This circuit was found in a 1967 General Electric manual. It shows a SCR control with unijunction and zener diode. The triac depends on the controlled load.
Using a BA1404 integrated circuit this small FM stereo transmitter was found in a Radio...
The operational amplifier is not very common today, but in its place an equivalent, even of...
This circuit was found in the February 1993 Radio Electronics magazine. The frequency depends on...