[sdiy] power-question

[Tony Allgood]

>You can still use the zener to drop the voltage. Its a better way than
a series resistor, which varies the drop with current.

I like to use resistors, they are cheaper and you can get them big
enough to handle the dissipated power. The fall in voltage drop at
decreasing currents is not a problem, since the regulator can handle
that. Plus, if the voltage to the regulator is rising, then the current
must be falling, therefore the heat dissipation in the reg is also
falling. Either way, the final output is stable and the reg doesn't
cook. But you need to do a bit of calculation to work out worse case pd
across the resistor under high load conditons.

Regards,

Tony Allgood  Penrith, Cumbria, England

Oakley Modular Synth and TB3030:
www.techrepairs.freeserve.co.uk/projects.htm
My music: www.mp3.com/taklamakan