High-power resistors from Nikkohm
To provide designers with highly reliable power resistors that operate with the lowest temperature rise on the market, Nikkohm has introduced the RPU800 series (800 Watt) for inverter applications and is available in additional power classes (1000 W & 2000 W).
These unique high power resistors use Nikkohm's proprietary thick film and thin film technology on aluminium oxide substrate and offer up to 10kV insulation at low inductance.
‘These are highly reliable resistors suitable for power electronics such as damping resistors of thyristor inverters in induction heaters,’ said Shigeru Hidaka, CTO of Nikkohm. ‘The thermal resistance, which indicates heat dissipation, is 0.8 K/W, which is particularly suitable for liquid cooling systems.’
This resistor is a high-performance film resistor that combines a pre-stressed technology combination of thick film and thin film on one resistor element. The inside of the resistor has a special structure that reduces thermal stress with a soft elastic material.
The resistor itself is housed in a rigid phenolic resin housing, thus ensuring long-term operation even under the most difficult conditions.
The operating temperature of the resistor ranges from -55 to +175 °C. De-rating sets in from +75/65 °C, which can be improved by a cooling system in the form of liquid cooling or forced air cooling.
The equivalent parallel capacitance is only 73 pF and the equivalent series inductance is only 108 nH, resulting in a very low reactance.
The connections are designed as M5 screw terminals and can therefore be connected directly to busbars. This connection enables short current surges to be converted directly into heat.
It shows excellent performance as a resistor of a snubber circuit R-C-D of a GTO thyristor.
The insulation resistance voltage is guaranteed by a 100% inspection between the terminals and the metal flange at 10 kV - 50 Hz - 2 mA. The creepage distance is 42 mm between connection and flange. The typical corona partial discharge reaches values of 5 kV - 30 kHz.
Since the resistance value range is from 0.5 Ω to 1 MΩ, the RPU is suitable for a variety of applications such as current measurement, damping, load resistance, harmonic filter, braking resistor and discharge resistor for power electronics, in industrial equipment such as high frequency induction heating, welding equipment, high voltage supply for high power generation, medical equipment, motor control, high speed charger and energy storage system.
Samples, price quotations, short-term delivery options and further information can be obtained via the contact form or from your usual contact person.
