Newbie help with reverse polarity and pushbottons controlling a motor

Thread Starter

bmor

Joined Apr 12, 2007
2
ok maybe just looking for anykind of help im stuck and i need to use something like this for a project. here is what i want to do.

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i have a push button ( not one that stays clicked down) ie. one that will be pushed and released. so. when this button is pressed it will cause the motor to turn and when it is released instead of stopping it will reverse and stop. ie.




 

hgmjr

Joined Jan 28, 2005
9,029
i have a push button ( not one that stays clicked down) ie. one that will be pushed and released.
So you have what is referred to as a momentary switch.
so. when this button is pressed it will cause the motor to turn and when it is released instead of stopping it will reverse and stop. ie.
Not exactly sure what you mean by "instead of stopping it will reverse and stop."

Can you clarify this a bit? It almost sounds as though you are describing some sort of braking action that involves a short motor reversal to stop the motor more quickly.

hgmjr
 

thingmaker3

Joined May 16, 2005
5,084
I think he wants to use a momentary switch to change the angular position of something. When pressed, angular position is A. When released, angular position is B.

Is this correct? (Or am I barking up yet another empty tree?)
 

hgmjr

Joined Jan 28, 2005
9,029
Aaaahhh! That makes sense.

I think this can be accomplished with simple mechanical limit switches. Is that what you had in mind or are you looking for something that involves electronic components? (i.e. mosfets, transistors, etc.)

hgmjr (1500)
 

thingmaker3

Joined May 16, 2005
5,084
You'll need some kind of sensor to detect "position 1" and another to detect "position 2." You'll need a thing called an "H-Bridge." (Use the search function to learn more about this.) You'll need some "logic" to control the H-Bridge based on input from your two sensors and your switch. http://www.allaboutcircuits.com/vol_4/index.html is an excellent introduction to digital electronics and logic circuits.
 

mrmeval

Joined Jun 30, 2006
833
Limit switch 1 is at position 1 and cuts power from switch.

Limit switch 2 is at position 2 and cuts power from switch

When switch is not being used the contacts will supply power to turn the motor in the direction to position 1 but limit switch 1 will kill power when it gets there.

When the switch is pressed power is removed from postion 1 and sent to position 2 which will turn on power in the direction to position 2 but limit switch 2 will kill power when it gets there.

It requires a more complex switch than simple on and off but it's doable. Limit switches 1 and 2 are simple normally closed switches. I leave it to you to figure out what switch to use as the 'push button' switch. It's a bit more complex than the limit switches but not by much.
 

dodie1002

Joined Jan 29, 2009
1
i think you need to built a circuit thats toggle one relay on and off using one switch using a flip flop ic once the button is press it trigger the relay on and power the motor forwad and when it touch the switch again it will turn off the relay and reverse the motor
 
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