Equivalent transistors can be used in this circuit for automotive applications in the 1980s. The frequency is given by the capacitor and the current of the lamp depends on the LM195 transistor.
This current meter with many scales was found in a 80s American documentation. The operational amplifier...
This dimmer, from an old publication, can use almost any triac and in shooting a neon lamp. The...
We found this circuit in a 1975 publication. The circuit can be made with more modern equivalent...