Inductive Loop Detector is detecting the inductance change of a buried wire coil and thus it can be used to detect metal objects. by elektronika.ba:
Inductive Loop Detector works by detecting an inductance change in wire loop (coil) that is buried in road. It does that by measuring the frequency of the internal oscillator which powers the mentioned coil. When a metallic object moves over the coil it changes its inductance and that in turn changes the oscillator frequency which is measured by the microcontroller.
It is used for vehicle access control at door and barrier controls, for monitoring the occupancy and for vehicle counting in parking garages, traffic light installations and traffic controllers, direction and speed detection of vehicle traffic (if dual channel version is used), in car-wash plants, etc.
Inductive Loop Detector - [Link]
Texas Instruments designers have developed an entirely new data converter with the LDC1000 inductance-to-digital converter (LDC) designed specifically for inductive sensing applications.
The LDC uniquely combines all of the external circuitry on chip that is normally required to simultaneously measure the impedance and resonant frequency of an LC resonator. It then regulates the oscillation amplitude in a closed loop to a constant level, while it monitors the dissipated energy of the resonator. This leads the accurate measurement of inductance of the front-end LC circuit, which enables precise measurement of linear/angular position, displacement, motion, compression, vibration, metal composition and new applications which will be conceived by designers. All of this can be done in the presence of oil, dust, dirt and moisture unlike most other solutions.
LDC1000 - Texas Instruments inductance to digital converter (LDC) - [Link]
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]