This simple low current circuit was found in a Radio Electronics magazine from August 1960. The circuit does not use transistors in regulation, but only zeners directly.
The figure shows how to use a CMOS amplifier as a crystal-controlled oscillator. The circuit is...
This is another one of the many versions of Nicad battery chargers that we have on the website and in...
This circuit generates short duration pulses using a 555 integrated circuit. The pulses are 120 ms...