It is the chemistry which slows down, mostly the chemistry in the batteries
but probably in any transistors or diodes too. The opposite happens with
extreme heat, a transistor radio will begin to howel and shriek when it gets
too hot in the sun. Well they used to anyway, I don't hear that so often now.
This is one main reason why cars don't start so well in the very cold too. the
battery just does not generate as much power. If you turn on the lights for a
couple of minutes then turn them off and try starting the battery will usually
generate a larger charge because of the warmth created by the internal
resistance of the battery. Of course cold stiff oil and grease will also add to
the load on the starter.
I tried using a wireless doorbell as a locater one winter on the Hospital sign
post which is located on a corner but a long way from anything to be used as a
landmark and of course with the changing landscape resulting from snow removal
it was and remains sometimes difficult to locate. At 40 below the bell would
sound continuously until the batttery died which apparently attracted the
concern of neighbours so it had to come down. I am guessing the failure here
was the threshold charge required to trigger some of the logic in the device.
----- Original Message -----
From: jim
To: blindhandyman@yahoogroups.com
Sent: Thursday, August 27, 2009 7:03 PM
Subject: Re: [BlindHandyMan] Mailbox alarms
hi tom
i have a mail box alarm.
it does work pretty good except when it gets very cold.
in the 20 below range.
i don't know why they say when its colder the resistance goes down in
electronics.
maybe the radio waves freeze grin.
Jim
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[Non-text portions of this message have been removed]
