Electronics Guru's.... How to use latching relays?

[JN]

Hi Guys,

I need to find a way of turning a momentary switch into a latching one. So far the "easiest" way seems to be using a latching relay to hold the circuit on once the button has been pressed. However i'm a little lost as to what relay I should buy...

1) The latching voltage (passing through the momentary switch) will be +5v

2) The circuit that the relay will be keeping 'on' is also +5v

3) Minimal current will be passing through the relay (less than 100mA)

4) The relay will need to be able to "unlatch" with the same +5v from the momentary switch.

 

[Rastalovich]

What is it ur switching m8 ?

Would it be enough to use the circuit`s 5V feed as a switch ? i.e. like a power-on/off.

 

[Marcus]

Could you not just replace the switch to one that locks on / off?

rocker switch

toggle switch

locking push switch

Can't answer the electonics side of it though.

 

[WinMXer]

You would need two seperate momentary switches to do what you are asking if using a relay in your latching circuit. The start button must be 'push to make' & the stop button must be 'push to break', or normally open (N/O) & normally closed (N/C) if you prefer.

Here's a simpe little schematic if you decide to make your own circuit:

I personally think you'd be better off with a latching switch, would be a whole lot easier!

 

[Rastalovich]

Think that wholey depends on what he`s turning on.

In the pc world, I`m thinking he wants to switch something on at the same time as a pc turns on or similar, so it will depend to an extent.

 

[JN]

Cheers for the feedback guys. The problem came about from my most recent project where I'd like to use the same "Anti-Vandal" switches for both my PC power switch and also a separate PSU and my phase change compressor.

Both the separate PSU and the compressor need latching switches, which are more than impossible to find in any decent styles (Black Delrin with white LED outer ring).

The diagram is more than helpful WMX, cheers. All I need to do now is apply that to the pin-outs on whatever relay I purchase. Over 1hr on RS has lead me to this one: http://rswww.com/cgi-bin/bv/rswww/searchBrowseAction.do?N=0&Ntk=I18NAll&Ntt=808-371

Suitable?