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Old 10-26-2008, 09:22 PM
gloriouss89 gloriouss89 is offline
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Question how to limit the current in a DC motor circuit?

Hi guys!
I need to use a circuit element(current limiter) between power source and DC motor circuit which limits the current at a specific value when it increase too much. For example, when it reaches 1 A it should stay at that value even if motor sensors want more current to accelerate the motor..Under 1 A current limiter should just allow that current without any changes. Since my dc motor's resistance changes with the speed of it, my current limiter should be designed independently from the resistance value of circuit..

And my internship supervisor doesn't want me to use mechanical circuit elements (switches, relays, fuses). I was searching about solutions with semiconductor relays and fault current limiters I've found some stuff but it seemed complicated to me. Anyway i'm very new to electronics since i'm not even a sophomore..
I was wondering if you guys have any idea about what i can use to limit this current without using any mechanical parts..
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Old 10-26-2008, 10:23 PM
scubasteve_911 scubasteve_911 is offline
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Check out about half way down, he shows a schematic that should do what you require.

You can read the analog guru Bob Pease's page on current limiter circuits here

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Old 10-26-2008, 10:28 PM
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mik3 mik3 is offline
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Here is a circuit to give you an idea:
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Old 10-27-2008, 11:00 AM
gloriouss89 gloriouss89 is offline
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Thanks for your help! I'm gonna check them out..
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