Questions tagged [voltage-measurement]
Act of measuring voltage
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Measuring 12V car battery voltage precisely from the output of an ideal diode controller
I'm designing a device that will be plugged into the OBD2-port.
One of the features is reading the battery voltage on demand directly from the diagnostics port.
In order to protect the device from a ...
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Comparator as a current detector with shunt resistor v2
I have a comparator with a shunt resistor that measures the voltage and when the voltage of 12 V from the source exceeds the Vref (1 V in my case) it switches to "high" output. I would like ...
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Comparator as a current detector with shunt resistor
I would like to design in OrCAD a comparator with a shunt resistor that will measure the voltage and when the voltage value is exceeded it will flip. I have designed the comparator but I don't know ...
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Peak voltmeter detector explanation
I'm designing a peak sinusoidal and impulse detector, based on the old design of a peak voltmeter designed by Haefely. I have the schematic, but I can't understand how this circuit works. The large ...
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I have low voltage circuit isolated from high voltage through using PC817 optocoupler and how do I measure the voltage for high voltage circuit
I need to measure the voltage of output supply which is of 24 V. I have used a voltage sensor for this but for this sensor I have to connect input supply which makes isolation redundant
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Transformer ratio changes when varying voltage on primary
I want to measure mains voltage using a transformer. bought a 9V transformer, removed the secondary and rewind it with 10 turns that gives me 2mV per volt 1:500.
The problem is that the ratio is not ...
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When I attempt to measure Vbc for the circuit below, the LED partially illuminates when the switch is open. Can someone explain why please?
When I measure Vb relative to ground I get a value of 0.00V and with Vc relative to ground I get a value of 7.15V when the circuit is open. Subtracting Vc from Vb I obtain -7.15V for Vbc which is ...
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Circuit for Reading Power Supply Voltage with Micro ADC
I am working on a project where I need a microcontroller ADC (3.3V range) to detect the voltage being put out by a 24V variable power supply. This is the circuit I came up with to accomplish this:
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Troubleshooting an Electrical Circuit - Is This an Expected Voltage Drop?
I am troubleshooting an electrical problem and am having trouble understanding the readings I am seeing on my digital multimeter. I am a DIYer with just the basics of electrical engineering knowledge,...
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How do I measure the noise at the top of a square wave?
I am trying to get a good measurement of the "quality" of a square wave, both in its flatness and lack of noise at both high and low levels.
Low level is easy, just use a preamp and zoom way ...
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Monitoring external battery voltage with ESP32
I'm trying to monitor a battery that is unrelated to my ESP32. The battery powers my gate and the ESP32 is powered by POE. The battery is a 12v battery. I am using a voltage divider and the ADC to ...
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How do I best protect a PLC and power supplies from voltage and current spikes coming from actuated components?
Problem
My PLC is getting voltage spikes in the onboard ADC readings when I turn on actuated components elsewhere in my electrical system. I need to protect my PLC from these spikes because they ...
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How to properly measure the power being delivered to a BLDC?
There's a battery connected to an ESC, connected to the Motor, coupled to a Dyno.
How can I measure the electrical power going into the BLDC?
As far as I'm concerned a simple measurement of line ...
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Measuring voltage but no power with DMM
Hello guys i am a novice electronic engineer and i run up to a question on some troubleshooting i was doing.
I have an old audio door phone system that has 2 designed outputs for the 12VAC electric ...
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UC3842 IC not working
I have a simple UC3842 IC and I want to test that. First I used the open loop circuit from the datasheet but it didn't work therefore I went through the datasheet again and found from the schematic ...
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Can I measure pinholes in a dielectric layer using LCR meter?
I have a thin dielectric film (~1 um) and I want to measure the quality of the film in terms of not allowing leakage current through pinholes. Can I use an LCR meter for this purpose? If yes, how? If ...
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How to measure the electrical properties to ensure the performance of a thin electrode/insulator stack-up?
I am a mechanical engineer by trade, and I am looking at some basic electrical properties that I need to measure to ensure the device meets the desired performance.
The device consists of a two-layer ...
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Why would my true RMS multimeter give me a different AC voltage reading than my scope at frequencies above 2 kHz?
Here’s the circuit and my problem. My function generator is simply parallel connected to a multimeter and my scope. No load is connected and I am not using a scope probe, just a BNC connector with ...
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Pipe to Soil Potential Measurement
I want to measure pipe to soil potential using a microcontroller. Generally, the potential difference between pipe to soil is negative. I found this circuit online.
Is this circuit correct for ...
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Questions about connecting ADS1115 for voltage measurement
Purpose: to measure the voltage on the DC bus (about 600VDC).
ADS1115 Datasheet
I looked at the use cases and saw two connection options (in the first case, we use two inputs, in the second, only one)....
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Why 230 V shows up in a staircase light circuit even though 'live' is disconnected? Why is there no continuity between the light bulb and neutral?
There's a staircase light circuit in my house similar to the one shown below.
I disconnected 'live' from the switch on the left and measured the voltage between its 'L1' terminal and neutral and then ...
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Sigma-delta modulator (ADC), can it be used without sinc3 filter?
Purpose: isolated measurement of DC voltage (about 600V).
For these purposes, I found two options:
ADS1115 (I2C ADC) + I2C digital isolator
CA-IS1204 Isolated Sigma-Delta modulator
I am considering ...
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Can I use capacitor to measure time?
I want to measure distance by electromagnetic wave travel time.
Capacitor charging voltage on time dependency is well-known:
\$V_{capacitor} = V_{source}(1-e^{\dfrac{-t}{RC}}) \$
Equation above is ...
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What is the best setup for low frequency AC simulation and recording?
I need to apply an AC signal (current) of frequency, 0.1 Hz to a device and record the resulting change in voltage over time. I've been thinking a for a long time the best way to achieve this. I have ...
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Op-amp subtractor circuit
While using Op-amp as a subtractor circuit the input applied to inverting and noninverting terminals are generally referenced to the DC ground of the circuit as shown in the picture below.
Pic credit:...
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Help on creating a Li-ion battery cutoff circuit
I am trying to make a PCB for a drone run off of Li-ion batteries for a project of mine. I wanted to protect the drone and cells from an Undervoltage situation and cut off the Li-ion battery from the ...
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I want to make use of an Allegro A1324LUA-T Hall sensor to sense a very small magnetic field change. Would it be possible?
I am looking into using an Allegro A1324LUA-T for sensing very small magnetic field changes.
The data sheet shows that the sensor gives a 5mV/G change in voltage so I can sense a 0.1 Gauss change if I ...
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Small circuit explanation
I apologize that this is really simple for specialists, but since I am not one, I would like some assistance in this regard.
What is the electrical condition of the resistors, please? They operate ...
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Back to back P-MOSFETS for power sources OR-ing
I am trying out a circuit that is supposed to allow for two power sources. It is based on the one at https://electronics.stackexchange.com/a/549083/35737
simulate this circuit – Schematic ...
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Checking voltage of battery with a USB connector
I soldered two wires on female USB type A pins,one wire to ground and the other to the VCC pin.
I was trying to check the battery voltage of the li-ion battery in my flashlight,
I connected the a ...
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Can you measure a powerbank's battery voltage at USB input connector?
I'm currently building a portable device, that is powered by a powerbank. I want to be able to measure the current battery "percentage" of the powerbank, with an esp32.
For this i thought ...
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Voltage divider circuit for DC voltage measurement with protection against AC voltage?
Need some help with making a simple voltage divider to sense DC voltage of 0-30 V range with my DAQ which accepts 0-10 V analog input.
I was wondering if the input voltage is by mistake an AC voltage, ...
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How to fix this error on DAC0808 with LF351?
I am testing this schematic from the DAC0808 datasheet at 10kHz frequency digital input, current 0, 1 and 2 mA but output had error see fig.Vout should slightly than this. How can I decrease this ...
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How to solder stainless steel electrode to PCB pad?
My goal is to solder stainless steel electrodes to a PCB in order to make a device that can measure differential voltage measurements from a surface.
How do I attach stainless steel to a PCB to create ...
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How to remove 5V from circuit so that my meter reads correctly after LiFePO4 upgrade on golf cart?
A while ago, I upgraded my lead acid batteries to LiFePO4 for my golf cart. The state of charge ("SOC"/battery gauge/voltmeter) is for a 48V cart but the new batteries put out 53.x volts so ...
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Do I need a pulldown resistor with a voltage follower?
As a school project we were given the task to build a remote controlled car. For monitoring the battery voltage, I chose to use a voltage divider with a voltage follower, as the battery has a voltage ...
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Adjusting signal voltage range for ADC [closed]
Can anyone please help me design a system using an LM324 op-amp to amplify a small voltage signal (from -20 mV to 31.1 mV) to a larger voltage range (0 to 5 V) so that it can be read by an Arduino's ...
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DMM showing voltage when one lead is hanging in air
My meter gives me a reading when I connect the positive lead to something and the com lead is just hanging there. Is this the voltage difference between the air and what ever my positive lead is ...
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What is the maximum Vref allowed on LM431?
I was looking at the answer given by Jasen Слава Україні in this thread High Voltage (0-600V) DC Voltage Sensing, Shared Ground with Isolated Converter and HV-
The author needs to detect a voltage ...
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Isolated DC voltage measurement via optocoupler
I am trying to make a circuit that measures 10-30V DC with isolation. The measurement is done by the circuit, not manual. The measured voltage level/information is sent via an optocoupler to the ADC ...
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Turn on LED when input is in range only
I have a car HVAC daughter board that set a pin to a specific voltage depending on which of the 6 physical buttons is pushed. I don't have any schematics neither datasheet.
I measured voltage of this ...
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How to design an accurate (1 μV error) meter
I want to design an accurate LV meter.
The range is from 2.5mV to 50mV both AC, with a 5uV accuracy. This comes from a shunt resistor that is connected to AC main (230V AC). Hence it will go below 0V. ...
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Help Testing ATX PSU 8 Pin PCIE Connector
I'm trying to do some pin swapping on an 8 pin PCIE power cable. It didn't come with my PSU, so I know it's probably not going to work how it is. I've done research on how to test and swap the pins ...
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Voltage control tri-phase current circuit at 10 kHz frequency
This is my circuit that use to control tri-phase current (tri-phase is positive, zero and negative).
This circuit include two voltage control current by first will release positive current at the top ...
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How do I find out if a product can work on 240 V? [closed]
How do I check if a product can work on 240VAC?
For the impending winter, I bought a desk heating mat from an online seller in Australia (where mains electricity runs on 220-240VAC). I received an ...
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Read battery voltage with ADS1110
I have an ADS1110 that should read a battery's voltage (2.8V - 4.2V).
I have built this schematic:
The problem is, I connected the battery's negative terminal to VIN- and the PCB is already assembled ...
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Measuring voltage across one end of a 50 ohm bias T and the other end is 50 ohm terminated
I was looking to measure the output voltage from one of the PCBs using a multimeter. I connected the center of the 50 ohm T adapter to the DMM, one end of the T adapter to the output port of the DUT i....
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Simulating HCPL-3700 using LTSpice
I am trying to simulate HCPL-3700 using the LTSpice model provided by Broadcom.
Following the application note 1004 example 1, I am able to successfully calculate the Rx value and simulate the model ...
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How to measure a specific part of a voltage range using a microprocessor like an Arduino
I wish to monitor a battery using an Arduino.
I can successfully measure the value using an Arduino via its Analog port, which gives me a 1024 bit value range.
Where I'm stuck is how to allocate that ...
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Why is my 3-phase power giving me two 180 V phases and a 40 V phase?
I have 3-phase power hooked up to my building. I also have solar panels feeding the grid. Most of the power in the building is functioning normally. I tested the phases with a multimeter and got 120 - ...
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