ECG semiconductors were originally intended for the replacement, hobbyist, and experimental markets and in time found applications in industrial repair and maintenance departments. Sylvania was an early manufacturer of semiconductors and they evolved the ECG series concept. Other manufacturers using the same idea were Motorola, G.E., and Raytheon. The ECG line of semiconductors was intended to minimize replacement parts inventory for repair and maintenance departments. An ECG replacement directory, which cross referenced as many as 200,000 JEDEC and manufacturer’s semiconductor part numbers was developed and they all crossed to ECG types which would replace them.
