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Hey guys
is it safe to put a 16v rated capacitor behind (to the output) of a 7815/7915 dual supply regulator? I have some lelons laying around that i want to use for the a hifi project. will the capacitors blow, or is the regulator stable enough to be at a constant 15v?
thanks
If it's a linear, it will only output 15v max so it's safe, just keep an eye on the cap make sure it's not getting too warm
I have a 16v on a 19v feed (but with a constant load most of the time lol) works fine
it's done all the time,
it's far from advisable
you should be using a cap rated at around double the working voltage
so a 25 - 35V rated cap
seriously !! , that is not good advice
Dave
Look, if this is powering a $$$ system then sure, a 19 - 24v is better than 16v but i kinda presumed it's not...
As for professionals, absolutely they do, the amount of caps from samsung, acer who use 22v caps on 20v so many it's not funny and then i agree with you completely ...
But is this a $$$ tv/amp/etc or just a linear regulator to power a simple circuit? If so then 16v is absolutely fine, just don't expect it to last 10 years...
I still stand by my answer in this instance...
However, we're talking about a linear reg, if that starts outputing > 15v something failed in which case the capacitor is least of your worries...
However, we're talking about a linear reg, if that starts outputing > 15v something failed in which case the capacitor is least of your worries...
For what it's worth, I personally choose a support capacitor with a working voltage at least 50% higher than required. It does depend also on the circuit and load. You might need to go even higher than 50%. You see it's not just the regulator that can cause issues with cap ratings.
Example: 12V Wall wart supplying 2 Amps in pulses to a regulator supplied with a 1 m cable. So we choose a 16 Volt capacitor because the input is only 12 Volts right?......Wrong! The inductance of the cable can cause considerable fly-back voltages which could approach 50 Volts. So over time the capacitor fails and no one knows why. The same can happen on the output of the regulator.
I think it's even more important if you are going to be driving different loads with varying frequency.
The cost of the capacitor won't always be significant. Actually my boss would be pleased for me to increase the voltage on a capacitor. As the 35 Volt one I found was cheaper than the 25 Volt one specified for the same value
Just my opinion.
Thanks
Adam