unclej Posted November 16, 2004 Report Share Posted November 16, 2004 i've just been re-reading the thread about discharging hi voltage caps and came up with a question. when you use the resistor method and bridge the cap where does the charge go? with lovekraft's light bulb it's easy to see that the stored voltage is used up. but what happens to it with the resistor? Quote Link to comment Share on other sites More sharing options...
Maiden69 Posted November 16, 2004 Report Share Posted November 16, 2004 Is used up in the resistor, just like the light bulb you just don't see it. Just like when you get shocked, you don't see light coming out of your arse, but you still feel it! PS Sorry for the SA answer I couldn't resist! Quote Link to comment Share on other sites More sharing options...
Paul Marossy Posted November 16, 2004 Report Share Posted November 16, 2004 The resistor just slows down the discharge of the caps, and keeps it from arcing like it would if you just shorted the caps directly to ground. The actual charge goes to everything that is connected to the discharge end of the resistor, which is traditionally ground. It's just a short burst of energy, so it can get dissipated pretty quickly through the circuitry that is connected to ground. Quote Link to comment Share on other sites More sharing options...
Cloud Posted November 16, 2004 Report Share Posted November 16, 2004 The resistor acts as a load and the electricity is transferred into heat energy and convects away. This is why high resistance in wires isn't good because then this can lead to the wires overheating and melting if there is to much load on them for there resistance. Quote Link to comment Share on other sites More sharing options...
lovekraft Posted November 17, 2004 Report Share Posted November 17, 2004 (edited) For the record, the light bulb was Ansil's - I just use a great honking power resistor. As for where it goes, think of voltage as the difference in potential energy between two areas - as soon as you short the cap to ground, the charges start to equalize, just like water running downhill, and when there's no difference left, no more current will flow. <edited for clarity> Edited November 17, 2004 by lovekraft Quote Link to comment Share on other sites More sharing options...
unclej Posted November 17, 2004 Author Report Share Posted November 17, 2004 great..four good clear answers and one SA reply that made me laugh out loud. thanks Quote Link to comment Share on other sites More sharing options...
Paul Marossy Posted November 17, 2004 Report Share Posted November 17, 2004 As for where it goes, think of voltage as the difference in potential energy between two areas - as soon as you short the cap to ground, the charges start to equalize, just like water running downhill, and when there's no difference left, no more current will flow. That's essentially what I was trying to say, but I worded it different... Quote Link to comment Share on other sites More sharing options...
unclej Posted November 17, 2004 Author Report Share Posted November 17, 2004 now if someone could just explain where e-mails go when you delete them i could die happy. Quote Link to comment Share on other sites More sharing options...
Paul Marossy Posted November 17, 2004 Report Share Posted November 17, 2004 now if someone could just explain where e-mails go when you delete them i could die happy. Well, if it's anything like deleting stuff off of your hard drive, the first character of the deleted file is altered so that the hard drive knows that it can now overwrite that file. At least that is how MS DOS worked. MS Windows works a little bit differently because it has the "recycle bin", which basically replaced the DOS "undelete" command, but once you've emptied the recylce bin, I think the basic process is the same... Quote Link to comment Share on other sites More sharing options...
Kyle Cavanaugh Posted November 17, 2004 Report Share Posted November 17, 2004 A resistor converts the electrical energy into heat energy and that heat dissipates therefore losing the energy. The easiest way to understand this is to think of any electrical device ("load") as a resistor, whether fixed or varying. You yourself will act like the "load" if you discharge the caps accidentally by going in and working on your amp without doing these proper steps first! Quote Link to comment Share on other sites More sharing options...
Maiden69 Posted November 18, 2004 Report Share Posted November 18, 2004 The actual charge goes to everything that is connected to the discharge end of the resistor, which is traditionally ground. Not realy. Just like cloud said, it disipates as heat in the resistor, you don't need it to be grounded, just place them between the contacts. now if someone could just explain where e-mails go when you delete them i could die happy. If I tell you I WILL have to kill you! Quote Link to comment Share on other sites More sharing options...
Paul Marossy Posted November 18, 2004 Report Share Posted November 18, 2004 This is the the method I have always understood that one should use for discharging filter caps: http://bwilliamson.home.mchsi.com/discharg.htm My understanding is that the resistor serves two purposes: 1. To protect the caps themselves from a sudden discharge to ground (short circuiting). 2. To assert some control in the discharging of the caps, at a controlled rate. It is true that some of the energy is dissipated as heat, but that would depend greatly on the size resistor that you use. The resistor presents a load to the filter caps, which is what makes it safe to discharge the caps. Quote Link to comment Share on other sites More sharing options...
unclej Posted November 18, 2004 Author Report Share Posted November 18, 2004 maiden hit on the real point of my question. i knew you could discharge one by taking it to ground but i wasn't sure what was happening if you just had a charged cap outside of a circuit and jumped it with the resistor. if i had taken the time to look up the definition of a resistor i probably wouldn't have had to ask. but hey, it was a good discussion and i appeciate it. Quote Link to comment Share on other sites More sharing options...
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