Drawn May 14, 2013. I plan on building it soon. I think it would be better to replace the 82k with a 130k and use a smaller value pot, maybe 25k. I may have to use some 1% precision resistors and capacitors to get the frequency to be stable over a temperature range and supply voltage range. The idea is to be able to receive this with the superregenerative receiver that I blogged earlier, and use the signal to close a relay to tell me the garage door is open. The receiver will have a band pass filter to prevent false triggering by noisy interference. I got the formula out of a website, but I think the formula should read Fo = 1 / (2 * Pi * R * C * sqrt(6)), in other words the 1 should be divided by the whole expression.
2013-05-15 Phase Shift Oscillator, JFET, Stabilized
