14 Dec
2011
14 Dec
'11
1:50 p.m.
> I once built a phase-shift oscillator [...]
> I considered trying to build some kind of AGC
for it, but never
> actually got the round tuits for that.
Perhaps an incandescent light bulb might help out
there. =)
Perhaps. But it requires enough current flowing in the feedback divider to warm the bulb's filament significantly.
I'd rather avoid
dissipating that much power - not to mention that I'm not sure the
op-amp I was using was capable of it.
There are some pretty low current light bulbs (such as ones that glow to
their specified intenisty at 20ma (with 6V across them). You can drive
thoee from most nroaml op-amps. I've got 6V 50mA wire-ended bulbs in my junk
box, I suspect htey would be suitable too (you don't need it to be
glowing that brightly.
It also requires the bulb. I have very few
incandescent bulbs that are
And the Op-amp, nd R's and C's, and a power supply and... If you are
goign to order those, ording the ligth bulb is not a big problem. Of
course you might have sall the other bits in your junk box, in whcih case
it is a pain having to order just one part...
-tony