch-Circuit%252520Diagram_thumb%25255B3%25255D.png?imgmax=800" style="border-color: -moz-use-text-color; border-style: none; border-width: 0px; display: block; float: none; margin-left: auto; margin-right: auto;" title="Green USB switch-Circuit Diagram" width="450" /></a></span> </div>
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<b>Green USB switch Circuit Diagram</b></div>
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It   is  not  necessary  to  spend  a  great  deal of money or time to  make a  difference on a personal  level. The  circuit described here  is  designed for use by laptop or  notebook  computers. It will automatically  switch off all mains  powered  peripheral equipment  including monitor,  printer, scanner, TV tuner and  USB hub etc  when it detects that the  notebook  is switched off. The  circuit is quite  straightforward; in  addition to an  optocoupler it  requires a 12 V  double-pole  relay   with  mains  rated contacts and a  small power  supply  for  the   optocoupler.  When the laptop is  switched on  5 V appears at the USB  socket,  activating the relay and  switching  through  the  mains   supply  on K3 and K4. The notebook’s   USB socket is still available to  be  used as normal but it’s worth  remembering that the optocoupler   takes a few milliamps from the  USB  supply and this may cause a  problem  if a high-current device  is  plugged into the USB socket.  In the case  where the laptop has  more  than enough USB sockets it may be worthwhile  us-ing one of them solely  for this  circuit, the extension USB connector  K2 would then not be   required. </div>
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The circuit is  mounted into a  mains plug  enclosure which  provides a socket where  the  mains extension strip  will be  plugged into. With any luck  there  will be sufﬁcient space  to  ﬁt the entire circuit into the  mains  extension strip enclosure and  save the need for a  separate enclosure.  The slow-blow 6.3-A fuse (F1)  protects  the equipment plugged into  the  strip. </div>
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In  addition  to  the  optocoupler  and   relay the circuit also has a  ‘freewheel’ diode D1 and a relay  driver   formed by T1 and its base  bias voltage divider network R2/ R4. The two   ‘snubber’ networks  C1/R3 and C2/R5 reduce the  possibility of arcing   which can  occur  when  the  relay  contacts  open (especially with   inductive  loads). Capacitors C1 and C2  must be class X2 types which    can handle mains voltage plus any  spikes.  The  power  supply  consists   of a small mains trans-former  (12 V,  50 mA),  bridge  rectiﬁer and   smoothing capacitor C3. </div>
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The laptop’s mains  adaptor itself  can also  be switched by this circuit when the laptop is  ﬁtted with  its  rechargeable battery which  allows the computer to boot  up  without a  mains supply. The en-tire USB switch circuit draws  cur-rent even when  it is off but this value  is  tiny  compared  to   the  combined standby  current of all  the peripherals. </div>
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Note  that parts of this circuit are   connected to the (potentially lethal)  mains supply voltage; it is   essential to provide protection  to ensure  that nothing can  accidentally make contact with these  parts of the  circuit. It is also  important to observe correct separation between  parts of the circuit  carrying low voltage and  those carrying the high  volt-age. Please  observe the electrical Electrical Safety guide-lines  which are  reprinted in  Elektor  Electronics  several  times a year. </div>
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The   circuit  is  less  suitable  for use  with desktop PCs be-cause  the   majority  of  these  machines supply 5 V  over the  USB socket even  though they  have been shut down via  soft-ware. The only way to turn  off  in this case is to reach around   the back of the machine and   switch off at the main switch. </div>
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<span style="color: black;"><a href="http://streampowers.blogspot.com/2012/06/green-usb-switch.html" target="_blank">http://streampowers.blogspot.com/2012/06/green-usb-switch.html</a></span></div>
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Green USB switch

According to the Energy Saving Trust, if you add up all the current drawn in standby mode by items such as stereos, TVs, VCRs and DVD...

Dual High Side Switch Controller

Controller, SWITCHS 08:03

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<b>Circuit diagram :</b><br />
<span style="color: black;"><a href="http://lh5.ggpht.com/-psNnO3TEQzU/Tywu4Zc_-EI/AAAAAAAAEis/DcIkk0d-D8M/s1600-h/image3.png" target="_blank"><img alt="Dual High-Side-Switch-Controller-Circuit-Diagram" border="0" height="398" src="http://lh6.ggpht.com/-XeLEQ_7fNWo/Tywu7HNtxEI/AAAAAAAAEi0/di3s1y0r8oE/image_thumb1.png?imgmax=800" style="border-bottom-width: 0px; border-left-width: 0px; border-right-width: 0px; border-top-width: 0px; display: block; float: none; margin-left: auto; margin-right: auto;" title="Dual High-Side-Switch-Controller-Circuit-Diagram" width="400" /></a></span> <br />
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<b>Dual High Side Switch Controller Circuit Diagram</b></div>
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One  of the most frequent uses of n-channel  MOSFET’s is as a voltage  controlled switch. To ensure that the MOSFET  delivers the full supply  voltage to the load it is necessary for the  gate voltage to be a few  volts above the supply voltage level. This can  be a problem if no other  suitable higher volt-age sources are  available for use elsewhere in the  circuit. The LTC 1982 dual high-side  switch controller from Lin-ear  Technology (www.linear-tech.com) solves  this problem by incorporating a  voltage tripler circuit in the gate  driver stage. The gate voltage is  limited to +7.5 V which is 2.0 V  above the IC’s maximum operating  voltage. It can directly drive the  gate of logic-level MOSFET with a  VGS(th) from 1.0 V to 2.0 V. A  suitable n-channel logic level MOSFET  would be the BSP 295. This device  can switch up to 1.5 A and is  available in an SOT 233 SMD package.<br />
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<span style="color: black;"><a href="http://streampowers.blogspot.com/2012/06/dual-high-side-switch-controller.html" target="_blank">http://streampowers.blogspot.com/2012/06/dual-high-side-switch-controller.html</a> </span></div>
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Dual High Side Switch Controller

Circuit diagram : Dual High Side Switch Controller Circuit Diagram One of the most frequent uses of n-channel MOSFET’s is...

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