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How to Make a Hand-Wound Resistor

Power resistors are commonly used in the design and manufacture of power supplies. Power supplies are the power source for battery chargers and provide the direct current supply (DC) for all electronic devices including computers, stereos and public address systems. Power resistors are of low resistance and in some cases specific in their resistance value. Off-the-shelf power resistors are of set values, so sometimes it's necessary to build one to obtain a specific resistance.

Things You'll Need

Roll of resistance wire
Existing resistor
Solder
Solder Iron
Multimeter

Instructions

- 1
  Determine the resistance you want your resistor to read and the maximum current it will carry. Wire-wound resistors are low ohm resistors that carry a lot of current. Measure out in centimeters or inches the length of resistance wire to obtain the required resistance. Before cutting confirm the resistance using a multimeter.
- 2
  Attach one end of the meter to the start of the roll. Attach the other end to the decided length of wire. Confirm the DC resistance is what you had determined theoretically. Allow a little extra to account for the winding on each end lead. Using a side cutter, cut the wire section off the roll.
- 3
  Use a commercial resistor with a core large enough to meet the need and with a large enough resistance not to interfere with the low resistance wire-wound resistor that is to be built. A 200 ohm or higher resistance will have little effect on a 5 ohm or less wire-wound resistor.
- 4
  Wind a couple of turns around the pin at one end. Evenly wind the remaining wire on the spindle with evenly spaced windings leaving enough left over to wrap around the pin on the opposite end of the resistor. Wrap the end of the wire around the pin.
- 5
  Solder the end pieces of resistance wire to the pins. Carry out a final check of the resistance of the newly manufactured resistor using a multimeter set to its lowest resistance reading.

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