Download VOLTAGE TO CURRENT CONVERTER USING OP AMP

ITM UNIVERSE
VOLTAGE TO CURRENT CONVERTER
USING OP AMP
Presented by –
Vyas Devanshi 140953109032
Raulji Shraddha 130950109076
Branch – Electrical B
Sem 3
VOLTAGE TO CURRENT CONVERTER
USING OP AMP
 (a) VOLTAGE TO CURRENT CONVERTER USING
OP AMP WITH FLOATING LOAD
 (b) VOLTAGE TO CURRENT CONVERTER USING
OP AMP WITH GROUNDED LOAD.
With Grounded Load
 In this circuit,one terminal of the load
is grounded and load current is
controlled by an input voltage.The
analysis of the circuit is accomplished
by first determining the voltage V1 at
the non inverting input terminal and
then establishing the relationship
between V1 and the load current.
Circuit Diagram
 Fig - VOLTAGE TO CURRENT CONVERTER USING
WITH GROUNDED LOAD




Writing KCL eqaution at node V1
I1+I2=IL
Vin-V1/R + V0-V1/R = IL
Vin V0-2V1=IL*R
 Therefore,
 V1=Vin+V0-IL*R/2
 Since the op-amp is connected in the
non inverting mode , the gain of the
circuit is
 1+R/R=2.
 Then the output voltage is
 V0=2V1

=Vin+V0-IL*R
 Vin=IL*R
 So IL=Vin/R
 That means the load current depends
on the input voltage Vin and resistor
R.Notice that all resistors are equal in
value.
 The VOLTAGE TO CURRENT CONVERTER
USING OP AMP shown in figure may aslo be
used in testing such devices as Zeners and
LEDs forming a ground load.
 However the circuit will perform
satisfactorily provided that load size less
than or equal to R value.
With Floated Load
 Fig shows a voltage to current
converter in which load resistor RL is
floating .The input voltage is applied
to the non inverting input terminal
and feedback voltgae across R1.
Circuit Diagram
 Voltage to current converter with
floating load
Writing KVL for input loop





Vin=Vid+Vf
But Vid=0Vm,since A is very large
Vin=Vf
Vin=R1*I0
I0=Vin/R1
Applications
 The voltage to current converter can
be used in such applications as low
voltage dc and ac voltmeters,diode
match finders,light emitting
diode,LEDs,and zener diode testers.
Thank You