Challenge of Voltage/Digital standards differences between USA and Singapore

[x9200]

This is how I checked my 200W before saying it was an autotransformer. N was not grounded.

[PNGMK]

This is how I checked my 200W before saying it was an autotransformer. N was not grounded.

Was the secondary and primary connected?

[x9200]

Yes. 20-70 ohms depending on the combination (In/Out/N/L). Plus probably a capacitor somewhere between N and L judging from the meter's slow response.

But I am not the OP, I am just exploring...

[PNGMK]

The meter's slow response may be due to the inductive affect of the TXR, similar to a capacitor.

[watours]

Mmm. I bet that's an auto transformer but can't be sure without a meter. I'd recommend something like this https://www.amazon.com/ACUPWR-AUD-1500- ... ransformer

i've ordered this transformer; will test with this and post results. Thanks for your help

[watours]

Mmm. I bet that's an auto transformer but can't be sure without a meter. I'd recommend something like this https://www.amazon.com/ACUPWR-AUD-1500- ... ransformer

Thanks you so much for your help. I had this transformer delivered over the weekend and it fixed the problem. As it turns out, it was a grounding issue.

You are a genius; and thank you so much once again for recommending a great product.

[PNGMK]

Mmm. I bet that's an auto transformer but can't be sure without a meter. I'd recommend something like this https://www.amazon.com/ACUPWR-AUD-1500- ... ransformer

Thanks you so much for your help. I had this transformer delivered over the weekend and it fixed the problem. As it turns out, it was a grounding issue.

You are a genius; and thank you so much once again for recommending a great product.

Well between myself and StrongEagle and the others you have a few decades of electrical engineering experience contributing. Glad to see the issue resolved.

[sundaymorningstaple]

PNGMK, you do yourself and SE a disservice. As old as you two old coots are, I'd say a LOT of decades of experience!

[PNGMK]

As a result of getting dragged into a dispute with Sim Lim type clowns on Carousell who are selling these I would remind you all that the use of Autotransformers is specifically banned in Singapore for the following cases:

No person shall use an auto-transformer to supply electricity to —
(a) a socket-outlet;
(b) a portable appliance, unless the auto-transformer is contained therein;
(c) an electric toy; or
(d) any extra-low voltage circuit.

https://sso.agc.gov.sg/SL-Rev/EA2001-RG ... vIds=pr20-

This specifically bans stand-alone autotransformers (as they are not contained in the appliance they are plugged into and of course they are fitted with a socket-outlet). This is a good thing. Unfortunately the tards at Sim Lim don't think so.

[x9200]

No person shall use an auto-transformer to supply electricity to —
(a) a socket-outlet;
(b) a portable appliance, unless the auto-transformer is contained therein;
(c) an electric toy; or
(d) any extra-low voltage circuit.

https://sso.agc.gov.sg/SL-Rev/EA2001-RG ... vIds=pr20-

This specifically bans stand-alone autotransformers (as they are not contained in the appliance they are plugged into and of course they are fitted with a socket-outlet). This is a good thing. Unfortunately the tards at Sim Lim don't think so.

Unfortunately "portable appliance" is not defined and:
2. In these Regulations, unless the context otherwise requires —
“appliance” means any device which uses electricity for a particular purpose but does not include a luminaire or an independent motor;

[PNGMK]

Yeah well appliance when I last read the Aussie regs was any none permanent electrical device. Sounds like they left a gap there.

[Strong Eagle]

Yeah well appliance when I last read the Aussie regs was any none permanent electrical device. Sounds like they left a gap there.

It's a typical Singapore consumer screw job. Business uber all. Selling a dangerous or completely worthless product? No problem. No recourse for consumer. Consumer complains? Seller sues under libel laws, now consumer is screwed two times.

[PNGMK]

Yeah well appliance when I last read the Aussie regs was any none permanent electrical device. Sounds like they left a gap there.

It's a typical Singapore consumer screw job. Business uber all. Selling a dangerous or completely worthless product? No problem. No recourse for consumer. Consumer complains? Seller sues under libel laws, now consumer is screwed two times.

Honestly if I had an auto transformer blow something up I'd take it to the SCT. The act is clear in intention if not in literal language. However the most irritating thing about this shitboxes is that they trip out the ELCB's. Everytime someone complains to me that their ELCB is tripping it comes down to the one of these devil black boxes plugged in somewhere.

[bgd]

And the problem is a flawed design or just poor implementation?

How do you tell an auto transformer from an ordinary one?

[Strong Eagle]

And the problem is a flawed design or just poor implementation?

How do you tell an auto transformer from an ordinary one?

It is a flawed design that is used because it is cheaper to make. In a standard transformer, there is a primary coil or winding and a secondary coil, both wound onto a common core. When alternating current flows in the primary coil, it generates a magnetic field in the core, which in turn generates a current flow in the secondary coil.

The ratio of the number of turns between the primary and secondary coils determines how much the voltage is stepped up or down. If you had 1000 turns in the primary coil, 500 turns in the secondary coil, and apply 240 volts to the primary coil, you get 120 volts in the secondary coil.

Another big, big benefit of a true transformer is that the secondary coil (and everything that is attached to it) is isolated from the primary coil, and this is the real subject of this thread. You'll see that there are no wires connecting the primary and secondary sides... therefore, if a short were to develop in the secondary coil, you're not going to get connected to the mains ground wire and get a shock. Isolation transformers used to be used in lots of electrical equipment (voltage in = voltage out) for precisely this reason... people would not get shocked if there is a short in the equipment.



Now, an auto transformer only has one set of windings or coils. The primary coil is connected to the mains and like the standard transformer, let's say it has a total of 1000 turns would around a magnetic core. Now, instead of having a secondary coil, you simply tap the primary coil 500 turns down with the output wire and voila, as above you halve the voltage.

But, you'll notice that the primary and second wires are connected together. If you have a short anywhere in the coil, the possibility of being shocked by becoming grounded to the mains is possible. And even small current leaks, not enough to shock you, cause GFCI circuits to trip.

Cheaper to make and much more potential to be deadly. A hot wire anywhere in the transformer itself OR in any appliance that is plugged into it that touches ground, or the appliance handle, or anything that you might touch, has the ability to deliver a lethal shock.