VCS Series Isolated Hall Effect Current Sensors provide high-bandwidth current sensing with amplified output. The 50Ω voltage output may be directly connected to an oscilloscope or data acquisition system.
VCS are magnetically isolated like clamp-on oscilloscope probes. VCS are designed for embedded or laboratory applications requiring accurate measurement of DC, pulsed DC, or AC current. The Isolated Hall Effect Current Sensors provide for secure cable attachment and reliable, repeatable measurements.
Connect to high impedance input or terminate in 50Ω for 1/2 amplitude output
Isolated current sensing
Pulsed current measurement
Data acquisition systems
High power LED/laser diode monitoring
Power supply testing
Better Than Shunt Resistors
Shunt measurements produce very small amplitude signals that are subject to noise and parasitic effects that reduce the measurement accuracy and distort the frequency response. The result is often poor rise time, extra overshoot, and extra undershoot. Shunts are also problematic when measuring high-side currents, as a differential amplifier must remove the high-side voltage before a safe measurement can be made.
Parallel Current Sensors for Higher Currents
VCS Current Sensors may be placed in parallel to sense currents higher than the maximum rating of a single sensor. For example, to sense +/-500A, use two VCS320 current sensors. To connect the sensors, split the circuit to be measured into two equal branches and connect one to the first VCS and the other to the second VCS sensor. Roughly half the current will then flow through each VCS sensor. The VCS outputs must then be added to obtain the correct result. This addition can be done at the system level, for example by adding two scope or data acquisition channels, or it can be done electrically. To do it electrically, simply wire the BNC outputs in series. Since the outputs are floating, the outputs can be connected in series to double the range.
Paralleling cables are available for purchase.
No Amp-Second Limitations
Many current probes have specifications on the duration of pulsed current. These specifications, called Amp-second products, severely limit the capability of the probe with high currents. For example, the Tektronix TCP303, which is rated at 150A, can only sustain the rated 150A for 100µs before going into overload. The VCS series does not have Amp-second limitations.
Frequency Response and Linearity
VCS have good frequency response and linearity along with accurate current tracking to 400A/µs. These characteristics mean pulsed waveforms with rise times to 2µs can be measured with good fidelity, even with a large DC component. The sensors can also be used for AC line harmonic measurements to support power factor testing.
To avoid overheating, cables must be attached with supplied brass 1/4” screws. Tighten between 25 in-lb min and 30 in-lb max.