The California Instruments Model 501TC Power Amplifier is a solid state, high performance, low distortion power source that provides up to 500 VA output when used with the proper plug-in oscillator. The Model 501TC Power Source is illustrated in Figure 1-1. Full power output is available in two different voltage ranges and over the frequency range from 45 Hz to 5 KHz. These full power voltage ranges are: 1) 105 to 135 volts rms for normal single phase 115 volt applications and for three phase 208 to 234 volt line-to-line applications. 2) 210 to 270 volts rms for normal single phase 230 volt applications and for three phase 208 to 270 volt applications where open delta operation is acceptable. For two phase and three phase operation, at least two power amplifiers must be combined together with the applicable multi-phase oscillator. Two power amplifiers will provide a total of 1000 VA two phase power (Model 1000TC/2-2), or 1000 VA of three phase power (Model 1000TC/2-3D) in the open delta configuration. Three power amplifiers will provide 1500 VA of three phase power in the wye configuration (Model 1500TC/3-3).