negative voltage spike

[khaled ragab]

hello,
i have a problem, if we have a coil e.g. lamp or any electrical devices in home(or conactors) that is controlled by a switch if i switch off the coil it is supposed to make a voltage spike(positive or negative) my question is how does home devices survive this voltage spike i know the answer if the spike is positive they use regulators but what if the spike is negative, does they use a special type of ac to dc converter that is not affected by the ac variation even if it is negative

 

[HTA]

Spike can be a problem and look like an under- or overvoltage for the power supply. Some equipment have special protection with a varistor or similar to supress overvoltage spikes. For a bridge rectifier negative spikes are the same as positive one. The rectifier diodes must have a high enough breakdown voltages.

Enjoy your design work.