From: Martin McCormick <martin.m@suddenlink.net>
To: Microcontroller discussion list - Public. <piclist@mit.edu>
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Date: Tue, 21 Apr 2020 10:05:46 -0700
Subject: [EE] SuperCaps
Thread-Topic: [EE] SuperCaps
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What would be the best supercap to buy and how much should one
normally pay for it?

	Ideally, it should tolerate 5 volts or at least 3 and not
be too easy to destroy as my plan is to use it to power a small
battery-operated talking timer which normally uses 2 1.5-volt
button cells for a total of 3 volts.

	The cells are about the size of the dull end of a #3
pencil, last about 6 months of daily use and are neigh impossible
to remove from their battery holder without tearing something up.

	I have a small Solar panel meant originally to
trickle-charge a cordless screw driver which produces 5 volts at
10 to 20 milliamps in full Sun .  If I could put it in enough
light to make 2 or 3 volts, the capacitor would charge and run
the timer virtually forever.

	Obviously, if one used it all day long, it might not keep
up but I usually use it in the morning to time a cup of tea and
sometimes to remind me to un-mute the TV during a barrage of ads
but the rest of the time, it actually runs a real-time clock
which is never used and wastes the batteries anyway so if the
timer is ready to go, we are good.

	I am about to order some stuff from Mouser and figure I
might add 1 or 2 supercaps to experiment with.

Martin McCormick
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