In the figure we have a circuit in which two moving bar/dot indicators are connected together to increase the number of LEDs. The circuit is from a Radio Electronics from October 1980.
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...