CHECK ENGINE WITH INDUCED CURRENT

In my project, I have two engines that go at constant speed.
I would like that when I brake or block an engine, recover (the current or voltage induced in the engine, I do not know) and speed up the speed of the other engine.
Is it possible?
Thank you

If you put a load on an electric motor which causes it to slow down the current will increase and it would be possible to use the change in current to detect the change in speed. However I don't know what sort of precision would be possible. And measuring small changes in current is not simple. For an Arduin you will need some sort of circuit that changes the variations in current into voltage variations and the normal Analog to Digital Converter is designed to work between 0 and 5v whereas your voltage variations are likely to be in the millivolt range.

IMHO it would be much simpler to put a detector on each motor that allows the Arduino to measure the time for each revolution. I use the QRE1113 reflective optical detector for that. I have a black disk on the motor shaft with a blob of white paint on the disk.

...R

bvking:
In my project, I have two engines that go at constant speed.
I would like that when I brake or block an engine, recover (the current or voltage induced in the engine, I do not know) and speed up the speed of the other engine.
Is it possible?
Thank you

Two PMDC motors in series will tend to do this, if I understand you right, they will tend to equalize
load torques.

I connected two engines in series and indeed when I block the engine closest to the battery the other accelerates. But when I block the other engine, the closer to the battery accelerates but less quickly.
If I want the rotation speed to be the same in both cases (when I block the first or second engine) what should I do?
I think that I will have to go through an accurate measurement of the voltage drop, put this information in Arduino and increment the speed of rotation according to the voltage drop.
Do you have a precise connection or sensor because my engines are running slowly and I would like to see the fact that a small rubbing on my part slightly accelerates the other engine.
thanks again

bvking:
If I want the rotation speed to be the same in both cases (when I block the first or second engine) what should I do?

You won't be able to achieve that unless you have completely separate control of the speed of both motors - in other words a situation where a load on one motor does not affect the other one.

And, as I suggested earlier, IMHO it will be much easier to control speed by measuring it with a suitable revolution detector rather than by measuring current.

...R

bvking:
If I want the rotation speed to be the same in both cases (when I block the first or second engine) what should I do?

Ensure the motors are well matched, as are their loads. Higher quality motors will behave better as they
have less losses (friction and electrical resistance).