Correct method of measuring a pulse

[James G Deye]

I am currently working a project to evaluate the power output of a single pulse through an air core transformer. Using a scope to measure the secondary output and I am confused on what voltage to use. Scope shows DC voltage, peak voltage, drop Voltage differntial of peak and drop voltage. Would a current probe also be advantages for these measurements. The single pulse we capture is about 26 microseconds from peak to end. We hope to calculate though these measurements the forcast of different wire guages and number of turns on the secondary.


Jamie

 

[berkeman]

I am currently working a project to evaluate the power output of a single pulse through an air core transformer. Using a scope to measure the secondary output and I am confused on what voltage to use. Scope shows DC voltage, peak voltage, drop Voltage differntial of peak and drop voltage. Would a current probe also be advantages for these measurements. The single pulse we capture is about 26 microseconds from peak to end. We hope to calculate though these measurements the forcast of different wire guages and number of turns on the secondary.

Welcome to the PF, Jamie. To get a clear picture of the power in the pulse, you will need to measure the instantaneous voltage and current, and calculate the product P(t) = V(t) * I(t).

If you have a good (high-bandwidth) current probe, then you can put that on Ch2 of your 'scope, and use the math function to give you the product to display the P(t) graph.

If you're current probe is not of high enough bandwidth, you could put a low-resistance shunt at the low-side of the coil that you are driving (with one side of the resistor to ground), and measure that voltage to get a picture of what the current is. This is slightly more invasive as measurements go, but as long as you keep the voltage drop across the shunt small compared to the total coil voltage, you should get a pretty accurate measurement.

 

[oswaler]

, your project sounds very interesting. To accurately measure the power output of a single pulse through an air core transformer, there are a few key steps you can follow.

Firstly, it is important to have a clear understanding of the different parameters being measured. In this case, you are interested in the voltage output of the secondary coil, so it would be best to use the peak voltage measurement on your scope. This will give you the maximum voltage reached during the pulse.

Next, it would be beneficial to also measure the current flowing through the secondary coil. This can be done using a current probe, which will give you a direct measurement of the current. By combining the voltage and current measurements, you can calculate the power output of the pulse using the formula P=VI.

When selecting the voltage range on your scope, it is important to choose a range that will capture the entire pulse without saturating the signal. This will ensure that you get an accurate measurement of the peak voltage.

In terms of the different wire gauges and number of turns on the secondary, it would be best to vary these parameters and record the corresponding voltage and current measurements. This will allow you to analyze the data and determine the optimal configuration for maximum power output.

In summary, to accurately measure the power output of a single pulse through an air core transformer, you will need to measure the peak voltage and current using appropriate equipment and carefully select the voltage range on your scope. By varying the wire gauges and number of turns, you can determine the most efficient configuration for your transformer. Good luck with your project!