The "hex inverter" is an integrated circuit that contains six ("hexa-") inverters. The origins of electromechanical inverters explain the source of the term "inverter". Small portable cryostats are available and can run off generators or vehicle inverters. VVVF inverters and AC traction motors provided by Mitsubishi. Thyratron relaxation oscillators were used in power inverters and oscilloscope sweep circuits. There were also noises from whining power inverters and whirring ringing generators. Additional types of welders also exist, besides the types using transformers, motor/generator, and inverters. Reverse conducting thyristors are often used in frequency changers and inverters. Other uses include subtractors, comparators, and controlled inverters. The produced power is usually then transformed by solar inverters. These polyphase machines are powered from GTO-, IGCT- or IGBT-based inverters. It is used in chokes for inverters and in high power applications. The solar farm uses 25 of the 1.25 MVA inverters and a collector system. The design used triodes as phase inverters and drivers. We sent 135 C-130 plane loads of machines, inverters, valves, flow meters, pressure gauges.