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.
The UAA170 integrated circuit is no longer common in our market. With it it is possible to...
This circuit that emits siren sound can be used in a fire alarm. We found it in an old American...
This double time constant circuit for resistive loads was found in documentation from the 1980s. The...