Found in a documentation from the 90's, this circuit already includes an amplification stage. The 12 V power supply allows its use in the car.
We find this circuit in a 1978 documentation. The circuit uses two inverters of a 4049 integrated...
We found this circuit in a 1986 documentation. Its purpose is to power a set of light bulbs (or...
For reference only, this is the second IF amplifier stage of a common transistor radio from the...