[DIY] LCR meter up to 10khz using AD9833 & dsPIC30F4012

[egberttheone]

I was in a search for a good LCR meter for my measurement devices collection.

I would like a LCR meter that has the option to select measurement frequentie and is able to measure equivalent series and parallel C & R.

I found a nice meter on eBay TH2821A its around 170 euro shipped to me.
It is able to do the measurements mentioned above at a maximum frequency of 10khz and with a
high accuracy about 0,3% tolerance (says the manual although).

I also knew of some DIY ESR meters which are MCU based, so i was wondering if there was a DIY project for a meter with my requirements.

I found out that there is a very nice solution for this, a guy called "Miguel Rusch" from Australia
has developed a LCR meter project for the design contest of microchip.

You can find the project here : Microchip 16-bit Embedded Control Design Contest

It is fully open source and claims to be within 1% accuracy, but i couldn't find the PCB for it

Any one has made this puppy ?
If the is enough interest for this project we could organise a group buy.

I attached the abstract manual from the project.

[johan]

I'm also searching for a good LCR and ESR meter. I found this through Google:

ESR meter LC LCF LCR LCFESR L/C L/C/F inductivity capacity frequency capacitor measurement instrument AVR ATMega8 Mega88P

I tried mailing the author. Looks interesting.

[egberttheone]

Nice find. You need to know what you want to measure/archive with these meters.
Most manufacturers give there ESR and inductance rate at a measurement frequency of 100 khz the atmega will be way to slow to do this.
My find measures up to 10 khz.
So if you want a good meter so you can measure if a component meets its standards you need to be-cable of measuring its LCR at 100 khz.
If you only use your components at lower frequency you will be fine with that design.

[johan]

From the description for the LCFesR 3.06 meter:

"Before each measurement the meter tries to discharge the capacitors in the measuring circuit for a half second. Afterward by giving a 5mA or 50 mA current pulse that holds in very short time (matched to 100 kHz measuring frequency), the meter measures the voltage that falls on the capacitor or on the measured resistance. From this it calculates the value of ESR."

[johan]

I ordered the kit. He also had ready assembled units.

[egberttheone]

Okey let us know how it preforms. Do you have any thing to make a reference ?

[johan]

I could try testing some more or less accurate components that I have. I do have a simple capacitance meter and two scopes, but I'm not sure if that helps. I could also show it to some lab guys at work. They should have more accurate equipment.

[jackinnj]

While you've already ordered the kit, check out Analog's site -- they have a lot of new circuitry which generates the real and imaginary components -- some of the aps seem to be in hematology, some in corrosion measurement.

I've used their AD5933/4 chips -- it's not really suited for low-Z measurement right out of the can, but you can trick it into low-Z measurement. They've got a really neat design tool: Analog Devices: Interactive Design Tools: Impedance Measurement :

[egberttheone]

I have noticed these devices, it can measure(analyze) up to 100 khz this is limited to the sample speed of 1MSPS. The design i found has only 100KSPS allowing up to 10 khz only.

[jaybien]

hi
i like buy
this lcr meter anybudy can help me
LCR meter up to 10khz using AD9833 & dsPIC30F4012 ("Miguel Rusch)