Raju Baddi writes:
Bipolar junction transistors transfer a current from a lower-resistance emitter to a higher-resistance collector. You can use this property to measure inductance by connecting a series inductance/resistance circuit in the emitter and biasing on the transistor long enough for the current to reach a maximum value that is at least five LR time constants. When the transistor’s off time is equal to its on time but is still biased by a silicon diode, the LR current decays exponentially toward 0A. Using the transistor’s current-source property, you can measure this current without hindering the decay process in the LR circuit.
Use a transistor and an ammeter to measure inductance - [Link]
An LCR meter is an extremely useful device for measuring three basic impedance elements, namely, Inductance (L), Capacitance (C), and Resistance (R). Recently, I got a TENMA 72-8155 digital LCR meter from Newark for review. I was very excited to receive it as I didn’t have a dedicated LCR meter in my home lab. Here’s my quick review of this product.
TENMA 72-8155 digital LCR meter - [Link]
Moser from ReiBot has developed a simple project for using an Arduino along with an LM399 and several discrete components to measure inductance. He says: [via]
So you need to make or measure an inductor, but you don’t have an oscilloscope or signal generator? Measuring inductance with a handful of cheap common parts is certainly possible. I’ve verified this method is accurate with a scope from 80uH to 30,000uH, but it should work for inductors a bit smaller or much larger.
Easily measure inductance using Arduino - [Link]
Hang around any electrical engineer long enough, and you’re bound to hear the word inductance tossed around. Or perhaps if you’re hanging around people dealing with high-speed signals, an ugly little thing called “cross talk” might get mentionned a lot (hint: it has nothing to do with speaking in an angry voice to your troublesome PCB, or any uncomfortable attempt to proselytize it and save it from eternal damnation in a lake of molten solder). If you’ve ever wondered what either of these terms mean (and how they’re related), you might find it worthwhile reading this relatively accessible ‘app note’ of sorts explaining what inductance is and why it matters: What Really is Inductance? (by Dr. Eric Bogatin)
What Really is Inductance? - [Link]
This is very accurate home made LC inductance/capacitance meter built with very common components which are very easy to find all around . The range of this LC Meter is extremely good at measuring very low value of capacitance and inductance.
LC Meter’s Inductance Measurement Ranges:
- 10nH – 1000nH
- 1uH – 1000uH
- 1mH – 100mH
LC Meter’s Capacitance Measurement Ranges:
- 0.1pF – 1000pF
- 1nF – 900nF
Very Accurate LC inductance / Capacitance Meter - [Link]
Some time previous to getting my ham license, I was at a friends house who showed me an LC (inductance) meter built from a kit. It was based on a PIC16C22A, and I certainly do like the PIC mcu’s, but decided I would embark on the task of re-engineering my own that uses an Atmel AVR chip, the Atmega168. It’s been a journey. Also, I am giving away for free the schematics, firmware, and source code as open source under the GPL.
Inductance meter - [Link]
This project is an Inductance and Capacitance Meter using Microchip’s PIC18F2550 connected to USB. Source code is available on the link below.
PIC18F USB LC Meter – [Link]
That’s a really nice LC Meter Based on the AVR Microcontroller. It calculates and displays L and C from oscillation frequency using reference components. No relays, no range switching, a minimum of controls. And it is pretty accurate too! The 2 line x 16 character LCD shows the calculated inductance and the oscillation frequency. The frequency might be of interest because inductors with cores can appear to vary in inductance with changing test conditions.
A Pretty Good LC Meter Based on the AVR Microcontroller - [Link]
This is one of the most accurate and simplest LC inductance / capacitance Meters that one can find, yet one that you can easily build yourself. This LC Meter allows to measure incredibly small inductances starting from 10nH to 1000nH, 1uH to 1000uH, 1mH to 100mH and capacitance from 0.1pF up to 900nF. LC Meter’s circuit uses an auto ranging system so that way you do not need to spend time selecting ranges manually. Another neat function is the “Zero Out” switch that will reset the initial inductance / capacitance, making sure that the final readings of the LC Meter are as accurate as possible.
Precise LC Meter on PIC16F84A microcontroller - [Link]