Public Domain

Tags
L-meter Arduino based
Recommend Projects

Arduino shield L_meter

2 years ago 698
• Description
• Documents
• BOM
• Attachments
• Members

Description

This is the adaptation for Arduino UNO R3 of Adrzej Janeczek project “AVT-2813” - Multimeter addition for L measurement.

AVT2813

Small and cheap shield for Arduino:

After build

You need connect this to Arduino UNO R3

Now we can think, how we can measure the inductance of coil…

Can we for example counting a magnetic fields lines around the coil ? – Of course NO :-) BUT… but people think and think and created indirectly methods for this…

So we can connect the coil into the circuit and we can check how she work. How fast she get the saturation and de-saturation. Simple scheme first:

This scheme is a bit low readable, we can look at this from easy side like this:

On the first gate we gave rectangular signal (about 128kHZ) from R1/C1 oscillator, which is separated by 3 next other gates. Now signal going to R3/R4/R5/Lx and we have the SAW signal, which going on the next gate. From this gate signal is converted to rectangular signal, where the fill factor is proportional to coil inductance. Last gate reversing this signal phase and send signal to R6/C3 integral circuit. This circuit get the average voltage level of this rectangular signal, and this is the value of inductance where any uH is after every one 10 mV (1uH/10mV).

Finally we using Arduino as V-meter, and additionally as F-meter for adjust signal from R1/C1 to 128 kHZ. For this we have one tactile switch, which we should pressing by about 1sec. and we can see something like this and using PR1 rotation resistor (this long one):

IMPROVE FOR HC SERIES 74HC14

You can use 74HC14, in this case F-meter adjust signal from R1/C1 should be about 260 kHZ.

CALIBRATION

If you have known value the coil about 20uH you can calibrate by turn PR1 up to properly value on the measure screen information.

Theory we can check on the oscilloscope diagrams:

And now Lx = 40uH, the fill factor is going up:

We can look how logic levels gate work:

This simple way gave possibility for us how catch the coil inductance.

Here you can get firmware for arduino hex and asm file. Lmeter firmware

INSTRUCTABLE

DIAGRAMS FOR HC SERIES

eot

BOM

ID Name Designator Footprint Quantity Manufacturer Part Manufacturer Supplier Supplier Part Price LCSC Assembly Mounted nameAlias
1 10k PR1 PR-TRIM_3006P 1 Value(Ω)
2 Listwa ARK2 ARK_L LISTWA ARK2 1
3 8x1F-H8.5 IOL,POWER 1X08 2
4 10x1F-H8.5 IOH 1X10 1
6 CD74HCT14E U1 DIP14 1
7 1.5 nF C1 C1 1 Value(F)
8 330 R5,R3,R4 R3 3 Value(Ω)
9 100 nF C2,C3 1206 2 Value(F)
10 10K R6,R1,R2 R3 3 Value(Ω)
11 10k PR2,PR3 HELITRIM 329Y 2 Value(Ω)
12 HD44780LCD X2 LCD1602 1
13 MODE MODE TACTILE-PTH-SIDEEZ 1
14 RESET RESET TACTILE-PTH-SIDEEZ 1
15 1 nF C4 1206 1 Value(F)
16 500 pF C5 1206 1 Value(F)
17 4K R7 R3 1 Value(Ω)

AVT2813.pdf
V_328.ZIP

Members

Success
The owner does not allow comments in this project now