BEHLMAN (Hauppauge, NY) Behlman Electronics Inc., known for its leadership in providing power products for aviation, industrial, commercial and military applications, has received customer acceptance for the modified Behlman BL+120 EWFR three-phase frequency converter.

The equipment to be tested by the BL+120 is on certain commercial aircraft. It has the ability to take the electrical power created over a wide range of variable aircraft engine speeds and convert it to a fixed 400 Hz, to power a variety of equipment on the aircraft. To test the proper operation of this airborne equipment during manufacture, installation and maintenance, a frequency converter had to be developed that would work across a 350 HZ to 2000 Hz Extreme-Wild-Frequency-Range (EWFR).

Modifying a standard Behlman frequency converter met this need. With a standard BL+120 already supplying most of what was needed, Behlman engineers were able to modify the unit to provide a number of specialized test functions and parameters, including Crowbar-shutdown, Current limit shutdown, Phase-angle adjustment, Fault alarms and Pulse-by-Pulse testing at an EWFR of 350 HZ to 2000 Hz. The Final Acceptance Test (FAT) was witnessed and accepted by the customer at Behlman's facilities in March 2007 and product shipped one week later. The number of units ordered by this customer is confidential.

The BL+120 is a low-cost, three-phase, solid state frequency converter with a small footprint that delivers clean, regulated high-power AC and has proven to be ultra-reliable for industrial product testing, precision avionic test, power conversion, ATE, bulk power and motor generator replacement.

The BL+120 incorporates a 36-pulse multi-phase input rectification that provides for low input current harmonics IAW MIL STD 1399 Section 300A. Input startup surges are reduced through the use of special soft start circuitry, and isolation is provided by the input transformer. Output voltage of 0-132 VAC or 0-264 VAC, L-N are standard. Optional output transformers are available for other voltages. The standard output frequency for unmodified units can be fixed at 50 Hz, 60 Hz or 400 Hz, or variable from 45 to 500 Hz. (The output frequency of the new EWFR model BL+120 is variable from 350 Hz to 2000 Hz.)

The BL + Series is available from 25 KVA to 120 KVA. Additional features include an input electronic circuit breaker, short-circuit and thermal protection, and a "constant current mode" that automatically causes voltage foldback to provide maximum current without distorting the output waveform. Available options include a MAC2000 manual controller with fixed and adjustable frequency and adjustable voltage, three DMMs for setting and readout of volts, current and frequency, a PAC2000 programmable controller with vacuum fluorescent display and front-panel pushbutton control, plus an RS232 interface for remote control. Also available is the standard WF (Wild Frequency) option, for output frequency of 350 to 880 Hz.