Questions tagged [meter]

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1answer
109 views

How do older-style meters still in use keep their clocks synced?

How accurate must the real time clock of an electricity meter be? Apologies if this is more a legal question than an electrical one. I am particularly interested in Western Europe but also interested ...
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0answers
58 views

How to test if a domestic 3 phase power company meter is reading wrong?

BACKGROUND: Domestic 3 phase 220VAC supply in Thailand. Power company meter is 4 wire GE 3 phase 15A/45A. Massive power bills when mains breakers were turned off (back in home country for 9 months ...
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1answer
49 views

Access meter readings remotely

I am not an expert on interfaces and communication protocols and I am trying to get data from several meters to read it remotely. The meters have an M-Bus interface to a Data-Logger. The Data-Logger ...
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0answers
51 views

Increase voltage level to frequency meter

I have a frequency meter that requires a minimum signal voltage of 10VDC to read the frequency. My output level is only about 2.5-3VDC. What is the easiest way I can amplify my signal voltage to ...
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1answer
91 views

Help understand the role of an inductor and its value (educated guess)

This circuit is a part of a field strength meter circuit in an old magazine, the value of inductor J1 is unknown (due to a print error in the magazine.) The circuit works like this: With S1 open and ...
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1answer
45 views

How to calculate energy added to grid using active and reactive power?

I have recently installed solar system that adds energy to the grid. My utility company has installed bi-directional meter at my place to record energy consumed as well as energy added to the grid. ...
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2answers
74 views

How does power factor show itself in this data from sensor readings?

Suppose I have a single phase system and I have a sensor attached to to measure both voltage and current. The sensor samples for 50 kHz and the data is saved to a file. When we then graph out the file ...
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5answers
3k views

Why is this meter giving different readings depending on its orientation?

My newly-restored (re-capped) 1950s vacuum tube voltmeter is now operational...but there's one further issue. The meter gives correct readings when lying on its back, but when oriented vertically- as ...
3
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1answer
246 views

Clamp meter readings

I have a Uni-t UT210e clamp meter. I noticed that when measuring AC current, the reading varies if I move the wire inside the clamp. The measured value displayed on the meter is higher when the wire ...
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1answer
47 views

Need diagnostic tips for ancient Sanwa YX-360TRe

I need to fix my sentimental value Sanwa YX-360TRe analog meter. It was bought in 1995, slightly used. It can correctly give DC voltage reading. The problem is, it cannot zero-ohm adjust in all ranges,...
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1answer
87 views

sensing dc current in wires for 12V systems [closed]

Recently I bought an ACS712 5A module. I hoped to make a current sensing meter to find which wire in my car loom is drawing current much like clamp meters sense large a.c. currents in wires. Only I ...
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0answers
94 views

How to correctly bond two 200 amp main panels on a 400 amp service

I currently have a 200 amp service with a single 200 amp meter. That meter feeds a 200 amp main panel on the other side of the wall that the meter is mounted to (think standard residential ...
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1answer
22 views

When using a Primera-Line Wattage and Current Meter, is it showing AC or DC measurements?

I am new to the electrical engineering stuff and am looking for some guidance. I'm going to be designing a off-grid power system for some devices. So I will need to get the power measurements from ...
26
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2answers
2k views

What do the line-and-circle symbols mean on these electric meters?

I was looking at an electrical installation and came across unfamiliar symbols on the front of a pair of meters. These are from three-phase 240v meters running on a timed system. One each for peak/off-...
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0answers
215 views

Sound level meter using a microphone with ADC

I'm working with STM32F4, MAX4466 amplifier and a condenser microphone. In other words, Adafruit 1063. I want to get the sound level in dB unit. I know: Microphone sensitivity: 0.0063096 V/Pa ...
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3answers
159 views

Drive a VU meter negative from "0dB" to show compression with VCA compressor

I have a simple VCA compressor based around the THAT 2180 VCA. http://www.thatcorp.com/datashts/dn115.pdf I would like to use a standard "VU meter" to indicate compression, but work in "...
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2answers
59 views

Add second sensing circuit to already wired reed switch

In my house I have a mechanical water meter with a 2 wire reed switch that sends a pulse every 10 liters to (I suppose) an electronic meter to witch I don't have access. I'd like to connect a circuit ...
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0answers
84 views

Where are the sensors of the EMF/RF meter on the circuit board?

In the attached photo you can see the PCB of a simple EMF/RF meter. This meter shows, at the same time, the values of the electric field, magnetic field, and power density (see small illustration on ...
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1answer
315 views

Energy meter neutral current measurement

I was reviewing an energy meter specification and I came across neutral current measurement. What is the importance of neutral current measurement in an energy meter for three phase power supply? I ...
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2answers
42 views

How do moving iron meters work on AC current? [duplicate]

I read on the internet that an iron vane is attracted to a coil and the vanr is attached to a pointer. Thus we get the reading. The article also said that we can measure both AC and DC using it. How ...
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0answers
111 views

What is 5th Jaw?

I just purchased this meter box and need to make sure it will work fine as a standard 240 volt residential meter. I noticed it says 5th Jaw in the title. What is ...
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1answer
98 views

What current transformer do I need?

I have a Prime Instruments model 60-579 watt meter for a gas generator. It has a scale of 0 to 3750 watts and is marked 125 volts. So its for a 30 amp circuit. I have searched extensively for the ...
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2answers
129 views

Smart meters setup

I want to monitor my exported solar energy. The solar inverter (L1+N) is already connected to my mains power meter (grid) through a smart meter (SDM630), which in return, transmit RS485 data back to ...
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2answers
59 views

Low amplitude curent measurement [closed]

Can someone from their experience share part number for equipment for low current measurement. The current to be measured is less than 6nA. I am aware that I can connect a resistor and by measuring ...
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1answer
183 views

Power factor down after solar connection

We installed solar plant in factory. After that power factor goes down to 0.16. Normally it never goes below 0.85 in history even if we keep APFC off. We always maintained it to 0.99. Note - Main ...
1
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1answer
293 views

2-wire vs. 3-wire watt-hour meter?

A kWh meter (electromechanical induction meter) is installed in front of each room in our apartment to measure the electricity usage of each room. Each room has its own breaker box to set up the 110-V ...
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0answers
33 views

Is there a reliable way to read an in-circuit capacitor? [duplicate]

Is there a reliable way to read an in-circuit capacitor? I have a PCB-type ESR meter with a zero-force insertion socket that works for components, but do not have a meter that was designed to read ...
1
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0answers
114 views

Will a lower resistance potentiometer improve a panel meter scale reading?

I have an analogue tacho/RPM panel meter on an auto distributor tester, c1950s. This is not the original meter. It has two scales 0 - 6000 rpm and 0 - 1000 rpm, with a toggle switch between the two. ...
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5answers
413 views

Can I connect this meter to 220vac?

Can I connect this analog meter directly to 220VAC without any additional components? And what is the meaning of writing on the right?
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3answers
1k views

In below picture, is ammeter AC or DC? Is there direction for connection with load in series? If so what if I connect in wrong direction?

This is front view of analog ammeter. There are 2 terminals with nut and bolt behind it but nothing marked neither plus nor minus.
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1answer
81 views

How Power measured by Meters is affected by Harmonics?

I want to know how energy meters (Electro-static or electronic) measure Energy (let's assume power, ignore time) when there are harmonics present. I know what are harmonics, how are they generated ...
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2answers
208 views

Multi-Conductor DC Clamp Meter

Does a multi-conductor DC clamp meter exist? Possibly using hall effect sensors in a specific orientation? I typically work with 24-28V DC solenoids valves & pressure transducers with 2 and 4-...
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0answers
104 views

Analog VU meter with 1 watt lm386 amp

I am building a small cigar box speaker with an lm386 and think it would be cool to have a working analog VU meter on the front. There are obviously a lot of cheap ones from China which I would be ...
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4answers
806 views

What are these transistors doing and how are they working in this VU Meter?

I was thinking of making KITT's voice box from Knight Rider, which is essentially a VU meter. I did some researching and found an appropriate IC, LM3916, http://www.mouser.com/ds/2/405/lm3915-443929....
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2answers
964 views

Mains AC Reverse Polarity - Has this damaged my fridge/freezer PCB? [closed]

In the UK, I had a smart meter installed a few weeks ago. My 4 year old Panasonic fridge/freezer (NR-B53VW2-WB) was working fine before the electric meter switch. After the install, after the engineer ...
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1answer
305 views

Why is a clamp meter unaffected by nearby wires?

I understand a clamp meter works by measuring the magnetic field generated by current flowing through a wire. It's well known that clamping 2 wires carrying the same current in opposite directions ...
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2answers
84 views

Higher precision with less digits?

Consider an ideal digital milliammeter (zero resistance, zero uncertainty on AD converter input) with realistic (noisy, hysteresic, etc.) AD converter output and a \$3½\$ -digit display. Often when we ...
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3answers
700 views

How can I run a 6.5V-100V power meter on 5V?

I have an eBay power meter (V/A/W/Wh) that is specced between DC 6.5V and 100V. It's wired with a 75mV 100A shunt, like this: If I wanted to run the thing at 5 volts what would be the easiest way? ...
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1answer
278 views

Changing the full scale deflection of an analogue volt meter

I've bought an old pocket style (think of an old pocket watch) analogue volt meter and the full scale reading is 6V. I would like to change this to 3V, however I have opened it up and there is no (...
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0answers
38 views

LCD Counter and Hour Meter

In an electronic board I've found an LCD Counter and Hour Meter. Here's the technical information. https://docs-emea.rs-online.com/webdocs/001a/0900766b8001abd9.pdf Since it's very expensive, I ...
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0answers
102 views

Acquire a "TIC" signal from a power meter

I'm trying to acquire the tic signal of a french power meter. From the datasheet available here of the TIC signal we can find out that the signal is (page 7/38): 6 Vrms +/- 10% at 50 kHz It comes ...
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1answer
97 views

Considering analog meters as displays, which would be more versatile - voltmeters or ammeters?

Note: I'm here to see if there's an objective reason to choose one type over the other. I've got some projects in mind that would use a microcontroller to drive one or more analog meters as displays, ...
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2answers
653 views

VuMeter using LM3915 not working properly

I built a simple Vu Meter on a breadboard using the LM3915 IC following a tutorial found on the web, all seems to works fine and the final result is something like this: The only difference is that, ...
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2answers
154 views

Can any meter be PT connected?

I have an EE background, but am new to metering hardware. Looking at metering equipment for high voltage measurements (up to 6.6 kV), it seems most only go up to 480 V, even when classified as ...
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1answer
1k views

Which one is better to build lux meter, either LDR or photodiode?

I want to add the lux meter to my application. My controller works with 3.3V and ADC max reading voltage is 1.2Vref. I tried with LDR but I'm not able to get accurate values and the values also not ...
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3answers
800 views

Why doesn't commercial LCR meters' band start from very low frequencies?

I'm wondering why I can't find an LCR meter with frequency band that starts for example from 1 Hz. Is there some specific reason? EDIT: My question comes from the need to measure the impedance of a ...
3
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1answer
103 views

Home-made impedance meter: what's the difference between voltage divider and active filter methods

I'm dealing with the measurement of impedance sweeping the frequency from 0,1Hz to 100KHz. On the web I found many methods but the most quoted seems to be the one which uses an operation amplifier in ...
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1answer
419 views

What does the 20-80A rating on an energy meter mean?

On the energy meter nameplate is a current rating 20-80A, which I can assume has something to do with max current. I'm particularly interested in the "20" part, though. What does this rating mean? I ...
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1answer
585 views

What is the correct shunt size for the following ammeter and configuration?

I have the following ammeter: https://www.aliexpress.com/item/Red-led-Display-Color-0-56-Digital-Ammeter-DC-0-100A-4-wires-3-digit-car/1301822575.html The seller recommends 75mV 100A shunt be placed ...
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2answers
2k views

Ammeter show half of the real current draw [closed]

I have a couple of ammeters from China, they have 2 connectors: Con 1: Yellow voltage sense, Black and Red to power the ammeter. Con 2: Thick Red and black for current sense. They are designed to ...