Hooking up using a capacitor.

mosc · Last edited by mosc on Thu Mar 05, 2009 12:08 pm; edited 1 time in total

On another topic, http://electro-music.com/forum/topic-30479.html , Droffset asked but was never answered

Blue Hell

mosc

droffset · Posted: Fri Mar 06, 2009 2:40 am Post subject:

Great info thanks!

Inventor · Posted: Fri May 15, 2009 7:17 am Post subject:

On this subject, there is one minor detail that has been annoying me for some time. Certainly we would use ceramic caps for 0.1uF, but as was mentioned this may attenuate some bass frequencies depending on the resulting filter characteristics. So what we would like to use is a nice, big fat electrolytic cap like a 10 uF or more. The question is: which way do you face the cap?

Of course the fail-safe approach is to use two caps in series with the negative terminals tied together. This gives us half the capacitance but it forms a non-polarized capacitor. I never understood actually why that works and I've asked fellow engineers many years ago why and nobody seemed to know. So perhaps a second question is: why does that work?

The thing is, if the load is unknown and you hook the cap up in the wrong direction... well, that's bad because either the cap won't work properly or it will become a tiny little exploding electrolytic-juice grenade, lol.

Would someone who knows about this little detail care to enlighten me?

Rykhaard · Joined: Sep 02, 2007 Posts: 1290 Location: Canada

mosc · Posted: Tue May 19, 2009 2:06 pm Post subject:

Hooking up two electrolytic caps in series will make the voltage on each cap 1/2 of what it would be if there were only one. That might reduce the danger of an exploding cap by 50%. In reality, an audio signal on a polarized cap is probably not going to blow it up, like it would by hooking one up backwards as a power supply filter.

It's best to make the input impedance as high as possible and then a little cap will not roll of the lows.