Voltage-controlled oscillator (CB20831E)

This circuit is from American documentation from the 90s. The transistor is general-purpose and operational amplifiers can be modern equivalents.

| Clique na imagem para ampliar |

Variable range moving point (CB25154E)
The figure shows how to use an LM3914 with a variable range moving point. The circuit has an...
Voltage-tunable VFH oscillator (CB9430E)
This circuit was found in a 90s Popular Electronics. It uses a varicap that admits equivalents. The...
500 Hz to 5 kHz OA oscillator (CB10490E)
This circuit is from an Electronics Now from 1998 and can be easily assembled with other JFET...