Resistors are labeled when they are new, but they can be easy to mistake once they are out of the packaging. Always test inductance using a resistor you are familiar with to ensure you get an accurate result.

Purchase power wires online or at a hardware store. They will usually be red and black so you can easily tell them apart. Touch the red wire to the exposed end of the resistor and the black wire to the opposite end of the inductor. If you don’t already have one, consider getting a breadboard. The holes in the board help a lot with connecting the wires and components.

A function generator is a piece of electrical testing equipment that sends electrical waves through the circuit. It allows you to control the signal moving through the coil so you can accurately calculate the inductance. The oscilloscope is used to detect and display the signal voltage running through the circuit. You need it to visualize the signal you’re setting up with the function generator.

Access the generator’s settings to change the wave type. Function generators can make square waves, triangular waves, and other varieties that aren’t useful for calculating inductance.

For example, set the generator frequency so the voltage between the peaks of both waves is listed as 1 V, which you will see on the oscilloscope. Then, change it until the voltage is 0. 5 V. The junction voltage is the difference between the sine waves on the oscilloscope. You need it to be half of the signal generator’s original voltage.

If you need to convert hertz (Hz) to kilohertz, remember that 1 kHz = 1,000 Hz. For instance, 1 Hz / (1,000 Hz/kHz) = 0. 001 kHz.

Start by multiplying the resistance of the resistor by the square root of 3. For instance, 100 ohms x 1. 73 = 173. Next, multiply 2, pi, and the frequency. For example, if the resistance was 20 kHz: 2 * 3. 14 * 20 = 125. 6. Finish by dividing the first number by the second number. In this case, 173 / 125. 6 = 1. 38 millihenries (mH). To convert millihenries into microhenries (uH), multiply by 1,000: 1. 38 x 1,000 = 1378 uH.

There are also larger electronic machines that make the testing process even easier than normal. They often have room for you to plug in the inductor coil for a more accurate result. Multimeters cannot be used to measure inductance. They don’t have the ability, but fortunately, inexpensive handheld LCR meters are available online.

LCR meters have multiple settings, so make sure you’re using the correct one. The C setting is for capacitance and the R is for resistance.

Using the wrong setting makes the test more inaccurate. Most LCR meters are meant to test at a low current, but you should still avoid making the current stronger than what the inductor coil can handle.

Some LCR meters have a slot where you can plug in testing objects like capacitors and coils. Fit the device’s terminals into the sockets to test it.

Another way to get a pulse is by building the circuit to make your own. It can damage nearby electronics, so be careful when using it. Pulse generators give you more control over the current than a custom-built circuit, so rely on a generator if you have one available.

Test the monitors after wiring everything into place. If everything works, you will see movement on the oscillator screen when the pulsed current activates. A current sense resistor is a special kind of resistor that takes up a minimal amount of power. It’s also called a shunt resistor and it’s necessary for getting an accurate voltage reading.

For example, the pulse could be active 1 second, then off 1 second. The wave pattern on the display would look very consistent since the pulse is only active for half the time.

There are 1,000,000 microseconds in a second. If you need to convert to seconds, divide the microseconds by 1,000,000.

For example, if a pulse of 50 volts is delivered every 5 microseconds: 50 x 5 = 250 volt-microseconds. Another option is to type the numbers into a calculator, such as the one at https://daycounter. com/Articles/How-To-Measure-Inductance. phtml.

For example, 250 volt-microseconds / 5 amperes = 50 microhenries (mH). Although the math seems pretty simple, setting up the measurement is more complex than other methods. Once you have everything working, figuring out the inductance is a snap!