Capacitance multiplier (CB7803E)

We found this circuit in an old Popular Electronics. The circuit can be applied to other operational amplifiers.

TTL Active Cycle Control (CB13825E)
In this circuit, from a documentation from the 70's, we have the way to control the active cycle of...
Zero Crossing Control Without Hysteresis (CB17517E)
This triac phase control circuit uses an integrated circuit not very common today. We found this...
Low Impedance Microphone Preamplifier III (CB963E)
The components of this circuit are exchanged for modern equivalent such as 470 K for the pot and...