This circuit of an Electronics Hobbyists Handbook uses a different configuration for a triac. The circuit uses an integrated frequency divider and a coupler with a fotodiac.
This low-noise, low-drift amplifier was found in a 90's EDN. It can be implemented with modern...
June 2016 - can already be obtained from the Mouser the Texas Instruments DRV10964 along with...
This circuit was obtained in the 1977 RCA CMOS manual. The circuit has the frequencies determined by the...