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#1
Posted to rec.audio.car
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What power supply...
What power supply should I use to test car amplifiers in my house?
Thanks. |
#2
Posted to rec.audio.car
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What power supply...
Use a 12 volt AC to DC adaptor. You can go to any Goodwill and buy a used
one for 50 cents (like an old one that used to power a printer). Just make sure you know which lead is positive and which lead is negative when you go to test something otherwise you will likely fry it. The amperage rating of the adaptor really doesn't matter (the more the better) as the component you are testing will draw the amperage it needs. MOSFET "Your name" wrote in message news:vzR2h.78$Ue.58@trndny03... What power supply should I use to test car amplifiers in my house? Thanks. |
#3
Posted to rec.audio.car
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What power supply...
Astron builds, IMHO, some of the best linear 12VDC power supplies out there. But a good 100A constant supply won't be cheap. -- JimJ[VT] |
#4
Posted to rec.audio.car
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What power supply...
BTW, that is EXACTLY how I aquired my 12 volt "bench" power supply. It is a
"Sino-American" (whatever that means) and it says: INPUT: 120VAC 60Hz 35W OUTPUT: 12 VDC 1100 mA It has been my power supply tester for years and has never let me down. I bought it for 50 cents from Goodwill and just clipped off the plug on the end. MOSFET "Your name" wrote in message news:vzR2h.78$Ue.58@trndny03... What power supply should I use to test car amplifiers in my house? Thanks. |
#5
Posted to rec.audio.car
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What power supply...
I guess I was thinking about how you define "test". Obviously, if you want
to test the limits of an amplifier, you will need a hefty, expensive bench power supply. I was thinking more in terms of "does it turn on or not", in which case a more simple approach could be used. MOSFET "JimJ[VT]" wrote in message ... Astron builds, IMHO, some of the best linear 12VDC power supplies out there. But a good 100A constant supply won't be cheap. -- JimJ[VT] |
#6
Posted to rec.audio.car
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What power supply...
MOSFET wrote:
Use a 12 volt AC to DC adaptor. You can go to any Goodwill and buy a used one for 50 cents (like an old one that used to power a printer). Just make sure you know which lead is positive and which lead is negative when you go to test something otherwise you will likely fry it. The amperage rating of the adaptor really doesn't matter (the more the better) as the component you are testing will draw the amperage it needs. ....up to the current limit of the adapter, after which the output voltage will start to drop, leading to the adapter itself dying, most likely from a blown rectifier diode. |
#7
Posted to rec.audio.car
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What power supply...
...up to the current limit of the adapter, after which the output voltage
will start to drop, leading to the adapter itself dying, most likely from a blown rectifier diode. Yes, as Dan has pointed out, in the fine tradition of RAC in pointing out any misstep, I SHOULD have said the thing you will be testing will draw the amps it needs, but IT OBVIOUSLY CAN'T EXCEED THE AMPERAGE RATING OF THE ADAPTOR. Again, I was thinking in terms of testing whether an amplifier (or any 12 volt accesory) turns on or not and can pass a signal, NOT testing the limits of an amplifier. If you just want to test whether an amp works or not, you do not need a $1000 Astron bench power supply. I have been using a simple AC converter for years as my "bench" supply and it has worked fine. If I want to test the limits of an amp, I take it out to my car. MOSFET |
#8
Posted to rec.audio.car
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What power supply...
MOSFET wrote:
Yes, as Dan has pointed out, in the fine tradition of RAC in pointing out any misstep, I SHOULD have said the thing you will be testing will draw the amps it needs, but IT OBVIOUSLY CAN'T EXCEED THE AMPERAGE RATING OF THE ADAPTOR. Obvious to us maybe, not necessarily to the original poster. Again, I was thinking in terms of testing whether an amplifier (or any 12 volt accesory) turns on or not and can pass a signal, NOT testing the limits of an amplifier. From your description, the OP may think any little 300mA wall wart will do... that'll barely be enough power to start up the deck, let alone the amp. Forget about actually getting any output from either. |
#9
Posted to rec.audio.car
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What power supply...
From your description, the OP may think any little 300mA wall wart will
do... that'll barely be enough power to start up the deck, let alone the amp. Good point. The idle current of some amps may exceed many small AC adaptors. I use an AC adaptor rated for 1100 mA as my "bench" power supply and it has been able to power up any amp or HU. And I have had no trouble getting those amps and HU's to pass a signal (obviously I don't blast it). So from my experience, as long as you get a 12VDC adaptor with at least 1000 mA, that should be sufficient to test (see whether it works or not) any 12 volt car audio device. MOSFET |
#10
Posted to rec.audio.car
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What power supply...
MOSFET wrote:
From your description, the OP may think any little 300mA wall wart will do... that'll barely be enough power to start up the deck, let alone the amp. Good point. The idle current of some amps may exceed many small AC adaptors. I use an AC adaptor rated for 1100 mA as my "bench" power supply and it has been able to power up any amp or HU. And I have had no trouble getting those amps and HU's to pass a signal (obviously I don't blast it). So from my experience, as long as you get a 12VDC adaptor with at least 1000 mA, that should be sufficient to test (see whether it works or not) any 12 volt car audio device. Yeah, a full amp (ampere, not amplifier) should be sufficient for a simple bench tester. If you need more, look into a 10-15A unit typically sold for CB base station use. |
#11
Posted to rec.audio.car
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What power supply...
Being you just out right sucks.
In article , "MOSFET" wrote: From your description, the OP may think any little 300mA wall wart will do... that'll barely be enough power to start up the deck, let alone the amp. Good point. The idle current of some amps may exceed many small AC adaptors. I use an AC adaptor rated for 1100 mA as my "bench" power supply and it has been able to power up any amp or HU. And I have had no trouble getting those amps and HU's to pass a signal (obviously I don't blast it). So from my experience, as long as you get a 12VDC adaptor with at least 1000 mA, that should be sufficient to test (see whether it works or not) any 12 volt car audio device. MOSFET |
#12
Posted to rec.audio.car
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What power supply...
In article , "MOSFET" wrote:
I guess I was thinking about how you define "test". Obviously, if you want to test the limits of an amplifier, you will need a hefty, expensive bench power supply. I was thinking more in terms of "does it turn on or not", in which case a more simple approach could be used. That cheap supply could have its benefits too. I would want at least 10-15 amp and with meters and adjustable voltage. The really nice thing is adjustable current limiting. If your playing around replacing parts, a current limit is great. i use current limiting when working on home amps. A light bulb. greg "JimJ[VT]" wrote in message ... Astron builds, IMHO, some of the best linear 12VDC power supplies out there. But a good 100A constant supply won't be cheap. -- JimJ[VT] |
#13
Posted to rec.audio.car
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What power supply...
I use 3 supplies.
The first is a bipolar 24V adjustable voltage/currnet (0-4A) supply. So I can do very low current testing on the power supply AND go into bipolar mode to power up the amp without the internal switcher. The second is an acopian lab grade 22A supply The third is a sky's the limit (limited to 200A by me) 6 golf cart batteries and a solar/pulse charger for testing the big stuff and putting stress on it. I have a 4th supply but it doesn't count for car audio BUT it's 0-600V, 0- (-150)V 6.3V, 12.6V, 0-120VAC. Guess what I use it for? I can't stress the importance of a bipolar supply if you want to tinker with amps. Chad "GregS" wrote in message ... In article , "MOSFET" wrote: I guess I was thinking about how you define "test". Obviously, if you want to test the limits of an amplifier, you will need a hefty, expensive bench power supply. I was thinking more in terms of "does it turn on or not", in which case a more simple approach could be used. That cheap supply could have its benefits too. I would want at least 10-15 amp and with meters and adjustable voltage. The really nice thing is adjustable current limiting. If your playing around replacing parts, a current limit is great. i use current limiting when working on home amps. A light bulb. greg "JimJ[VT]" wrote in message ... Astron builds, IMHO, some of the best linear 12VDC power supplies out there. But a good 100A constant supply won't be cheap. -- JimJ[VT] |
#14
Posted to rec.audio.car
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What power supply...
In article , "Chad Wahls" wrote:
I use 3 supplies. The first is a bipolar 24V adjustable voltage/currnet (0-4A) supply. So I can do very low current testing on the power supply AND go into bipolar mode to power up the amp without the internal switcher. Thats a bit more than I get into right now. Sounds like a good idea if you are really doing a lot of amps. I would rather not do car amps though. I have made suggestions to perhaps make some manufacturers consider converting their car voltage switchers into 120 VAC switchers and use the same amps fopr home or mobile installations. greg |
#15
Posted to rec.audio.car
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What power supply...
It don't work that way, sure would be nice though
A lot of Ham Radio places sell great power supplies that are switchers and high ish current. Shall I send you some links? Chad "GregS" wrote in message ... In article , "Chad Wahls" wrote: I use 3 supplies. The first is a bipolar 24V adjustable voltage/currnet (0-4A) supply. So I can do very low current testing on the power supply AND go into bipolar mode to power up the amp without the internal switcher. Thats a bit more than I get into right now. Sounds like a good idea if you are really doing a lot of amps. I would rather not do car amps though. I have made suggestions to perhaps make some manufacturers consider converting their car voltage switchers into 120 VAC switchers and use the same amps fopr home or mobile installations. greg |
#16
Posted to rec.audio.car
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What power supply...
(-150)V 6.3V, 12.6V, 0-120VAC. Guess what I use it for? Your own home-made electric-chair? I don't know, what. MOSFET |
#17
Posted to rec.audio.car
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What power supply...
"MOSFET" wrote in message m... (-150)V 6.3V, 12.6V, 0-120VAC. Guess what I use it for? Your own home-made electric-chair? I don't know, what. MOSFET Prototyping and repairing tube amps Plate voltage, bias voltage (the negative number) and filament voltage. The little variac inside gets used rarely in lieu of the big stancor on the bench. Chad |
#18
Posted to rec.audio.car
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What power supply...
Plate voltage, bias voltage (the negative number) and filament voltage.
The little variac inside gets used rarely in lieu of the big stancor on the bench. Chad OK, thanks. That's what I get for asking. I don't know what a "variac" and a "stancor" are. But I appreciate the answer. MOSFET |
#19
Posted to rec.audio.car
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What power supply...
MOSFET wrote:
Plate voltage, bias voltage (the negative number) and filament voltage. The little variac inside gets used rarely in lieu of the big stancor on the bench. Chad OK, thanks. That's what I get for asking. I don't know what a "variac" and a "stancor" are. But I appreciate the answer. http://en.wikipedia.org/wiki/Variac Stancor is a company that makes transformers and assorted other power-control products: http://www.stancor.com/ |
#20
Posted to rec.audio.car
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What power supply...
In article liz4h.280943$5R2.186492@pd7urf3no, Matt Ion wrote:
MOSFET wrote: Plate voltage, bias voltage (the negative number) and filament voltage. The little variac inside gets used rarely in lieu of the big stancor on the bench. Chad OK, thanks. That's what I get for asking. I don't know what a "variac" and a "stancor" are. But I appreciate the answer. http://en.wikipedia.org/wiki/Variac Stancor is a company that makes transformers and assorted other power-control products: http://www.stancor.com/ Wikipedia does not come out and say what it is. A variable transformer, and it doesn't have to be an auto transformer. I have use of a Stancor with big voltage an current meters, and I also installed another transformer inside to perform the isolation trick. I can use the isolated output or the standard autotransformer output. greg |
#21
Posted to rec.audio.car
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What power supply...
"Matt Ion" wrote in message news:liz4h.280943$5R2.186492@pd7urf3no... MOSFET wrote: Plate voltage, bias voltage (the negative number) and filament voltage. The little variac inside gets used rarely in lieu of the big stancor on the bench. Chad OK, thanks. That's what I get for asking. I don't know what a "variac" and a "stancor" are. But I appreciate the answer. http://en.wikipedia.org/wiki/Variac Stancor is a company that makes transformers and assorted other power-control products: http://www.stancor.com/ My Variac is not on that site, Hmmmm, it WAS built in the 60's though! A variac allows me to bring something up REALLY slow by adjusting the voltage from 0V to 140V. It allows full current though (20A). For example if an amp has blown finals I can bring it up without doing more damage, although I prefer current limiting for this. I'm more likely to bring it up on the variac after it's complete to make sure it's not going to take off again. Variacs are also good for re-forming caps in tube stuff to at least get it going to see if it's worth a re-furb. A 500V cap that's sat for a while doesn't really like to be hit with 500V right away, it wants to be eased into the situation. For car stuff you really only need a variable voltage/current bipolar supply (or two) and a 12V (13.8) that will supply enough current to do unloaded testing or testing under light load/low power to make sure the drivers are good. If you have an open driver circuit the amp will make a darn purdy waveform under no load but will collapse when load is applied. The 20A supply does good for this and even for mild burn in. Then it goes over to the mutha of supplies for final cooking and torture to make sure I won't see it again until someone does something stupid again. Contrary to consumer popular belief 99.9% of all major repairs of amplifiers are due to ignorance on the consumer's/Installer's part. RARELY do I find failed power supplies/blown finals in amps that are "driven on Sundays by grandmas" Low impedance driving and overzealous use of the loudness, bass bost, and bass control onthe head unit at once are the primary causes. As in "What! You mean I can't bridge this amp at 2 ohms?" Another 2 common problems are burnt protection resistors (acting as fuses) on the signal ground path from improper installation or loss of amplifier ground. And the ominous cold solder joints. Most of these problems can be sussed out in triage and the amp can be repaired and returned to the customer on the spot as long as the bench is clear. So... Woofer boxes don't make good mounting surfaces Chad |
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