Reversing Polarity

[Molotov]

Ive been working on a project and seem to have run into a problem. Im trying to wire up a DC motor w/ reverse using two spring push button switches and a single DC power source. I need to wire it up so that when one of the switches is pressed the motor will move foward and when the other pressed it will move in reverse.

 

Ive been working on it for a long while and all Ive accomplished is frying some diodes. Could someone with a better understanding of electronics help me out?

[ed84c]

You need a DPDT switch

[5614]

indeed you do.

 

exapnsion just in case you need it:

 

DPDT = double pole double throw

 

instead of having the ordinary 2 pins it has 6 and has a symbol like this:

 

 

ignore the random writing, i just found any old pic on the net! but as you can see it has 2 inputs and four outputs.

 

from image:

c1 = battery +

c2 = battery -

NC1 = motor side x

NO1 = motor side opposite to x

NC2 = motor side opposite to x

NO2 = motor side x

 

where x is one side of the motor and 'opposite x' is the other!

 

so when the two 'connectors' in the symbol are up the current will go up top round to side x and out via 'opposite x' at NC2.

when they are both down (remember they move together) current will come in NO1 firstly into side 'opposite x' of the motor and thus the current has effectively reversed.

 

remember to buy a DC motor as AC motors have a communtator which you dont want.

[Molotov]

Is there any way that I could use the single pole switches?

[The Rebel]

Is there any way that I could use the single pole switches?

 

What type of switches are they? Normally open or normally closed, and are they latching.

 

If you only use push switches, you'd have to start adding relays in. If the switches are latching you could probably get away with a DPDT relay, if not then a TPDT (i.e. triple pole) relay. Otherwise, and if the switches are of the same type, you'll need two relays.

 

Depends whats available.

[5614]

you could do it with 4 'normal' SPST (single) switches.... but youd HAVE to press the correct 2 down at the same time, imagine you have switches A, B, C & D

 

then you'd have to have A + B at the same time or C + D at the same time, if you have A+B+C or basically anything other than 'A+B' or 'C+D' or none, it'd ruin the circuit.

[TheBigDino]

How about this? You could use a 4069 IC for this, although I don't know if it will provide enough current...but I doubt it wouldn't.