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Questions tagged [multimeter]

Single universal measurement device that can be used to measure voltage [V] and current [A] in both AC and DC, as well as resistance [Ω]. Often many other ranges are available like frequency [Hz], duty cycle [%], capacity [F], ... Most are hand held, some more expensive ones come as a bench model.

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80 views

Is this transformer working?

I found this transformer and I am not sure if it is working. I am confused with the multimeter readings. For example: when I am using the buzzer option to check the connectivity it buzzes when I ...
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1answer
70 views

Seared my circuit while checking voltage [on hold]

I was attempting to diagnose a problem with my dvd player as I was not getting any power, I wanted to use my multi-meter to see where the circuit was shorting out, I set the setting on the multi-meter ...
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1answer
53 views

Measuring USB power adapter quality using multimeter

I have heard horror stories about poor quality USB power adapter. I have a collection of no less than 20 USB power adapters, most are from cell phone manufacturers and some from small projects. I ...
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4answers
1k views

Why do LCR meter manufacturers give the details of measurement frequency to us?

When you want to purchase a DMM, more probably you don't see at what frequency the DMM you considered would work, but in the situation you're considering to purchase an LCR meter, manufacturers give ...
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1answer
39 views

Continuity testing - Why does swapping DMM probes give differing results?

Continuity query - Can anyone explain this? Circuit is a simple 12v DC, wired as follows -battery pos to bulb to spst switch back to battery earth. Testing with DMM in the dedicated audible ...
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0answers
70 views

Darlington Transistor TIP142 same type but different values

I have a bunch of Darlington NPN Transistors TIP142 that are removed from two separate identical boards. The 1st one have the TO−218 CASE (left side of the image) and the 2nd the TO−247 CASE (right ...
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2answers
53 views

CB blew when trying to measure the current using multi meter. What went wrong?

I set my multimeter like this. Plug the black lead to the short tab of NEMA5-15 receptacle first and the red lead to the long tab. The moment I put the red lead in, there was a big spark. The ...
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2answers
112 views

Can I use any HV Probe for a Voltmeter/Ampmeter gauge?

I purchased the multimeter pictured below for a high voltage power supply I'm working on. It's rated for 100V DC and 10A, but I hope to measure several thousand volts. Is it possible to use a HV ...
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3answers
86 views

how to avoid brownout caused by a multimeter on esp32

I am using the VOLTCRAFT VC130 multimeter for measurement of current through my esp32. The microcontroller runs perfectly with two 1.5V batteries(~3V as read by multimeter in voltage mode). But when I ...
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3answers
98 views

What is line to line voltage supposed to meter at?

I'm pretty new to this but I know that in three phase power, when I'm metering line to line its usually at 208V, but I've been told that line to line meters at 240V. I don't know what would cause for ...
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3answers
805 views

Is a multimeter with 1,200,000 counts actually a 6½ digit multimeter?

The Keysight 34465A Digital Multimeter is specified as a 6½ digit multimeter. However, the meter is actually a 1,200,000 counts meter, since the meter wraps at 1.2, so if measuring a 1.19 kOhm ...
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1answer
59 views

How can I make my measurements of full-wave rectified AC using an A/D match a Fluke meter on its DC range?

I am trying to measure the DC voltage of a full-wave rectified 60Hz AC signal using an A/D and have it match what a Fluke meter reads on its DC scale. My current approach is to take as many (16 bit) ...
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1answer
62 views

Which current can a multimeter measure for an indefinite duration?

It might vary, depending on multimeter. But if on a multimeter, there is printed "10A for 30sec. MAX every 15 min" or "20A for 15 sec (time unspecified)", below which approximate threshold is the ...
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0answers
40 views

What is the difference between voltage across battery and voltage across a resistor?

simulate this circuit – Schematic created using CircuitLab I am doing an experiment for a lab and I am confused as to what they are asking. They ask to measure the voltage across the battery, ...
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3answers
992 views

Measuring a small resistance, ~0.001 ohm

I have a low resistance resistor that I would like to use to measure the current through another circuit, but first I need to accurately determine its resistance. Its data sheet says it is 0.001 ohm +...
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1answer
43 views

Trouble testing capacitor

I have a Radio Shack DMM (Cat #2200811). I'm trying to test a 100uf 16v electrolytic capacitor on the auto range capacitance setting. I tried it with a 30uf 160v cap. and it worked (measured as 29uf)...
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1answer
100 views

Is it safe to use my multimeter to test UK wall outlet voltage?

From the question it should be clear I'm no expert. Just want to learn. I have a digital multimeter. If I connect the multimeter to hot+ground & hot+neutral on the 240v 50hz (max ~30A) AC wall ...
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0answers
52 views

Did my multimeter corrupt the ROM/EEPROM in my TV remote?

So I got my first multimeter today... I understand the basics needed, but maybe I was a bit overzealous... My TV remote has 6 pins sticking out next to where the batteries go. I assume these are for ...
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0answers
27 views

Measuring MOSFET Voltages not adding up. Vgs /= GNDs - GNDg

I am measuring a power mosfet with a multimeter. The voltage at the source with respect to GND is ~291V. The voltage at the drain with respect to GND is ~16V. The P-type mosfet is rated for 250V, so I'...
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1answer
42 views

How to fix 4AA battery pack holder

I have a battery pack holder. I have tested the batteries with my multi meter. It appears that the ground and power wires on my pack holder are not working. Does this mean that the wires are not ...
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3answers
95 views

How does the multimeter measure the voltage? [closed]

I am using the fluke 88 multimeter and I know this digital multimeter measure the voltage drops when measuring the current(ampere) in a series connection because the current flows into the multimeter(...
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4answers
107 views

Multimeter, outlet and a Spark: the question of simple Voltage measurement

So I got a TekPower TP4000ZC MultiMeter. (Image source) It has COM port and two red ports: V-Ohm-etc. set at 600V Max and 500mA Max Fused 10A red fused port. Unlike other multimeters, there are no ...
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0answers
42 views

Multimeter ammeter resistance increasing

Recently I have been doing some measurements with a multimeter on some new transformers for my company. Lately I have noticed the resistance of the multimeter in current mode (ammeter) has increased. ...
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2answers
97 views

Why do different resistors of the same power rating burn out / not burn out?

I have a circuit board for a small LED light, which comes with an annoying strobe mode. To disable this I have found that I can wire a resistor from a pin on a chip to ground and the LED will stay in ...
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0answers
91 views

Voltmeter showing incorrect value when reading 12V battery

I'm building a battery box from a 75 AH deep cycle AGM battery, I have installed a voltmeter, but for some reason it doesn't display the correct value. I measured the volt with a multimeter directly ...
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0answers
69 views

Testing function generator with multimeter

I bought a used signal generator today. I want to check if it works with no problem but I don't have access to an oscilloscope right now. I have a multimeter that can measure dc and ac voltage and ...
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1answer
84 views

Using Voltage Regulator (9v to 5v)

I’m trying to ‘hack’ a LED Fire-effect light bulb to work on a 9v battery. Using a multimeter I can see that the bulb converts mains voltage to 5v. I’ve got my hands on a 9v-to-5v voltage regulator ...
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1answer
53 views

How to know voltage used on a data bus?

How do you find out what voltage is being used on a data bus for the high signal? On a small electronics I guess you can assume it will be 3.3v or 5v but what about other circuits, say in a car or on ...
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1answer
41 views

Discriminate MOS from BJT easily

I have a transistor for which no datasheet is available the transistor is supposed to be NPN (which implies BJT). (BD247C-Transistor-NPN, 100V 25A, 120W in TO220) how can I find out easily if it's ...
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2answers
69 views

Why does this resistor network simulate differently from the physical package?

I am trying to simulate a Bourns 4310R-R2R-104 dual terminator 104 circuit resistor network. According to the datasheet, the circuit looks like this: When I read the resistance between pin 1 and pin ...
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1answer
113 views

How to test transistor with Built-In Biasing Resistors

On a GPS device pcb, I found a small smd component that is marked as "22p V2". I found (tell me if I am wrong here) that it is a transistor like DDTA144WCA-7-F SOT-23-3 package, with built in biasing ...
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9answers
3k views

In which scenarios is it important to measure microampere?

With the situation of finding a new multimeter, I found myself lost to the number of available devices on the market. For sure, to find the most suitable device I have to set some requirements. While ...
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0answers
29 views

Measuring (I vs. t) and (V vs. t) during welding

I am welding two plates using TIG machine welding. Before start welding I adjust the current value (i.e. 200 A) and voltage is 20 V. But, the real values of current and voltage will be changed when ...
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0answers
35 views

Mistakenly performed continuity test when power is on

I forgot to turn off the power of system before I did some continuity test using a multimeter. Basically an +-V dual supply was powering a transducer. Transducer was outputting very small offset like ...
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1answer
61 views

Any way to use external power for multi-meter instead of the 9V battery?

I have read discussions on NOT to use external power, say an ac adapter, instead of the 9V battery. But what if I mostly do is to test for continuity, would it be acceptable in such case? What other ...
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1answer
221 views

Why do I measure 5V in this circuit when I should measure 3.3V?

I have an audio processor board that has a 5V -> 3.3V LDO. For some very strange reason, when I measure the voltage of the output of the LDO, I read 5 instead of 3.3V -- which by the way is a lethal ...
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2answers
92 views

My multimeter probes are too big to measure a laptop battery

I'm having laptop battery problems, and the hardware manual gave diagnostic instructions involving measuring the voltage in the battery. So I bought a multimeter (never used one before in my life) and ...
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1answer
65 views

Can you determine RGB pinouts with a multi meter?

I have a Swiftech Apogee XL2 that has an addressable LED inside it. I want to connect it to my other RGB setups but I need to know the pin signals and voltage of the LED. I have a multi-meter at the ...
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2answers
750 views

Multimeter true RMS [closed]

I'm just getting started with electronics (arduinos and friends) and I would like to get a multimeter. As far as I can tell arduinos and any other logic chips and circuits I'm gonna be using are using ...
0
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1answer
41 views

Multimeter temperature coefficient - Specified accuracy

I want to calculate the temperature coefficient for a digital multimeter. The datasheet I read it is calculated as: 0.1*(specified accuracy)/°C (<18°C or >28°C) Do you know what specified ...
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2answers
1k views

Test a transistor with a multimeter

I used the guide at https://vetco.net/blog/test-a-transistor-with-a-multimeter/2017-05-04-12-25-37-07 to test a transistor with my DMM. The NPN transistor I used to test is the "mospec tip130 No11D" ...
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2answers
127 views

True value of skin resistance

When I googled about skin resistance I find people mentioning values as low as 500ohm but usually around 10-100kohm. When i measured the resistance of my own skin by putting the probes on the inner ...
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2answers
90 views

Please Critique my HV Measuring Setup

At the moment, I am working on a device that will be able to measure the out put of a high voltage DC power source with an adjustable output of 0 - -60 kVDC and 0-15 mA (the typical power being 600 ...
5
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3answers
596 views

High Voltage Measuring System

I am looking to set up a voltage-measuring system for the output of a recently purchased HV power source. The source supplies around 0 - -60 kV DC and 10 mA to my load. Unfortunately, the source does ...
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3answers
198 views

Tool for Measuring Low Current

I currently have a power supply that will be able to supply around -60 kV DC and 10 mA under the load that I will be hooking up to it. However, the internal resistance of the load will fluctuate and ...
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0answers
25 views

LED COB, Meter reading voltage on isolated backplane when powered

I'm setting up a project lamp for my workbench using one of these LED COB I checked for continuity while doing a test setup, the live and neutral connectors are isolated from each other, and the ...
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1answer
126 views

Did I ruin my multimeter with a current measurement?

I am trying to do a current measurement. Probably I accidentally put it it parallel instead of in series. What I tried before/after that (cannot remember exactly putting it parallel but might have ...
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2answers
70 views

Getting Rid of Annoying Buzzing Sound from Multimeter

my multimeter has been bugging me with this buzzing sound that turns on and off while I'm using it. I think it has something to do with its autoranging feature, but I couldn't find the manual for this ...
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3answers
88 views

How to know when to tune up a digital multimeter?

I have bought the multimeter with temperature measurement from the following website: http://futurlec.com/Multimeters.shtml Currently I use the voltage, resistance, and short circuit detection ...
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1answer
169 views

How to add a LED to a Multimeter for use it with the buzzer in continuity testing?

I want to add a notification LED to my digital multimeter which i need to glow with the multimeter`s inbuilt speaker (piezo/buzzer/beeper) while in Continuity testing mode. MM Model : DT830D If i ...