Low frequency multiplier (CB8239E)

This circuit was found in a 90s Electronic Design. The integrated circuits are from that time. Frequency multiplication can be done for odd integers.

| Clique na imagem para ampliar |

Headphone Extensions (CB23790E)
The figure shows three circuits for using headphones in amplifiers with speakers that do not have...
Nicad charger (CB9540E)
In this charger, the charging current is basically limited by the LEDs. The transformer is a low...
Fast Voltage Follower (CB4904E)
This configuration is from an old integrated circuit manual. The circuit can be applied to modern...