CPU benchtop power supply load resistor heat

Discussion in 'The Projects Forum' started by rifme, Jan 24, 2013.

  1. rifme

    Thread Starter New Member

    Jan 14, 2013

    I didn't find anything relating to my question in previous threads, so I'll ask here....

    I just converted a computer power supply to a bench-top power supply. I soldered a 10 ohm, 10 watt power resistor between the 5V output and Grnd to stabilize the unit. I just read that this resistor needs to be heat-sinked and am curious as to why. The resistor's operating temperature limits are -50 degs.C to +275 degs.C at a maximum of 350 volts. It has a high thermal conductance potting. At 5 volts there is only 0.5a current which equates to 2.5 watts. Is it really necessary to heat-sink it?


    PS-I attempted to submit this thread earlier (several hours ago) and it didn't work; so am trying again. If it shows up twice, you'll know why... [​IMG]
  2. crutschow


    Mar 14, 2008
    If the 10 watt resistor is mounted in free air at room temperature then you should be fine.
    rifme likes this.