0.3A fusible link?

[JohnD]

I have an old moving coil meter, which resolves to less than half an ohm, but I have melted its 0.3A fusible link (doubtless connected probes wrong) as you see in the pic, it is formed like a strip of copper with a screw-hole in each end, and is 22.5mm between hole centres. the instrument case has insufficient clearance to attach a fuseholder

I looked at Rapidonline, does anyone use this kind of thing?

View media item 1923 View media item 1925

 

[RF Lighting]

Hmmm, not sure I've ever come across that stuff.

I've a couple of ideas for you to try though.

How about an axial lead fuse instead? that would just screw inplace of the copper wire, although RS only seem to do 0.25A or 0.5A versions. Would that be sufficient? part no. 422-028 or 422-034

Or, could you remove the screw connectors, and solder some fuse holding pins in their place? This would allow you to use a 5mm x 20mm glass fuse in its place. I think it should fit ok looking at your picture.
holding pins part no. 167-8367

Each end of the fuse fits into the cup part, and the pin solders onto the PCB. It may even fit in your screw terminals.

 

[JohnD]

thanks for the ideas! the fuse is just to protect the Ohms ranges.

I looked at the Axial fuses, RS seem to sell them in minimum quantities of 10 and also say Discontinued product See replacement 541-3243 I have not found their P&P page yet.

The glass fuse would not fit as there is only about 1.5mm clearance between the PCB and the case and on the other side of that part of the PCB is the plug for AC mains measurement of high resistance and frequency. Very annoyingly, I see from the manual that in the version following my meter, they changed the layout and fitted a fuseholder for a glass cartridge, which would have been so much easier.

Unless I can find a supplier who will sell me just a couple of Axial fuses, which would be very neat, I will think about an inline fuseholder. I think I can connect its tails at the screw terminals, and tuck the holder into the battery compartment. This is not the sort of thing I usually do though and I am quite clumsy

Again RS have a minimum order quantity so I will see if I can get a single elsewhere.

 

[333rocky333]

rs used to be free p+p for next day delivery, not sure if it still is .

http://uk.rs-online.com/web/generalDisplay.html?id=help&file=delivery
Account only now by the look of it

 

[RF Lighting]

It's only free P&P for account holders

 

[JohnD]

I will try Rapid when their website is mended. they are fairly relaxed about small orders. I can't see Axials but they have 32mm.

 

[RF Lighting]

Do RS have a trade counter near you?

I had a look on maplins' website, but it seems they don't stock them.

 

[JohnD]

nearest is 30 miles

 

[Adam_151]

John, Rapid will ship you as small an order as you want, but if its sub £25, they will charge £3.50

(and if its a small order, they will just send it as a small package through royal mail...)

 

[Wontdothatagain]

Have a look at this coumpany. They are a instument repair and calibration specialist and i have found them to be one of the best around. Most small items they will just pop in a jiffey bag and charge you normal postage. They do deal in very old and obscure instruments.
http://www.algo-sales.co.uk/index.htm

 

[JohnD]

thanks!

they don't appear to have a "parts" section but I have emailed with a description.