This circuit was obtained from Radio Electronics magazine, October 1987. The circuit uses a triac to control the heating element current. The transistors are general purpose.
This circuit, suggested by National Semiconductor, provides an output voltage proportional to the...
Found in 1980s documentation, this amplifier uses a symmetric source and the gain is given by the...
This modulated light transmitter was found in a 90s Popular Electronics. In place of the lamp with...