@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.
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.
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!
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?
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.
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
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.
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.
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.
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.
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....😖
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.
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..
He's 100% Correct. If you go Directly to the Pos and Neg Post with the Multimeter? You'll blow The Multimeter... Why I'm Telling you this is? Because I FREAKING FORGOT!!! THAT'S WHY!!! LOLOLOL Which is why I came to this Video... I haven't tested Amps IN OVER 20 YEARS... They say If You Don't Stay working with Electronics? YOU'LL FORGET STUFF... I'm Proof "Positive" of that reminder. However, Luckily? I didn't blow The Multimeter. But The Wires caught hell... LOLOLOL!!! Great Video, and Thanks... I'll Be Bock...
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.
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?
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.
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?
Great question. In the circuit I have shown, the current is the same through all parts. There are no parallel branches. So your meter will read the same current after the light bulb or before the light bulb.
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 ?
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?
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
All these TH-cam 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.
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?
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.
Each circuit on a car is protected by a fuse. Each fuse is labeled with its maximum amperage. Almost every fuse in a car is at least 10 Amps, but the circuits generally draw much less current. The best use for the ammeter in a car is to find small "leaky" or "vampire" currents, meaning devices which are drawing current when you expect them to be off. A lot of electronics in modern cars (stereo, alarm systems, door locks) stay alive all the time and draw a small amount of current (10s of milliamps). So it can be useful to use the ammeter to find vampires if your battery is dying rapidly. For example, I had a car which drained the battery in a few days. It turned out that there was a small current drain in the power seat memory. One of the buttons was stuck "on" so it continued to draw current and kill the battery. Using the ammeter on a powered-on device like headlamps or stereo is very risky since they will likely draw more than 10 Amps and blow the multimeter's fuse. It is less risky to use a voltmeter at the device to see if it is receiving power. See my video "Measuring Voltage with a Digital Multimeter".
Great vid - thanks - looks like I have to replace my fuse now, lol. I usually only deal with voltage/resistance for diagnosing car electronics, but I inherited a battery charger and wanted to test if it worked. Multimeter only supports 10A current, battery charger had a 2A (12v DC) option I wanted to test. I hooked it up in parallel to the battery on the loaded circuit, it sparked (the probes arched) a little when I connected the probes, no good reading, then unloaded, tried again, same results, now no sparks, lmao. Hopefully can replace that fuse. Should have watched this video first!!! I'll replace the fuse and try it in series this time... For the 20A and 60A settings, I have to buy a new multimeter I guess. Any easier way to validate these? Seems most multimeters I find only go up to 10A on the current.. EDIT: As a side note, if I test the voltage on the loaded circuit it's ~12.85 (typical charging output on a 12v auto DC circuit), but if I don't load it (if I test both alligator clamps that you'd connect to the battery) I only get ~9v. Is this normal? I would have expected to see 12.85 with or without a load. Thoughts?
To measure currents greater than 10 Amps, you will probably need an inductive-clamp type meter. It has a sensor that clamps around one wire and uses magnetic field to measure current. The clamp units do not require you to break the circuit, but the clamp can be clumsy to use in tight spaces. Make sure the one you use has capability of measuring both DC as AC (some only measure AC).
Hi MrChanPhysics. I just watched your video. it looks great for me without any electricity or electronics background. I followed your tutorial piece by piece, setting exactly as you did BUT my multimeter read (1.) I am using 3AA batteries to operated a 3-led diodes of a PIR sensor light and I need to know the current so that I replace the batteries with a mobile telephone charger using the USB. Am I doing something wrong pls?
If the meter reads "1. " it probably means it is set to a scale too low to display the current. Try starting with the 10 Amp setting.. This may require you to move the red test lead to a different socket as I have shown in the video.
Good job! But what I don't know now, is how to do this (measuring current) off of a solar panel. Could you tell me pls? I have searched and couldn't see your video on this. Thank you in advance.
First, a warning. Do not attempt this with a large solar array. Some of them put out many amps at several hundred volts. This type of system is extremely hazardous and not for amateurs. I will assume you are trying to measure a small panel, up to 12 V and a few amps. To do it with this type of meter you will have to disconnect the positive output wire that goes from the panel to the load. Configure the meter for the 10 A setting (assuming your panel puts out less than 10A), then connect the red (+) probe to the panel output, and the black (-) probe to the load wire you disconnected from the panel. The load must be connected to get a useful current reading. Be careful with this much current. A better type of meter for measuring high power circuits is a clamp-on meter, which clamps around a single wire and does not require breaking the circuit or touching any live wires. Make sure you get one that measure DC current if you want to work with solar panels.
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?
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
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.
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!
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?
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?
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.
Thank you for being my physics teacher, Mr. Chan. May you Rest In Peace. ❤️
@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.
@@marianellaramirez3786 @Avery Callan you dudes are massive jerks.
@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 :(
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.
You explained it to me in five minutes better than my professors did. Great video.
true
Lucky you, my professor didn't even explained it properly.
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!
Thanks for the lesson Mr Chan. I wish there were more but know there won't be. You sound like an wonderful teacher
How much fire is acceptable when performing this procedure?
Hey this is the best explanation ever on ampere measuring! Slow accurate and really newbie proof!
FINALLY.....a Clear explanation for measuring Current/Amps ........Kudos!.............Z
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?
Simple, quick, and useful. Thank you😊.
Thank you so much :) I never thought it should be connected in series to the circuit.
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.
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
Excellent , well done the best I have seen on TH-cam ! Thank you for posting. :-)
Love your vids and the quizzes . That is a really awesome thing so a person can actually obtain the information your supplying. 👍👍 ⭐️⭐️⭐️⭐️⭐️
Wish I would have watched this before I fried my meter.DOOOOH!
You and me both i killed some very hard to replace fuses.
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).
Yeah guys I also have this problem. My multimeter just wanted to blow his fuse.
Same here hehhe
lol. me too. my red wire got hot and the insulation melted. i caught it just before the meter fried.
What is the resistor for? And what will happen to the multimeter if you don't connect a resistor in your example?
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.
I am glad I found this video. I may or may not have blown a fuse because of my ignorance.
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.
Very Clear and useful, Thank you.
I understood before I finished watching..thx man
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.
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.
Thanks Bro! Your video tutorial is well explained and I just learned something new.
Thank you! I watched that video after I connected meter dirrectly to the source👌
Glad I watch your video first. Thanks for the info.
You've just answered my question :) I probably blown my fuse by now ^^ Thanks.
Great explanation. Short, crisp, and to the point. Thank you.
How much fire is acceptable when performing this procedure?
very concise and to the point, thank you
Thanks you dumbed it down perfectly for me ....thanks big
Thank you very much. I've been looking for this video for a while
I feel very dumb about myself since I do it by attaching the leads on both poles. Thanks!
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....😖
Great Tips Good Stuff Very Clear Understanding 👍 Thanks!
Hi sir.....what is the Value of your Resistor use?
Now I get it....thanks for making it easy to understand 👍
Very very good tutorial. Thumbs up!
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.
Thank you.. It seems D) would actually measure the current through the resistor, but alter the circuit by shorting through the bulb.🙂
Thanks for making this video!
Thanks for a great demo.
thanks saved me some time!
Thanks a lot. (Delightful to watch real english electronics, bcoz indian electronics have flooded youtube. Not good)
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..
Finally a simple easy to understand explanation.
How much fire is acceptable when performing this procedure?
Excellent presentation and demonstration! By the way, is a Bulb necessary to be linked?
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
Thank You... Just the instruction I needed.
Isn't the current decreases when it passes through the resistor?
This way we don't get the value of current of the battery
He's 100% Correct. If you go Directly to the Pos and Neg Post with the Multimeter? You'll blow The Multimeter... Why I'm Telling you this is? Because I FREAKING FORGOT!!! THAT'S WHY!!! LOLOLOL Which is why I came to this Video... I haven't tested Amps IN OVER 20 YEARS... They say If You Don't Stay working with Electronics? YOU'LL FORGET STUFF...
I'm Proof "Positive" of that reminder. However, Luckily? I didn't blow The Multimeter. But The Wires caught hell... LOLOLOL!!! Great Video, and Thanks... I'll Be Bock...
very nice tutorial.
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.
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?
best explanation, thanks you!
This really helped me.. thank u very much
Thanks. Just look this up. Very helpful video. 👍👍
hello Sir, can i do that in AC? I wanna know how much power my electric fan is consuming. thank you
Great tutorial. Thanks!
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.
Won't the current drop because of the load or Will it show the correct amps of the battery with load connected..?
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?
Strait!!! I subscribe!!! I like how this video is ran.
It is true. I blew up mines yesterday in a wall socket. It was wild 😂😂
Great question. In the circuit I have shown, the current is the same through all parts. There are no parallel branches. So your meter will read the same current after the light bulb or before the light bulb.
Omg best explanation ever tomorrow I have exam and this helped me so much thx
How much fire is acceptable when performing this procedure?
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 ?
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?
does this multi meter need a battery? I do not get a display when its turned on
How do we measure peak amps? How do we determine how much of a load the battery can handle? Larger watt bulbs?
This test shows the positive line used. Can the negative line be used?
Thanks I have the same metter this is so helpful thanks alot
Thanks
Great work
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
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
All these TH-cam 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.
thanks I was closing to damage my multi-meter through attach the terminals to the power source (laptop charger)
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?
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.
Great info, thanks.So when measuring automotive devices I should know roughly how many amps the part puts out first?
Each circuit on a car is protected by a fuse. Each fuse is labeled with its maximum amperage. Almost every fuse in a car is at least 10 Amps, but the circuits generally draw much less current. The best use for the ammeter in a car is to find small "leaky" or "vampire" currents, meaning devices which are drawing current when you expect them to be off. A lot of electronics in modern cars (stereo, alarm systems, door locks) stay alive all the time and draw a small amount of current (10s of milliamps). So it can be useful to use the ammeter to find vampires if your battery is dying rapidly. For example, I had a car which drained the battery in a few days. It turned out that there was a small current drain in the power seat memory. One of the buttons was stuck "on" so it continued to draw current and kill the battery.
Using the ammeter on a powered-on device like headlamps or stereo is very risky since they will likely draw more than 10 Amps and blow the multimeter's fuse. It is less risky to use a voltmeter at the device to see if it is receiving power. See my video "Measuring Voltage with a Digital Multimeter".
Hi, you mentioned it reads 0.15amps wht do other people say its actualy 1.5amps and otheres angain say its 150mAps?
I was just about to do the dumb thing, but the thought i should look up if i'm doing it right
Excellent video..👌👌
Will the battery be damaged if u connect direct to battery from leads?
Nice informative video thanks.
What if it’s a 12 volt battery do you move the settings to 20m and where do the leads go
hello sir, if i connect the multimeter after the led will the reading be different?
My amp meter won't complete circuit might that be the fuse inside ?
Great vid - thanks - looks like I have to replace my fuse now, lol.
I usually only deal with voltage/resistance for diagnosing car electronics, but I inherited a battery charger and wanted to test if it worked. Multimeter only supports 10A current, battery charger had a 2A (12v DC) option I wanted to test. I hooked it up in parallel to the battery on the loaded circuit, it sparked (the probes arched) a little when I connected the probes, no good reading, then unloaded, tried again, same results, now no sparks, lmao. Hopefully can replace that fuse. Should have watched this video first!!!
I'll replace the fuse and try it in series this time... For the 20A and 60A settings, I have to buy a new multimeter I guess. Any easier way to validate these? Seems most multimeters I find only go up to 10A on the current..
EDIT:
As a side note, if I test the voltage on the loaded circuit it's ~12.85 (typical charging output on a 12v auto DC circuit), but if I don't load it (if I test both alligator clamps that you'd connect to the battery) I only get ~9v. Is this normal? I would have expected to see 12.85 with or without a load. Thoughts?
To measure currents greater than 10 Amps, you will probably need an inductive-clamp type meter. It has a sensor that clamps around one wire and uses magnetic field to measure current. The clamp units do not require you to break the circuit, but the clamp can be clumsy to use in tight spaces. Make sure the one you use has capability of measuring both DC as AC (some only measure AC).
very helpful video thanks !
Hi MrChanPhysics. I just watched your video. it looks great for me without any electricity or electronics background. I followed your tutorial piece by piece, setting exactly as you did BUT my multimeter read (1.) I am using 3AA batteries to operated a 3-led diodes of a PIR sensor light and I need to know the current so that I replace the batteries with a mobile telephone charger using the USB. Am I doing something wrong pls?
If the meter reads "1. " it probably means it is set to a scale too low to display the current. Try starting with the 10 Amp setting.. This may require you to move the red test lead to a different socket as I have shown in the video.
Good job! But what I don't know now, is how to do this (measuring current) off of a solar panel. Could you tell me pls? I have searched and couldn't see your video on this. Thank you in advance.
First, a warning. Do not attempt this with a large solar array. Some of them put out many amps at several hundred volts. This type of system is extremely hazardous and not for amateurs. I will assume you are trying to measure a small panel, up to 12 V and a few amps. To do it with this type of meter you will have to disconnect the positive output wire that goes from the panel to the load. Configure the meter for the 10 A setting (assuming your panel puts out less than 10A), then connect the red (+) probe to the panel output, and the black (-) probe to the load wire you disconnected from the panel. The load must be connected to get a useful current reading. Be careful with this much current.
A better type of meter for measuring high power circuits is a clamp-on meter, which clamps around a single wire and does not require breaking the circuit or touching any live wires. Make sure you get one that measure DC current if you want to work with solar panels.
Does it matter if you connect it before our after whatever is drawing power??
Can I touch the meter the the battery if the battery is a 9V battery?
Love your vids
how about measureing current not on a circuit ? i.e. generator;; motor..back up battery .. etc,
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?
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
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.
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!
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?
Just measures as negative if you reverse the leads.
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?
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.
You the man !
If thats the case how can i measure my battary amp since its lebal is peeled off and missing?!
You can only check DC amps with this unit no AC.