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.
This interesting circuit for SMD assembly appeared in the November 1987 issue of Radio Electronics...
This circuit was found in the June 1986 issue of Radio Electronics magazine. It is based on two...
Found in a 1980s documentation, this circuit works with a 12V relay. The horn is the boat's own. |...