I have found that these exact meters are VERY nonlinear, especially as you go lower in voltages. Looks like they are good only for small ranges of voltage around where you calibrate them. The meters I had were off by more than a half volt at 2 volts if it was calibrated at 12 volts. If it was then calibrated at 2 volts, the 12 volts was off by a half volt. (this was using a separate supply for the meter supply) A simpson digital meter ($65) was within one digit from lower than .1 volt to 19.99 volts (full scale) Get what you pay for??
Ah, the exact reason why I was watching this video. I have one which is practically unusable for current measuring. Got replacement under warranty but the new one - although better - is so un linear it still is only just useful. Very cheap meter though, possibly constructed differently or with lesser parts.
One detail to be aware of with these meters is that the current is always measured on the "low side" of the circuit, therefore your load "ground" voltage will change depending on how much current is flowing through the shunt resistor. You might be able to measure on the "high side" by using a separate power supply for the meter (with a completely different ground), but then the voltmeter section will be useless since there is no common reference. In any case, these cheap meters are still quite useful for many applications. Thank you for sharing this video.
Hi, do you have a schematic for wiring a 50a 75mV shunt to volt/ammeter when using 4v to 30v power to supply meter but measuring load from another source?
Thank you for another good video. The TH-camr TheHWcave does a good series on adapting the PeaceFair brand of V/A meters... Particularly separating the meter's power supply from the DUT measurement. But, most of these meters are similar enough to employ his adaptations. Cheers!
hello, I have exactly the same voltmeter. only the ampere still shows 14, even if I only have 1 ampere set, where could the error be? I tried setting it with the potentiometer, no change thanks
Luckily the Chinese manufacturers usually provide a diagram. The wording can be a little confusing. I had one that referred to a reverse protection diode as a regurgitation diode .
You can buy complete multimeters for $5 which are pretty accurate for measuring voltage and current so I'm surprised these simple little meters are way less accurate while costing about the same.
@@IMSAIGuy I must be having a stupid moment because I really didn't get it. The voltmeter part yes, but Is that resistor that you show at 6 minutes into the recording representing the load that is being placed on the power supply, the thing being powered? So is the blue wire the one connected to the positive terminal on the case of the power supply so that current can be measured?
@@InteraliaTony the thing being powered is that resistor I have drawn at 6:00. if you connect + and- to the resistor then you are powering it. if you connect red and black to the resistor then you measure the voltage across the resistor. in order to measure current you need to insert an amp meter in series with the resistor. the amp meter is the blue/black wires. the current will flow through the resistor then into the blue wire, then through the amp meter (the shunt resistor in the meter) then out of the black wire.
@@IMSAIGuy That's the bit I wasn't sure of. So whatever you are supplying out of this, it is via the blue wire and back to black in order to measure current. That's great. Thanks for your time.
Very useful video. The documentation for such meters is notoriously bad. However, adjusting the current reading in your demo doesn't take into account the actual resistance, which I am guessing does not have 0% tolerance.
Given you show your fingers most of the time, my wife says you need to have your nails manicured for public display,, nail color is optional....LOL GREAT channel!
At the 4:33 mark you say "How are we going to hook this up?". You then cut out and come back after you have it hooked up and say, "I've hooked up this circuit.", referring to you hand drawn diagram, which you do in all your videos. But for those of us who are not as knowledgeable as you...we need to see the actual "how to" aspect. And you do this in most all your videos. Instead of putting out videos everyday, try doing vlogs where you actually put some thought and preparation into the video. Better camera work, review, revise, edit...isn't this what your're getting paid for by you viewers?
I have found that these exact meters are VERY nonlinear, especially as you go lower in voltages. Looks like they are good only for small ranges of voltage around where you calibrate them. The meters I had were off by more than a half volt at 2 volts if it was calibrated at 12 volts. If it was then calibrated at 2 volts, the 12 volts was off by a half volt. (this was using a separate supply for the meter supply) A simpson digital meter ($65) was within one digit from lower than .1 volt to 19.99 volts (full scale) Get what you pay for??
You're right on it my friend!
Ah, the exact reason why I was watching this video.
I have one which is practically unusable for current measuring. Got replacement under warranty but the new one - although better - is so un linear it still is only just useful.
Very cheap meter though, possibly constructed differently or with lesser parts.
Good job. You never know, until you teach. At least a day a week, help the kids trying to understand.
One detail to be aware of with these meters is that the current is always measured on the "low side" of the circuit, therefore your load "ground" voltage will change depending on how much current is flowing through the shunt resistor. You might be able to measure on the "high side" by using a separate power supply for the meter (with a completely different ground), but then the voltmeter section will be useless since there is no common reference. In any case, these cheap meters are still quite useful for many applications. Thank you for sharing this video.
that is true and these have common grounds so that makes it even more difficult.
This is a really helpful explanation. The mystery is gone, many thanks.
Hi, do you have a schematic for wiring a 50a 75mV shunt to volt/ammeter when using 4v to 30v power to supply meter but measuring load from another source?
Thank you for another good video. The TH-camr TheHWcave does a good series on adapting the PeaceFair brand of V/A meters... Particularly separating the meter's power supply from the DUT measurement. But, most of these meters are similar enough to employ his adaptations. Cheers!
hello, I have exactly the same voltmeter. only the ampere still shows 14, even if I only have 1 ampere set, where could the error be? I tried setting it with the potentiometer, no change thanks
Why do you have six wires coming in?
Luckily the Chinese manufacturers usually provide a diagram. The wording can be a little confusing. I had one that referred to a reverse protection diode as a regurgitation diode .
Nice, I'll call it that from now on
You can buy complete multimeters for $5 which are pretty accurate for measuring voltage and current so I'm surprised these simple little meters are way less accurate while costing about the same.
Hello, Could you make a video on how to connect this meter to 0-30V 3A Power supply kit EQKIT. I have both on order. Thank you.
Yes, that would be a useful video please.
Really? I show a diagram with a + wire and a - wire. the EQKIT has a + and a -. all power supplies are connected the same way
@@IMSAIGuy I must be having a stupid moment because I really didn't get it.
The voltmeter part yes, but Is that resistor that you show at 6 minutes into the recording representing the load that is being placed on the power supply, the thing being powered?
So is the blue wire the one connected to the positive terminal on the case of the power supply so that current can be measured?
@@InteraliaTony the thing being powered is that resistor I have drawn at 6:00. if you connect + and- to the resistor then you are powering it. if you connect red and black to the resistor then you measure the voltage across the resistor. in order to measure current you need to insert an amp meter in series with the resistor. the amp meter is the blue/black wires. the current will flow through the resistor then into the blue wire, then through the amp meter (the shunt resistor in the meter) then out of the black wire.
@@IMSAIGuy That's the bit I wasn't sure of. So whatever you are supplying out of this, it is via the blue wire and back to black in order to measure current.
That's great. Thanks for your time.
Why do you keep putting your hand over the diagram?
Very useful video. The documentation for such meters is notoriously bad. However, adjusting the current reading in your demo doesn't take into account the actual resistance, which I am guessing does not have 0% tolerance.
Given you show your fingers most of the time, my wife says you need to have your nails manicured for public display,, nail color is optional....LOL GREAT channel!
And shave your hairy fingers, or wear white gloves.
I like you just the way you are.
Do not buy this 99% not working i am telling this throgh my experience belive it dont belive up to you .
At the 4:33 mark you say "How are we going to hook this up?". You then cut out and come back after you have it hooked up and say, "I've hooked up this circuit.", referring to you hand drawn diagram, which you do in all your videos. But for those of us who are not as knowledgeable as you...we need to see the actual "how to" aspect. And you do this in most all your videos. Instead of putting out videos everyday, try doing vlogs where you actually put some thought and preparation into the video. Better camera work, review, revise, edit...isn't this what your're getting paid for by you viewers?
I agree 100%, the targeted viewers are those with basic knowledge , teaching newbies is a great skill , but only a few on youtube have what it takes.
oh shit, I've been paying him to do the thing you described. sorry.
Worthwhile video for this little display, but I agree with Glassy on quality, still; somewhat useable for non critical work. Thanks for the look.