Digital Capacitor 1 Farad
in [Basics]
|
Prev: Portable Oscilloscope
Next: Components Store
From: Bill Bowden on 27 Jul 2010 22:36 I bought a digital 1 farad cap (ICBM-7244CRP) at a swap meet for $15 thinking I could sell it on ebay for a $30 or more. I'm not sure how it works since it has a 40 amp relay inside to disconnect the cap from the outside world. I think the display is for power or voltage, but there are no switches to select a function. Only two connections to make. Anyway, it doesn't do anything when connected to a 12 volt PS. But I can occasionally get it to turn on by interrupting the PS connections. And when it does turn on, it displays strange numbers of 00, 55 or whatever and then turns itself off after a few minutes. I'm sure the actual cap is good since when it goes on, I can disconnect the PS, and the display keeps reading for awhile using the cap energy before going out completely. And as it goes out the display reads changing numbers and then dies out. I don't understand the function of the 40 amp relay. Seems like with power applied, the cap could just sit there charged and the display could time out when there is no change for a long time to save the display power. Is this cap any good, or does it have problems? What is a good test? -Bill
From: Grant on 27 Jul 2010 23:09 On Tue, 27 Jul 2010 19:36:42 -0700 (PDT), Bill Bowden <wrongaddress(a)att.net> wrote: >I bought a digital 1 farad cap (ICBM-7244CRP) at a swap meet for $15 >thinking I could sell it on ebay for a $30 or more. > >I'm not sure how it works since it has a 40 amp relay inside to >disconnect the cap from the outside world. I think the display is for >power or voltage, but there are no switches to select a function. Only >two connections to make. > >Anyway, it doesn't do anything when connected to a 12 volt PS. But I >can occasionally get it to turn on by interrupting the PS connections. >And when it does turn on, it displays strange numbers of 00, 55 or >whatever and then turns itself off after a few minutes. > >I'm sure the actual cap is good since when it goes on, I can >disconnect the PS, and the display keeps reading for awhile using the >cap energy before going out completely. And as it goes out the display >reads changing numbers and then dies out. > >I don't understand the function of the 40 amp relay. Seems like with >power applied, the cap could just sit there charged and the display >could time out when there is no change for a long time to save the >display power. > >Is this cap any good, or does it have problems? >What is a good test? From how far can you throw it into the bin? :) Grant. > >-Bill
From: default on 29 Jul 2010 22:12 On Tue, 27 Jul 2010 19:36:42 -0700 (PDT), Bill Bowden <wrongaddress(a)att.net> wrote: >I bought a digital 1 farad cap (ICBM-7244CRP) at a swap meet for $15 >thinking I could sell it on ebay for a $30 or more. > >I'm not sure how it works since it has a 40 amp relay inside to >disconnect the cap from the outside world. I think the display is for >power or voltage, but there are no switches to select a function. Only >two connections to make. > >Anyway, it doesn't do anything when connected to a 12 volt PS. But I >can occasionally get it to turn on by interrupting the PS connections. >And when it does turn on, it displays strange numbers of 00, 55 or >whatever and then turns itself off after a few minutes. > >I'm sure the actual cap is good since when it goes on, I can >disconnect the PS, and the display keeps reading for awhile using the >cap energy before going out completely. And as it goes out the display >reads changing numbers and then dies out. > >I don't understand the function of the 40 amp relay. Seems like with >power applied, the cap could just sit there charged and the display >could time out when there is no change for a long time to save the >display power. > >Is this cap any good, or does it have problems? >What is a good test? > >-Bill Maybe the relay is there to prevent the cap from blowing fuses or killing switches from surge current? Charge the cap slowly through a resistor then short the resistor when the cap is charged and ready to supply the peak power? Just a theory . . . I did something like that on my homebrew stereo amp - it was killing switches trying to charge the cap banks. --
From: Jamie on 31 Jul 2010 11:54 default wrote: > On Tue, 27 Jul 2010 19:36:42 -0700 (PDT), Bill Bowden > <wrongaddress(a)att.net> wrote: > > >>I bought a digital 1 farad cap (ICBM-7244CRP) at a swap meet for $15 >>thinking I could sell it on ebay for a $30 or more. >> >>I'm not sure how it works since it has a 40 amp relay inside to >>disconnect the cap from the outside world. I think the display is for >>power or voltage, but there are no switches to select a function. Only >>two connections to make. >> >>Anyway, it doesn't do anything when connected to a 12 volt PS. But I >>can occasionally get it to turn on by interrupting the PS connections. >>And when it does turn on, it displays strange numbers of 00, 55 or >>whatever and then turns itself off after a few minutes. >> >>I'm sure the actual cap is good since when it goes on, I can >>disconnect the PS, and the display keeps reading for awhile using the >>cap energy before going out completely. And as it goes out the display >>reads changing numbers and then dies out. >> >>I don't understand the function of the 40 amp relay. Seems like with >>power applied, the cap could just sit there charged and the display >>could time out when there is no change for a long time to save the >>display power. >> >>Is this cap any good, or does it have problems? >>What is a good test? >> >>-Bill > > > Maybe the relay is there to prevent the cap from blowing fuses or > killing switches from surge current? Charge the cap slowly through a > resistor then short the resistor when the cap is charged and ready to > supply the peak power? > > Just a theory . . . I did something like that on my homebrew stereo > amp - it was killing switches trying to charge the cap banks. > > sounds like a static time delay off relay..
From: Bill Bowden on 1 Aug 2010 18:51
On Jul 29, 7:12 pm, default <defa...(a)defaulter.net> wrote: > On Tue, 27 Jul 2010 19:36:42 -0700 (PDT), Bill Bowden > > > > <wrongaddr...(a)att.net> wrote: > >I bought a digital 1 farad cap (ICBM-7244CRP) at a swap meet for $15 > >thinking I could sell it on ebay for a $30 or more. > > >I'm not sure how it works since it has a 40 amp relay inside to > >disconnect the cap from the outside world. I think the display is for > >power or voltage, but there are no switches to select a function. Only > >two connections to make. > > >Anyway, it doesn't do anything when connected to a 12 volt PS. But I > >can occasionally get it to turn on by interrupting the PS connections. > >And when it does turn on, it displays strange numbers of 00, 55 or > >whatever and then turns itself off after a few minutes. > > >I'm sure the actual cap is good since when it goes on, I can > >disconnect the PS, and the display keeps reading for awhile using the > >cap energy before going out completely. And as it goes out the display > >reads changing numbers and then dies out. > > >I don't understand the function of the 40 amp relay. Seems like with > >power applied, the cap could just sit there charged and the display > >could time out when there is no change for a long time to save the > >display power. > > >Is this cap any good, or does it have problems? > >What is a good test? > > >-Bill > > Maybe the relay is there to prevent the cap from blowing fuses or > killing switches from surge current? Charge the cap slowly through a > resistor then short the resistor when the cap is charged and ready to > supply the peak power? > > Just a theory . . . I did something like that on my homebrew stereo > amp - it was killing switches trying to charge the cap banks. > > -- Sounds like a good theory. The cap draws about 10mA when first connected, but I can't tell if the 10mA is used for charge, or just to power the electronics. It takes a long time for the cap to engage and results are inconsistent. The display never reads any useful numbers. But I don't know what the display is supposed to read, power or voltage. I imagine it would read power to the amp, but can't figure out how it would make such a measurement. It would have to detect very small voltage changes and convert that current and power. So, it would seem if gets very large voltage changes it would read high numbers, but all I get is 0 or 5 or other meaningless numbers. Think I'll sell it on ebay "as is" and just describe the problems. Some buyer might know how to fix it. I think it has a processor, so if that's gone, may be hard to fix. But the relay could be bypassed so the thing operates as a normal cap. Might be worth $10 in that mode. -Bill |