Vitrohm KWV Series, Ceramic Case Resistor
Vitrohm Wirewound resistors are constructed by winding a metal wire, typically nichrome, around a ceramic, plastic, or fiberglass core. The wire ends are then soldered or welded to caps or rings at the core’s ends, with the entire assembly coated in paint, molded plastic, or enamel baked at high temperatures. These resistors are designed to endure temperatures up to 450 °C. Low-power wirewound resistors have wire leads between 0.6 and 0.8 mm in diameter, tinned for easy soldering. High-power wirewound resistors use either a ceramic or aluminum outer case; the ceramic-cased types are sometimes referred to as “cement” resistors, although they do not contain traditional cement.
Description
Vitrohm Power Wirewound Ceramic Case Resistor | Radial
Vitrohm ceramic resistors are constructed by winding or depositing material onto a fine non-alkali ceramic core, which is then encased in a ceramic housing. Vitrohm’s cement-cased wirewound and Fiberglass core, Power Non-Inductive flat wire ceramic, and Metal Oxide Film Element resistors are available in both standard and non-inductive types, with power ratings ranging from 2 watts to 10 watts.
Ceramic is an excellent electrical insulator and heat conductor, allowing the cores of these resistors to handle low to moderate electrical currents without overheating or damage. Additionally, ceramic resistors are highly chemically inert.
Due to their coil structure, wirewound resistors have higher inductance than other resistor types, but techniques like sectioning the winding with reversed directions, bifilar winding, or using a flat, thin former can minimize this. For the most demanding circuits, resistors with Ayrton-Perry winding are used.
Wirewound resistors are generally used in applications similar to composition resistors, except in high-frequency scenarios where their performance is inferior.
The KWV Series of Power Wirewound Resistors features elements made of either wire or power oxide film, wound or deposited on a fine non-alkali ceramic core, then encased and sealed in ceramic. This design results in resistors with high insulation resistance, low surface temperature, excellent TCR, and completely fireproof construction. They are ideal for applications requiring cost-efficiency and superior thermal performance. For higher resistor values, metal film cores adjusted by laser spiral are used, providing similar performance, though with a slightly reduced short-term overload capability.
Features:
- KWV Fiberglass Core (F): Pulse version available, board space-saving, high power-to-size ratio.
- KWV Ceramic Core (C): Board space-saving, high power-to-size ratio.
- KWV Non-Inductive Style (N): Board space-saving, high power-to-size ratio.
- KWV Metal Oxide (M): Heat and flame resistant, insulated, high resistance value.
Types:
- KWV200 to KWV10A
- Historical Types: KWV302-X to KWV310-X
Resistance Range:
- 0.015Ω to 1MΩ
Rated Power:
- 2W to 10W
Technology:
- Wirewound with Ceramic Case
Main Characteristic:
- Power resistors
Applications:
- Power and Energy
AVAILABLE TYPES
| TYPE | HISTORICAL TYPE | SIZE | RATED POWER (W) | RESISTANCE RANGES | TOL.(%) | MOUNTING | FEATURES | |
|---|---|---|---|---|---|---|---|---|
| From | To | |||||||
| KWV200 Ceramic Case | KWV302-0 | 20x11x7 | 2.0 | 0R03 | 36R | 5% | Vertical – TH | Flame retardant |
| KWV300 Ceramic Case | KWV304-0 | 25x12x8 | 3.0 | 0R015 | 68R | 5% | Vertical – TH | Flame retardant |
| KWV500 Ceramic Case | KWV306-0 | 25x13x9 | 5.0 | 0R015 | 130R | 5% | Vertical – TH | Flame retardant |
| KWV700 Ceramic Case | KWV308-0 | 39x13x9 | 7.0 | 0R05 | 330R | 5% | Vertical – TH | Flame retardant |
| KWV10S Ceramic Case | KWV309-0 | 35x16x12 | 10.0 | 0R03 | 270R | 5% | Vertical – TH | Flame retardant |
| KWV10A Ceramic Case | KWV310-0 | 51x13x9 | 10.0 | 0R08 | 510R | 5% | Vertical – TH | Flame retardant |
| KWV200 Non-Inductive | KWV302-2 | 20x11x7 | 2.0 | 0R08 | 10R | 5% | Vertical – TH | Flame retardant |
| KWV300 Non-Inductive | KWV304-2 | 25x12x8 | 3.0 | 0R033 | 30R | 5% | Vertical – TH | Flame retardant |
| KWV500 Non-Inductive | KWV306-2 | 25x13x9 | 5.0 | 0R15 | 65R | 5% | Vertical – TH | Flame retardant |
| KWV700 Non-Inductive | KWV308-2 | 39x13x9 | 7.0 | 0R25 | 100R | 5% | Vertical – TH | Flame retardant |
| KWV10S Non-Inductive | KWV309-2 | 35x16x12 | 10.0 | 0R12 | 50R | 5% | Vertical – TH | Flame retardant |
| KWV10A Non-Inductive | KWV310-2 | 51x13x9 | 10.0 | 0R12 | 100R | 5% | Vertical – TH | Flame retardant |
| KWV200 Fiberglass | KWV302-3 | 20x11x7 | 2.0 | 0R1 | 1K | 5% | Vertical – TH | Flame retardant, High pulse loading capability |
| KWV300 Fiberglass | KWV304-3 | 25x12x8 | 3.0 | 0R1 | 4K7 | 5% | Vertical – TH | Flame retardant, High pulse loading capability |
| KWV500 Fiberglass | KWV306-3 | 25x13x9 | 5.0 | 0R1 | 4K7 | 5% | Vertical – TH | Flame retardant, High pulse loading capability |
| KWV700 Fiberglass | KWV308-3 | 39x13x9 | 7.0 | 0R1 | 10K | 5% | Vertical – TH | Flame retardant, High pulse loading capability |
| KWV10S Fiberglass | KWV309-3 | 35x16x12 | 10.0 | 0R1 | 4K7 | 5% | Vertical – TH | Flame retardant, High pulse loading capability |
| KWV10A Fiberglass | KWV310-3 | 51x13x9 | 10.0 | 0R1 | 16K | 5% | Vertical – TH | Flame retardant, High pulse loading capability |
| KWV200 Metox | KWV302-5 | 20x11x7 | 2.0 | 39R | 1M | 5% | Vertical – TH | Flame retardant |
| KWV300 Metox | KWV304-5 | 25x12x8 | 3.0 | 75R | 1M | 5% | Vertical – TH | Flame retardant |
| KWV500 Metox | KWV306-5 | 25x13x9 | 5.0 | 150R | 1M | 5% | Vertical – TH | Flame retardant |
| KWV700 Metox | KWV308-5 | 39x13x9 | 7.0 | 360R | 1M | 5% | Vertical – TH | Flame retardant |
| KWV10S Metox | KWV309-5 | 35x16x12 | 10.0 | 300R | 1M | 5% | Vertical – TH | Flame retardant |
| KWV10A Metox | KWV310-5 | 51x13x9 | 10.0 | 560R | 1M | 5% | Vertical – TH | Flame retardant |