Batteryless current clamps?

Fester Bestertester · 2009-11-17T08:18:55+00:00

I'm curious how the Fluke i200s current clamp probe can give mV output without the use of batteries. How is this done? If one is measuring 200A I can see how the magnetic field could generate enough current in the probe to support some high-impedance, low-draw circuitry. But when measuring on the low scale, say, 2 or 3 amps, how could the probe output a few hundred mV? (The clamp is spec'd to output 100mV / amp on the 20A low scale, 10mV on the 200A high scale.) Can someone explain this to me? I'm fascinated to see it's possible & curious to know how. Thanks.