Solar charger MC34064 (CB14537E)

The integrated circuit used in this charger is not very common today. The circuit is from Motorola's 1990 Linear Databook.

LC Oscillator Using the 4069 (CIR093E)
Here we show an oscillator that uses an LC network. The upper limit depends on the power-supply...
DVM to PC adapter (CB7924E)
This circuit from a Popular Electronics from the 90s allows you to use an old PC as a digital...
DC Amplifier with Drift Compensation (CB14068E)
of the National Semiconductor of 1994. The same technique can be used with other operators and the...