[sdiy] cheap sine wave osc

[Derek Holzer]

Doing some research, I ran across this:

http://www.njqrp.org/geo-oscillator/index.html
http://www.njqrp.org/quickies/osc_1.jpg

Which seems like a cheap, one-transistor workable solution. But I'm 
hardly an engineer, and failed just about every math class I ever took ;-)

But it can't be too hard to work out a formula for cap values from the 
following constants:

F= 500 Hz when C1 = 0.047 uF and C2/3 = 0.022 uF
F= 1000 Hz when C1 = 0.022 uF and C2/3 = 0.01 uF

Although I also see that R1/R2 has some effect on output frequency. I 
have some variable caps from a transmitter project laying around that 
might come to good use here for dialing in the frequency.

Other suggestions that might be a bit more stable are welcome. The name 
of this oscillator (Good Enough Oscillator) seems to indicate that 
getting a precise/stable tuning might be troublesome.

thx+best,
d.

Derek Holzer wrote:
> Hi all,
> 
> I'm planning a small light-activated installation, based a bit on the 
> Russian ANS synthesizer, and I'm wondering what the easiest, cheapest 
> sine wave oscillator I could construct would be. It will not be voltage 
> controlled, in fact the frequency of each of the oscillators will be 
> fixed, with tones produced by additive synthesis and the gain controlled 
> by photopotentiometers. Any suggestions for a chip/circuit that I could 
> easily make 64 or more of?
> 
> thanks + best,
> derek
> 

-- 
derek holzer ::: http://www.umatic.nl ::: http://blog.myspace.com/macumbista
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