The tachometer circuit works in step with this principle; the pulses created by the reed contacts are counted inside an explicit time interval. The ensuing count is then displayed and represents the speed of the bike. 2 4026 ICs are used to count the pulses, decode the counter and management 2 7-segment LED show. RS flip-flops U3 and U4 perform as anti-bounce.
Electronic bicycle SP tachometer circuit diagram
Since batteries are used to power the circuit, it's not sensible to support the continual show of speed data. This circuit isn't continuously active. The circuit is activated solely once a button is pressed. a minimum of 3 permanent magnets should be put in on the wheel. The circuit are often calibrated with the assistance of another pre-calibrated tachometer.