Hello,

I have read the completed projects section.

I need to limit the current supplied to a DC bike motor.

Max values are 48 VDC input @ 26 amp.
Motor is rated to supply 1 KW. Is a permanent magnet motor.
I will only take 300 watts (mechanic energy) so I think motor will take about 400 from batteries.

I know how to build a current limiter with a high voltage and currect transistor, driven by a low power transistor driver that senses voltage over an Rsense series resistor. That works, but is inefficient. And my energy is lioke gold, Is a solar off grid farm. Motor will power a water pump for cattle.

I am thinking about a simple IC 555 timer to control duty cycle, and a MOSFET of logic level that can be triggered at 5 vdc.

Any help to start with ?

Thanks a lot,
And nice week end !
Horacio

 

A simple 555 PWM such as http://www.discovercircuits.com/DJ-Circuits/simplepwm2.htm
Or they are very cheap on ebay, <$10.00
Max.

 

Thanks a lot !
Horacio