I'm catching up after my trip abroad so pardon me if this has been covered...
>>>>> On Mon, 6 Apr 1992 09:18:38 -0400,
>pei.pei.com!sgi!crux1.cit.cornell.edu!sggy (Roger Garnett) said:
Roger> The "Diodes" which may appear on new pumps will be Zener diodes.
Roger> They are speced with a particular "reverse breakdown voltage",
Roger> which basicly means they act as a shunt to bleed off excess
Roger> voltage spikes generated by the coil when you open the points.
Roger> They are used on most relay/soleniod designs today, in order to
Roger> protect any electronics which is turning on the coil.
As I recall from my process control days, putting a diode across the
relay coil is indeed common, and is called a "catch diode". It shunts
the spike formed as the field in the coil collapses.
However, I think a Zener is not needed and an ordinary diode will
work. We used to use 1N914s, about as generic a diode as you can get.
Of course, I was just a software weenie and may be misremembering...
--berry
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