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.
This circuit was found in an old Electronic Design used to apply digital signals to an analog...
The figure shows two ways to power a common LED flasher. The suggestion comes from an article in...
The circuit in figure 12 is ideal for interfaces for microcomputers or digital circuits subject to...