EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: Tetzly on February 15, 2023, 08:38:14 pm
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I have a 12 volt brushed DC turntable motor that has a max rated Amps of 2. Under my load it is drawing .460 Amps at 12volts, but I need this thing to go a little faster. When I feed it 16-18 volts it gets to the right speed I need and draws about the same amps (.510 amps at 16 volts). I have good airflow on the motor itself and it does not appear to be getting any warmer than it does under 12 volt operation.
Is this OK or am I gonna fry the motor?
Thanks up front.
Michael
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How does the sparking in the brushes looks like compared to normal operation?
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The end is sealed and I cannot really see anything. It's a worm drive motor, and I'm sorry I honestly do not know much about it, I thought the small gearbox that is attached was the worm drive part....ran on a brushed DC motor.
The actual motor description is: Bringsmart 12V 12rpm DC Worm Gear Motor 70kg.cm High Torque Self-locking Reversed Mini Turbine Geared Motor for DIY Robot Rotating Table Door Lock Curtain Machine (12V 12rpm) and pics enclosed...
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Motors tolerate over-voltage better than over-current. It will work, but the life of the brushes will be reduced slightly.
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Probably going to be fine if the current is similar and it's not getting noticeably hotter.
Motors are pretty forgiving
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Thanks for the responses. I should probably get a higher RPM motor to do the job I need, but ones with enough kg.cm at higher RPM's start to get pretty high in cost. I only plan on using this a few hours a month, so your words give me some encouragement. Usually when I try to skimp out on power/ability for cost, it usually ends up biting me in the butt and costing more when I finally have to buy the expensive thing...let's hope this isn't the case with this project.
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Look up the spec for the motor.
Its on this aliexpress page: https://www.aliexpress.com/item/32866180974.html (https://www.aliexpress.com/item/32866180974.html)
6-18V
The only issue is if you'll see additional wear or heating from the gears. If you are saying airflow/temperature is good it should be fine.
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Brushed motors can tolerate being "boosted" much better than brushless ones. The limit is heat dissipation and commutator wear.
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You'd probably be fine even at double the rated voltage so long as you're not loading it so heavily that it draws excessive current. When I was a kid I ran a salvaged 12V motor up to something like 60-70V before it failed.
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I always thought that provided you weren't going crazy with voltage to the point of insulation breakdown or brush arcing that current was the bigger factor when driving motors. Certainly steppers are nearly always driven with voltages much greater than their nameplate suggests.
I don't think 4-6 volts is going to really harm your motor. But it's worth confirming that the current doesn't increase under load.