Found in a 1969 Ferranti documentation, this circuit uses only bipolar transistors from that time. Transistors can be replaced with modern equivalents.
Found in a 1980s Electronics Now, this circuit uses common components. Transistors are commonly...
This integrating circuit multiplies the time that can be obtained with a 555 timer. We find it in...
Found in a 1967 Ferranti documentation, this circuit uses a LDR from that time as a sensor....