This timer was found in Japanese documentation from the 1960s. The transistor can be replaced by an equivalent and the relay must be of the sensitive type with voltage according to the power supply.
Based on common components, this circuit was found in an English publication. The circuit is...
This circuit is from Mullard 1969 documentation. The circuit operates at a relatively high supply...
In relation to the previous circuit (CB18493E) this spy has an extra transistor, which can be a...