Power High Voltage Resistors (RI85)

Direct High Voltage Resistors (RI85) Break Through 800 Wattage in High Power Applications.

Direct Electronics RI85 series has been developed to provide design engineers with high quality, high power, high voltage dividers for use in sophisticated system.

The RI85 resistors use Direct's proprietary thick film metal glaze resistive element and Serpentine Pattern Design which provides ideal cost efficient, stability, high power and high voltage characteristics for a wide range of measurement, voltage divider circuits, and control functions in high voltage power electronics applications.

Direct RI85 Voltage Power Resistors are able to absorb large amounts of energy at high voltage while remaining non-inductive and heavy load characteristics. RI85 Resistors conform to the RoHS directives and Lead-free. Customed design, low TCR, resistance values, and tighter tolerances are available on request.

The RI85 non-inductive metal glazed resistors are manufactured on proceeding of tube designed with tab terminal, thick-film printing, firing and laser trimming.

By utilizing specific ceramic core materials with optimum processing, Direct are able to control, very tightly in manufacturing, the important ultra-stable performance parameters TCR less than 100 ppm/°C. Voltage handle up to 100 KV and Wattage available 200W to 800W. This unique process is also offered in specific resistance values in a wide variety of sizes and terminations. The extraordinary operating stability of the Type RI85 resistors will improve the performance of your high voltage system.

The RI85 Power Voltage Series is RoHS compliant and lead free. For customed designs, tighter tolerances, non-standard technical requirements, or custom special applications, please contact us.

Download complete PDF Power High Voltage Resistors (RI85).

Features :
  1. Max Working Voltage from 50KV to 100KV.
  2. Temperature Coefficient ≤ 100 ppm/°C.
  3. Resistance Range from 100KΩ to 1TeraΩ.
  4. Resistance Tolerance K(±10%), M(±20%).
  5. Rated Wattage from 200W to 800W.
Applications :
  1. X-ray/imaging equipment,
  2. EMI/lightning supression, Energy research,
  3. Pulse modulators, Radar Pulse-forming networks,
  4. Impulse voltage generators, Arc furnace damping,
  5. Capacitor crowbar circuits, High voltage snubber circuits.
Dimensions & Specification (RI85)
Tubular High Voltage Ceramic Resistors (RI85) Dimensions
Tubular High Voltage Ceramic Resistors (RI85) Dimensions
Type Power
Rating
Resistance
Value
(Ω)
Resistance
Tolerance
Temperature
Coefficient
(PPM/°C)
Dimensions (Unit: mm) Max working
voltage
ΦD±2 Φd±2 L1±5 L2±5 T±1
RI85 200W 100K~100G 10% (K)
20% (M)
≤100 28 15 185 200 10.5 50KV
RI85 500W 100K~500G ≤100 34 20 205 220 15 50KV
RI85 800W 100K~1T ≤100 55 40 205 220 15 100KV
Remark: Rated Continuous Working Voltage (RCWV) shall be determined from
RCWV = square root (power rating × resistance value) or Max Working Voltage listed above, whichever less.
Power Derating Curve (RI85)
(RI85) Power Derating Curve
(RI85) Power Derating Curve
Performance Specifications (RI85)
Test Item Test Methods Characteristics
Moisture resistance MIL Std. 202, method 106 (IEC68-2-3) ΔR/R≤±0.1% typ., 0.25% Max.
Insulation resistance 500V 25°C 75% relative humidity 10GΩ Min.
Dielectric strength 25°C 75% relative humidity 1000V Min.
Overload 1.5×Pnom. 5 sec (do not exceed max. voltage) ΔR/R≤±0.1% typ., 0.25% Max.
Thermal shock MIL Std. 202, method 107 Cond. C (IEC68-2-14) ΔR/R≤±0.1% typ., 0.2% Max.
Load life 1000h at rated power (IEC115-1) ΔR/R≤±0.1% typ., 0.25% Max.

The Advantages of Non-Inductance & Serpentine Pattern - (RI85)

(RI85) Serpentine Pattern

Non-Inductive Performance:

  1. RI85 Non-Inductive Design which uses a serpentine resistive pattern that offers for zigzagging lines to carry current in opposite directions, thereby achieving maximum neutralization of flux fields over the entire length of the resistor.

  2. This efficient non-inductive construction without derating of any performance advantages is ideal for applications where high frequency is required.

Serpentine Pattern Screen Printing Design:

  1. The RI85 High Voltage Power Resistor combines Direct's Non-Inductive serpentine pattern, high thru-put screen printed silicone coating.

  2. The alignment of the gap in the serpentine resistor pattern with the gap in the coating pattern provides a complete encapsulation of the resistor element.

  3. The cap and lead assemblies are pressed onto the resistor core, finishing the resistor and providing rugged terminal attachment.
Order Codes (RI85)
RI85 200W 1M K
Product Type.
Rated Power.(W)
Resistance Value. (Ω)
Resistance Tolerance.