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
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