# Inrush (and during operation) current limiter to 100Amps on small tractor?



## johnogbirk (Jun 4, 2011)

My controller went up in smoke, but tractor is going pretty well still  
A controller priced at several 100$ is beyond my budget, so what do I do? 
The tractor starts and works without controller, but Im afraid it wont last, because 
1) Inrush current is tough and
2) It will be used by "unauthorised personel", so Im afraid Amps during operation may climb too high...

Motor is 24 V 80A cont. I want to limit it to 100A max. Could be done with a fuse... Easy to replace in the field. I guess people will learn not to set the hoe too deep ;-)

Would it be possible to use something like Lee Harts Zener or light bulb plans, for no 1 or for both?
I have bulbs for 230V AC 500, 1000 or 2000W...
Any ideas anyone. As you may have guessed, Im quite new at this, so please bear with me. Regards John in Denmark.


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## cricketo (Oct 4, 2018)

There is a Hungarian joint on Ebay selling pretty inexpensive controllers for brush motors. Here is one of their units that may work for you :








150A-10-40V-12V-24V-current-limited-DC-motor-speed-controller-PWM-RS232-arduino | eBay


Find many great new & used options and get the best deals for 150A-10-40V-12V-24V-current-limited-DC-motor-speed-controller-PWM-RS232-arduino at the best online prices at eBay! Free shipping for many products!



www.ebay.com


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## johnogbirk (Jun 4, 2011)

cricketo said:


> There is a Hungarian joint on Ebay selling pretty inexpensive controllers for brush motors. Here is one of their units that may work for you :
> 
> 
> 
> ...


Looks like the one I have fried ;-) Its rated at 50 Volts and 100Amps. I use 24 volts, so I guess my Amps must have been through the roof...


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## cricketo (Oct 4, 2018)

They have beefier models too. Also being an open design, you should be able to resolder the MOSFETs pretty easily.


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## johnogbirk (Jun 4, 2011)

An idea came up:
My old Mercedes 508 Light truck, around 1975, had 12V electrics, but used a relay to create 24V when starting the engine. 
Would 12V in my tractor serve as softstart, going back to 24V when its moving?
If Amps grow too much in 12V mode, maybe a seperat larger fuse during start, could do the trick?
As for current limiting during normal work, a large Amp meter in front of the driver, combined with a 100Amp fuse, may do the trick?
Any thoughts?
Regards John


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## remy_martian (Feb 4, 2019)

Ammeter with a yellow and redline on it and a $400 damage deposit to use the tractor


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