Power Resistor

500 Watt Power Resistor – Selecting Wire Wound Resistors

16 February 2015. Continuing on with out wire wound resistor selection series, this week we take the example of a high power resistor – namely a 500 watt power resistor. In this example our application calls for a 500 watt rated resistor that has a 5 percent tolerance and 470 ohm adjustable resistance.

A 500 watt rated resistor, by its very power rating, calls for a rugged, highly reliable method of construction, with the ability to dissipate significant amounts of heat from the body of the resistor. From our wire wound resistor product selection guide, we can see that the Y Series […]

Wire Wound Resistor Selection

Selecting the correct wire wound resistor for your application is critical in insuring excellent long term reliability for your circuitry and equipment in which the power resistor is being used. Once you have determined the appropriate power rating for your application, by, for example, using ohms law, you can then select the type of resistor based on these parameters:

Physical size
Required method of mounting the resistor
Electrical pulse handling capability
Requirement of the resistor to be adjustable or fixed in value
Required tolerance of resistance
Mechanical construction of the resistor
Non Inductive winding

As you will see from the products page, we can offer a resistor that […]

January 13th, 2015|Power Resistor, Resistor Applications, Wire Wound Resistors|

50 Watt Rheostat

50 Watt Rheostat – High Power Rheostat Example
Rheostats have been used in industry for over 50 years. A rheostat has the electrical characteristics of being able to offer an adjustable resistance specified at time of ordering the rheostat and being able to dissipate significant power – 50 watts in the case of the APR50 rheostat. This is useful in applications such as:

motor control
lighting control
industrial controllers
sound level control
laboratory test setups

Rheostat Specification
Parameters used to specify a rheostat include the following:

Resistance tolerance – typically +- 10% in the case of the APR series rheostats.
Insulation Resistance – Typically 100M ohms at 500 volts d.c.
Rotational […]

October 3rd, 2014|Power Resistor, Resistor Applications, Wire Wound Resistors|

100 Watt Power Resistor Example

100 Watt Resistor Application And Specification
We had a recent enquiry for a power resistor that was to be used in the mining industry for a braking resistor for a conveyor belt system used in a coal loading terminal in Newcastle. The motor requiring the braking resistor was slightly unusual in that it was a d.c. (direct current) motor. The resistor required had the following requirements in its specification:

3.9 ohm resistance
Maximum current rating 4.5 amps (d.c.)

Using basic resistor theory we determined that the most appropriate power rating for the resistor would be found by using the formula Power (dissipated in the resistor) = […]

September 8th, 2014|Applications, Power Resistor, Resistor Applications, Wire Wound Resistors|

200 Watt Power Resistor

200 watt rated power resistors  are commonly used in industry in a wide range of applications including:

resistor load banks
dropping resistors in large power supplies
power conversion circuits
braking applications

Tubular power wire wound resistors are often considered to be the ‘standard’ in high power resistors as they offer a ‘tried and tested’ solution and offer high reliability and low cost. The HO Series power resistor is often used when a 200 watt rated resistor is required. This resistor specification includes:

200 watt rating
267 mm ceramic former length
29 mm ceramic former diameter or 33 mm when coated
Mounting feet centres are 292 mm
For the standard fixed power […]

Laboratory Resistor Applications

The Laboratory Resistor – Invaluable In Many Applications
The laboratory resistor (also referred to a a slider resistor) has been used for a convenient way to achieve and easily adjustable power resistance for over 50 years. Whereas a wire wound potentiometer offers a variable power resistor via a rotary form of adjustment, the laboratory resistor offers a way of adjusting the resistance via a linear form of resistance.

Many educational institutions such as universities, technical colleges and high schools use laboratory resistors in their electrical and electronics courses as they allow students to easily and accurately set a specific resistance value via the sliding […]

July 23rd, 2014|Power Resistor, Resistor Applications, resistor theory|

Wirewound Resistors – Basic Resistor Principles

Understanding Critical Parameters In Resistor Selection – Ohms Law
Going back to college fundamental physics is helpful in understanding the most commonly used parameters used in specifying wirewound and power resistors. Good engineering practice will generally mean that a certain degree of ‘over specifying’ will result in long term reliability and performance of the final product – be it a motor control circuit, power supply, resistor bank, heating or cooling appliances or printed circuit board control circuitry.

Resistance – Ohms Law

Ohms law is possibly the most fundamental equation taught in electrical engineering. It is the foundation principle used to determine the relationship […]

Power Resistors – Light Rail Braking Load Bank

Power Resistor Range And Specifications
There are many applications for a power resistor where a very substantial power rating is required that exceeds the wattage available from our range of power resistors. The current range of power resistors covers a range from power ratings from 5 watts to 1000 watts.

The corresponding ceramic former lengths range from, for example, 51mm for the DG series resistor rated at 20 watts, to 165mm for the HA series 100 watt resistor up to the YM type power resistor that has a 1Kwatt rating and has a ceramic length of 475mm.

There are numerous applications where a […]

January 16th, 2014|Power Resistor|

Power Resistor – HP 250 Watt Tubular Resistor

The range of tubular power resistors has been expanded to include a 250 watt version of this versatile range of resistors. This makes a useful addition to the range and higher power ratings are now available including 200 watt, 250 watt and 350 watt. High power resistors have been used in hundreds of applications by Australian industry over the last 40 years.
Termination Options For Power Resistors
This range of power resistors has a very versatile range of terminal options to suit different end applications and wiring situations giving manufacturers the ability to quickly wire up the resistors into the finished product. Termination […]

December 6th, 2013|Power Resistor|

Power Resistors – HA series power resistor application – Industrial Fan Speed Control

Application In Industrial Oven Manufacture
A Sydney based client approached us as they needed assistance in finding a suitable solution for an oven fan speed control application. The client manufactures a range of industrial ovens used for a variety of purposes from paint curing to baking enamel finishes onto metallic machined components. The ovens are constructed and designed using a motorised conveyer belt system that feeds the required items into a heating chamber which is heated by way of a number of high power industrial heating elements. When the items exit through the oven they then need to be slowly cooled […]

November 18th, 2013|Power Resistor|