Battery status indicator (CB9136E)

Found in old National Semiconductor documentation, this indicator uses an integrated circuit from that time, which is uncommon nowadays.

Wien Bridge Generator (CB39010E)
This sophisticated sinusoidal audio signal generator uses a Wien bridge configuration with an...
Gain 100 with the 741 (CB902E)
This AC amplifier using the 741 operational amplifier uses a dual supply from 5 to 12 V. The input...
5V Voltage Reducer (CB5000E)
This circuit was found in the Spanish magazine No longer in existence, Mundo Electrónico, in a...