PC address decoder (CB20536E)

This TTL decoder circuit for PC ports was found in a document from 1992. The power supply can be PC's own circuit.

Gain 100 Operational Amplifier 741 (MSB018E)
The gain of the Operational Amplifier in the figure is given by the ratio between R1 and R2. In...
Comarator Isolated Interface (CB4593E)
In the figure we have an interface using an optical coupler and the comparator LM339 or any...
Simple Preamplifier (CB931E)
This circuit uses two JFET such as the BF244 or BF245 and has an excellent gain with small...