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.
Some old analog multimeters use a 22.5 V battery for high resistance measures. These batteries can no...
This simple SCR alarm circuit was found in an old Poptronics, but can be easily assembled as all...
This circuit is found in the Italian magazine Radio Elettronica, August 1975 issue. There is a...