Useful Circuit Current Drain Tester

[Montana5]

Saw this in my Maplin e-mail this morning, thinking of ordering one, at £13.29 it looks like it could be put to good use in our power hungry Cars.

http://www.maplin.co.uk/automotive-curr ... 3#overview

Doug.

[J44EAG]

Very handy unit, Doug.

Think I`ll get one myself to add to my test gear.

Mike

[J44EAG]

That`s it! Had enough. I need one. Fed up with flat batteries and rather easier and quicker to use than my cable clamp test unit although it is a great piece of kit.

Plug this into each fuse in turn and you car see the current flow that is on that circuit immediately.

Thanks to Montana5 for the link.

http://www.maplin.co.uk/p/400mm-automot ... &#overview

Great Uncle Joe needed one the other day.

Mike

[jeff1954]

I'm off to get one now

Jeff

[oldtimer]

Hi Mike & Doug,
Perhaps I'm being extra dull but what does this device actually do?

If a fuse has blown, which could well be a dead short downstream of the fuse, if the device is plugged in, could it take out the device?

If it is an open circuit, surely no reading at all.

What readings are displayed on the screen?

On the face of it I can't work out it's purpose - kindly explain

Oldtimer

[oldtimer]

Hi Mike & Doug,
Perhaps I'm being extra dull but what does this device actually do?

If a fuse has blown, which could well be a dead short downstream of the fuse, if the device is plugged in, could it take out the device?

If it is an open circuit, surely no reading at all.

What readings are displayed on the screen?

On the face of it I can't work out it's purpose - kindly explain

Oldtimer

[oldtimer]

That's clever 2X dull

[J44EAG]

Sorry Phil. Missed your post.

The unit can be plugged in to test what an individual circuit is drawing when switched on. So for instance when I build a 12v boat electrical system which has maybe 10 lights on the circuit each fitted with say 20w lamp, I would then have to calculate the result of 10 x 20 = 200 to find out what the current flow was in AMPS. To save my brain strain, I substitute the blade fuse in the circuit fuse box for the tester for a few moments. That gives me a current flow figure in amps and I then am able to select an appropriate permanent fuse for that circuit. So that is one reason for buying.

The second is to use the unit to test what circuits and current levels are being maintained when a car is switched off. Repetitive flat discharged batteries cause many tears on occasions and use of one of these testers would highlight any unusual current drain which may point towards a circuit that is detrimentally causing the battery to discharge.

The unit is only for testing, not for permanent fixture.

Mike

[steve_m]

Now all we need is one that does the glass fuses for the older cars.

[J44EAG]

A relatively small mod should I would have thought be easy to carry out.

Stand alone in line blade fuse holders can be found in many High street motoring outlets. The tester can plug into such a fuse holder.

Take an old blown fuse and solder the two wires from the fuse holder above onto both ends of the metal glass fuse end caps.

There you go. Suitable for glass fuse fuse boxes!!!

Mike

[oldtimer]

Thanks Mike - got that - and makes sense

One final question , Does the screen display anything more than load in Amps?

P

[J44EAG]

The screen only shows amps and the button is for on and off.

Unit is supplied with a little 12v A23 battery. Fuse protection is via a separate blade fuse inserted into the case of the probe. Fuse size would be above the maximum current draw of the unit you are testing.

It is a nice useful little gizmo. Fits in the palm of your hand. Here it is.

Wish I had one of these years ago.

Mike

[oldtimer]

OK Mike, now I'm convinced.

I shall pick one up next time I pass Maplins

P

[jeff1954]

Hi Mike
Do I insert say a high rate fuse into the tester and leave it in or use the fuse from the circuit that I am testing?

Jeff

[J44EAG]

The unit comes without a fuse and instructions are sparse in relation to what to put in the prong.

I put a spare 10amp fuse in the prong just to get the unit going.

Makes sense that each circuit being tested gets its fuse transferred to the prong. Somewhat tedious though. A fuse larger than 10amp in the prong would probably make sense in service.

Mike