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Clamp metesr and DC current

M

MoiInAust

Jan 1, 1970
0
Can clamp meters measure DC current using the clamp(as round a car battery
lead)? If so, how do they work? Surely they need a varying current, as in
AC?
 
D

David L. Jones

Jan 1, 1970
0
C

Chas

Jan 1, 1970
0
MoiInAust said:
Can clamp meters measure DC current using the clamp(as round a car battery
lead)? If so, how do they work? Surely they need a varying current, as in
AC?
IIRC, before the advent of solid state electronics, they consisted of a
pivoted permanent magnet which aligned itself with the magnetic field around
the cable. This was spring loaded and was linked to the pointer. A cable
groove was included in the rear of the meter, which was placed in contact
with the cable insulation to take a reading.
--
Regards,

Chas.

(To email me, replace "xxx" with letters tango papa golf.)
 
J

john jardine

Jan 1, 1970
0
MoiInAust said:
Can clamp meters measure DC current using the clamp(as round a car battery
lead)? If so, how do they work? Surely they need a varying current, as in
AC?
They use a 'Hall effect' sensor built into the clamp. Can do AC and DC.
Bought one of these last year ... (beware of line break)
http://cgi.ebay.co.uk/DIGITAL-AC-DC-CLAMP-MULTIMETER-AUTOMOTIVE-BATTERY-METE
R_W0QQitemZ400037674266QQihZ027QQcategoryZ294QQssPageNameZWDVWQQrdZ1QQcmdZVi
ewItem
Really weird to be able to clip on and see the direction of charging current
into a battery, or how much current some circuitry is taking.
 
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