# Resistor 0.5 ohm alternate

I need 0.5 ohm resistor in my circuit. Unfortunately, I am unable to find it in my nearby market. Can I use a piece of wire (with specific length) instead?

• You're going to need a fair bit of wire to get to half and Ohm. Make sure the added inductance won't be a problem. Commented Jan 12, 2018 at 3:32
• What do you need it for? Commented Jan 12, 2018 at 3:35
• In addition to Russel's answer, if you don't have any low-value resistor to connect in parallel then you can use these as a last option :) IIRC one part is about 1 Ohm, so you may need to apply a current/voltage and make measurement. Commented Jan 12, 2018 at 3:45
• Can you find 1 Ohm? You can put two 1 Ohm resistors in parallel to make 0.5 Ohm. Commented Jan 12, 2018 at 3:46
• You could maybe carefully tweak a potentiometer. I know there are 5 Ohm pots available - maybe you have some low(ish) resistance pots nearby? Commented Jan 12, 2018 at 4:23

Probably the easiest solution would be parallel resistors. If you have 1 ohm resistors, two in parallel would give you 0.5 ohm; if you have 2 ohm resistors, four in parallel, and so forth.

Yes easily. Your choice of wire diameter, length and material depend on your specific requirements. You need to take the maximum current expected and the maximum allowable temperature rise you can tolerate.

A resistive wire makes things more compact but may be hard to connect to without compression terminals or a spot welder as many resistance wire materials do not solder well.

If you use crimp lugs on iron, steel, stainless steel, nichrome or Kanthal wire you should be able to screw down or solder onto the crimp lug. This is a good technique if you do not make your wire get too hot.

If the stability of the resistance value is critical you shift your choices to materials with smaller temperature coefficients. One metal alloy developed for this purpose is Constantan and it is very good compared to a resistance heating wire.

There are some constants and a basic resistance calculator online.

• Thanks for detailed expert opinion. It was really not as simple as had assumed it. Thanks ! Commented Jan 12, 2018 at 5:41

If you can figure out a way of soldering/mounting it, a piece of pencil lead from a mechanical pencil may do the job. Maybe 0.5mm or 0.3mm so that you don't have to use such a long length.