1. ALPHA COLLEGE OF ENGINEERING & TECHNOLOGY

2. GROUP : 5 Korat Hardeep (130510109033) Kotadia Smith (130510109034)
Makvana Chirag ( )
Kunjadiya Abhishek ( )
Makwana Nikhil ( )
Chauhan Maulik ( )
Guided by :
Proff. DHARMESH GEHLOT

3. VOLTAGE TO CURRENT CONVERTERS
Voltage to Current Converter with Floating Load.
Low Voltage AC Voltmeter.
Voltage to Current Converter with Grounded Load.

4. Voltage to Current Converter with Floating Load.
Fig.-voltage to current converter with floating load

5. The load( ) is called as floating load because it is not connected to ground.
In this the input voltage is applied to the non-inverting terminal of OP-AMP. Load resistance is connected in place of the feedback resistor( )
This circuit is also called current series negative feedback amplifier. This is because of the feedback voltage across is proportional to output current & appear in series with the input voltage.
Apply KVL to the input loop of circuit,
Assume that the op-amp is an ideal one. Hence Substituting this value into upper equation ,

6. But …(as )
Sensitivity of this circuit is 1/ .
Hence sensitivity can be increased by decreasing the value of R1.
Voltage To Current Converters is used in application such as low voltage AC voltmeters, LED and zener diode testers etc.

7. Low Voltage AC Voltmeter
In this finger a combination of bridge rectifier and ammeter is connected in place of of V to I converter.
The rectifier converts ac current to dc current. Thus the unidirectional dc current flows through the ammeter. Hence the ammeter measures the average value of the rectified current.

8. Fig.-Voltage-to-current converter (Transconductance amplifier).
Voltage to Current Converter with Grounded Load
Fig.-Voltage-to-current converter (Transconductance amplifier).

9. Fig.-Voltage-to-current converter with grounded load.
Voltage to Current Converter (Inverting)
Fig.-Voltage-to-current converter with grounded load.

10. Fig.- Voltage-to-current converter with grounded load.
Voltage to Current Converter (Non Inverting)
Fig.- Voltage-to-current converter with grounded load.

11. Voltage to Current Converter (non Inverting) (step 1)

12. Voltage to Current converter (step 2)

13. LED Tester
We can use this this circuit as LED tester by putting the switch into position-3.
The LED test current i.e. is set by setting the values of and .
We can test different LEDs for their brightness fir the same test current .

14. Thank You