5V / 100mA power supply.
Hi Ikalogic,
This is only an example how things could be done.
When no load is present, the 100mA will have to be dissipated by the
12V/5W zener diode, at full load the regulator will have to dissipate
about 7V multiplied by the maximum load current. So both require a
suitable heatsink. It would have been better to use a 10V zener diode
and a low drop regulator, but I had to use what was on hand.
The multimeter measures the voltage accross the zener diode and you
can see that is has dropped below it's zener voltage indicating that the
maximum load current has been reached.
I used six blue led's each with a 100
hm: resistor in series to load
the regulator. Total supply current is 6 times 19mA.
If Nigel sees this circuit I think he's gonna blow a gasket.
on1aag.