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# Measuring Power

303 Threads found on edaboard.com: Measuring Power

## Voltage divider/Comparator Resistance change on power up

hi, How are you measuring the Rth resistance when the 3.3v is connected across the the resistor.? E

## Battery Internat Resistance Without OCV

I think what it is doing is measuring voltage directly across the battery and using a Hall sensor to monitor the current to one or more batteries in a chain (the current will be the same in them all as they are in series). That allows power to charge the battery to be measured and power drawn from the battery to be measured but I can't see (...)

## Can I used CT insted of 350 micro Ohm Resistor to measuring the current

Hello, I am using ADE7757 Energy measuring IC in that They are using the 350 micro Ohm Shunt Resistor. SO can i USE the CT instead of 350 micro Ohm? Thank You

## Single Phase System: Neutral and Earth shorted together will it cause power tripped?

no it would not RCCB detects the current flow from Hot line to earth by measuring the current difference of inpout Hot and NULL in normal operation HOT and NULL inputs has the same amount of current in opposite direction so the difference is zero but in case of Ground fault the difference is not zero showing that an amount of current has flow fro

## [Moved]: Battery voltage sensing using hardware circuit

1. What is the power supply for your IC? Is it the same battery whose voltage you are measuring? If so then you may not be able get correct readings. 2. To measure AC ripple riding a DC component, put in a series capacitor to block the DC. Then amplify the AC which comes through.

## Measuring the energy used to recharge a 1mF electrolytic capacitor

Please see this quote from an Epcos/TDK application note that explains well the observed energy differences ("General technical information" from )

## Measuring inductance of Ferrite core Power tindictor using Meter

hi, In which mode Ferrite Core power Inductor inductance is measured? There are two modes in my LCR meter labeled SER and PAL. And what is the difference?

## LED burns when oscilloscope is connected to it

Not sure if I can picture what you described, but I also accidentally burned equipment connected to the oscilloscope, on two occasions. In the first case, the oscilloscope was connected to the power socket without isolating transformer, and the ground of the probe shorted to earth of theelectric mains. In the second case, it was measuring 2 signals

## I wonder if it is possible to design a device to debug short-circuits based on ohms.

Finding shorts by measuring voltage drops works quite well with PCBs, except for shorts between continuous overall power and ground planes. You need a constant current respectively current limited voltage supply to source a short circuit current that doesn't damage the board or components. A few 100 mA to several A are appropriate, depending on

## checking a solid state relay (SSR)

when I use an ohm meter to test between #1 and #2 it shows closed regardless if #3 has power or not. I bought a new SSR and I get the same reading. Need to disconnect the motor wires before measuring resistance, at least from one of the terminals. Did you? According to your previous report, the problem is false open (never brea

## Measuring Hfe of a NPN power transistor with 5A of collector current

The graphs in a datasheet are for a "typical" device that you cannot buy. Most of the devices you buy are considered "typical". Parameter variations, although the distribution is not specified, are normally "normally distributed". This distribution has two tails and both tails are cut off by the quality control c

## Application of sine wave oscillator

For designing and measuring an audio amplifier I use a sinewave to measure its output power at clipping and its distortion. A sinewave has a defined peak to RMS relationship (peak V= 1.414 times RMS V) and has no harmonics. SPWM has switching artifacts that must be filtered out with a very good filter or the PWM switching frequency must be very hig

## RF Harmonics Measurement not following expected slope

Hi All When measuring the Pin vs Pout (fundamental, 2nd & 3rd harmonics) of switch or transmission line, what can cause the 2nd and 3rd harmonics not to follow a slope of 2 and 3 respectively? I have checked and my fundamental is still responding linearly with a loss of about 2dB at the power output.

## Efficiency of active rectifer not true - only 50%?

The input power is Pin=rms(Iin(t)*Vin(t)). The correct expression for the input power is rather: Pin = (1/T) ∫ ( Iin(t)*Vin(t) )dt Anyway, the way you're doing seems more like measuring the power rectified, which is under no circumstances related to power lost/transferred pow

## Measuring 3 Phase voltage through PIC micro controller

Not using neutral means that the phase-to-neutral voltages are unknown. You can only measure phase-to-phase voltages and calculate nominal phase-to-neutral voltage, if necessary. Devices with three phase supply, e.g. VFD inverters are usually working with phase-to-phase voltages only. Typically they are measuring two voltages and are calculating

## [moved] Measuring high speed changing currents

Hi, I guess max current drawn is what i need to know You guess.. You should know instead of guessing. What´s your goal of measuring the current? * Estimate battery lifetime? * Estimate battery health satus? * switch OFF printer? * activate an alarm? ***** Often the peak current is not very informative. But a scope should give

## measuring impedance using spectrum analyser

but how can i do this by using a spectrum analyzer. i am using 2437 MHz so the only way i am getting the idea about the impedance is that one of the ports where it is properly matched(50 ohm) i measured the power and then try to measure the power level at the ports where i need to get the matching. i know there will be some loss in power (...)

## 3 core power cable leakage issue

i am measuring 3 phase voltage using pic micro , for that i am scalling 440v to 1.5v using resister 2.2meg and 6.8k. every thing works fine i can see the 3 phase voltage on lcd but if i disconnect 1 phase in the 3 core wire i can see some leakage voltage present the line tester glows bot very little current if i touch in hand no shock. my problem

## AC current direction Measuring circuit

Any Circuit diagram to measure direction of AC current using PIC microcontroller (18Family) ? i.e, If direction of current changes the output of circuit should be changed from (high to low) OR (low to high) Thanks

## Measuring RF power, tricky thing

Hi there, I have found measuring RF power a tricky thing to do if not special equipment is available and I would like your comments on this. I have an HF power oscillator that is supposed to output 2W. When I measure this in the watt meter it outputs 2W. When I measure it in the scope, it outputs about 28Vpp ie 2W, and the waveform seems (...)

## Measuring a 100 w power amplifier at 6.78 MHz

Friends, I am gonna measure my 100 w PA at 6.78 MHz. Because I have not worked before with this much power, I need your help! First, I wanna use spectrum analyzer and an attenuator to see output power. What kind of connector should I use? Is SMA ok? Second, how can I produce a square wave to drive the PA (I need in input 1W power and 5 (...)

## Low side current sense of 6 IGBT

At first glance, you are measuring current ripple of a full-bridge input rectifier. Or your current sense amplifier doesn't have appropriate common mode range, respectively wrong power supply.

## measuring power factor in pic micro

i tried to measure power factor using ct and pt but failed. have any one tried measuring pf kindly share the hardware and software. regards kalyan.

## CW power vs pulse power

The difference is named duty cycle, or a time-smoothed power of a pulse. CW power is typically measured by calorimetric power meters that deduce power by measuring heat. Pulsed power can be measured by calibrated detectors or by an oscilloscope reading voltage on a calibrated resistor. (...)

## GSM Module GND pin connecting to 220V AC Power phase line !

Hello, I am working on a circuit in which the GND ping of GSM module connects electrically to phase line of 220V AC power line ! the power supply of the circuit is supplied by a SMPS, but the connection of gnd to phase line is done because i am measuring the phase line current through a shunt resistor. now, does it make any problem (...)

## Measuring transmitter power, do and don't

Hello, I usually see measurements of power of HF transmitters using just a common power meter (broadband coupler and diode inside). Please tell me if my next thoughts are correct: 1. Since these power meters are broadband, and they have just a needle analogue meter to measure power (non selective), they not only measure (...)

## Low voltage conducted emissions setup(10-40V)

I would think load dump suppression devices should be satisfied with a bipolar TVS and conducted noise improved with low ESR C on input or series choke. A LISN (50Ω/5?H) is used for AC power line conducted emissions measuring voltage for AC line external connections. Battery conducted emissions , can be done with a current probe or 50

## How to achieve the lowest current consumption during sleep mode?

Give more details on other components on board. Where u r measuring current, How?.....

## Can we measure floating voltage (of power supply) with reference to chassis ground?

Hi, read below "similar threads" In my eyes measuring this voltage makes no sense, because it is "floating". The voltage ins inpredictable an may change any time. (Caused by airflow, humidity, touching, connections of other floating devices...) Additionally the measurement device usually has a finite input impedance, so the measurement itself aff

## Measuring miniscule currents during microcontroller low power modes

Folks, Out there is there a good app note on tools and techniques for measuring low power microcontroller modes? How does one usually go about measuring the consumption at the low power modes? uA levels. Imagine the situation when sleep current is in single-digit uA (micro), and active current peaks at tens of mA (...)

## [moved] power measuring with benchmark circuits

Hi I want to help me to use the benchmark circuits in my work for power calculations ( dynamic and static). how can modify the benchmark to meet my design? and how can I obtain the final hspice netlist to simulate the modified circuit? Thanks

## Clarification about measuring power consumption in LNA circuit.

I used single pHEMT transistor to design my LNA, and set Vds = 3 V,and Ids = 60 mA. I have got the power consumption as Pdc = Vds * Ids = 3 V * 60 mA = 180 mW. I used the single supply voltage as Vdd = 3 Volts. I used the same three pHEMT transistors for design of my LNA. I set the each transistors biasing as Vds = 2 V, and Ids = 15 mA. When I m

## Voltage multiplier output power

Hi! I have 880mV 8Hz AC signal and doing two experiments : diode bridge and voltage multiplier rectification and output power measuring depending on load. So i connected diode bridge and precision potentiometer as a load. Measured current and voltage and got maximum power with 500Ohm load (240mV * 0.97mA = 232.8mW) . The did same experiment (...)

## Flyback efficiency calculation: RMS or AVERAGE power?

Hi, I'm a bit confused. I'm measuring the efficiency of my off-line 230 V flyback converter. I sampled the mains voltage Vin which is a sinus wave. I sampled the Input current flowing from the mains into the converter which is a non linear curve. To evaluate the efficiency I need to evaluate the input power. QUESTION: Which of

## Measuring S21 of FET using diode mixers and external generator. Feasible?

Setup: 1) PCB board with two parallel microstrip lines connected to power divider from one side and to two identical diode mixers from other side. One of lines have a gap for common source FET placement. Before placement gap is soldered with copper foil piece for calibration purposes. 2) Frequency generator for freq

## Measuring output current of a switching power supply ?

Hi, I'm trying to measure output current of a switching power supply. input voltage is 220 ac. output voltage is 22 dc. the load that is connected to the switching power supply has a resistance about 10 Ohms. I use a 0.22 ohm resistor for converting the current into voltage and then i measure the voltage and convert it into current. theorical

## Measuring leakage current of mains using Current transformer

Hello everyone, I am trying to measure leakage current using current transformer.I am using this circuit And instead of LM324 I am using OP07. But when I try to leak current the transformer don't respond to any leakage.

## [moved] How to charge a power capacitor bank properly?

I would start with measuring a set characteristic curves output current versus duty cycle for different output voltages. This can be also used to calibrate the CT measurement in a multi-dimensional table. Then setup the controller according to the determined control process characteristic. Or - if feasible - define a duty cycle versus output vol

## Need Help for CS5460A ADC

CS5460A isn't an ADC, it's a complete single phase energy measurement system, measuring voltage and current and calculating RMS, power and energy quantities. Basic device operation, registers and how to access it through I2C protocol is described in the datasheet, in so far I don't know what your actual problem is. Besides Cyrrus support, you'll

## Significance of Pi Filter in SMPS Power supply.

It is an input filter to reduce EMC to meet compliance requirements. Normally, you will design the filter after measuring the attenuation required at a certain frequency to meet a specific emission's standard. So after doing a pre compliance measurement with an LISN box, you will know which frequencies need attenuation to meet the standard.

## measuring high voltage/power

If you have a light sealed, but variable spark gap, you could include a fast photo cell which can then trigger a pulse extender, so short pulses can be detected. There is little prospect of measuring the power in high voltage nano second pulses. One Heath Robinson way would be to allow the arc to occur in an acoustic chamber with a microphone in

## RF detector power meter

RF diode detector is not linear or Vdc/Vac is not constant but vary with input AC voltage amplitude. Thus linear DC voltmeter or oscilloscope is rather used as indicator if not calibrated in mW or dBm. When voltmeter is calibrated it shows correct power only for sine wave signal if calibrated using such signal. measuring signals like square wave or

## comparing 4 different signals

Are you wanting to measuring total noise power or noise density?

## Mutual inductance calculation or measuring

plz help how can I calculate or measure the mutual inductance between 2 planar coils based on contactless power transfer. thanks a lot

## 140VAC out of the wall outlet

When measuring AC outlets at different nightclubs, the AC outlets are higher at 140VAC. Can power Conditioners or a UPS system handle 140VAC outlets as the power source? I would think it can cause the power transformers in a power conditioner or UPS system to open or short out? I'm not sure how (...)

## 50Hz Hum Noise in power supply

What if your adapter is switching mode and has low enough 50Hz ripple on output and problem is bad ground on your measuring instruments so called ground loop problem?

## kelvin type Ohm Meter

Kelvin method is 4 wire and eliminates contact resistance error with outer 2 leads supplying current and inner 2 measuring voltage. CC method with voltage sense and power limit prevents target burnout. I think an auto-scale approach might start with 10, 100, 1000 mA where it steps down or up according to voltage threshold of >100mV & <10mV.

## joining 0V lines from two power supplies

Should be OK. The only thing that worries me is your Hall Effect sensor, is it measuring magnetic field around the 0V wire or is the dotted line just a way of joining the connection on the schematic? As long as the two PSUs either have isolated outputs or their grounds are joined elsewhere it should work fine though. Brian.

## EVM and ACPR issue of Power amplifier

108225 Schematic is attached. It is a simple 3stage cascade PA. The frequency of the PA is from 1710MHz to 1910MHz. I swept the frequency when measuring the EVM and ACPR and I could not see any difference between channels. The EVM is really bad for all the frequencies.

## measuring load current (current sensor)

Your circuit cannot operate as shown. Besides the 741 problem, there's no negative feedback to the op amp so it's running open-loop and there is no power to the collector of Q1. Below is the simulation of a current-measuring circuit using a rail-rail op amp and a single 5V supply. Since a rail-rail op amp cannot go totally to the rail with an ou