This circuit was found in a 1966 General Electric book. The triac and the day are from that time and can be replaced by modern equivalents depending on the load.
We found this circuit in a 1975 publication. The circuit can be made with BC548 transistors for...
This circuit was found in the December 1992 Radio Electronics magazine. Range depends on optical...
This circuit is from the National Semiconductor CMOS manual of 1977. What this circuit does is to...