DC Load Balancing Circuit for Equal Current Sharing Between Two 24V Fan Motors

Given a single DC source for example 24vdc, and two dc fan motors, is there a simple circuit, maybe with pass transistors, that would actively manage that both fans flowed the same amount of current?

Lets assume that the conditions of the two fans would be at different pressures and air densities, so just choosing identical fans would not assure equal current draw.

It would help if you could provide more details of what you are trying to do.

You could create two constant current sources and trim the for the same current. Or you could select one fan as the master and drive it through a current source and the second from a current mirror.

In both cases the voltage across the fans will differ- and I have no idea of the characteristic performance of each fan vis-a-vis voltage or current.

Aubrey,

Thanks for your response.

This "current mirror" you mention sounds like just the device to solve all my problems. After a very brief internet research session on the topic, I am sure it would work.

Problem is, I couldn't seem to find any for sale. Other side of the problem is: I'm a great technician, but lousy at transistor circuit design, so I cannot really roll my own without much help.

I need a current mirror with the following specs:
source/monitored circuit characteristics: 20~30vdc, 0.5~6 amperes continuous
4 output channels
1:1 ratio. output current needs to directly track monitored current

Is this really is power design tell me more about this I am curious