Current alarm, for a motor

[Rimrock]

Hey,

Are there anybody here that are into electronic circuits?
I'm planning making a winch, and have an idea to connect a alarm to the motor that will give sound if the current draw exceed e.g 3A (12V), to protect a rather expencive motor from overload. This instead of a fuse.
it should be something similar as the LiPo alarms, but for current, not voltage.
Is it complicated to make?

[Cooper]

Lots of telemetry stuff with radios, I don't know about a stand alone current alarm.

[Bo Wallen]

This one might work http://www.eachbuyer.com/dc-dc-conve...UkiRoCvR_w_wcB
Bo

[doodlebug]

Have you looked at 12 volt circuit breakers at Napa or other parts stores?
Cheers, Neil.

[9W Monighan]

Perhaps limit the voltage to have it stall when max amperage or torque is reached. Or build in an adjustable slip clutch on the winch drum for max torque needed.

[Rimrock]

Hi, thanks so far. I have not found a finished circuit on the marked yet, that has a 'current buzzer'. There are the cheap current testers e.g on ebay, with a diplay, 0-10A. I guess it's possible to make it from some drawings and a circuit board, but I am still looking. I find some small circuit breakers, for 3A, on ebay. This winch will be a part of a wrecker boom/unit. When the current will pass the max allowed, and circuit to break, or a buzzer to buzz, one quite possible need to walk over to the model and re-arrange something on the rigging anyway.

[Rimrock]

A slip clutch would been good, if I had room, put it's too compact

[Supermario]

A buzzer or warning device is much more complex of a device compared to a circuit breaker. Using a breaker you also don't have to worry about not hearing the buzzer due to noise or other equipment around you?
It does get loud at RC shows with lots of trucks running around.

Not sure if they make small versions but on the 1:1 machines I work on, some are equipped with auto reset breakers. Those would be perfect for you.

[doodlebug]

5 AMP is the smallest, I have seen, http://www.littelfuse.com/~/media/au..._breakers2.pdf

http://www.delcity.net/store/Auto-Re...AEcBoCQETw_wcB
Cheers, Neil.

[Rimrock]

Originally Posted by Supermario

A buzzer or warning device is much more complex of a device compared to a circuit breaker. Using a breaker you also don't have to worry about not hearing the buzzer due to noise or other equipment around you?
It does get loud at RC shows with lots of trucks running around.

Not sure if they make small versions but on the 1:1 machines I work on, some are equipped with auto reset breakers. Those would be perfect for you.

You are correct I agree to that, it sure can be noisy when out in the 'field' and it could be difficult hearing the buzzer.

I guess a auto reset breaker will be the thing to go for), and forget about any alarm. I see now that my breaker must not be larger than 2 amps, and I managed to find some auto reset ones with this value, where they sell parts for scale trains. After being tripped, they need some time for cooling down to reset, I don't know how long.
http://www.microminiatures.co.uk/aca...-Breakers.html