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.
Thank you for another good video. The RU-vidr 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!
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.
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 .
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
@@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?
