3046

[Tony Allgood]

Hi Ken and all,

Three things come to mind here. Why not use a power resistor in series
with the 3046's supply, which would limit the voltage sufficiently to
not take it above its maximum power disipation? It might take a little
longer to warm up though. The 723 IC is the best way of course. You can
program a current limit, and even include a little foldback to stop the
regulator overheating. You could even include the 723 into the 3046
heater design. That way you have regulator and heater control in one.
Another way is to use a second three terminal regulator configured as a
current limit.

I'm happy with the Mini's VCO with just a temp co. 'Warms up' faster and
takes less current too. For my version see:

http://www.techrepairs.freeserve.co.uk/vco.htm

BTW: The Prodigy VCO is based on the mark 3 MiniMoog circuit, although
the expo in the Prodigy uses a heated 3046 type, cf the Mini's uA726.
The Mark 2 used 3046s in the expo, but the core is discrete. The Mark 1
is all discrete, including the op-amp summing circuit.

I only looked at the prodigy circuit yesterday. I was suprised to see
that the Prodigy used the Mark 3 Mini circuit with a few changes. The
reset circuit is subtley different, and the expo, but thats about it.

Regards,

Tony Allgood  Penrith, Cumbria, UK

Modular synth circuits, TB303 clone and Filter Rack

http://www.techrepairs.freeserve.co.uk/projects.htm