Found in a 1967 Ferranti documentation, this circuit uses a LDR from that time as a sensor. Transistors can be replaced with modern equivalents.
This is a Serial In - Parallel Out or Serial Out [SIPO or SISO] shift register using the...
This circuit was obtained in a 1973s documentation. The transistors may be BC558 for the PNP and...
This circuit was obtained from a 1978 Practical Wireless. It causes an LED to flash at a frequency that...