9 ELECTRONIC APPARATUS AND INSTRUMENTS, NAMELY, TELEVISIONS, AUDIO AND VIDEO CASSETTE RECORDERS, OSCILLOSCOPES, POWER SUPPLIES, AC/DC INVERTERS, ISOLATION TRANSFORMERS, ELECTRONIC ASSEMBLY STATIONS COMPRISING OSCILLOSCOPES AND POWER SUPPLIES, TIME AND FREQUENCY COUNTERS, FREQUENCY CHANGERS, CIRCUIT FUNCTIONS TESTERS, MEMORY (PROM) PROGRAMMING UNITS, VARIABLE DC SUPPLIES, WAVE SOLDERING APPARATUS FOR PRINTED CIRCUIT BOARDS, AND INDUCTANCE-CAPACITANCE-RESISTANCE (LCR) TESTERS