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 circuit makes na incandescent lamp flash fast producing the stroboscopic effect. The speed is...
This circuit is intended for communications receivers. We can find it in a documentation from the...
The transistor of this constant current source may be the BC548 or equivalent. Resistor R2 may be...