Inverter Power Resistor Applications
The image below shows a typical inverter topology with the various resistor requirements highlighted. These requirements may include filter resistors, snubbers, gate resistors, bleeders, balancing resistors, voltage dividers, braking/regenerative braking resistors, power factor control, surge current protection, pre-charge resistors, and even current shunts. Here we will discuss the various resistor solutions.
Example inverter schematic
| Applications | Resistors | P/N |
| Filter Resistors | Power Film | PF2470, PF2270 |
| Snubber Resistors | Power Film | PF2270 |
| Gate Resistors | Power Film | PFS35, PFC10, PF2200 |
| Bleeder Resistors | Power Film | PF2200, PF2470, PF2270 |
| Balancing Resistors | Power Film | PF2200, PF2470, PF2270 |
| Voltage Divider, HV | Power film | PF2270 |
| Braking Resistors | Wire Wound | UAL, UB, UT |
| Regenerative Braking | Wire Wound | UAL, UB, UT |
| Power Factor Control | Wire Wound | UAL, UB, UT |
| Surge Current Protection | Wire Wound | UAL, UB, UT |
| Pre-charge Resistors | Wire Wound | UAL, UB, UT |
| Current Shunt | Metal Plate, Foil | PCS, CSR, SHUNTS |
Power Film Resistor Solutions
Riedon offers a multitude of power film resistors in transistor outline packages that would be appropriate for many of these requirements. Our PF2470 series features power ratings up to 140 watts in a convenient TO-247 package with a resistance range beginning at 0.02Ω and extending to 51KΩ. The PF2270 is an extremely versatile series with a power rating as high as 600 watts in a compact TO-227 package. The broad resistance range of the PF2270 stretches from 0.1Ω to 1MΩ, with tolerances as tight as 1%. Lower power requirements are supported with our PF2200 (TO-220) series with power ratings to 50 watts and the 20 watt PF1262 (TO-126). In applications requiring surface mount technology we offer our PFS35, a TO-263 packaged device with power capabilities of 35 watts and a resistance range beginning as low as 0.01Ω and topping out at 51KΩ. If a low profile is needed, we offer our PFC10, utilizing the same TO-263 footprint, but featuring a height off the board of less than 1mm vs. the 4.5mm height of the PFS35.
Wire Wound Resistor Solutions
Riedon’s expansive line of wire wound resistors work exceptionally well for use in the high energy locations in the diagram such as braking and surge current protection. The UAL series offers high power handling capability in an easy to package aluminum housing. With a very wide range of available resistance values and power handling from 5 watts to 300 watts, this series is appropriate for a wide variety of applications. Our power wire wound UT or UB series offer superior power handling capability in a small package. All of our power wire wound products can be readily optimized for high pulse applications.
Current Shunt Solutions
Finally, for current sensing we offer a number of technologies. For surface mounted products, our CSR and CSRL line of metal element shunts are available in case sizes from 1206 to 2512 with power ratings up to 3 watts. Our PCS series features a true Kelvin connection in a compact package capable of handling up to 40 watts all with an extremely low available TCR of 2ppm. Our rugged RS series of ammeter shunts provide numerous mechanical options with current handling from 1 amp to 10,000 amps.