Quick Adder (CB20155E)

This is a factory circuit from an 80's manual. The circuit can be implemented with modern operationals and the power supply must be symmetrical.

| Clique na imagem para ampliar |

High Impedance Voltmeter (CB10525E)
This circuit was published in a 1981 magazine, but it can be easily assembled using a BC548 paraQ1...
Triac Two Power Switch (CB12323E)
This circuit is from a 1967 publication, but it can be implemented with any Triac of the TIC...
Low Battery Detector (CB6515E)
This circuit was found in an 80's EDN. The circuit uses a current common CMOS, the 4093 powering...