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4 Bit Adder Circuit (No Fault)
The GIF animation below shows how a good 4 Bit Adder Assembly works. The display shows exactly what you would see if you had a Logic clip on all five IC's. Red is High (above 1.2 Vdc). Blue is Low. Circuit is TTL. Schematic and Test are shown below.
GIF Preview( If you want to stop the action and analyse circuit you must download .AVI version)
Download Adder with no fault(AVI).
Adder Test Setup