Ladder Generator (CB21245E)

Using a 4017 as a base, this circuit from a 1990s Popular Electronics generates low-frequency ladder-like signals. The frequency is given by 4011.

Symmetrical 15 V Power Supply (CB19622E)
This source is used to supply circuits with operational amplifiers, being originally created for...
Square Wave Generator (CB19372E)
The transistors in this 80's documentation project may be BC548, the most modern equivalents of...
Constant Current Source for LEDs (CB915E)
This circuit uses a FET to drive an LED with constante currente. The current up to 20 mA can be...