We found this circuit in a 1978 publication. It can be implemented with modern transistors like the BC558 if the transformers are found. The first is a driver and the second an output transformer. The lamp can be 50 mA for 6 or 12 V, depending on the voltage used in the supply. The capacitor next to the 250k (220k) resistor determines the frequency of the sound produced.

 


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