Ask for the advice of theorists) There is a wheel, say a Bicycle, which revolves with very high speed (tens of revolutions per minute, for example). The need to record how many turns it has made and depending on this, to output a voltage if spun quickly, say 5 volts, not spun 0. All doing to use for you do not want this(although you can), I would like to do a number of analog circuit. Have any options or is it better not to split hairs and use a microcontroller?
Magnets on the rim/spokes and the coil on the plug. Then a diode bridge and a smoothing capacitor.
nicklaus answered on July 9th 19 at 13:44
Sounds like you need a conventional transistor switch. The base current from the generator to the wheel via a trimming resistor. The collector/emitter your 5 volts. Resistor select this value to open the transistor that you need.
catalina_Sawa answered on July 9th 19 at 13:46
there are many options, but spoils the fact that the wheel bike.
optical sensor and ultrasonic sensor to exclude dirt.
remains contact and magnetic
magnetic - magnet mounted at a convenient point, and using the integrating resistor and capacitor the resulting voltage can flavor the amplifier at operatsionnyi to integration and after adjusting the gain to achieve the desired range. or take dorino and count the pulses.
contact - for example, microswich from the mouse clings to him arm so that the needle during the passage the meaning is the same integration and or durin, and count the pulses.
And you can make a knight's move and take the generator for a Bicycle, he will generate a voltage depending on revs.