This circuit is from the 80's documentation. The integrated circuit is from the time but can be implemented with modern equivalents. The power supply must be symmetrical.
This circuit can operate with signals from 1.5 to 150 MHz. C1 is 36 pF and C2 is 4n7. The diode...
This circuit was found in a 90s Popular Electronics. It prevents the power from being switched...
Any high-gain Darlington transistor can be used on this touch circuit. The load can be formed by...