F v converter circuit

Most of the tachometers include reflective strip which is placed on the object to be measured. The frequency to voltage converter is used in many applications where repeating event measurement requires like a wheel making a complete rotation.

This F to V converter is also used in place of the current encoders for the robots to measure velocity. The LM IC is a highly stable integrating circuit, that is used to produce precise oscillation or time delays. Extra terminals are provided for resetting or activating if desired. During time delay mode operation, the time is controlled by one external resistor or capacitor. The LM timer comprises of 8-pins and function of the each pin are discussed below. The F to V converter circuit requires a power supply circuit.

For the below circuit. This circuit uses a 12V DC supply for powering the owl circuit In the power supply circuit diagram the D4 and D3 bridges can be made using diodes 1N, and 1A bridge rectifier modules also exist in the market.

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. There are 3 books in store. You can buy them after reading our reviews. I am looking for a pulse width of about 1ms that can be pulsed over a period up to 1 second.

Thank you in advance. R5 and C4 determine the pulse width multiply these to values together in farads and ohms and you will get the time constant in seconds i. R5 and C4 lead to nowhere and can be omitted.

C1 and R1 define the fixed pulse width, but only for square wave signal with constant amplitude. R2 and R3 can be neglected while R1 is much smaller than R2 and R3. Otherwise a paralel combination of R1, R2 and R3 with some influence of D1 and Q1 must be considered. The IC1 act only as comparator with hysteresis.

R6 and C5 are that additional circuitry which was mentioned in the circuit description, but work only when R6 C5 time constant is longer than period of the input signal. This circuit is to decode contents of a modulated FM signal. In simple words this section of the circuit can be generally termed as a level shifter. The TC manufacturers claim that it can accept a signal of any frequency at its input. In the practical side, for the proper working of this circuit the positive half of the input signal must have at least 5uS pulse width and for the negative half it must be greater than or equal to 5uS.

For calibration adjust the offset adjust trimpot to obtain 0V at the output with no input frequency applied. If you have a function generator, set frequency input to 10KHz and make adjustments in the value of C ref to get around 2. This calibration is meant for a maximum input frequency of 10KHz. TC based frequency to voltage converter working from a dual supply is shown above. Compared to the single supply version, this circuit requires less number of components.

The circuit works only on a bipolar input frequency and if the frequency available to you is unipolar a positive pulse train , then convert it to bipolar using the circuit shown below. The output voltage of the based F to V converter is super imposed with a saw tooth ripple voltage which is inversely proportional to the value of the integrating capacitor C int. For low frequency inputs the ripple voltage can be reduced by increasing the value of C int. But this method is not suitable for high frequency inputs because the larger capacitance value will dramatically reduce the response time of the converter circuit.

A method for reducing the output ripple voltage without affecting the circuits response time is shown below. The circuit is nothing but an operational amplifier working in the common mode. Due to the common mode operation the AC ripple is rejected and pure DC level will be available at the output.

Trimpot R16 is used to adjust gain of inverting and non inverting inputs to the same value. This circuit will also act as a buffer.