This circuit generates the busy tone of ordinary telephones. The transistors can be the BC548 and the components of the T filter and the multivibrator can be changed to obtain the exact tone.
Combined with the two previous circuits, we can create a simple multimeter with this circuit. The...
This 1.5V instrumentation amplifier was found in National Semiconductor documentation from the...
This simple circuit helps to save incandescent lamps by leaving their filament slightly heated and thus...