900 Watt resistor in SOT-227 housing
The Japanese resistor specialist Nikkohm has introduced the new RPK900 and RPK900L series – two ultra-precise power resistors in a compact SOT-227 package that deliver exceptional power density and stability.
The series achieves an impressive rated power of 900 watts and sets new benchmarks in thermal performance and high-voltage withstand capability. This is made possible by using an AlN (aluminum nitride) ceramic substrate with very high thermal conductivity combined with state-of-the-art thin-film technology. As a result, the resistors offer outstanding long-term stability of their electrical parameters.
The RPK900 features a large copper flange with excellent heat dissipation, enabling an insulation voltage of 2.5 kV AC. The RPK900L variant takes it even further: by adding wire-lead terminals, the insulation capability is increased to 10 kV AC.
The thermal path from the resistive element to the flange has an extremely low thermal resistance of 0.10 °C/W – resulting in a temperature rise of only about 90 °C at rated power. To utilize the full 900 W capability, however, the temperature at the copper flange must be kept below 25 °C. This requires active cooling using forced-air cooling or water cooling.
Key technical specifications at a glance:
- Rated power: 900 W
- Resistance range: 25 Ω to 1 kΩ
- Tolerance: ±5 %
- Temperature coefficient (TCR): ±50 ppm/°C
- Operating temperature range: –55 °C to +155 °C
The new resistors are particularly suited for demanding applications in high-voltage and pulse power technology, including:
- High-voltage pulse power supplies for industrial laser oscillators
- Excimer laser power supplies
- Electron-beam equipment
- Particle accelerators
- Medical X-ray CT systems
- MRI analysis equipment
- Voltage-divider resistors and output-voltage sensing resistors in high-voltage power supplies
With the RPK900 series, Nikkohm specifically targets the growing demand for compact, highly stable, and extremely high-voltage-rated power resistors in power electronics, medical technology, and large-scale scientific equipment. The combination of high power density, excellent heat dissipation, and superior voltage withstand makes the series an attractive solution for challenging industrial and medical high-power applications.
Samples, price quotations, short-term delivery options and further information are available via the contact form or from your usual contact person.