[sdiy] Basic circuit safety...

[Christian Bergmiller]

Hello,

> Basically, for example, if someone was to plug an AC adapter into a DC socket - or if one of those multi-socket DC adapters went in with the tip and ring reversed

a) use a diode (1n4007) in series with the dc socket (you will loose
0.7 Volt diode drop)
b) use a diode in parallel with the dc socket (wrong polarity voltages
will be short cut / no good idea in case of AC adapters)
c) use a bridge rectifier after the dc socket (this would accept DC/AC
but looses 1.4V)

> or if a 7809 suddenly found itself having to deal with 15 volts - what are some simple things I can do to at least minimise the damage

maximum input voltage is 35V (7809) worry only about the generated
heat (be generous on the heatsink)

bye
Christian