741 Filter (CB24265E)

The 1 kHz tuned filter shown uses a 741 op-amp. The components can be re-scaled to suit the desired frequency.

Sine and Cosine Oscillator with the 741 IC (CB9513E)
This circuit generates sinusoidal and cosine signals of 2 kHz given basically by the values of C1...
Speedometer (CB6337E)
This circuit was found in a Dutch documentation from 1970. The circuit makes use of semiconductors that...
Astable 555 with two potentiometers (CB25510E)
This circuit has both frequency and duty cycle control. We found it in the October 1992 Radio...