Bench thermometer (CB20501E)

With an ultra-low consumption, this circuit can be powered by solar cells. The circuit is from a 1991 documentation.

CMOS VFO (CB8090E)
Found in a Popular Electronics from the 90s, this circuit generates signals from 2 Hz to 30 kHz in...
Two Solenoid Intelligent CMOS Control (CB11880E)
According to the logic level applied to the input of this circuit, X1 is activated and X2 turns...
Buzzer (CB17504E)
This circuit produces an intermittent sound in a ceramic piezoelectric transducer, for example, a simple...