Phil Allison wrote:

"Spehro Pefhany"
"Phil Allison"

** See pics of AC supply adaptor:

Something here is not kosher.

Aside from my other comments .....

I'd like to see the clearance / creepage distances for that switch. Can
they seriously meet Class II ?

** Not an issue, as input and output circuits are both at mains voltages.

There is a serious safety issue with this device.


Only one issue?

Flammable plastic?

Non-FRP plastic melted through leaving a gaping hole and exposing
mains potential?

LED at mains potential without adequate insulation/creepage?

** I was not able to open the unit as it belonged to a customer.

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What is wrong is that it is * NOT * a safety isolation transformer.

It IS an AUTO-TRANSFORMER - falsely marked !!!!

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The big clue is the power maker's rating of 70 watts - suspiciously high
for a unit so small.

The other clue is that a "safety isolation transformer " must not exceed 50
volts on the output side.

Similar size units which ARE mains isolation types have ratings of only 25
to 30 VA.

The 240 volt input measures 140 ohms ( room temp) and the output side 70
ohms and the neutral terminals are common.
So - at the rated 70 watt (should be VA ) load it will get very hot (
dissipation about 18 watts) and likely send the 105C thermal fuse open.

Wot a dangerous, horrible POS !!!!!!!!!!!!!

But easy to find on-line or eBay - I bet.

This the shonky maker's site:

http://www.goldenedge.com.hk/

..... Phil

Its not the only shonky thing one might buy, and
I bought a 500W rated variac from Jaycar last summer.
It wasn't a very nice POS, because it hummed badly, but
didn't get hot without a load, so I could live with the hum.
But after only a month's use, and while using it to control the speed
setting of an electric drill used as a motor for a lathe for very
easy work, there was a flash and spark and smoke, and I turned it off.
I had a look inside and boy what a mess.
Apart from melted wiring, the wiper for the output
had penetrated through the windings and against the toroidal core.

The fuse didn't blow though.
The fuse is on the input.
But it was rated for 500VA, you'd think that'd mean that for
50Vout, Iout could be up to 10A.
But I doubt the unit would withstand that, because the
winding wire was 1mm dia I guess, good for a continuous 2.5 amps maybe.
I wasn't overcurrenting the output afaik.


So I take it back to Jaycar and they sent it away to their tech.
After waiting a month they give me the refund I'd asked them for.
It must have been unrepairable.

The construction quality of that was very poor, typical
asian CRAP.

I figure jaycar would buy them for $5, and sell for nearly $200
which was what I paid.
Absolute junk though.

Now I don't have a variac, and have to use a couple
of step down trannies in series to get a low voltage to apply to a
suspicious
device under test.

Patrick Turner.