Re: Relay Problem - Mystery Solved ??

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Scott Hanson by way of Terry Fritz <teslalist-at-qwest-dot-net>" <huil888-at-surfside-dot-net>

Dan -

I'm really confused by your relay chattering problem, and the "solution".

If your circuit is actually wired per your schematic, its not a latching
circuit, its a chattering circuit, and the relay MUST chatter as soon as
voltage is applied to the points labeled "control power". It can't work as a
latching circuit if it is wired as shown.

Per the schematic, one end of the relay's coil (leg L2) is tied to AC line
neutral (effectively, ground). The other leg (L1) is directly tied to
"control power" through normally-closed push-buttons PB4 and PB3B and
through the relay's normally-closed contacts. So as soon as "control power"
is applied, the coil is energized (even if normally open pushbutton PB3 is
not touched). As soon as the coil is energized, the relay contacts open, the
connection to "control power" is broken, and the relay drops out, which
again allows the coil to be energized, etc, etc resulting in the relay
continuously chattering as power is cycled to the relay coil.

When normally-open pushbutton PB3 is actuated, the relay stops chattering
and stays energized because it is now directly connected to "control power",
bypassing the relay contacts, but only as long as the pushbutton stays
depressed. As soon as PB3 is released, the chattering must resume. There is
no self-latching function initiated by PB3 that I can see.

If the schematic is correct, and there is a latching function initiated by
PB3, can you explain to a mechanical guy how it works?

Thanks!
Scott Hanson



----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Thursday, January 16, 2003 5:47 PM
Subject: Re: Relay Problem - Mystery Solved


 > Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<dhmccauley-at-spacecatlighting-dot-com>
 >
 > Well, after some major troubleshooting, I figured the problem out.
 >
 > Turns out the relay was being "current starved."
 >
 > I had used 16 AWG wire going through my latch circuit etc... and for some
 > reason, it wasn't good enough.
 > Replaced the wire with 12 AWG and it works fine now.
 >
 > Dan
 >
 >