Author Topic: problem blowing fuses  (Read 1097 times)

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Offline DomTopic starter

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problem blowing fuses
« on: September 20, 2009, 04:42:59 PM »
Good Morning all,
have a problem with a robot biggie, I'm two 24 volt wheelchair motors via a sabertooth DC motor controller, the saber tooth is a 25 amp duel motor controller with r/c signal input
Ive connected it up to the exact specs and its works for a short while and then blows fuses Ive steadily increased fuse to 30 amp, with doubts of going any higher,
i have connected the motore to an amp meter and had a total of 16 amps at full stall, per motor, when i connected the motors to a volt meter there is a voltage produced(of coarse is is a brushed motor, a generator)

can any one help please??

Offline Admin

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Re: problem blowing fuses
« Reply #1 on: September 21, 2009, 06:46:24 AM »
http://www.societyofrobots.com/electronics_fuse_tutorial.shtml

I suspect you are using a fast blow fuse, and current spikes (much higher than at stall current) are causing the blow.

How much current can your battery supply? Choose a fuse more like:

(max_current_drawn + max_battery_current)/2 = fuse rating

Offline DomTopic starter

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Re: problem blowing fuses
« Reply #2 on: September 21, 2009, 03:06:19 PM »
Many thanks, Will give it a go  :)

Offline RoboGeek

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Re: problem blowing fuses
« Reply #3 on: September 22, 2009, 12:16:41 PM »
If you put large capacitors on the power leads right at the controllers, these will supply the controller current peaks instead of the current peaks coming from the battery through the fuses.

Most controllers have SOME internal capacitors but they rarely have enough as caps are big and can be expensive.

 


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