SMPS input 127Vac, output 13.8VCC / 200A, true or fake ? to see this video:

[albert_emule]

SMPS input 127Vac, output 13.8VCC / 200A, true or fake ?

to see this video:

YouTube - Poison Usina 200-Ampéres (teste)

[event horizon]

I'll be honest & say i have never seen a clamp meter that reads DC current that way AC is a different animal & can be measured via a clamp meter in that fashion.

I'd have prefered to see it run through a current shunt

[theAnonymous1]

Originally Posted by event horizon

I'll be honest & say i have never seen a clamp meter that reads DC current that way AC is a different animal & can be measured via a clamp meter in that fashion.

I'd have prefered to see it run through a current shunt

Really? I thought they were quite common.

Fluke 337 Current Clamp Meter

A shunt is probably more accurate though.

[event horizon]

Well make that a first

I fail to see how a transformer works at DC, after all that is effectively what the clamp is (as far as i'm aware).

I actually took a look at a load on ebay before i posted my reply & every one i looked at even though they were described as AC/DC clamp meters only read current in AC. They measured voltage in AC & DC though.

Perhaps i'm missing something

E2A:- Fluke may have been clever about it & devised a way to reverse the windings (similar to AC) & then convert back to DC for all i know, this is the only way i can possibly figure they can measure DC current with the clamp.

& i still might be out by a country mile...

[albert_emule]

they are not only a Current Clamp Meter, It is also a sensor haus.

[djQUAN]

Originally Posted by event horizon

Well make that a first

I fail to see how a transformer works at DC, after all that is effectively what the clamp is (as far as i'm aware).

I actually took a look at a load on ebay before i posted my reply & every one i looked at even though they were described as AC/DC clamp meters only read current in AC. They measured voltage in AC & DC though.

Perhaps i'm missing something

E2A:- Fluke may have been clever about it & devised a way to reverse the windings (similar to AC) & then convert back to DC for all i know, this is the only way i can possibly figure they can measure DC current with the clamp.

& i still might be out by a country mile...

I've read about it before. they probably use hall effect sensors to detect DC magnetic fields and output a corresponding DC voltage.

[Cristi]

the real clamp-meters which can read both AC and DC currents use both windings, and Hall-effect sensors. they don't measure the current value, just detect the presence of the magnetic field, and there is a bias winding which generate a magnetic field which is opposite of of the field generated by the wire carring the current to be measured. the winding is biased with a current proportional to the current to be measured, so the field on the hall sensor will be cancelled. measuring the bias current actually can get the value of the measured current.
at least the ones which i use work in this way....

[BADFLOPPY]

The direct current measuring Tong Tester I have also. It's working principle is precision and simple and works on saturation type. Suppose a AC is give in addition to DC. Now induced AC will depend on the magnitising slope position of that core curve and can be calculated through a microcontroller.

The traction current is measured on the same principle in the Kolkata metro Railway Coaches and was known as DCCT. All traction series motors current is measured using either DCCT or measuring shunt and isolation transducer. (magnitically coupled) two side electronics component.

Hope you can realise.

[event horizon]

This is why i like this site, you learn new stuff nearly every day

Thanks for the enlightening, i bow down to your vastly greater knowledge of clamp meters