F to V Converter Circuit using LM555 Timer
Here is a very simple circuit diagram of a frequency to voltage (F to V) converter. Such a circuit finds numerous applications in projects like digital frequency meters, tachometers etc. The circuit is mainly based on a LM555 timer IC. The IC is wired in mono shot mode to convert the input frequency into a fixed pulse width, variable frequency PWM signal. Resistors R4 and capacitor C2 provides the necessary timing for the circuit. The transistor T1 forms a discharge path parallel to C2 which is necessary for re triggering the IC. Capacitor C1 acts as an input DC decoupler.
- The circuit can be assembled on a Vero board.
- Use 12V DC for powering the circuit.
- LM555 must be mounted on a holder.
- The output of the circuit is not a pure DC but a PWM waveform. Additional circuitry is required to convert this PWM waveform to pure DC.
CircuitsToday.com has introduced an online store to buy books that provide the basics and applications of 555 timer IC. There are 3 books in store. You can buy them after reading our reviews. Know more- 3 Great Books to Learn 555 Timer Circuits and Projects