Relay Power On Circuit
 

On Aug 4, 9:41*pm, raypsi wrote:
On Aug 3, 5:30*pm, Gary wrote:





On Aug 2, 9:30*pm, Fred McKenzie wrote:

In article ,
*"John W" wrote:

A while ago in RadCom there was a circuit diagram for a power supply on-off
switch which allowed a large current load to be switched on and off using a
small push button switch. *The circuit used a relay which was switched on by
the push button which was across the relay contacts. *I can't find the
circuit diagram anywhere. *Could someone please send me the diagram.

John-

This sounds like a bistable multivibrator using relay logic. *Perhaps
someone into digital design could figure out how to do it. *It probably
requires two relays.

I found this at eng-tips.com:

"Ordinary relays can be made into a bistable or "latch" by
cross-coupling a spare pair of contacts on the relay to keep the coil
energised once the "trigger" (e.g. from a push-switch) ceases. To make
things "toggle" alternately you need at least two relays in a cross
coupled configuration to break the hold-in contact of the first relay at
the next push of the switch."

Fred
K4DII

Hi Fred, *They have made it simpler these days. *You can get a push on-
push off pushbutton switch, and use just one relay to achieve bistable
operation. *Asumming the contacts are open, the first time you push
the switch, the contacts close, and stay closed until you push again,
at which time they will open. *This is done with mechanical do-hickeys
in the switch.

Gary N4AST

Hey OM::

My g/f has a few of those do hickeys on her neck does that mean she
always stays on?

73 OM
de n8zu- Hide quoted text -

- Show quoted text -

Hi OM, That is just plain ol hickeys. Whether she is on all the time
depends on how she got them. A do-hickey is something you know is
there, and you know what it does, but you don't know how it does it.

Example: A CBer might say "I can get the SWRs down on my antenna by
spraying a can of SWR remover on it, but it does better if I put this
do-hickey (tuner) between my kicker and the antenna.

Gary N4AST