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Fredxx[_3_] Fredxx[_3_] is offline
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Default 240 V Transistors and chips

On 28/09/2020 14:48:07, Jeff Layman wrote:
On 28/09/2020 12:11, Fredxx wrote:

A resistor, diode and zener can get you a low power 5V.


Not low power - you are dropping around 230V through that resistor. Even
at only 5mA that is 1.65W to be dissipated, and that is considerably
more than a standard resistor will handle .


It would be less than 1.2W but I take your point. There could also be a
series cap to drop some of the volts.

Hardly an ornate solution but cheap.

Interestingly, Paul's post
notes "There is a large resistor that does the dropping to bring the
240V down to some lower level."