This small control for DC motors up to approximately 1 A uses an operational amplifier that admits equivalent. The transistor can be TIP29 for currents up to 1 A or BD135 for 500 mA.
The original frequency of the Pierce Oscillator with bipolar transistor is given by the crystal, which...
Of course, the design indicates a specific application for a touch switch. Thus, analyzing the...
This circuit converts signals from the 350 to 500 kHz band to the 4.36 to 4.5 MHz band, enabling...