Shortwiring AC/DC power adapter

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nedtron
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Re: Shortwiring AC/DC power adapter

Post by nedtron » Thu Apr 24, 2003 8:08 am

Wall worts / AC-DC wall adapters: UL listed wall mounted transformers are required to have thermal / current fuses. The thermal / current fuses will fault with excessive temperature or current. The fuses are about the size of a 1/4 watt resistor and may be difficult to locate as they may be placed any where in series with the winding.
In this case, where as the LED is still illuminated, if the transformer is equpped with a fuse, the fuse is still conducting and the source of the failure is most likely the rectifier diode.
As recommended in previous posts, a replacement power source would be the most reliable solution.<p>Ned

gadgeteer
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Re: Shortwiring AC/DC power adapter

Post by gadgeteer » Sun Apr 27, 2003 1:19 am

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>As recommended in previous posts, a replacement power source would be the most reliable solution.<hr></blockquote>But not nearly as fun...<p>I have an Amana microwave oven (from the early 80's). The blower motor died. Replaced it, but the replacement was ½ amp (original 1 amp). Of course the reduced airflow means that I popped a couple of thermal fuses. The motor had three terminals, obviously some kind of thermal fuse (probably "microtemp") wired into the windings. I'm afraid I bussed the two microtemp terminals together and re-installed the original motor. But I also attached some large TO-3 heat sinks; no way that fan motor's gonna get hot now. (But it IS "unprotected". It's a simple shaded-pole squirrel cage, who cares if it's "unprotected"...)

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