Simple variable current source

[Ray Parkhurst]

Hi...my first post on the new forum.

Anyone have a schematic for a simple variable current source? I need to drive up to 1A, plus or minus, from a 12V supply. Controlled by a rotary switch with resistive divider or similar. Needs to go to zero on the way from minus to plus.

 

[mich4el.crx]

For schematics, I'd suggest checking websites like Texas Instruments or Analog Devices. They have tons of great reference designs for this kind of thing.

 

[J Deauxman]

TI’s improved Howland current pump can deliver ±1 A from 12V using a sense resistor and a rotary set reference, with a rail‑to‑rail op amp driving a push pull stage to maintain compliance and manage heat. What load resistance range are you targeting, since that determines the required compliance voltage and dissipation?

 

[Circuitsmith]

You could also check out the LT3092, or other similar programmable current source chips. They're easy to use and steady. Plus, you can copy them for bipolar output using an op-amp inverter.