PR-Series Resistors

At the core of the design are robust aluminium-oxide ceramic substrates onto which the low-inductance, conductive paste is precisely printed.7 The resistive elements are tin-welded to copper terminals and enclosed in a protective, UL94V-0-rated housing.8 Power ratings range from approximately 9$100 text{W}$ up to 10$800 text{W}$ (depending on base temperature and heatsink configuration).11 Working voltages are equally impressive, reaching up to $1500 text{VAC}$ for the smaller variants and up to $5 text{kVAC}$ for PR250/PR600/PR800 designs.

Because these power modules rely entirely on a customer-supplied heatsink, the integrity of the thermal interface is paramount: thermal grease or conductive foil between the resistor and the heatsink is mandatory to unlock full power ratings and guarantee stability.

Engineers rely on these resistors for their measured electrical precision: low self-inductance ($text{typically} approx 40-80 text{nH}$) and low parasitic capacitance to the heatsink ($< 150 text{pF}$) make them perfectly suited for fast-switching snubber networks, EMI filters, and high-voltage charge/discharge circuits.

With compact housings, high dielectric strength, metallic base-plate mounting, and flexible tolerance options (standard $pm 10 %$, optional $pm 1 %$), the PR-series provides exceptional design freedom across automation, traction, power electronics, and industrial filter systems.