Remote control tester (CB7823E)

This circuit from a 90s Electronics Now, uses a 4010 gate as a signal amplifier. The circuit triggers an indicator LED.

Conductivity Meter (CB13503E)
This circuit measures the conductivity of a saline solution, which is affected by the electrolysis effect....
Capacitance Comparator (CB12453E)
With this circuit it is possible to compare the values of two capacitors in the range of 100pF to...
Monostable 4047 II (CB12735E)
For triggering with the negative transition of the input signal, the circuit indicated for 0 4047...