Discussion Overview
The discussion centers around measuring inrush current using a 0.1 ohm resistor in conjunction with a Chroma 61605 AC source. Participants explore the impedance issues encountered when attempting to capture accurate inrush current measurements within the first 50 microseconds after activating a relay.
Discussion Character
- Technical explanation
- Debate/contested
- Experimental/applied
Main Points Raised
- One participant notes that the Chroma 61605 is a switching type controller and questions its ability to regulate current at very short time intervals (<50 microseconds).
- Another participant suggests that inrush current typically lasts from half a cycle to several cycles (8.3 to 167 milliseconds), indicating a potential misunderstanding of the inrush current duration in this context.
- It is mentioned that the peak current in the specific case occurs and dissipates within the first 50 microseconds of switching the relay, suggesting that the characteristics of the device may influence the inrush current behavior.
- A suggestion is made to add two capacitors (a 10 µF film capacitor and a 0.1 µF mica capacitor) to the output of the Chroma to potentially mitigate the impedance issue, with a caution to ensure the capacitors are rated for AC operation.
- One participant raises the possibility of measuring transient voltage instead of transient current, proposing a method to check for transient voltage using an oscilloscope.
Areas of Agreement / Disagreement
Participants express differing views on the nature of inrush current and the capabilities of the Chroma 61605, indicating that there is no consensus on the best approach to overcome the impedance issues for accurate measurements.
Contextual Notes
There are unresolved assumptions regarding the characteristics of inrush current and the specific limitations of the Chroma 61605 in this measurement context. The discussion also highlights potential dependencies on the specific devices being tested.