14v 62A variable current circuit help!

[beanman]

Hello all, I am attempting to find a kit of some sort that can handle 14v at 60 amps (i said 62 because i want some safety room) The unit is going to control a electric power steering pump in a drift car, the driver wants to be able to adjust the amount of current that can go to the pump, effectively controlling how much or how little the pump helps him steer the car. I do not need a kit but I would like to have one to save time, if you have a suggestion on how to go about designing something like this I would very much appreciate it.

Thank you.

 

[(*steve*)]

Have you considered PWM modulation of the power being applied to the pump?

A 14V 60A power supply (presumably running from 12V) isn't intrinsically going to allow you to vary the current.

PWM involved turning the power on and off very quickly to the motor (perhaps thousands of times per second). If the power is on 90% of the time and off 10%, then the pump receives approximately 90% of the power it would draw if it was connected directly. By varying the duty cycle (on time compared to off time) the power can be continuously varied from almost 0% to almost 100%.

Also, please ask your questions just once. Apart from cluttering up the forum, you may get different information in different threads leading to confusion for all of us.

 

[beanman]

My apologies for asking numerous times.

Thank you for the PWM idea i would have never thought of that. Would it be possible to use a Arduion Uno and feed the pwm signal into a relay? Would a relay even be able to switch at such high speeds or do you think a transistor would be more suitable?

Much apricated!

 

[(*steve*)]

You would not use a relay. You would use a mosfet.

For switching such a large load you may need more than one mosfet and you may need gate drivers to ensure the mosfet switches rapidly and does not spend too long in its linear region.

You will also need protection in the form of diodes to catch the inductive spike generated when power is removed from the motor. These will need to be fast diodes and rated for 62 amps as well.

Depending what you want to do, an Arduino may be massive overkill/

 

[beanman]

I may be getting in over my head...

 

[beanman]

The mosfets would be hooked up in parallel correct? Im sorry if im asking basic knowledge questions

 

[(*steve*)]

yes they would be.

 

[beanman]

Well thank you for your words of wisdom. They have certainly helped.