My mom complained recently that she got a shock from touching the two leads of the cord for the toaster while it was unplugged. I tried it and sure enough, got zapped. I’m not surprised that it has a capacitor in it. It is an Oster 6240, and has a LED display of the darkness setting. I am surprised that the capacitor is not discharged once you press the button to eject the toast.
I don’t have a circuit diagram, nor all the skills necessary to read it if I had it, but this behavior seems unusual to me. I know that televisions have capactiors charged to high voltages that can take a long time to discharge, but this refers (I think) to repairing it, not to touching the disconnected plug. Is there something defective with the toaster? What other household items can zap in this way?
Sounds quite unusual to me. How old is the toaster? If it’s fairly new and you still have the receipt I would return it for a replacement.
It’s becoming common for this to happen. I copped a shock from a nightlight which has a photo-sensor to turn it on when it gets dark.
The problem is that these devices don’t use transformers to derive their low voltage supplies. They have a capacitor in series with a resistor wired across the mains voltage. The resistor will have, say, 10 V across it, and the capacitor will have the balance of the voltage drop across it (100 - 230 V, depending on the mains voltage). They get the low voltage from across the resistor.
When the device is switched off or unplugged, the capacitor can have anything from zero up to close to the full mains voltage, depending where on the ac waveform the switching occurred.
A good design would include a high resistance “bleeder” resistor in parallel with the capacitor. In practice, that’d mean an extra 1.5 cents on the cost, so it gets left out.
The marketers have won. It’s a race to the bottom. I’m shocked, shocked I tell you, that the red, white and blue, all-American, free enterprise system would produce such a result.