Glytch3r

modified 8 years ago

Help - question about DC motor

252

04:02:32

Hello, i am building a mouse trap that uses DC motor to remove a stick that will make trap close, the trigger is a simple normally closed switch . When the mouse enters the trap the platform will then remove itself from holding the switch so then the motor will rotate. Im planning to use a capacitor to make this movement single burst but i dont know much about capacitors and would probably make the motor somewhat weak and wont be able to close the trap. So for now the switch only makes the motor rotate but untill i reinitiate the trap, it will continue to rotate,. So the circuit is closed and working however the motor gets stuck ,.

So in short my question is
Would it break the motor if voltage passes thru even if  its denied the rotation?
I hope my explanation is clear, feel free to ask questions and ill be glad to hear any suggestions. Thank you in advance

published 8 years ago

eekee

8 years ago

Usually yes. Can you design the trap so that it cuts power to the motor when it closes? If not, what you want is a pulse limiter or monostable multivibrator. It's a bit more complex than just a capacitor. You can build one with a 555. There are several other ways too, but the 555 is designed to make it easy. I think you could use just a capacitor, but I think it would have to be a very big one. Not sure, haven't tried it. :)

rich11292000

8 years ago

20F at 5.5 volt is smaller than a coin. You can buy a kit of 15 assorted supercaps from amazon for $20. The answer is yes, it's bad to keep a motor "stalled", but a few seconds won't hurt. Just don't exceed the capacitors max voltage, they are 2.75v per cell, and usually come as two cells packaged together for 5.5 volts. Provide more specs. 1. What is the motor voltage and amperage. 2 what voltage are you applying. 3. How hard is it to close the door?

hurz

8 years ago

http://everycircuit.com/circuit/5240262195675136

Glytch3r

8 years ago

Dont worry about the type of capacitor cuz i have quite alot of various capactors that i salveged , i rarely buy my parts, and i rare need to. I have 555 ICs to but i dont think i need to make this one complicated. About the power supply, i have alot of USB based chargers, so as you know they are 5-5.5v 500mA-2A however my current choice of powersupply is a Lithium ion recharable battery 3.7v and i forgot the Amp tho .. so new question , will it burn the capacitor its plugged directly for a long period of time? And how much uF does it take to actually give it atleast 3-4 rotation. The motor will just pull a string that is attached to stick and it works and doesnt stall. Im just asking around so that i might upgrade it since there is alot of room for improvement. If only i could provide pictures

Glytch3r

8 years ago

@hurz. I could tap the link so i typed it manually and saw the thumbnail but couldnt see the uF rating u used. I know i could make this setup too but my idea uses a switch that has NC NO and the editor doesnt have that part and so didnt add the capacitor.

hurz

8 years ago

The capacitance is unknow since you havn't specified anything around the motor and energy you need to close the trap. Question, what do you think will the mouse do if it hears this DC motor noise?

lmccoig

8 years ago

Powered with weights as tensions cuckoo clock seems better than electric motor.

eekee

8 years ago

20F smaller than a coin? I feel old. :) I learned electronics around 1990; dropped it until now. Supercaps were mostly off my radar. Are they common in salvaged gear? And what is it with Americans omitting the 'not' part of "couldn't"? I'm no grammar nazi, but negative matters, people!

ViolationMad

8 years ago

I dont really think supercaps are that common. The only thing i can imangine you could salvage them from are emergency shake flashlights or high end electronics. But anyway i dont think a motor suits a mousetrap too well.

hurz

8 years ago

Glytch3r is gone, mouse dinner con salsa.

rich11292000

8 years ago

You have a slim chance finding a 20F supercap to salvage. When using a big cap for your car audio(2000watt), some manufactures put a few of these coin caps(24VDC) in to a larger enclosure to fool the consumer into thinking they have 20F of raw capacitance. Boss uses a raw capacitor, while poweracoustik uses supercaps.

Glytch3r

8 years ago

Im planning to add another switch that turns off circuit one the platform lowers . So initial state is open then when triggered it becomes closed and eventualy turns off when it hits the bottom. But i think i will need a transistor and a simple tactile switch

Glytch3r

8 years ago

Like an H bridge

hurz

8 years ago

You are also planning to condition the mouse to like DC motor noise, LOL

hurz

8 years ago

Dinner for a other mouse? Jammy

Glytch3r

8 years ago

The motor will only run when the mouse is inside.. but anyways im closing this thread, thnx for all the help, the project is done

hurz

8 years ago

Yoy have no idea how quick a mouse is...

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