Measuring Current with a Digital Multimeter

[@davidb2206]

Thank you for posting. This is the best and simplest explanation I've ever seen. If you ever expand it, please add the same test for the amperage output of a solar panel.

[@brettpenza5149]

Thanks very much for this. Outstanding demonstration. Makes sense. You have to break the circuit to see the flow of current. I was very lucky I didn't break the meter before I saw this. Thanks very much.

[@mostafajento]

Simple, quick, and useful. Thank you😊.

[@loafandjug321]

How much fire is acceptable when performing this procedure?

[@mplites7160]

Thank you so much :) I never thought it should be connected in series to the circuit.

[@jholmesgt]

Great explanation. Short, crisp, and to the point. Thank you.

[@loafandjug321]

How much fire is acceptable when performing this procedure?

[@DeputatKaktus]

I am glad I found this video. I may or may not have blown a fuse because of my ignorance.

[@brionfranks478]

very concise and to the point, thank you

[@gregbradford7963]

Thank you.. It seems D) would actually measure the current through the resistor, but alter the circuit by shorting through the bulb.🙂

[@MultiTHUNDER00]

thanks saved me some time!

[@chongshenchang9367]

Won't the current drop because of the load or Will it show the correct amps of the battery with load connected..?

[@davidm3210]

Nice informative video thanks.

[@aviv931]

best explanation, thanks you!

[@IgorSilva-fh2pr]

Great tutorial. Thanks!

[@hydrolink5297]

I was just about to do the dumb thing, but the thought i should look up if i'm doing it right

[@dansmith9770]

very helpful video thanks !

[@JunPalen520]

Nice video sir

[@saddlebroncSilver]

So that's DC power, but for measure AC current in 110v or 220v house electricity, most have something connected on outlet running on, that's right ? eg: transformer, coffee maker or something like that, drawing power.

[@bhadrabdrshahi5539]

God be with u sir

[@scottygdaman]

how about measureing current not on a circuit ? i.e. generator;; motor..back up battery .. etc,

[@ronanrogers4127]

Can you check the amps of a circuit when it's not under load? I have a 12v power distribution module for which each circuit can have the amperage set by a computer program. I lost the programming cable, so now I want to check how many amps each circuit is set to so I can be sure I wire a new accessory to a circuit with the appropriate amps set. Or does the circuit need to be under load, and would I need to increase the load until the breaker tripped?

[@MrChanPhysics]

Current must be measured on a live, loaded circuit (unlike voltage , which can be measured on a live but unloaded circuit). Electric current is just like water flowing in a pipe; only when it runs is there anything to measure. If you do test the breakers for maximum load, please make sure that you don't burn down your shop.

[@gonkuz]

Nice Tutorial.

[@muhamadazrinadnan6976]

hi Alls, may I know what value voltage and watt of the lamp that used in this video? I already tried and follow the step in this video with 24VDC 70W lamp and should be 2.9A by calculation right. but I only get 0.25mA. any idea?

[@lvtbus3167]

Urgent question for daughter's 3rd grade science project! We measure batteries in series and parallel connection. 2 AAA 1.5V batteries in Series go to 3V and supposedly the 1000 MAh stay the same, 2 AAA 1.5V in parallel stay at 1.5V but the Mah doubles to 2000, and 2 x 2 series connected in parallel go to 3V and doubles to 2000 MAh. I can measure the voltage increase or stay at same with the multimeter, plus I use a light bulb showing dimmer or brighter light, but how can I demonstrate the mAH increase for this purpose? I thought your video did that, but I get a reading of 0.12 and in parallel nothing changed. Using D or 9v I get the same readings when I though it would definitely be higher then the AAA battery. Do I need something else to show this or can this only be measure over time? Just a simple proof of hypothesis to double the mAh in parallel would be needed. Thanks.

[@MrChanPhysics]

The current (mA) will not change between 1 battery or 2 batteries in parallel (as long as the batteries are fresh and the bulb is a low-power flashlight type). The bulb is a type of resistor (R). The "formula" for current (I) is I=V/R. This is known as Ohm's Law. Since AAA, AA, C, D batteries all have the same voltage Vbatt, they will all supply the same amount of current I through a resistor or bulb R. If you put two batteries in series, then you have doubled the voltage Vbatt and according to Ohm's Law, you will see a doubling of the current I, and the bulb will glow much brighter. I=2Vbatt/R This also assumes that the bulb's resistance (R) stays constant. However, the resistance in real light bulbs increases as they get hotter, so you will probably see a little less than 2x the current I when you double the voltage. Putting 2 batteries in parallel will not double the current I. The way to show that is with 1 battery driving 2 bulbs in parallel. Each of the bulbs will use an amount of current I=Vbatt/R, so the battery must double its current output. Good luck with the science project!

[@lawrencej6278]

Can I measure Ac ampere for this multimeter

[@markg7700]

I have a rechargeable shaver that has a power transformer that puts out 3VDC 120 mA. I want to see if the charging circuit is putting out the proper current. the battery is failing. (2/3 AA size - 2.4VDC 500 ma (two 1.2V cells in series. ) The shaver will not run if the battery is removed even when plugged in. So with battery removed and the circuit plugged in I measure on the + and minus pads where the battery was connect a voltage of 2.77 VDC. Can I test the current by putting the leads on the +/- pads on the board. (battery is removed) Would that be putting the leads in series?

[@MrChanPhysics]

No, that would create a short circuit and undesirable heat and/or smoke. To see if current is flowing, the ammeter must be in series between the battery and charger. Use an alligator clip lead to connect the neg. side of battery to neg. charger pad. Then connect red probe to the pos. charger pad, and the black probe to the pos. battery connection. Now the meter is in series. More than likely, however, is you have a dead battery.

[@aboivanka6104]

If thats the case how can i measure my battary amp since its lebal is peeled off and missing?!

[@recommendedforyou157]

how about testing current on circuit board like on laptop motherboard?

[@Libouh]

Is the resistor necessary?

[@MrChanPhysics]

No, the resistor is not necessary for this task, but it is part of the same circuit that is explained in my Measuring Resistance and Measuring Voltage videos.

[@andreamitchell4758]

so this will just measure the current being drawn for the circuit right? but what if we want to know the total current the power supply can put out? or is there no way to tell unless you know what the power supply is rated for already? i have an old power supply harvested from a PC and i use the the 5v out to power some led lanterns i have hanging on my porch but now i want to add a USB to it to power a security cam , i am just afraid it might be too much current though i read that current of the power supply should not excede double or 2 and half times what the load runs on , for exampe the camera comes with a 1A USB power brick and you can daisy chain up to 3 cameras off that one brick , but i will say 1A for the camera load , so if the PC power supply is rated at over 2.5A then will that be too much current and fry the camera?

[@CraigMansfield]

HomeMade DIY HowTo Electronic It would be necessary to not blow the light. Maybe. Unless it's a 12v light and battery.

[@iTs_Turbine_Time_in_Turbonia]

What would happen if you connect the negative lead(-) coming from the the amp meter/multimeter to the negative terminal(-) of the light bulb instead of the resistor(+) connected that's connected to the positive(+) terminal of the bulb? Would the amp meter/ multimeter still measure amperage drawn?

[@levithatcher142]

Just measures as negative if you reverse the leads.

[@roncooke2188]

hi is there a way to measure dc carbon brushes to say if they are ok for 12v or the difference if they are for 24v or 36v

[@MrChanPhysics]

I don't think the digital multimeter will tell the difference. A motor brush should be very low resistance for any application.

[@MarkThomas123]

This can be used to test a 12volt car battery charger,, I'm pretty sure.. Mine has 2/10 amp charge plus a 50 amp boost... Tell me, what would your particular meter do, if you did the same test, 2amp/10am, and ran the Battery charger on boost at 50 amps with it in series.. Would it just register at 5 amps, since it could not go over 10, to get to 50, or stop at 10, or freak out? And, what if it went over 10 amps? What would it show? Say 10.2 or 10.3 amps? Reason I am asking.. When I tested 2 amps, it ranged around 2.2 amps.. I got no reading on the 10 amp charge... (seemed if it went over 10 amps it would have registered at least 10 amps and stopped. I got 5 amps on the 50 amp boost charge, but, you have to hear it making the noise and watch the meter needle on the charger itself.. Not sure if the meter would register 10, or 5 for 50amps, or 5 for 5 amps.. I am using the same meter you are using.. But, it was making a heck of a lot of noise on boost, and the reason I was testing it was,,, I was just about positive the 10 amp circuit was not working to begin with.. I really was not sure what I was doing, but, I am even more certain the 10 amp charging circuit does not work, and I am pretty sure that the boost is not working either.. Or, not working at 50 amps... Do you have a few minutes to comment? I did the video because I was pretty sure you could test one like this.. I found your video later after posting mine.. kzbin.info/www/bejne/e4TRgah8jreVgck Thanks for your videos.. I can almost always find something to help figure things out when I run into something strange.. Measuring amps is something I really have not done on DC.. Thanks.

[@MrChanPhysics]

If you run more than 10 Amps thru this type of meter it will blow its fuse. This particular meter uses a cheap $1 fuse you can buy at a hardware store. A professional grade Fluke meter uses a $10 fuse that you have to order from an electronics supplier (I've blown a couple testing automotive circuits). If you really need to measure current greater than 10 Amps, you'll need a clamp-on style ammeter, which uses an inductive sensor. It has jaws which clamp around the wire you want to test. You don't have to break the circuit to use it. The jaws are large and clumsy and are not useful for small circuits, but will work for car batteries and household wiring. .Make sure you get one which measures DC as well as AC current.

[@MarkThomas123]

Thanks for your comment.. As I suspected, the Boost was only putting out 5 amps, because I went back and tested the amp meter on a wall wart transformer 1 amp.. Worked still.. No blown fuse.. And,, I am sure the 10 amp circuit produces more than 10 amps, if it is like the 2 amp circuit, and it didn't blow a fuse either, so, it was not working either.. I have one of the Clamp On Meters, but AC only, and I have never used it for that.. I need to hook it up just to see how it works.. Ha.. Again.. Thanks for your knowledge.. Helps to know I'll just get a refund on this one.. Don't need a third charger doing the same thing.. I'll check on getting a clamp on AC/DC meter.. Something tells me they won't be cheap... Cheers.

[@joem1349]

I have the class record for blowing up 9 fuses in 3 hours

[@jacksonwoodard5967]

Thats a big ass AA battery

[@NicholasRiviera-Dr]

I think it’s actually a triple A battery. But your right, it’s a big ASS battery 👍

[@beeriyobarwaaqo372]

Can i use this way to test house hold current where the volt is 220v

[@LearnFunTvv]

A

[@mupcountry7153]

Why does the resistor have to be in the circuit?

[@loafandjug321]

How much fire is acceptable when performing this procedure?

[@leo-rq2ei]

Keep calm and don’t blow a fuse If you know where that comes from you get a 🍬

[@Icdezines]

So how do i know if ive blown my meter?..............kinda seen this video after atempting to the test. Hoping i didn’t destroy my meter

[@MrChanPhysics]

Put the meter in Voltage mode (see related video) and measure the voltage of a battery. A good AA, AAA, C, or D cell will read about 1.5 volts. If you get no reading, then you may have blown a fuse. Another way is to put it in Ohmmeter mode (see related video). Touch the 2 leads together; you should see a reading of less than 2 ohms. If the meter stays blank or reading is off scale, you've probably blown a fuse.

[@Icdezines]

MrChanPhysics thanks alot, i ended up just taking it apart and just testing the fuses for continuity. Learned my lesson for sure, read the instructions manual haha

[@omkarmhatre3565]

u r not measuring current u measures current loss...

[@boyfrom75]

Omkar Mhatre Yes, you are correct.. He is giving the wrong information..

[@vanwang110]

Thank you for being my physics teacher, Mr. Chan. May you Rest In Peace. ❤️

[@marianellaramirez3786]

@Van Wang Appreciate Video clip! Sorry for butting in, I would love your initial thoughts. Have you tried - Franaar Shining Shape Formula (just google it)? It is a great one of a kind guide for revealing the secret to repair your electronic devices minus the headache. Ive heard some amazing things about it and my m8 finally got amazing success with it.

[@RussellTeapot]

@@marianellaramirez3786 @Avery Callan you dudes are massive jerks.

[@labscience8271]

@Adrian HD He passed away in the M/V Conception dive boat accident on September 2, 2019. Read his channel's description. Rest in peace :(

[@fungames24]

Doesn't say why there is a resistor, or what size resistor, or what happens if there is no resistor. If I don't have a resistor and bulb, can I use a PC fan instead?

[@RaysBlueBasementWorkshop]

Wish I would have watched this before I fried my meter.DOOOOH!

[@AdamTheAd-vanc3d]

You and me both i killed some very hard to replace fuses.

[@alberoDiSpazio]

I have the same brand, strangly the fuse was intact. Upon closer look of the circuit I fried a tiny resistor (I could have re soldered).

[@furkan10ky]

Yeah guys I also have this problem. My multimeter just wanted to blow his fuse.

[@BocaRetroGames]

Same here hehhe

[@equallywrong]

lol. me too. my red wire got hot and the insulation melted. i caught it just before the meter fried.

[@lxc1227]

What is the resistor for? And what will happen to the multimeter if you don't connect a resistor in your example?

[@Hasan...]

If he had done without the resistor, more current would then flow (higher reading would be measured on the multimeter). But he used the resistor to protect the bulb, so it's likely that without the resistor, the high current and full voltage across the bulb would have blown the bulb.

[@wunderwaffeyt4077]

I feel very dumb about myself since I do it by attaching the leads on both poles. Thanks!

[@hipstarchild]

So are you telling me, I have to buy a bulb, a bulb holder and a resistor to measure the amps on a battery?...and how the heck do I know what resistor to use for all the different types of batteries....😖

[@ThankGodImBlack370]

You explained it to me in five minutes better than my professors did. Great video.

[@technicalsohil4063]

true

[@glenniie.forbes7527]

Lucky you, my professor didn't even explained it properly.

[@horacesawyer2487]

Great job. I'm sorry he passed away. Wanted to ask why its okay to put the multimeter probes on directly on a battery to measure voltage, but not in the amperage setting? Anyone welcome to chime in.

[@andycruz4261]

just learned in school, measure current going through, voltage across. Essentially when measuring voltage it’s okay considering you’re just measuring a potential different between two terminals. Thus measuring the open circuit voltage whilst putting a positive on hot, negative on ground. When measuring current, putting an anmeter in parallel to a source, you’re shorting it, like connecting a wire, infinite current passes through the short and which drains your battery because V=IR.

[@chovansatiroen4264]

I have a cheap multimeter with 20A fuse that can do 15 sec. max C test. A couple of times i have tested batteries under 20A (without a circuit) and the cable got hot, so i always do 4 sec test. My meter is still okay, your advice is also good

[@nuclearbox2]

Thanks for the lesson Mr Chan. I wish there were more but know there won't be. You sound like an wonderful teacher

[@GravityOfLife]

Thanks a lot. (Delightful to watch real english electronics, bcoz indian electronics have flooded youtube. Not good)

[@charlesjohnson-qc6hj]

More of them than us, world over that is.. And by far more in need of money.. So You-Tube pays per view, thus they flooded You-Tube with crap video's.. Most are not good or right, just in need of $7.23 per month from stupid-tube.. Sad..

[@s6a6n6d6m6a6n]

It's a Cen-Tech multimeter for crying out loud. They're free at Harbor Freight with any purchase.

[@nicholassanjayowo8955]

lmao I have like 2 or 3 of them.

[@dryan8377]

Everytime I'm at harbor freight I always pick up an extra one for like 3.99!

[@GDMHificationranpitc]

I broke 4 of those centech multimeters push leads lightly . Poor design.

[@Avalanche_Ride_92]

Funny I have one and I can't even find it in my household I wish I can get one for free

[@aredditchanneltopissoffapa6940]

Ha, well the guy in this video is literally a teacher at my school. Never underestimate the inadequate funding of the public education system.

[@welshpete12]

Excellent , well done the best I have seen on KZbin ! Thank you for posting. :-)

[@JoseongKaTsinoyTV]

Hi sir.....what is the Value of your Resistor use?

[@TemujinKhan8]

1:30 Ah shit. I just messed up my dad's multimeter. I was wondering what the point of the bulb was LOL. That was my fault, but maybe you can add a warning at the beginning for future, impatient watchers?

[@liquidmocofilmsllc4915]

All these KZbin video show how to measure current on a simple circuit. Most of the time you will be trying to measure current in a wire so it becomes somewhat of a mess. For example, if you want to measure the current on a lamp, you would have to cut the wire just to get to one wire to get in series to measure it. If you're lucky your lamp will have one of the double wires where all you have to do is separate the two wires and put a clamp meter on it. If you don't have a clamp meter then you will have to cut one of the wires or both because you won't know which is the hot wire. These guys show you how to measure it but it is no where near a real world way to measure. Get's even more complicated when you are dealing with a big circuit where everything is grounded to a common wire.

[@balasikoutdoor1594]

Nice video, new friend here! Then how to measure the battery capacity? Let's say on battery cover mentioned 3500mah, how to know if it is really 3500mah or not, using the multimeter.

[@TechsScience]

Isn't the current decreases when it passes through the resistor? This way we don't get the value of current of the battery

[@aristidepalermo3591]

Hey this is the best explanation ever on ampere measuring! Slow accurate and really newbie proof!

[@SirWatkinsProductions]

Thank you so much for this! My professor didn’t explain this well at all.

[@bharatganji9901]

Very Clear and useful, Thank you.

[@edwardmanuelpaderna3830]

hello Sir, can i do that in AC? I wanna know how much power my electric fan is consuming. thank you

[@jgwalling]

You can only check DC amps with this unit no AC.

[@DonaldDrennan]

I am installing a video doorbell. It says my transformer has to be min of 16 vAC 10 VA, but how do I measure that? The meter only seems to measure DC amps. Why is that? Thanks.

[@shawn7236]

This feller think's he's funny..buy me a new meter I have enough trouble keeping my meter going probably bought 100s of the dam thing's just always have the dam thing on the wrong settings and poof there's a nother meter up in smoke... Good video thanks for your advice bud.

[@t.rhawthorne9671]

Love your vids and the quizzes . That is a really awesome thing so a person can actually obtain the information your supplying. 👍👍 ⭐️⭐️⭐️⭐️⭐️

[@koollee]

How would u check currents (amperage) of a used Harbor Freight 25 watt Solar Panel with the same type of Ammeter .. is there a way to test the panel alone with no battery or load?

[@jacobuskai4594]

Hi, you mentioned it reads 0.15amps wht do other people say its actualy 1.5amps and otheres angain say its 150mAps?

[@micharogalewicz6249]

You've just answered my question :) I probably blown my fuse by now ^^ Thanks.

[@yurioliveira3846]

Those adds suck!. Do you also play them when it comes to save someone's life?Imagine if my son swallowed something and I need to act fast to avoid his death and the add is playing before?

[@adamsher4950]

Hi wat if I don't use a Resistor with the light ,, will that still work if I want to find the mAh of my 18650 lithium ion battery

[@Good-Enuff-Garage]

I love those big batteries but you can't find them any more

[@CarlosGarcia-ij4yg]

I would really like the comments from the 138 people who gave this a thumbs down!

[@ArcanePath360]

I've done this but it doesn't make a circuit and reads 0.00. Has the fuse blown previously with something I did long ago? I would have thought the mulitmeter just wouldn't work if that was the case By the way got the test correct at the end. EDIT: It is showing low battery on the multimeter... maybe that's why?

[@LearnFunTvv]

very nice tutorial.

[@JGC_TV]

does this multi meter need a battery? I do not get a display when its turned on

[@minskie]

It would me help if zoomed out so we could actually SEE the wiring!

[@QuickCookie]

Thanks for making this video!

[@worldbiss1831]

Excellent presentation and demonstration! By the way, is a Bulb necessary to be linked?

[@sraros]

Too late I guess, but anyway… Anything to draw current will do like a watt resistor, bulb or the actual circuit you want to test

[@sahalstudio799]

use another load such as PC fan and the Ampere reading will change; therefore the Ampere reading is not consistent so test is fault

[@midoabdo2190]

thanks I was closing to damage my multi-meter through attach the terminals to the power source (laptop charger)

[@joealva6711]

How can I measure a higher Amp capacity battery?

[@ignisGladius]

It is true. I blew up mines yesterday in a wall socket. It was wild 😂😂

[@rgraz4929]

So how do you measure the amps on a USB port? I have USB ports on a portable solar panel charger that I want to measure. I cut an old USB cable to access the wires with the leads. I have the same multimeter. Thanks. EDIT: found the answer although the guy has his leads backwards giving him a neg number. kzbin.info/www/bejne/hn6Qq6SHeLGHgpY

[@superdon1chw]

My amp meter won't complete circuit might that be the fuse inside ?

[@ikeo8666]

great.. but WHY

[@rangiroa100]

Hi MrChanPhysics. I have a stun gun that produces about 14,000 volt and I want to measure current on that gun. 1) Can I measure the current even though the multimeter can only handle 600 Volt ? Understand that I am measuring the current not the voltage because if I measure voltage it would burn out my fuse. 2) If it can be done then how would I measure the current in such a device ?

[@joeblowjohnny2297]

Hi , I'm trying to do an amperage test on my stanley Jumpit jumper starter pack . Jumpit Jump pack rated at 1000 peak battery amps and 500 instant starting power . ..... On my jump lead of my pack red & black clamp ....... would you walk me through the setting on my multimeter to read amperage out from my pack lead ? Greatly appreciated .... thanks

[@trealwilliams1563]

Should of said how it damages in the quick questionnaire!

[@michaeloyewole2583]

Don't do what?? 😮 Why do you think I'm here... Gotta find a new fuse now

[@-cancode-3701]

Can I touch the meter the the battery if the battery is a 9V battery?

[@mrEz87]

Silly newbie question, what if i want to work out the amps of the battery (not knowing what it is) so i can use this reading to work out my required resistor in the circuit?

[@kennys5819]

Where do the leads coming off the multi meter go, as they are not within the videos range? A picture is worth a thousand words, but only if the complete picture is shown. Thanks for the video.

[@haciendadad]

I did exactly what you said not to do. I just charged my 18650 battery and wanted to get a current capacity reading and I blew the fuses on both my digital multimeters and I just now purchased new ones from Amazon, I spent like $40 to get 4 fuses for both meters. Hence, why I am here.

[@kint5ugee]

No wonder I was getting a spark when trying to measure lol

[@SteveH-TN]

Thanks for sharing this video and information. It’s a great review as I initially studied Electronics in Lane Tech High School Chicago 1964. I am preparing to build a model train layout. I’m retired 74 years old. Appreciate your help though your videos!

[@Maher-]

Hi, i have a power supply 12v 20A connected to a step down convertor, i want to get a current of 5A using the convertor, like in your video where you used a lamp and resistor, what should i use so i can adjust the current from 20A to 5A? Thanks

[@zardiw]

FINALLY.....a Clear explanation for measuring Current/Amps ........Kudos!.............Z

[@stevenleigh3617]

Okay, so you are using a "conventional view" of current flow. Actually in d-c circuits does not the flow come from the negative side of the battery? Should the set up and schematic show this?

[@acatisfinetoo3018]

Okay...I was doing it the wrong way. So there has to be some resistence in the path else the current will be too much.