The only "expensive" part is the capacitor bank itself. For my 4 ohm sub to get a cutoff at 4 Hz (probably didn't need to go that low) I had to use $17 worth of caps.
I imagine the day when I finish my VC temp circuit and put an LED display at the front-of-house mixer and I can watch how hot the subs get.
How much power have you run through that circuit? I'm trying to imagine 1000uf electrolytic carrying several amps without eventually putting on a spectacular show in itself.
It's the volts between the plates that matter. You can get bi-polar caps to 100V. For me, now that I looked, I used 17 470uF/50V bi-polar caps. Mouser p/n 647-UVP1H471MHD
F = 1/(2pi(R*C))
F = 1/(6.28 * 4ohms * 17*470uF)
F = 4.98 Hz
F = 1/(2pi(R*C))
F = 1/(6.28 * 4ohms * 17*470uF)
F = 4.98 Hz
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It looks like you calculated the corner frequency at 4 Ohms with 7990uF.
In any case the average dissipation and current is an issue, though maybe not much of a problem with that much capacitor.
In any case the average dissipation and current is an issue, though maybe not much of a problem with that much capacitor.
With regards to power supplies, cap life is directly related to ripple current combined with operating temp. Not sure how it works here though.
I think it gets complicated far beyond my understanding, but keeping it below an amp per 1000uF should get you some years good running time, maybe. 10 A RMS through 1000uf, for example, no.
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I used those values for testing tweeters. Absolutely don't use 1000uF for a sub. How many times have i repeated that in this thread so far? The medium of text in a forum just stinks
I think for woofers I would use a current transformer. With some filter amplifiers you might even be able to come up with a universal impedance monitor this way.
i do i know if 20000uF is enough for my speaker? what will happen if i "miss" by a thousand uF? will it hum or make noise or something? can i overshoot this number just to make sure?
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Actually, you won't need a PC. Look closer at the equation. It is a linear expression. What can one do with linear expressions in electronics?
Sure, that's one way. Even simpler if say you are using an analog meter is to amplify it while removing extraneous DC and place paper over the back face and mark lines with a pen. done!
Do use the PC to align it 😉
There are also volt meter chips that drive displays. You still have to condition the input to set things in the proper scale. The "removing DC" part is as simple as using an opamp with the non-inverting input offset from zero.
You can do a lot with a linear expression in the analog domain. And even non-linear expressions, too, but that's a whole different topic.
Do use the PC to align it 😉
There are also volt meter chips that drive displays. You still have to condition the input to set things in the proper scale. The "removing DC" part is as simple as using an opamp with the non-inverting input offset from zero.
You can do a lot with a linear expression in the analog domain. And even non-linear expressions, too, but that's a whole different topic.
i am very new to this and the schematics are difficult to follow do you have a picture of one that is completed?
Try this:
😀
An externally hosted image should be here but it was not working when we last tested it.
😀
davygrvy
I may need to build this right into my ppp KT88 sub amp when I get around to building it. I have been working on a digital VU gauge, that and a coil temp on the front would look amazing. Should have no DC off set using an opt but how will this change the sound/output of the amp? Running a DC bias on the out of a OPT just sounds like a bad idea
and off topic but when you end a sentence with a smiley where do you put the punctuation mark?
I may need to build this right into my ppp KT88 sub amp when I get around to building it. I have been working on a digital VU gauge, that and a coil temp on the front would look amazing. Should have no DC off set using an opt but how will this change the sound/output of the amp? Running a DC bias on the out of a OPT just sounds like a bad idea
and off topic but when you end a sentence with a smiley where do you put the punctuation mark?
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