WIRE WOUND RESISTORS VS OTHER TYPES

 

There is one common thread: when modern circuits need power resistors, the choice is often wire wound. Today‰s wire wound resistors are rugged and reliable. They are small and compatible with modern

PC-board and surface mount manufacturing systems. New technology resistors still fall short of wire wounds. Look at the chart below: although metal foil technology is a close second to wire wounds, other technologies are generally unable to measure up in power rating, tolerance and TCR.
Power Resistors - Technology Comparison
 
Wire-wound
Metal Oxide
Thick Film
Metal Film
Metal Foil
Resistance
(Ohms)		 0.003 to 260K 0.5 to 250K 10 to 3 Meg 0.02 to 30 Meg 0.4 to 10K
Power
ć(Watts)
to 15
to 5
to 5<
to 1
to 10
Tolerance
.01% to 5%
2% to 5%
5%
.1% to 1%
.01% to 5%

TCR
(ppm/C)
5 to 20 typical
200 typical >
200 typical
30 to 300
5 to 20 typical


Surge current capability and stability are other important specifications often not found in data sheets. Wire wounds have 2 to 5 times the surge current capability of film products. Stability is hard to define, but wire wounds may be from 10 to 100 times more stable. Most experienced users agree that wire wounds are superior in these characteristics.

 

So, be rest assured, wire wound power resistors aren‰t taking a back seat in today's electronic technology! They still do the best job in many contemporary applications.