DC non invasive current clamp for oscilloscope DIY

Aug 15th, 2019 | by: ELECTRONOOBS
Category: Electronics Basic Circuits
Views 677
Having an oscilloscope it's a very nice thing. It's a quite useful tool. But with the basic probes you could only observe voltage values. What if we want to observe current??? There are many types of oscilloscope probes each with its own field of application. The probe takes care of the very critical coupling between the measured object and the oscilloscope. In this video we will talk about current probes, and to be more specific about the non-invasive current probes which means that we don’t have to directly connect it to the open circuit in order to take a measurement. Currents can be measured by measuring the voltage across a known resistance. A major disadvantage is that the circuit has to be opened to insert this shunt resistor. We’ve seen this kind of current meter in one of my past tutorials of the Arduino based multimeter. You have the link of that tutorial below.


See full tutorial here. In this video we will do something different because that additional resistance can also affect the measurement by its burden voltage. Currents can also be measured with a current probe, also known as a current clamp. These probes don't have the disadvantages of shunt resistors as we’ve just described. A current probe is simply clamped over the current carrying wire and the circuit doesn't have to be opened which is a huge advantage. 
Current probes are roughly divided into two types: AC and DC current clamps. I’ll try to explain how both of these types work. To understand that let’s first have a look at my hantek current clamp that I’ve just receive. It’s a quite useful tool.


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