This triac circuit was taken from an article in the July 1970 Radio Electronics magazine. Note the snubber formed by R5 and C3 for controlling inductive loads.
This circuit has a voltage gain of 30 times and passband of 14 MHz. The circuit is from the 1974...
In the figure we have an oscillator circuit by Wien Bridge (Wien Bridge Oscillator). The frequency of...
This timer with 1 second accuracy was obtained in a 1973 documentation. The Buzzer is a low-power type...