This circuit was found in a Signetics documentation from the 1980s. The integrated is a PLL and the SCR is a general purpose type The pitch frequency is given by R1 and C1 as formula next to the diagram.
The four gates of a 40111 IC are used in thes two-out circuit. The output chages their state in a...
The sensor of this circuit is a 2N3055 transistor from which the housing cover has been removed to...
Found in the November 1984 issue of Radio Electronics magazine, this circuit is based on the CMOS...