I have a small circuit with a 100uF cap that is usually charged with 6V. However it can be accidentally charged at -6V for few hours per day. I cannot add a diode in series as the cap must be able to discharge through a load. Would a diode or a Schottky in parallel be enough to protect it against reverse voltage? I mean, is -0.7V or -0.2V bad for an electrolytic (or tantalum) cap over a long time?
Or a non-polar electrolytic would simply be a better choice?
Octavio
"Octavio"
** Total bullshit. ** Shame about the voltage sound being shorted out.** Electros no - tants are more delicate.
** Its kinda obvious - isn't it ?
....... Phil
Bad idea all round.
Yes it would, obviously.
Dave.
. Solid tantalum capacitors can take a small reverse voltage (up to a volt or so) without damage, so a Schottky diode in parallel to protect against reverse polarity would work. . Wet-slug tantalums and aluminum electrolytics will be damaged by application of even a small reverse voltage. Don't do it!
** Totally false.
Such caps can easily be rendered permanently leaky by a reverse voltages of
1 volt.** Bollocks.
...... Phil
circuit with a 100uF cap that is usually charged with 6V.
You can't say that without knowing the OP's application. A bi-polar cap is by far the best solution.
Dave.
The cap is part of a classic charge pump that adds its voltage to give +12V (or so) to a light load. However the driver may stay locked to a positive voltage for some time (and I can't do anything about this driver, out of reach). This means the cap will now be charged in reverse.
Octavio
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