This Wien bridge oscillator circuit uses a Texas Instruments 709 amplifier. It was found in an article in the September 1972 issue of Radio Electronics magazine. It is powered by a 24 V voltage.
This circuit, found in a 1986 documentation, uses an optical sensor to count pulses and, in its...
This circuit, found in a 1997 publication, activates a lamp or a monitoring camera when the bell...
We found this circuit in an English publication in 1981. It can be improved by exchanging T1 for a...