ESR Measurement Using Multimeter and Function Generator
Рет қаралды 7,100
Күн бұрынThis video illustrates the measurement of capacitor ESR using a multimeter and a function generator.
@PapasDino 8 жыл бұрын
Nice overview Kerry, thanks. You got me thinking so when I get some free time I'm going to compare the signal generator/DMM procedure with my Peak ESR meter and compare the result just for grins.
@KerryWongBlog 8 жыл бұрын
+Dino Papas It would definitely be nice to see the result comparison with a proper ESR meter.
@MrWasim100100 4 жыл бұрын
do you mean a precision rectifier (active rectifier) using op amp and diode ?
@dedskin1 8 жыл бұрын
hey nice work , but idont get it , you are reading milivolts , and saying Ohms are you calculating it on the fly or am i not getting something. You show a voltage divider circuit in the beginning and then no additional know resistance in example just AC source and meter probes ...im confused
@KerryWongBlog 8 жыл бұрын
+Pavle Pavlovic Thanks for your comment! Because the signal generator has a 50 Ohm output impedance, that resistance is in series with the ESR under measurement. So if you take a look at the chart on my website (www.kerrywong.com/2015/11/23/esr-measurement-using-multimeter-and-function-generator/) you will see that the measured resistance is roughly half of the current reading in Ohms (1mV translates to 0.5 Ohm).
@dedskin1 8 жыл бұрын
Kerry Wong oh, now i get it , probes are known resistance, and milivolts rufly translate in to 0.5ohms.. now i get it ...thanks a lot
@technology520 6 жыл бұрын
Hello! I do not have a function generator.What would you recommend a simple and inexpensive function generator?I want to easily measure esr.I'm not financially good to buy a new device.
@KerryWongBlog 6 жыл бұрын
You could use a 555 to generate the required frequency.
@technology520 6 жыл бұрын
How do I set 100mV on the 555 ic output?555 ic output is not a square wave?Would it be possible to use a square wave in esr calculation?
@technology520 6 жыл бұрын
Hello Kerry Wong.There are instruments measuring esr.Are the correct measurements taken with these instruments?Can you make another video about this subject?
@technology520 6 жыл бұрын
I calculated 1KHz Resr = 0.178 ohm for a 1000 microfarad / 16V capacitor. Is that right?
@MrWasim100100 4 жыл бұрын
nice video but i don't have such a nice bench multimeter having 100 kHz bandwidth i have ut61e only 10KHz bandwidth please make a video on how to build an active rectifier can i use ut61e to test ESR of pc power supply caps using your approach?
@technology520 6 жыл бұрын
The Rs in the form will be 50 ohms. Is this true?
@ZhuraYuki 4 жыл бұрын
What about signal generator current limit? At 0.1V and 0.05 Ohm ESR there is no signal at all from generator. My Ketihely 2100 shows 0.0000A current after connecting the capacitor. Are you sure that this methodology will work? Maybe you need to add 1M resistor at series with capacitor and look for a current drop?
@technology520 6 жыл бұрын
Hello Kerry Wong.Note that in order to measure the high frequency AC voltage accurately, you will need to use a multimeter with comparable bandwidth.You stated in your article.Don't you give a little explanation?I could not understand.
@KerryWongBlog 6 жыл бұрын
Most multimeters have a frequency bandwidth up to a few kHz and if the frequency is too high the AC voltage measurement will become inaccurate. Basically, you want to make sure that your meter's bandwidth is higher than the AC frequency you are using for the measurement. Hope it helps.
@technology520 6 жыл бұрын
Thank you.
@armandine2 2 жыл бұрын
It wasn't clear to me what frequency you set your function generator to. You said: "I set it to sine wave and right now I'm setting the frequency range to 55K and output a 1 kilo Hertz sine wave". May be you realised that you were in the 5K range and corrected yourself from the initial 50K? Either way I'm confused as a 1 kHz sine wave won't trouble an inexpensive dvm.
Kerry Wong
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Alva Welding
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