Push Button

[mikeannneale]

I have been searching for a low voltage double pole push button. Simple push on/release off. However, I need to reverse the polarity when the button is released so that when the button is pressed again the polarity is reversed. I have been unsuccessful, maybe because I do not know the precise technical description. Can anyone assist?

[barhamd]

try double pole double throw push buttton
something like https://www.gapco.co.uk/Pushbutton-Swit ... ction.html
David

[steamraiser]

You may have to wire a two pole two way relay to the button to get what you want.

[zebedeesknees]

Or something like this:- https://www.aliexpress.com/item/1005005782802078.html

This is the two coil version, the ground to the coils could be common, and depending on what the switched part of the circuit needs to do, an output could be used to enable a simple pushbutton to power the coils alternately.

A fuller explanation of what the circuit is for would help.

Ted.

[davebradwell]

Agree, a clearer explanation of the required function would help. It's quite possible that the first suggestion does the business but surely if a relay is required a latching switch would, in most cases, eliminate the need for anything other than a basic relay.

DaveB

[Tony Wilkins]

I have been searching for a low voltage double pole push button. Simple push on/release off. However, I need to reverse the polarity when the button is released so that when the button is pressed again the polarity is reversed. I have been unsuccessful, maybe because I do not know the precise technical description. Can anyone assist?

Hi Mike.
I am somewhat unclear why you wish the switch to change the polarity when the button is released. Push button switches are available in latching and non-latching versions. A latching double pole, double throw, would I think do what you are trying to achieve. Push once to reverse, push again to reset. To do that with a non-latching switch will require external circuitry as has already been stated.
Regards
Tony.

[zebedeesknees]

Agree, a clearer explanation of the required function would help. It's quite possible that the first suggestion does the business but surely if a relay is required a latching switch would, in most cases, eliminate the need for anything other than a basic relay.

DaveB

Agree too, but the advantages of a latching relay is that it does not draw current in either position, and remains in that position after powering down the circuit, staying the same on the next power-up. The latter may be an advantage - or not!

Ted.

[Martin Wynne]

I have been searching for a low voltage double pole push button. Simple push on/release off. However, I need to reverse the polarity when the button is released so that when the button is pressed again the polarity is reversed. I have been unsuccessful, maybe because I do not know the precise technical description. Can anyone assist?

hi Mike,

Is this what you are looking for?

press it once and it swaps the polarity of 2 wires. press it again and it swaps them back.

https://uk.rs-online.com/web/p/push-but ... 39052?gb=s

if, not, we need more explanation of what you are trying to do.

cheers,

Martin.

[mikeannneale]

Thank you one and all. I was fascinated by the article in MRJ 296 by Bob Isgar about the 'hacking' of cheap and simple Chinese servos. By taking out all the electronics and attaching two wires to the motor they can be operated by 1 1/2 volts. Control is by DPDT sprung switch
with centre off. I found this works excellently for point blades but you do have to be able to see the blades to ensure you switch in the right direction. It did then occur to me that a pushbutton which automatically switched the polarity would resolve that problem. I had never heard of 'latching' but that seems to be the answer to my prayer. I have ordered some and will experiment with them. Thanks again.

[davebradwell]

Your reversing switch doesn't give the 'centre-off' function and power would be applied continuously. Probably better to use the motor in a stalled condition by adding a suitable resistor to limit the current. I'll then ask the question as to why you don't keep the toggle switch without c/o as it will indicate the point setting.

DaveB