The Series 500 Power Sources provide AC power at precise frequencies for testing, motor operation, and frequency conversion. The basic power amplifier consists »of two DC supplies and a 4-stage, transformer-coupled amplifier with an adjustable power output transformer. The output transformer provides nominal output voltages of 28, 115, and 230 VAC. Total available power is 500 volt-amperesat full-rated outputs of 28, 115, or 230 VAC. Power at less than füll voltages is derated as illustrated in Figure 1-1. Input power is 115 or 230 VAC at 50 or 60 Hz. Units operating with 400 Hz input power are available on special order. Output power frequency is established by a plug-in oscillator. Output frequency range is 45 to 10,000 Hz. The output is derated to half power at frequencies above 5 KHz. A variety of plug-in oscillators are available, with frequency accuracy up to 0.0001%. The Elgar Power Source facilitates equipment tests to meet military-specification operating requirements over the frequency range of 47 to 63 Hz or 47 to 425 Hz. The basic power amplifier output is single phase, but multiphase power output can be obtained by stacking two or three power amplifiers, all driven by thesame plug-in oscillator. GENERAL DESCRIPTION The Series 500 Power Source is contained in a rack- mount enclosure with a meter for power output monitoring, 130 110 90 70 50 30 10 0 OUTPUT VOLTAGE (RM$f FIGURE 1-1. POWER OUTPUT DERATING VS OUTPUT VOLTAGE a POWER ON indicator lamp, an output voltage AMPLl- TUDEcontrolandaPOWERswitch-circuit breaker located on the front panel. Cooling air is drawn through a front panel grill and exhausted at the rear of the enclosure. The enclosure contains two heatsinks which comprise a power amplifier. Control circuitry is mounted on a circuit board with test points and adjustment controls available at the top of the board. Output power is available atarear panel terminal strip and at front panel connectors. An input power cord is located on the rear panel.