Ammeter

[robertager]

Can anyone help? I am trying to obtain a 5 amp +/- ammeter and am stumped for finding any suppliers. Last year managed to track down a company who produced them for old Velocette Motor scooters but after a computer crash, lost the link and can't find it again!

We only use a solar panel and the outboard (which has a 3 amp charger) so the 60 - 0 - 60 that are available for cars wouldn't even show a wiggle.

I have tried RS and Maplins but no luck. Any pointers would be greatfully received.

Robert

 

[paddywackcocker]

Have a look in Clasic motorcycle magazine, in the spares section, that should doit

 

[TrueBlue]

No Probs:

http://cpc.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=PM11333&N=411

For a princely sum of £3.33 plus VAT. Just a fly in the ointment they charge £4.99 for delivery if you spend under £30... Perhaps you could find some other goodies - most things are well priced, lamps, batteries leads etc etc.

It's a moving iron instrument which means that the scale is non-linear - but that may be an advantage for you.

Failing that any Amateur Radio fairs in your neighbourhood? There are usually well stocked with components.

 

[Goldie]

Try Ampair, they have a selection of analogue ammeters in various ranges - I use their 0-3A and 0-10A meters for solar and wind respectively.

 

[Strathglass]

Robert

Had a good look. Vern expensive lab quality ones only.

Plenty of 0-5A ammeters, in RS,Farnell etc. as have been sugested by some formites, but I hav'nt found any Centre Zero Ammeters with a +/- 5A FSD in the UK.

One possible solution would be to use a low cost digital multimeter with a 5 Amp current range. This would show -ve or +ve depending upon charge or discharge and could be built in. Even the cheapest digital multimeter could be used with an external current shunt.

One possible solution

Iain

 

[robertager]

Many thanks for your help and I certainly think that I can work these to suit. However I was thinking about a meter to show both charge and discharge and these all seem to be single directional.

 

[LadyInBed]

I would go for a cheap (£5) digital multimeter. It can be wall mounted with the leads connected via banana plugs and sockets across a switch so it doesn’t have to be in circuit all the time. It can then also be used as designed, as a multimeter.

 

[William_H]

Hi Rob most analogue moving coil meters have a little screw for zero set of the pointer. You can adjust this so the needle sits up to 20% above zero. You can recalibrate the numbers to suit. If you buy any moving coil meter you need a shunt which may be internal or external. A new shunt can be made with nichrome( out of a heating element) or iron wire thin fencing wire or a strand of stainless steel lock wire. The wire is clamped between screws that the meter terminals and power wires go to. More shunt wire equals more resistance equals more sensitive meter. You will need a multimeter with suitable amp range to calibrate (by shortening the shunt resistor wire) this will give you any range you want. Don't forget 2 fuses near the shunt in the wires to the meter as these wires if shorted to neg. can carry full battery power and cause a fire.
Some old hifi stereo receivers had a centre zero meter for tuning which though small may suit you. That is for us with short arms and deep pockets. good luck olewill

 

[Kristal]

There appears to be a good selection on Ebay, mainly of the type used in the automotive modifying game, but they are Centre Zero (-30 - 0 - +30)...

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