We found this circuit in a Philips documentation from 1965. The circuit uses a common LDR sensor and the transistors are general purpose types. TR2 can be a BD135.
Twin-T oscillator are designed to produce sine low frequency signals. These oscillator are...
This circuit keeps an LED on briefly when S1 is pressed. The time depends on C1. The circuit is...
This stage was used in old audio ampliiers and radios from the 1950s and 1960s. It uses one of the...