The power supply for this 1972 circuit must be symmetrical and the BC549 transistors. Care with the layout is important to avoid capturing tinnitus.
When the input voltage is higher than 2/3 of the power supply voltage the green LEDs glows. When...
This circuit was found in the December 1971 issue of Radio Electronics magazine. The circuit is...
The circuit of a 1968 publication can be implemented with more modern transistors such as BC548 for...