Current indicator (CB22132E)

In this circuit the voltage across the LED is limited by the diodes. The maximum current also depends on the resistor.

TTL Data Transmission (CB16024E)
The circuit shown in the figure is suggested by Texas Instruments and allows data transmission on TTL devices...
Vibrato (CB3823E)
We find this vibrato configuration with transistors in a 1987 documentation. The components are still...
Quadrature Outputs Sinusoidal Oscillator (CB13232E)
This circuit, from a documentation from the 1970s, produces two sinusoidal signals given by C2 and...