UK What kind of resistor as there are so many?

[Rather be Fishing]

Hello and thanks for taking
a look at my question.

Basically I am struggling to source some resitors that I need to connect into a circuit so my instrument can read realistic measurements on a small rig.

I need 1ohm, 2ohm, and some 0.5ohm, 0.2ohm and 0.1ohm resistors.

When I ring RS they say that they have thousands of different types and need more information.

When I type them sizes into eBay I'm left perplexed on what would be the right purchase

I've got some one who said they help me install them but I don't want to keep asking him stupid questions as I've already asked him what size resistors to get and was called needy ? so I don't want to push my luck.

If anyone knows what it is I need to be asking for would you mind telling me so I can order them please?

Thank you for any help

 

[Rather be Fishing]

Just wanted to say thank you to everyone who has helped me out with my question.

It's very decent of all of you to take some time out of your day to do so.

Cheers ??

 

[Lister1987]

Power resistors are what you're after ircc, our test rigs at college have them and they ain't cheap

 

[Lister1987]

Cheers for dropping in @pc1966. Appreciate it.

Going on what you two have just said and the fact that I was told they are only cheap for packs of 10 I think it's either like you and @SparkyChick say, a through hole style one or the metal ones with solder lugs. Not that I new that before.

I'll ring RS back armed with that new information.

Thanks alot you two ?

Wire them via a bank of grid switches so you can easily switch them in and out

 

[marconi]

I asked Megger at Dover about the currents which circulated when one of their MFT's is used. A very helpful reply which I can summarise as:

1. To comply with BS7671 the current is at least 200mA during continuity tests;

2. During high voltage insulation tests the current is about 1mA;

3. During two-wire high current loop tests the current is about 20A in older MFTs and about 5A for newer models - these tests only last milli-seconds so the Ohmic heating (IsquaredR) in any test resistor will be negligible.

The resistor power ratings I have recommended will therefore be suitable.

 

[Rather be Fishing]

Thank you @marconi
?

 

[marconi]

Any chance of some photos of the finished test rig or it in use for other trainees to copy?

 

[Rather be Fishing]

Yes for sure @ Marconi.

I've been advised to focus my energy on passing the multiple choice bit first but I've taken delivery of the resistors and am keen to build something so Ill be back to show what I've done once I've got the multiple choice bit done ?