This constant current charger from 1997 Linear Technology Applications uses common components at the time. The transformer is the critical component, being designed according to the load voltage.
Using neon lamps, this circuit from a 1969 publication provides 17 V of maximum voltage or else...
A passive mixer with few components is that of the circuit shown, found in a 1982 documentation. As readers...
This is the traditional configuration of an adjustable tone filter with the LM567. The circuit uses a...