Digital LED ammeter

[plainsman]

Thinking of fitting a cheapo digital ammeter. Read on this forum some of these units can be powered from the source being measured, also that some units need separate supply. Have looked on ebay but can't find any that indicate the power can be drawn from the measured source.

 

Can anyone suggest which can use the power input from the source being measured?

 

Help appreciated

[Ex- Member]

Thinking of fitting a cheapo digital ammeter. Read on this forum some of these units can be powered from the source being measured, also that some units need separate supply. Have looked on ebay but can't find any that indicate the power can be drawn from the measured source.

 

Can anyone suggest which can use the power input from the source being measured?

 

Help appreciated

 

We have an led ammeter fitted with shunt, it just tells us the amps we're using, in reality it's not much use. Some members on here suggested a clamp meter so we bought one of these.

 

http://uk.rs-online.com/web/p/clampmeters/6973982/?origin=PSF_437001|alt

 

Note I didn't pay any way near the price on the link. It happened to pop up on e-bay brand new still in box and I got if for a bargain price.

 

Fantastic bit of kit and extremely accurate. I've formed loops in all the different charging leads to take readings, we use it daily to monitor charging. There are many models at reasonable prices, members will probably recommend. They are a must have IMO

[smileypete]

Thinking of fitting a cheapo digital ammeter. Read on this forum some of these units can be powered from the source being measured, also that some units need separate supply. Have looked on ebay but can't find any that indicate the power can be drawn from the measured source.

 

Can anyone suggest which can use the power input from the source being measured?

 

Help appreciated

 

Seems that the cheaper ones that can read amps both ways need to be powered by a separate source when doing so.

 

An easy way to generate a separate source of power is with a little 'isolated DC converter' like this:

 

http://www.ebay.co.uk/itm/Isolated-Power-Module-w-4pins-DC-DC-Converter-In-10-16V-Out-12V-1W-High-Quality-/400553394797

 

I'd be interested to know if anyone's got one that can read both ways when using the same source of power.

 

As an aside something I bought recently is a little combo ammeter and voltmeter, only reads up to 3 amps on it's internal shunt, but I'm going to see if I can convert it to use an external shunt to read high currents:

 

http://www.buyincoins.com/item/41038.html

 

 

But it still only reads currents one way...

 

As Julynian says a DC clamp ammeter is invaluable for monitoring and fault finding, usually about £25-30 online or £40 from Maplins, common models are the Unitrend UT-203 or Mastech MS2108A.

 

cheers, Pete.

~smpt~

Edited January 12, 2014 by smileypete

[plainsman]

 

Seems that the cheaper ones that can read amps both ways need to be powered by a separate source when doing so.

 

An easy way to generate a separate source of power is with a little 'isolated DC converter' like this:

 

http://www.ebay.co.uk/itm/Isolated-Power-Module-w-4pins-DC-DC-Converter-In-10-16V-Out-12V-1W-High-Quality-/400553394797

 

I'd be interested to know if anyone's got one that can read both ways when using the same source of power.

 

As an aside something I bought recently is a little combo ammeter and voltmeter, only reads up to 3 amps on it's internal shunt, but I'm going to see if I can convert it to use an external shunt to read high currents:

 

http://www.buyincoins.com/item/41038.html

 

 

But it still only reads currents one way...

 

As Julynian says a DC clamp ammeter is invaluable for monitoring and fault finding, usually about £25-30 online or £40 from Maplins, common models are the Unitrend UT-203 or Mastech MS2108A.

 

cheers, Pete.

 

Thanks Julynian and Pete,

 

Is it reasonable to assume all these digital meters can read both ways (using the alternative power source)? I already have a Smartgauge but thought an ammeter would indicate roughly how the alternator (90amp) is performing, but I suppose in and out measurement is no bad thing. Thinking about it with a 90 amp alternator never (?) producing full output do I need a 100 amp ammeter. I also have a 1600w inverter/70 amp mains charger if that is significant.

I note the comments re a clampmeter for more accurate measurement

 

Thanks for your time on this

[Taslim]

I can vouch for the Mastech MS2108A. A very versitile bit of kit and cheap as chips.

[Ex- Member]

 

Thanks Julynian and Pete,

 

Is it reasonable to assume all these digital meters can read both ways (using the alternative power source)? I already have a Smartgauge but thought an ammeter would indicate roughly how the alternator (90amp) is performing, but I suppose in and out measurement is no bad thing. Thinking about it with a 90 amp alternator never (?) producing full output do I need a 100 amp ammeter. I also have a 1600w inverter/70 amp mains charger if that is significant.

I note the comments re a clampmeter for more accurate measurement

 

Thanks for your time on this

 

It's really useful when charging via boat engine, we generally cease charging by engine alternator when the batteries accept only 35 to 40 amps. We then switch to a small generator which charges up to a rate of 28 amps, after running for an hour we can further check the amps going in then change the charging regime to suite if necessary. It's battery operated. The model I have is very accurate, I assess this as it reads exactly the same as the Outback charger which is supposed to be top of the range equipment.

 

If you can get access to live cables you can check out amp readings on all your equipment, really good for assessing your usage and some very interesting results sometimes.

 

I would have gone for one of the cheaper models already mentioned, I was just lucky I came across this particularly expensive unit that no one had bid on so I snapped it up for just the £25 start price.

[smileypete]

 

Thanks Julynian and Pete,

 

Is it reasonable to assume all these digital meters can read both ways (using the alternative power source)?

 

No, some do and some don't. The ones that can only use an isolated source should be able to read both ways.

 

This looks like it reads both ways with an isolated power source, it's priced reasonably with shunt included, and has screw terminals for connecting the wires which is nice:

 

http://www.ebay.co.uk/itm/DC-0-200A-Ammeter-Digital-Blue-LCD-Panel-Amp-Current-Meter-With-Shunt-For-Motor-/190940094211

 

cheers, Pete.

~smpt~

Edited January 12, 2014 by smileypete

[plainsman]

 

It's really useful when charging via boat engine, we generally cease charging by engine alternator when the batteries accept only 35 to 40 amps. We then switch to a small generator which charges up to a rate of 28 amps, after running for an hour we can further check the amps going in then change the charging regime to suite if necessary. It's battery operated. The model I have is very accurate, I assess this as it reads exactly the same as the Outback charger which is supposed to be top of the range equipment.

 

If you can get access to live cables you can check out amp readings on all your equipment, really good for assessing your usage and some very interesting results sometimes.

 

I would have gone for one of the cheaper models already mentioned, I was just lucky I came across this particularly expensive unit that no one had bid on so I snapped it up for just the £25 start price.

 

Thanks for this I'll look out on ebay

 

No, some do and some don't. The ones that can only use an isolated source should be able to read both ways.

 

This looks like it reads both ways with an isolated power source, it's priced reasonably with shunt included, and has screw terminals for connecting the wires which is nice:

 

http://www.ebay.co.uk/itm/DC-0-200A-Ammeter-Digital-Blue-LCD-Panel-Amp-Current-Meter-With-Shunt-For-Motor-/190940094211

 

cheers, Pete.

~smpt~

Thanks for digging this one out

[WotEver]

 

Thanks for this I'll look out on ebay

 

There was one recently listed for £25 and it had no offers, so keep looking and you may well find one (and might even get it for less than £25!)

 

Cheers,

Tony