thermal management for 23k ohm,5W resistors

[P.Copper]

Hi all,

Is there a way to reduce the heat generated in the 27k ohm, 5W resistor? I'm working with voltage sensor(LV25-P) and part of the design is to include the resistor specified, my concern is that the resistor gets so hot. I fear that over prolonged used the resistor will fail. Any suggestions to reduce the heat produced are welcome. Thanks

 

[jiripolivka]

You cannot reduce heat which is generated by the current flowing through your resistor. You can reduce resistor temperature by removing the heat from it, by attaching a heat sink. Some 5W resistors are enclosed on an aluminum tube with a screw- mountable flange, to be attached to a large aluminum plate or block. Resistors mounted in a ceramic block can be mounted with a special aluminum bracket to a larger block or a plate to radiate the heat.
Special heat sinks have ridges or needles for better radiation, and are blackened, too. It is also recommended to use a contact silicone paste or a better heat transfer.

 

[schmitt trigger]

As the previous poster (jiripolivka) mentions, the amount of heat (power dissipation) is a given by your circuit operating conditions.
If you cannot modify those operating conditions, the only thing you can do is to remove the heat more efficiently.