12v dc killed my 9v booster

modmod · February 02, 2005, 11:17:24 AM

i'd like to know if 4558 capable of 12v ? which component will got toasted first under 12v dc, diodes ? transistor ? or the 4558 ? thansk a lot

R.G. · February 02, 2005, 11:23:39 AM

The 4558 is capable of 30V at least.

First component toasted? Probably a 10V capacitor. Depends on the circuit and components of the booster. Can't tell any more without a schematic and parts list.

modmod · February 02, 2005, 11:28:57 AM

thx R.G, actually it's a rc booster,and i see most caps are 50v,could it be transistors ? thanks again

Marek · February 02, 2005, 12:21:07 PM

9VDC - (+) is very different from a
12VDC +( -) supply, and that's not just the voltage,
unless there is some kind of gretz rectifier which is quite
unlikely in a booster.

MArek

RDV · February 02, 2005, 05:10:43 PM

Are you sure you didn't reverse the voltage?
In that case, you might have fried a protection diode perhaps.
I've never seen an RC Booster's innards though.

RDV

modmod · February 03, 2005, 01:59:50 AM

yes,reversed polarity,should i change those polarity caps first ? those are 25v nichicon polarity caps. thanks guys

Mike Burgundy · February 03, 2005, 02:14:31 AM

Electrolytic caps DO NOT like reverse polarity, but they probably didn't fail (yet). They *might* in time, so you might want to replace them (it all depends on how good the polarity protection was)
This will most probably not solve your problem. As said therewill probably be some sort of polarity protection. This will be fried, so needs to be replaced. The most likely form is a 1N400x diode.
After replacing that, carefully measure the power pins on any IC's to see if theyre supplied correctly. If that's ok, you should probably get sound.

Paul Perry (Frostwave) · February 03, 2005, 08:10:36 AM

I'm sure the diode would have blown (if it has) well before any electrolytic damage. It might be different with tants, though. I wouldn't replace any electros unless there is a clear fault involving one.

modmod · February 03, 2005, 09:58:34 AM

thx guys,i believe there are no protection diodes.........in fact there are diodes marked "V4148",i wonder if it is 1n4148 ?

bwanasonic · February 03, 2005, 11:40:46 AM

Have you tried contacting the maker of the RC (I forget who makes it)? They might have a pretty good clue.

Kerry M

NaBo · February 03, 2005, 02:13:40 PM

i keep glancing over this topic and reading "12v dc killed my brother" :shock:

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12v dc killed my 9v booster