Need to reverse a dc motor with two, on/off switches

[keithskye]

reversing a motor with 2 switches

I want to set up a reversible fuel pump for hobby use, powered by a 12v brushed dc motor. Is there a way to wire it so that I can use two simple on/off switches such that one switch will run the motor/pump in one direction when selected on, and the other will run it in the reverse direction?

I'd appreciate any help with this, especially a schematic. Don't know much about eletronics or circuitry, but I can do a decent job of soldering small components.

Thanks!

Keith

 

[Razamuhammad]

you should use some darlington chip like uln2003. make a bridge using internally provided darlington trnasistor. each can drive 500mA. if u need more you can combine two to have 1 A. Just you have to control the direction of current!
it is easy see the attached data sheet otherwise i will make a circuit and will mail you!

if ur motors are too much current like 5A or more then you have to switch to some other solution that i can help you if needed

let me know proceeding!

 

[Razamuhammad]

go and check

https://www.cs.uiowa.edu/~jones/step/circuits.html

 

[MikeOhio]

If you can follow this crude sketch, you can reverse direction on your DC motor simply by reversing the polarity of the power source. Two switches are all it takes, one to turn the motor on (S-1/SPST) and the other to control the direction (S2/DPDT).

HTH -- Mike

 

[keithskye]

Mike,

Your solution looks simple, but I have a couple of questions regarding how I wire up the second switch (S2/DPDT). Am I correct in assuming that this second switch is a double pole? I'm a complete newbie to this stuff and trying to learn some of the terminology. If you'll shoot me an email with your number, I'd like to give you a call on my dime so that you can give me a quick rundown on exactly what I need. Right now, I have the 10-cell, 3300mah NiCad battery pack, 12v dc motor driven pump (just two leads coming out of the back of the pump/motor), two guarded (covered) toggle switches, each of which has only two connectors (I assume now that this means they are single pole switches) and the PVC housing for the battery and switches (the pump will mount on top of the housing). What I'm shooting for is something that looks like the setup in the photo I've attached. I saw this at a model flying field recently and it was a great setup! With both switches off (plastic guards down), pump is not running. "Fuel" switch on - pump runs one direction, outputting fuel to model airplane. "Fuel" switch off and "DeFuel" switch on - pump runs in reverse and sucks fuel out of the model airplanes fuel tank (normal thing to do at the end of the day). I would settle for using both switches being flipped on to reverse direction, which is how your setup would seem to work.
~ Keith (1st2fly@msn.com)

 

[MikeOhio]

Keith-
No problem on calling me but I am out of town on business until Wednesday (darn day job keeps getting in the way of fun!). I'll email you my telephone number when I return so that you know I am home - will send it to your regular email address.

Just as another thought for you to consider - you might want to model your pump after the way a cordless drill works. Most drills have a forward/reverse switch on them which does nothing more than switch the polarity to the motor. The trigger is simply a type of potentiometer (variable resistor) that controls the actual voltage to the motor allowing you to adjust the speed of the motor. This may be worth considering since you are working with a relatively small amount of fuel and fuel tank size. We can discuss this on the phone.

Mike