Measurements of the current flowing through a circuit
2
votes
0answers
115 views
How is this ground fault circuit working?
I am having a difficult time understanding a few things in regards to the ground fault detection circuit below. I have found this circuit while investigating ground fault detection. I intend to build ...
0
votes
0answers
60 views
Solar panel current/voltage sensing
My project involves designing an inverter (220V/50Hz AC output) for a 250W solar panel.
Main question: Is it better to use high-side or low-side sensing on the solar panel? I'm finding it a bit ...
3
votes
5answers
136 views
Is there a simpler solution for highside current sensing here?
I have an existing automotive circuit simplified in the image. The loads (2 or more solenoids in parallel) share a 12V supply and are individually switched to ground through the car's ECU.
I need ...
1
vote
1answer
54 views
Cable thickness for solar borehole pump
I have a solar borehole pump: 24 volts - 270 watts panels (two x 135W). I want to move my panels 300 to 350 meters away from the borehole, reducing the risk of theft. What size of cable should I use ...
0
votes
0answers
30 views
Power consumption in wireless mesh network
I want to calculate the current consumption of a wireless mesh network. The network will use 6LoWPAN in a fire alarm application. I want to sense fire or smoke and have response time of 10s. Also, the ...
-4
votes
1answer
113 views
How to find the current and Resistance?
Ok Everyone DownVoted! i am sorry about the diagram! So i Updated it
this is my new diagram:
simulate this circuit – Schematic created using CircuitLab
Then Now how to find I1? what is ...
0
votes
2answers
296 views
how to use CT to measure current [duplicate]
I have purchased CT but don't know what his terminals means and how to identify primary and secondary coils terminals. I am software engineer but currently learning pic controller. as for I have read ...
0
votes
1answer
278 views
Current Transformer with pic16f877a
I am currently working with a current transformer (CT) to measure the load current of a system. I am connecting the CT with a pic16f877a microcontroller using a basic circuit I found on the internet. ...
1
vote
1answer
249 views
How to use PIC A/D converter with ACS712 Hall effect current sensor
I have built a one amp power supply and want to use a Sparkfun ACS712 Hall effect current sensor with a PIC and 7 segment LED display to show the current in milli-amps. The PIC A/D input has ground as ...
-1
votes
1answer
74 views
Battery Monitoring IC for 24V 480Ahr SLA
I'm building a battery monitoring system for a large automotive application. Is there any IC tuned to measure a Lead-Acid battery pack's voltage, current and state of charge? The closest I got was ...
1
vote
1answer
205 views
How to find currents of all nodes using superposition theorem
Given this circuit:
simulate this circuit – Schematic created using CircuitLab
Using the superposition theorem, I need to find the current of all the 3 nodes of the circuit.
Using ...
1
vote
2answers
92 views
Logging the output from a solar cell
I am trying to create a small low cost circuit that will allow me to log the output of a solar cell over the course of a month as a student project.
Currently I have a 5V Silicon PV cell and am ...
1
vote
2answers
168 views
Fix the Problem for Shunt Resistor due to Temperature & Current Sensor
I am trying to build a current sensor here. My original thoughts starts from this paper [real-time current-waveform sensor with plugless energy harvesting from AC power lines for home/building ...
0
votes
3answers
82 views
Measuring a high dynamic range current decay with different amplifier gains
I would like to see a current decay from a photodiode with a high dynamic range. By saying "high dynamic range", I mean it decayed from about 1uA down to 100pA or 10pA. I tried with a linear ...
3
votes
2answers
177 views
Measure current in high voltage (10kV)
In a plasma application (Helium or Argon Plasma), we would like to measure the current. The voltage is around 10kV AC and modulated with a function generator.
Currently we only have one of those ...
2
votes
1answer
157 views
Opamp topology without a stable voltage reference
I have an opamp configured as a constant current sink like this:
As you can see, the reference voltage for the SENSE pin is set by the voltage divider on the left. This requires a stable voltage on ...
0
votes
0answers
145 views
PIR sensor current consumption too high. Need a different PIR?
I am trying to build a wireless motion detector that can work on a battery for a really long time. I am using this PIR sensor:
http://www.digikey.ca/product-detail/en/555-28027/555-28027-ND/1774435
...
1
vote
3answers
184 views
Math to predict current in circuit with different voltages in parallel
I was playing around with my voltmeter and I came across something I don't know how to work the math of.
The circuit built was the one below, the right power supply was a 9V battery and the left was ...
1
vote
3answers
92 views
Embedded system-current draw logging
I have an embedded application that wakes up every 15 minutes and performs some specific function for a period of two minutes.
I need to log the current consumption of this specific function on the ...
0
votes
3answers
104 views
Detect if a microwave is running
At work we have a alcove hidden from direct view with a wall covered in "standard" domestic microwave ovens (MO). You put in you food there and then you join your fellow colleges chatting; after a ...
3
votes
1answer
578 views
ACS758 current sensor output voltage cannot be read by Arduino
I have two ACS758 current sensors, specifically the 050B and the 200B. I want to monitor the current coming in to and out from my buck converter circuit. I attached the output of the ACS758 directly ...
1
vote
0answers
400 views
ACS714 5A AC Current Sensing arduino
hey guys i just got my ACS714 -5 to +5A IC i am new the current and voltage sensing i googled for tutorials on ACS714 5A but couldn't find a suitable tutorial with AC sensing.
I got the code below ...
6
votes
2answers
104 views
AA cells depletion
Currently I have two AA cells in series powering a 3.0v bus line for my application.Recently I am finding that one of these AA cells gets completely dead before the other. What could be the possible ...
1
vote
1answer
108 views
ZXCT1009 as a current monitor
I am currently using ZXCT1009 high side monitor for monitoring the current consumption on a bus line for an embedded system we are developing. I am currently using tek scope with Labview for ...
2
votes
3answers
245 views
Hand-matching resistors: high-end DMM vs Wheatstone bridge
I wrote an article dealing with the question of hand-matching resistors to high tolerances using a DMM. The driving purpose behind that article is to show that it's harder to do that than one might ...
1
vote
1answer
98 views
Read-out circuitry for resistive biosensor
I have a biosensor. It's resistivity changes while sensing the analyte I want.
Resistivity of biosensor is around 10 Ohms.
I normally use Keithley 2400 sourcemeter for experiments. I apply a constant ...
0
votes
2answers
109 views
Calculate current load for 8 motors
I have 8 DC brushless motors that are connected parallel to a DC source.
According to the motor manufacture each motor powered with a 12V DC and need 11A.
How can I calculate the the current load of ...
1
vote
2answers
357 views
Current measuring with PIC
I know it is possible to measure analog voltages with the ADC peripheral of advanced PIC microcontrollers. There is no peripheral to measure current though.
Is it possible to convert a current to a ...
1
vote
0answers
84 views
Need help with generating a bi-phasic current
I'm trying to generate a symmetric biphasic current pulse using a Grass S88 Stimulator.
Here's a diagram:
SG is a signal generator with two outputs, S1 and S2, which are generating a periodic ...
0
votes
1answer
146 views
Battery monitor gauge for embedded development
For one of our upcoming projects, we have a battery pack consisting of 12 Energizer L91(Lithium /Iron disulphide AA Battery).
We divide this battery pack into three sets of 2 ,5 and 5. In order to ...
3
votes
4answers
238 views
Checking maximum current provided by charger, how?
Using only an entry-level multimeter (and an assortment of common discrete PTH components, say on a breadboard), what could be a reliable way to check the maximum current that a switched-mode AC-DC ...
2
votes
4answers
336 views
How to shift differential signal to read with single ended adc?
I'm using a current sense resistor (0.02 ohms) for a high current battery monitor for a hobby project. I'd like to shift this to a 0-5 V range to monitor using an ADC input (single ended.)
I ...
1
vote
1answer
168 views
Reading a Open Loop Current sensor
I am using a LEM HAIS 200-P and I never have worked with Open Loop current sensors before.
I have some questions about the datasheet:
What is the difference between Primary nominal RMS current and
...
1
vote
1answer
459 views
Difference between Open Loop and Closed Loop Hall Effect Current Sensor
I think the title says it all, but in any case, I want to know the difference between the open loop, and closed loop, hall effect current sensors, such as the LEM HAIS 200-P.
0
votes
2answers
247 views
Simple way to measure amps with a volt meter?
I've got a simple voltmeter that I'd like to use to measure the power load of some components that I have no idea of. Some are simple (like an LED) and some are more complex sub-assemblies. I'm not ...
0
votes
1answer
45 views
Searching for phase change device
Anyone knowing of a module that can monitor three incoming electrical phases to a home. If the load goes over a certain maximum, the device changes to one of the other phases for supply to e.g ...
3
votes
2answers
606 views
How do I measure startup/inrush current?
I have some small devices that draw 20mA. I'd like to add a resettable (PPTC) fuse to them but I am not sure what value to select.
My thought is I need to find a value that will tolerate the startup ...
2
votes
2answers
109 views
Simple rig to measure current drawn in very short bursts?
I have a microcontroller based circuit that sleeps most of the time and works in short bursts of less than 1 milisecond and I don't have access to a digital osciloscope so I could record this. I only ...
1
vote
1answer
110 views
Need to know the exact values for sense resistor, resistors in op-amp and power supplies
I am computer scientist and I don't know much about electronics.
In my master work, I have to design a circuit that measure the energy consumption of receiving single tweet from mobile ...
2
votes
1answer
148 views
computing shunt resistence for a microammeter
Let's suppose I have a dc microammeter with a range of 100 ua that claim to have an internal resistence of 1Kohm.
I want to use this instrument to measure a range of 1A. I'm assuming I need a shunt ...
-1
votes
1answer
44 views
Charge current needed for Capacitor Charging
I need the charge current of a polyacene capacitor.
I have the voltage and time only.
For example: The Capacitor charges to 100mv at 1 hour,
what then is the uAH? (micro) charging current?
Or ...
0
votes
2answers
433 views
SCT sensor to 0-10v analog input
I'm trying to read values from a SCT-013-030 sensor that gives 0-1vac readings .
My board analog inputs are 0-10vdc,giving me a value from 0 to 65500 .
I need to know what is the best method of ...
1
vote
1answer
288 views
Help with PCB design with current sense resistor
I have to perfomr battery characterization(power and current consumption measurement) of an embedded system module. I have embedded PCD and an Battery pack PCB.Therefore I am planning to include the ...
0
votes
2answers
180 views
Automating the measurement of current consumption of an embedded system
I have two circuit board.
1.PCB for battery pack
2.Embedded PC with various modules.
I was wondering if there could be an automated way of measuring current consumption by the embedded module during ...
5
votes
5answers
1k views
How to calculate Power Rating for Zero Ohm Resistors?
Base on my earlier question, since there supposed to be zero voltage (V=IR) drop across a 0Ω resistor, how do we select the power rating of such component?
Example, let say I were to connect a zero ...
7
votes
5answers
2k views
What is the usage of Zero Ohm & MiliOhm Resistor?
I am new to PCB design and I noticed that some schematics use 0Ω or 100mΩ resistors. What is their purpose and why do we need to use them in our PCB design?
Normally if we wish to probe how much ...
1
vote
0answers
53 views
Power measurement with buffered solution
How can I design a power measurement unit for my slow logger?
I want to measure AC current and would like to use a CT coil.
This will give a output of 1 V when 30 Amps are flowing through my cable.
...
0
votes
1answer
221 views
Every time I connect ADE measuring chip , it blows up
My current system:-
I'm working on a electricity metering system ,
I'm using shunt resistor configured in high side mode (a current sensor ) ,
I'm also using ADE7755 measuring chip ,
A ...
4
votes
1answer
164 views
ambient light rejection in absorbance sensor
I'm making a sensor to measure light absorbance in a sample where the geometry varies over time.
I found a very nice transimpedance amplifier, the AD8304 designed for use with PIN photodiodes with a ...
10
votes
2answers
177 views
Why do some of my IE converter circuits have a large offset voltage?
The following circuit is an active current to voltage converter with switchable gain.
Schematic
Not shown: The inverting input is held low through a 10K resistor when the circuit is powered on but ...
