# Replacement switching wallwarts



## AntAltMike (Nov 21, 2004)

I have to replace a large number of 5.5VDC, 1.72 amp switching wallwarts, but the original part and the only known OEM are no longer in production or readily available. The orignial part is numbered HB12-055172, and a replacement product that is no longer readily available was FM055017.

I have found two affordable and available wallwarts with higher current ratings, but they each were apparently designed to output one of four preselected voltages: 4.0. 4.5. 5.0 of 5.5 VDC. On the pictures of them I've seen, there is a table stamped on each with the four voltages listed in the top line and a single amperage value is entered into the line below, so as to indicate the selected voltage. One eBay page for such a product actually specifies in its product description that it has been set at 5.0 VDC out, for example.

Unfortunately, I can't find any that have been set to 5.5VDC. My only experiences in attempting to service wallwarts has led me to discover that the cases are all glued closed, but if there is some reasonable chance of me being able to change the output voltage without too much work (I doubt I'd want to find and change a zener diode), I will probably buy a dozen and sit down and do them all at once.

Is anyone at all familiar with the inner construction of such multi-output value supplies?

Here are the two that can commonly be found in adequate quantities and at reasonable prices.

*I.T.E. AC Adapter AD1805C 4-5.5VDC 3.8Amax*
http://www.ebay.com/itm/I-T-E-AC-Ad...412?pt=LH_DefaultDomain_0&hash=item23144c464c

Here is another adaptor that can be somehow configured to put out 4.0 to 5.5DVC, but at currents of 2.6 to 2.3V

http://www.ebay.com/itm/Linksys-Ada...243?pt=LH_DefaultDomain_0&hash=item519113d203


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## dennisj00 (Sep 27, 2007)

It sounds to me that the voltage settings aren't selectable but approximately what is output at the current rating. . . higher current, lower voltage is output.

While what you're looking for has a rating of 5.5 volts @ 1.72 amp, if you can measure the operating voltage, say it's 5.25, find a wart that can output 1.72 at 5.25 volts and you should be ok.

You say a large quantity -- you may want to look at Mouser or Jameco rather than ebay and get a few samples for test.


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## AntAltMike (Nov 21, 2004)

dennisj00 said:


> It sounds to me that the voltage settings aren't selectable but approximately what is output at the current rating. . . higher current, lower voltage is output..


Switching supplies that I have previously evaluated all had excellent voltage regulation regardless of current draw.

In one unit I broke open, which is labeled to have a dedicated 5.5 volt output, I see what might be a pair of jumpers, so it might be that no jumpers is 4.0 volts, just one jumper is 4.5 volts, just the other is 5.0 and both installed is 5.5. If someone doesn't furnish additional info, I'll probably peck around with it next week.


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## AntAltMike (Nov 21, 2004)

153 thread views, one response. Looks like it's time to start talking to myself.

I just ganged together a couple of identical Sharp. 5.5 VDC, 700 mA switching wallwarts together and they powered one tuner box in spite of being 320 mA "light". I'm actually surprised this worked. When I began using switching power supplies in bootleg commercial video games I was building 30 years ago, I tried pairing a couple of 5 VDC, 3A supplies when we ran out of 5 amp supplies but it didn't work. What seemed to be happening was, unless we could adjust the pot-controlled outputs to be absolutely, exactly equal, one would sense overvoltage and either shut down or at least reduce its duty cycle, which would force the other to ratchet its voltage up, which would force the other to decline further, and within an hour the power supplies burned out.

If I absolutely, positively had to pair together half-sized switching regulator supplies, I' probably put a 1/10 ohm resister on each output. I figure that if these boxes draw about 1.4 amps, then they must have an effective resistance of 4 ohms, so adding 1/10 ohm would only drop the voltage by about a tenth of a volt or so... but unfortunately, I don't have a bulk quantity supplier for the little Sharp supplies, either, so if I can't make do with either of the 4.0 to 5.5V supplies linked in the opening post, of which I ordered one each, then once I have accumulated about a dozen of the original 1.72 amp supplies, I'll just have to find a way to repair them. I never have succeeded at repairing a switching supply. I have previously checked the rectifier diodes, filter capacitor adequacy and transformer coils continuity, since those are the easiest things to check, but they were never the cause of any failures. If I don't come up with an affordable replacement in another couple of weeks, then I'll have to slug out the repairs.


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## AntAltMike (Nov 21, 2004)

Looks like I won't be becoming a bench repair tech after all. I was scrounging through my van and found an old, left over D-Link, 5VDC, 2.5 amp adaptor that came with a Riser Bond cable fault finder that failed long ago. The measured no-load voltage was 5.16 VDC and the plug matched, so I plugged it into a tuner box and it seemed to work fine. I can get vast quantities of D-Link plug compatible replacement converters for under $10 each including shipping, so if this one holds up in the field for a week, then I'll order a couple of dozen from Hong Kong.


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## tmpmustang (Jan 24, 2015)

DID IT WORK?

I am trying to find a replacement for my power supply hb12-055172spa

Switch Power Supply

MODEL: HB12-055172SPA
ADDIT: E315659 Listed 3MVE
OUTPUT: 5.5V / 1.72A
TIP: +
USED FOR: Access HD TV Digital to Analog Converter DTA1080
REF:

THE COMPANY IS OUT OF BUSINESS AND NO LONGER AVAILABLE BY TELEPHONE.

MISPLACED POWER SUPPLY AFTER LAST HURRICANE.....

ANY SUGGESTIONS?

THANKS


 
Registered
3,002 posts

LocationCollege Park MD (just outside Wash, DC)
Joined: Nov 20, 2004

Posted 20 December 2011 - 01:44 PM
Looks like I won't be becoming a bench repair tech after all. I was scrounging through my van and found an old, left over D-Link, 5VDC, 2.5 amp adaptor that came with a Riser Bond cable fault finder that failed long ago. The measured no-load voltage was 5.16 VDC and the plug matched, so I plugged it into a tuner box and it seemed to work fine. I can get vast quantities of D-Link plug compatible replacement converters for under $10 each including shipping, so if this one holds up in the field for a week, then I'll order a couple of dozen from Hong Kong.


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