The robust design of the R-400 heavy-duty power transformer ensures easy handling of high-current demands, without compromising reliability and long life. Multiple taps on the transformer secondary allow the output voltage to be adjusted, and a resistor network permits the output current to be limited. These functions are conveniently controlled from the front panel using multi-position switches.

The R-400 DC Output is fully filtered to eliminate ripple voltages and spikes from entering avionics, and to suppress RFI energy produced by the transient generating circuits to better than MIL-STD-461A.  In addition to its highly rugged construction, the R-400 offers the user many ergonomic and convenience design features such as separate, easy-to-read voltage and current analog meters, and large, pneumatic rear-wheel tires for ease-of-mobility on the ramp of in the hangar. Additional standard features include a 115 VAC convenience duplex outlet for accessories, lighting of power tools, and side cable hooks for storage of input and output cables.