E ELECTRO

AMPLIFIERS * - * NAMELY, [ VACUUM TUBE AMPLIFIERS, TRANSISTOR AMPLIFIERS ] * ; * [ , MAGNETIC AMPLIFIERS; RELAYS, INVERTERS, ] MAGNETIC PICK-UPS AND CONNECTING CABLES THEREFOR [ : ] * ; * [ RECTIFIER-TYPE DIRECT CURRENT POWER SUPPLIES; AND ] ELECTRONIC EQUIPMENT FOR DETECTING THE OCCURRENCE OR NON-OCCURENCE OF EVENTS IN THE OPERATION OF AUTOMATIC MACHINERY, AND GIVING AN ALARM OR STOPPING THE MACHINES ON OCCURRENCE OF A MALFUNCTION