An operational Amplifier IC LM741 used as a voltage to current. It is used for signal transmission of instrumentation like RTD THEROCOUPLE single from long distance to control circuits. Two type of current converter are.,
- Floating load Voltage to Current converter.
- Ground load Voltage to Current converter.
Floating load V to I converters are used as low voltage ac and dc voltmeters, diode,LED and zener diode testers. Voltage to current converters Grounded load are used in testing such devices as zener and LED forming a ground load.
Float Load V to I converter Circuit.
Formula: Floating load:- V – I converter.
Vin = Vid + Vf where Vid is input difference voltage and Vf is the feedback voltage
But Vid = 0
Vin = Vf = R1RL
IL = Vin/RL
- Give input voltage to the non-inverting terminal of 741 and vary the input voltage.
- Measure the ammeter reading for various values of input voltage.
Ground load V to I converter.
Formula: Ground load V – I converter.
I1+I2=IL
(Vin-V1)/R+(Vo-V1)/R=IL
Vin+Vo-2Vi=ILR
Since op-amp is non inverting
Gain=1+(R/R)=2
Vo=2Vi
Vin=Vo-Vo+ILR
IL=Vin/R
- First switch on the op-amp dual power supply.
- Give input voltage to the non-inverting terminal of 741 and vary the input voltage.
- Measure the ammeter reading for various values of input voltage
Greetings,
I wanted to know whether the V-I converter using IC 741 as designed here is working efficiently and also whether it can drive current upto 660 mA.
Thank You,
Chinmai P
Why voltage to current converter ia used for zenor diode test
Explain how a voltage to current converter can be used as
DC Voltmeter ?
AC Voltmete?r