What are the advantages and disadvantages of passive and active AC current probes?

The difference between passive and active AC current probes:

The head of an AC passive probe is actually a coil of wire wrapped around a magnetic core. When the probe head is held in a specified orientation and close to a conductor carrying AC current, the probe outputs a linear voltage that is a known ratio to the voltage in the conductor. This current-dependent voltage can be displayed as a current-scale waveform on an oscilloscope.

Advantages: The response speed is relatively fast, and the high-frequency bandwidth reaches the ns level or even higher; the disadvantage is that the measured current is generally small, usually below 100A, and the measured wire must be disconnected during measurement, the wire must be passed through the converter, and then the wire must be reconnected to the circuit before measurement can be performed.

Disadvantages: DC models cannot be measured, and the low-frequency cutoff point is usually above 100Hz. The advantage is low cost. Passive AC probes can be divided into split-core and solid-core types according to the embedded head structure. The split-core embedded mouth can be opened and closed manually. The advantage is that the probe can be easily clamped on the conductor for measuring current. When the measurement is completed, the jaws can be opened and the probe can be moved to other conductors; the disadvantage is that the high-frequency response speed is relatively slow.

AC active probes are divided into two types according to the common form of the jaws: one is a common embedded structure, and the other is a flexible structure. Common embedded structure current probes generally use iron cores made of strong magnetic materials. When a large primary current flows through this type of core, it is easy to produce magnetic saturation, making it impossible to perform accurate measurements; while flexible probes use air-core AC current sensors, so they are not saturated even under large current conditions. Therefore, flexible probes are generally used to measure large currents and can only measure AC.

In any case, AC current probes also have a low-frequency cutoff point, which includes direct current (DC), because DC does not cause a changing magnetic flux field and therefore does not cause a switching action. In addition, at frequencies very close to DC, such as 0.01Hz, the magnetic flux field does not change fast enough to achieve a switching action. However, a switching action can be produced within the bandwidth of the probe, and a measurable output can be obtained. In addition, depending on the design of the probe coil, the low frequency of the bandwidth may be as low as 0.5Hz or 1.2kHz.