Illustrate the working of V-to-I and I-to-V converters with neat circuit diagrams.

1. I to V converter :- Current to voltage converter is required for circuits which need off In the form of voltage to control the further process. The converters are required to control the solenoid valves of actuator or valves. The voltage obtained at the O/P of the convertor is proportional to change of current at the input. If instrument which requires O/P in the form of voltage has I/P imedance very large than the converting resistor then the O/P can be easily obtained by using simple resistor circuit. But if the value of converting resister is larger than the input impedance of the instrument then the convertor with op-amp. The current to voltage converter is analyze by using KCL, If the KCL is applied at inverting voltage then,

$$\frac{V_{out} - V}{R_f} = I_p + I^-$$

As The O/P is connected to inverting V through feedback resistor $R_p$. Negative feedback configuration of op amp is given as $V^{-} = V^+ = 0$. Assuming $I^- = 0$ and the output voltage is obtained by follow equation -

$$V_{out} = I_p R_p$$

1. V to I convertors :- In this circuit the load resistor $R_L$ is kept floating and not linked to ground. In input voltage $V_{in}$ is given to non-inverting terminal. The feedback voltage across the the load resistor $R_L$ is used to drive the inverting terminal. The load voltage is in series with $V_D$ voltage i.e. the differential voltage between both the I/P terminal. The load voltage is in series with $V_D$ voltage, the differential voltage between both the I/P terminals. The load current is used to determine the feedback to voltage.

For the input loop, the voltage equation is -

$$V_{in} = V_D + V_F$$

$$Since\ F\ is\ very\ large,$$

$$V_D = 0$$

$$So,\ V_{in} = V_F$$

$$Since,\ the\ input\ to\ the\ op-amp.$$

$$I_B = 0$$

$$V_{in} = I_L * R$$

$$Therefore,\ I_I = I_L = \frac{V_{in}}{R}$$

To determine the load current e should known the I/P voltage and I/P resistance between $I_L \lt V_{in}.$

The load current is directly proportional to input voltage and controlled by resistor R.