Computerised power saver plug (with schematic)

Yet another fake power saver plug, but with with an unexpectedly complex twist.

I've since scoped the triac gate drive and it is hard driven (not pulses) so the software is probably only using the zero crossing detection to ensure the triac only turns on at the zero crossing point to avoid a huge current spike through the triac if it turned the capacitor on at the peak of the sinewave.  By default the triac will turn off at the zero crossing point itself when the on/off button is used.  But when directly unplugged while active the capacitor will be left in a random state of charge as demonstrated by my fingers.  That's where the discharge resistors could have helped avoid a zap and also avoided a triac current spike when turned on again.

It's bizarre that so much effort has gone into the circuitry design when they could just have had the capacitor connected between live and neutral (with a discharge resistor) and just put on a lightshow when the button was pressed.  It's professional fakery where the circuit does make sense even if it is just a scam product.  Possibly just to make it look more convincing.  But why would they even have an on and off button on a power saver anyway.

It's worth mentioning that the vague 10kW rating is just fluff to indicate the household load which it could correct if it was a real thing.  The unit does not actually pass actual load current.

Note that while active, the unit presents an apparent power of 40VA which will increase your electricity bill significantly over a year if you are charged for apparent power.  It would effectively cost 1 unit per day on 230V, so over a year that would be about 365 units, which at local costing would be about £80 a year.

If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
This also keeps the channel independent of YouTube's algorithm quirks, allowing it to be a bit more dangerous and naughty.


Leave a Reply

Your email address will not be published. Required fields are marked *