Express Transformers offer a range of 300 watt wire wound power resistors with up to 24 ohmic values in the range. Each resistor is supplied with a tapping band and is cement coated for stability and durability.
The resistors are wound on a sturdy ceramic former using nickel/copper wire to BS 115. The stability is ensured by holding the winding in place with a cement coating that prevents the turns from moving and shorting out.
The ohmic values shown in the table overleaf are the maximum values obtainable with each gauge of wire within a tolerance of ±10%. The tapping bands can be used to obtain intermediate values. One band is provided as standard and others can be fitted if required.
The current rating shown produces a temperature rise of approximately 300°C on the surface of the wire when the resistor is mounted vertically in an ambient temperature of 20°C.
For each 15°C increase in the ambient temperature the current ratings are to be reduced by 5%.
All terminals are nickel silver bands with nickel plated brass screws and nuts and have the facility for either a solder or screw type extra connection.
|Dimensions in mm|
Resistor Slider Clips
Each resistor is fitted with one slider clip as standard. Extra clips can be supplied on request and should be specified from the following table.