Author Topic: 8050A Transformer  (Read 1447 times)

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Offline mentaldemiseTopic starter

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8050A Transformer
« on: June 25, 2016, 09:05:46 pm »
Does anyone know a US trasnformer I can get for the 8050A?

Preface:
I bought two broken on Ebay. They both seem to have an issue with the transformer. I guess it could be the rectifier. One that has the battery option works just fine if I provide it 2.4V to each battery terminal. Not when I provide 5 to just one. This requires that I use two channels of my power supply. I believe this uses a DC-DC converter and by passes the AC->DC side of the power supply. The other without the battery option on it I removed the transformer. If i put my dual supply in series and provide +12 and -12 the meter works fine if I connect the common to ground on the board.

The internet has led me to believe that I need a center tap 15-0-15 transformer. The center tap for the US transformer is not connected as can be seen in the image. The red circle is where center tap is hooked up for non-120. The two wires that are soldered in are going to a dual power supply with it in series for +/- 12

Any suggestions or help would be great! They both work and only one of the sections of one of the LCDs is bad!!! *the one with the battery option actually measures 2V low but the other is accurate to other meters I have.
 

Offline vgamesx2

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Re: 8050A Transformer
« Reply #1 on: June 26, 2016, 07:30:49 am »
If I may, might I suggest to grab a power brick of whatever voltage and a little DC converter set to 2.4V instead? I dunno, its what I'd do anyway.
Also, I don't understand why you need to use both channels on your power supply... Why can't you just attach it to one terminal, then tack on a lead or an alligator clip from there to the other terminal?
 

Offline bitseeker

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Re: 8050A Transformer
« Reply #2 on: June 26, 2016, 07:40:27 am »
Since you questioned the rectifier's condition, did you check it? It's not uncommon for them to short out. In other words, check the transformer on its own and then the rectification section on its own to isolate and narrow down the source of the fault(s).
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Offline mentaldemiseTopic starter

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Re: 8050A Transformer
« Reply #3 on: June 26, 2016, 10:53:41 pm »
Well, checked the transformer, 12V AC out. Checked the rectifier, just under 12V DC out. Guess I'll start pulling and testing caps now. :'(
 

Offline bitseeker

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Re: 8050A Transformer
« Reply #4 on: June 27, 2016, 02:53:52 am »
Yeah, 12V DC out sounds low. Was the rectifier still connected to the circuitry after it? Something pulling the voltage down.

Note that you don't have to completely remove the caps, just free one side. Do you have an ESR meter? Checking capacitance only gives you part of the picture, which might look OK.
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