Found in a 1980’s documentation, this circuit must have its signal applied to an amplifier stage. The unijunction transistors can be 2N2646.
ON Semiconductor AMIS−3910XGEVB Evaluation Board demonstrates the features and capabilities of the...
This circuit was obtained in a Popular Electronics of the 90s. It against a kitchen hood based on...
The original version of this circuit was found in an old English publication that comes to...