Questions tagged [multimeter]
A multifunction measuring instrument used for measuring AC and DC voltage [V] and current [A] as well as resistance [Ω]. Many digital multimeters can also measure frequency [Hz], duty cycle [%], capacitance [F], temperature [°C], and/or other electrical or physical properties. Most are handheld; more expensive bench models are also available for applications requiring high precision.
938
questions
-1
votes
0
answers
73
views
Do I need a new multimeter, mine seems to be reading double what the DC volts should be
I was measuring my car battery, which works fine, as a test and my multimeter read 26 volts. Not sure if I'm reading it wrong, or if it just likes to double volts to make me happy. It's a GMT-312 from ...
0
votes
1
answer
49
views
How to Read Unipolar Square Waves on TRMS Multimeter
I'm trying to switch from reading my high-voltage unipolar square wave signal from a benchtop oscilloscope to a handheld multimeter, but I don't understand why my multimeter is giving the voltages it'...
0
votes
1
answer
89
views
Tinkercad multimeter doesn't work [closed]
Measuring voltage and current in Tinkercad, tell me why the voltage does not change when connected in series and the current in the circuit does not change when connected in parallel.
1
vote
0
answers
52
views
Current Measurement of a Brushless DC motor
I am trying to measure the current drawn by a brushless DC motor under load. This is to check if the propeller and the motor are a correct fit at the desired conditions (a range of rpm, say 0-8000rpm)....
1
vote
1
answer
52
views
While Identifying Transistor terminals with Multimeter diode mode, why does B-E junction yields a slightly higher forward voltage then B-C junction?
I've learned that multimeter produces a small current in the diode mode and then measures the voltage drop across the diode. So a high resistance should produce a high voltage difference.
Since ...
0
votes
0
answers
43
views
What would cause an AC multimeter reading to change if you reverse the probes?
I'm measuring the voltage in to a thermostat.
It's supposed to be AC.
When I measure wire1 and wire2 with black and red probes I get 0VAC
When I reverse the leads I get 1.8VAC
How can that even happen?...
2
votes
1
answer
86
views
How does a multimeter measure small voltages without being connected to ground?
I have a multimeter powered by a 9 volt battery.
I put it in AC voltage mode that allows me to measure 0.001 volts.
I have the red probe connected and the black probe (common / ground) detached.
When ...
0
votes
1
answer
48
views
No voltage difference between driven MOSFET gate and floating drain/source
I'm measuring the voltage of a discrete MOSFET using a multimeter. The gate is connected to the output of a logic circuitry, while drain and source are floating. The voltage difference between drain/...
0
votes
3
answers
79
views
Error measuring the voltage with a multimeter?
When testing my batteries, I wanted to test the battery on my multimeter without taking it out because I wouldn't have other new 9v batteries if I did. But, it just displayed a 1 (which means an error)...
3
votes
1
answer
180
views
Trying to understand (and mimic) the multimeter's interference with a circuit
I am trying to use a microcontroller to regulate the speed control of a sewing machine, rather than the foot pedal that normally serves this purpose. The pedal cord has 2 wires that connect it to the ...
0
votes
2
answers
71
views
Best tool for measuring short duration voltage/current?
I'm reusing a watering timer (Melnor 4-port) by removing the circuitry and using only the latching solenoid-driven valves with my own microcontroller. I'd like to determine exactly how much voltage/...
4
votes
3
answers
1k
views
Measuring the resistance of an LED -> getting conflicting values
I couldn't find the resistance values for an LED so I tried to measure it and ended up much more confused than before:
I have a plain (red) LED and initially I used a multimeter to measure the ...
0
votes
3
answers
66
views
UNI-T UT181A question: what is confidence interval used in the datasheet?
So the question is: https://www.batronix.com/pdf/uni-t/UT181A-Manual-English.pdf
The manual has
So if you are measuring perfect 50 Hz source you have resolution 0.001 Hz the values are in interval ...
0
votes
0
answers
58
views
Determining if a multimeter will damage ICs - How to confirm?
I’m looking for a straightforward way to determine if a particular multimeter will damage sensitive electronics such as ICs.
Specifically, let’s say I have a Fluke 117 multimeter and I am trying to ...
4
votes
2
answers
220
views
Capacitance on floating terminals of a multimeter
Why does a multimeter show some capacitance when its terminal are not connected to any capacitor?
My multimeter is showing 30pF. Does this imply that my multimeter is not calibrated properly or it is ...