This circuit is from Mullard 1969 documentation. The circuit operates at a relatively high supply voltage and has a 10 Vpp output. The transistors are of the time, but admit equivalents.
Using a standard multimeter, this circuit from a 73 magazine for radio amateurs provides an output...
This capacitive switch or approximation relay was found in a 1980s US publication. Power should...
This circuit uses a 6-bit A / D converter from Philips, and has its output compatible with most...