Found in a 1960s documentation, this circuit uses a transistor to drive a relay as well as a set of neon lamps with high voltage power supply.
In the figure we have the simple way to obtain an integrator with an operational amplifier of type...
Found in a Popular Electronics from 1992, this circuit uses a PLL567 in an audio meter bridge that...
The circuit shown in the figure is indicated for medical applications where the sector in contact...