Toy siren (CB8655E)

Found in 90’s English documentation, this rising and falling siren, manually activated, drives a low impedance earphone. The UJT can be 2N2646.

Basic Voltage Comparator C (CB25867E)
This circuit uses an LM339 and was found in the July 1995 Electronics Now magazine. The LED lights...
555 Car Alarm (CB3990E)
We found this circuit in an old Mullard (Philips) documentation on the 555 and 556 integrated circuit...
Photodiode Current to Voltage Converter (CB6104E)
This circuit was obtained from an 80's documentation from General Electric. The circuit uses an...