How to measure inductance?

Hi guys,

i am trying to making a FM transmitter. So, for that i need to make a inductor with winding specification of  7 to 9 turns of 16 – 20 gauge wire around a ¼ inch former.

But how to check the inductance of that inductor, as my multimeter is not having inductance measuring option.

Please suggest me a circuit for inductance measurement and if anyone have made FM transmitter circuit suggest me for this one also...

Thanks 

 

Hi meenal,

Normally the value of inductors can be measured using LCR meters. There are some multimeters which could do that task but they are mosly not accurate.

In your case the simplest thing that you can do it use a formulae to calculate the inductance value of your inductor. The formulae is shown below

Capture.PNG

This formulae is applicable only for air-cored single layer inductor. Do keep in mind that the obtained value will only be close to practical value 

 

  Joined May 19, 2015      213
Tuesday at 03:45 PM

marry roser

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Multiply these amounts and divide the product by the peak current. This is the amount of inductance of the device being tested. Another method for measuring inductance using an oscilloscope involves connecting a resistor of known value in series with the inductor under test and applying a signal.

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  Joined November 21, 2019      36
Thursday at 02:40 PM

Inductance is usually measured in units called millihenrys or microhenrys. It is commonly measured by using a frequency generator and an oscilloscope or an LCM multimeter. It can also be calculated through a voltage-current slope measuring the change in the electrical current passing through the coil.

  Joined February 27, 2020      55
Thursday at 11:08 AM

Few things in addition.
You are making a aircore coil. It is extremely difficult to make because even simple change in the turning or space between each turn will drastically drift the inductance value. However, such microhenry measurements are also critical in any measurements tool because of the added inductance of the probes.

I will suggest you to use dedicated lcr meter for this. Otherwise try to used a wide range of capacitive trimmer possible from 5pF to 250pF amd tune the circuit. It will be easier for you.

Always use proper pcb.

  Joined February 12, 2018      696
Monday at 02:11 PM

Few things in addition.
You are making a aircore coil. It is extremely difficult to make because even simple change in the turning or space between each turn will drastically drift the inductance value. However, such microhenry measurements are also critical in any measurements tool because of the added inductance of the probes.

I will suggest you to use dedicated lcr meter for this. Otherwise try to used a wide range of capacitive trimmer possible from 5pF to 250pF amd tune the circuit. It will be easier for you.

Always use proper pcb.

  Joined February 12, 2018      696
Monday at 02:11 PM

Few things in addition.
You are making a aircore coil. It is extremely difficult to make because even simple change in the turning or space between each turn will drastically drift the inductance value. However, such microhenry measurements are also critical in any measurements tool because of the added inductance of the probes.

I will suggest you to use dedicated lcr meter for this. Otherwise try to used a wide range of capacitive trimmer possible from 5pF to 250pF amd tune the circuit. It will be easier for you.

Always use proper pcb.

  Joined February 12, 2018      696
Monday at 02:11 PM