This circuit with two transistors was found in ancient European documentation. Transistors support equivalents. The indicator on this circuit is an ordinary 50 to 100 mA lamp.
Found in a magazine 73 for radio amateurs, in a 90's edition, this circuit uses a general-purpose FET...
The selected circuit causes a 12 V lamp with a current of up to 500 mA for the BD135 transistor to flash at...
This is one of the many applications of the 555. We found it in the November 1992 Radio...