DC Alternator to Motor

Thread Starter


Joined Feb 21, 2021
Can I directly connect a DC alternator to a DC motor

So as my wind machine turns at different speeds the DC alternator it would power a DC motor driving a pump at different speed

Looking for 100 watt application.


Joined Nov 6, 2012
Yes, BUT,
If you could arrange a Direct-Drive Mechanical Connection, it would be substantially more Efficient.
You are probably loosing ~50% or more of your available Power by changing Energy Formats Twice.
A Direct Bicycle Chain Drive is easily over ~95%+ in Power Transfer Efficiency.
A solid Drive-Shaft with Universal Joints is that high also .


Joined Oct 6, 2013
If you are keeping the motor speed the same as the alternator speed it's pretty simple. Best way is to have two identical units. Cut out the diodes and wire the stator connections from the alternator end to the motor end. You will have to power the field of each one also which will take some trial and error to get right. You will want to use the least amount of power you can use and still get the job done for the field. The field can draw over 5A usually if I remember what I have read correctly so possibly 10A between the two at full power.

Long story short it can be done, but a mechanical system will be way more efficient.