Hello every one.

Need a suggestions on constant current source with 1 mA to 500 mA range using a Digital Potentiometer.
Precision is 1mA difference.

Please view the uploaded file. the circuit is somehow am modifiy to the range of 1mA to 500mA range using Digital pot.

Present am using analog pot where am unable to change the output in the required range.
How can i set to the range of 1mA to 100mA by modifying the circuit?????

Please suggest on the circuit and also any other circuits will be appreciated.

input= 12v
current adjustment output= 1mA to 10omA
Voltage adjustment output= 1v to 12v
Precision current = 1mA difference

Best Regards.

 

Seems overly complex.

 

Seems overly complex.

can i find any other circuit by using DIGITAL POTENTIOMETER for required outputs. Please suggest or provide any links.

Thanks

 

I don't see how your circuit can provide controlled current over a 1-100mA range, and certainly not with 1mA accuracy? The current flowing from the LM317 pin 2 to the load is not monitored.

 

What is you load resistance?

 

If you need more precision with an analog pot, use a 10-turn type. Or add a second pot to provide a vernier adjust to the main pot (pot with smaller resistance connected as a rheostat in series with the main pot).