Testing two outputs with one electronic load?

[jwhitmore]

I've a uC controlling two 12V outputs that I'd like to test, but I've only got one electronic load. The obvious solution is to simply buy another electronic load, but for the moment, as a thought experiment, I was trying to think of a simple solution. Both 12V DC outputs are being switched from the same voltage source, so can be connected in parallel to give the same 12V output but the currents summed. So if both outputs are connected to the electronic load, which is measuring 10Amps then the sum of both outputs is giving 10Amps. Assuming both channels are more or less identical.

If I wanted to independently test the two output channels, A & B: say taking 1Amp from both but then stepping up channel A from 1A to 2A, 3A, 4A and finally 5A. So now 6Amps would be going to the electronic load. Then step up Channel B's output from 1A to 5A so 10Amps is being burned off in the electronic load.

I can't think of a way to do this, sort of having two independent electronic loads. That doesn't mean there isn't a way, it just means I can't think of one. There is an eevblog video on setting the current output with a FET but that FET would be getting hot burning off the power rather then my present electronic load.

[ogden]

I've a uC controlling two 12V outputs that I'd like to test, but I've only got one electronic load. The obvious solution is to simply buy another electronic load, but for the moment, as a thought experiment, I was trying to think of a simple solution. Both 12V DC outputs are being switched from the same voltage source, so can be connected in parallel to give the same 12V output but the currents summed. So if both outputs are connected to the electronic load, which is measuring 10Amps then the sum of both outputs is giving 10Amps. Assuming both channels are more or less identical.

If I wanted to independently test the two output channels, A & B: say taking 1Amp from both but then stepping up channel A from 1A to 2A, 3A, 4A and finally 5A. So now 6Amps would be going to the electronic load. Then step up Channel B's output from 1A to 5A so 10Amps is being burned off in the electronic load.

I can't think of a way to do this, sort of having two independent electronic loads. That doesn't mean there isn't a way, it just means I can't think of one. There is an eevblog video on setting the current output with a FET but that FET would be getting hot burning off the power rather then my present electronic load.

Most of voltage regulators do not like paralleled outputs. Even if both regulators are stable - slightest voltage regulation difference error will put most of the load on one regulator only.

As you have quite popular 12V voltage, you can use 12V light bulb(s) as load on 2nd channel. Just two cents.