# Tagged Questions

Flow of electric charge - typically movement of charge carriers, such as electrons. Measured in amperes (A).

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### “General Purpose” Current Limiter?

So i have been trying for a few weeks to create a current limiter that fills my needs but i have failed/i don't even know if it's possible. Basically i want to make a current limiter that can work ...
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### If a mosfet 2N7000 is rated 60v 200mA will it work with 12v 800mA?

If the mosfet 2N7000 is rated at a maximum 60v 200mA which give us a power of 12W will it work on 12v 800mA which is a 9,6W? My question is also about the maxium current rating, is it for any voltage?...
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### Current across high speed mechanical switch contact even if it can’t be measured?

If I am cycling a mechanical switch at a frequency higher than the bandwidth of a current amplifier and biased using a DC source, is current actually flowing across the contact? The following ...
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### How to design a circuit checking if 12V car battery is charging?

I have a small solar power charging module and load balancer, that takes input from a solar panel, has connectors for a car battery (12V) and output terminals. These things are pretty common on thing ...
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### Can I measure voltage and current at the same time by using two multimeters?

I think the title is revealing. I'm planning to use 2 multi-meters to get a better perspective of my circuits. Is there any drawback in this situation i should be aware?
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### Body interference in my analog multiplexer, maybe AC electromagnetism induction?

I just wired a CD74HC4067 analog/digital multiplexer to a matrix of leds. The multiplexer is wired to control the LEDs, and is connected to an arduino board, which is connected via USB to my macbook ...
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### OP AMP CONVERT CURRENT TO VOLTAGE

I see in a schematic , a op amp(lf357 or lf411)convert current to voltage amplifier .(current come from a loop of wire) . Now I want implement that circuit with LT1468. but not work correctly. what ...
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### Where to find Vectran cable [on hold]

I would like to order a Vectran cable were 12 strand tubular braids with about 200 strands and were manufactured without an oil finish for low outgassing. I live in Denmark and I can not find the ...
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### Sensor trim error and output trim error

I have calculated the amount of sensor trim error as well as the amount of output trim error, both expressed in percent of span. However I am not sure about. This is what I have: Sensor trim error ...
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### How do I compute the average and RMS of a series of triangular pulses?

I'm trying to calculate the Average and RMS values of the current through a diode with the waveform image attached. I'm struggling to work out which equations to use. Any feedback would be appreciated....
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### When is noise a factor in basic analog circuits?

I have a good understanding of circuit theory, but only a few large projects under my belt. In practical applications, at what voltage level does noise really become an issue. Is there any 'typical' ...
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### Maximum current through an LED

I have these LEDs for which the max current was not specified. However I know that the voltage is 3.2V-3.6V and the power is 1W. Is it correct to assume that the maximum current is therefore 0.27A ? ...
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### What are the current ratings for this chip?

I've been looking at the allwinner H3 datasheet, which can be found here. But no where in the datasheet is there mention of how much current it draws. Which is annoying when your're trying to figure ...
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### why leading power factor cause rising system voltage?

why leading power factor will cause rising voltage? how can it happen in mathematical calculation? i think the voltage in power factor correction will be stable but the current will change because of ...
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### Stability of Constant Current circuit

we are developing constant current circuit with "High" current rate, about 3A. We are testing the second prototype, the circuit is this: Behaviour its ok, but we have observed, when we set high ...
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### Reed switch wiring

I'm trying to connect a simple reed switch to my Raspberry to check if my door is open or not. I found plenty of tutorials online, but all of their schematics behave different, so I decided to create ...
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### How is the ampere percentage of a circuit breaker selected for different loads

This document below specifies rules according to which a circuit breaker is selected, it specifies Maximum Circuit Breaker Size % of Current for different loads in table 2 http://www.fs.fed.us/...
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### What is difference between 2 transformers rated to give output the same voltage but different current (ampere)?

What is difference between 2 transformers rated to give output the same voltage but different current (ampere)? Such as, if a stepdown transformer is rated as 12V 600mA, and another is rated as 12V ...
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### Using diodes to channel battery charging current

I have a setup with Solar PV, battery, inverter, and AC load. Between the battery and inverter I have connected a custom circuit with DC power/energy/charge measurement, and a relay. Problem is, ...
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### What is the significance of the current rating of a power source?

Assume, I have a copper coil (solenoid) with exactly 1000 turns. When I connect a multimeter across the 2 ends of the coil, the multimeter gives a resistance value of 20 ohms. Now I have 2 power ...
549 views

### Does running LED at higher voltage damages the LED?

I want to run 12v 6 watt LED at 19v by keeping maximum watts constant (current controlled). By doing so will damage the LED? I.e 12v x 0.5000 A = 6W 19v x 0.3157 A = 6W update1: I am ...
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### why would one use a current transformer with both live and neutral lines?

Could one use this to measure the phase difference if one had the voltage measurement? I have looked at the below household power meter, and was baffled by (what seems to be) the current transformer ...
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### Did I correctly use the Voltage divider rule to derive the transfer function?

Question and diagram are on link and NOTICE Rs is assumed to be a short. I believe the transfer function is going to be: A(jw) = 1/(jw*C1*R3+1) I arrived at this answer by using a simple voltage ...
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### Two batteries in parallel by a long cable

I want to build a system where I have a solar charger connected to one 12V battery, which is then wired in parallel by a long cable (30 meter, 2.5 mm2) to the other battery. Will both batteries ...
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### I was explaining a transistor to someone, and I realized: I don't really understand several key concepts at a low level. Help?

(Surplus story removed.) I was explaining MOSFETs, CMOS, and logic gates to someone and realized I didn't grasp some concepts as well as I thought. It culminated when he drew a single transistor, ...
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### How to measure current with a multimeter? Currently getting inconsistent measurements

I have a current controlled power supply giving out 8 A (at least that's what I'm setting), plugged into a cable (call it #1) which is then connected via screws&crimps to a copper coil (call it #2,...
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### How can 12ma illuminate 3 LEDs in series as brightly as 48ma can illuminate 3 LEDs in parallel?

I have a 16ma 9volt current source which I connected 3 LEDs to in series. I measured the current flowing through the positive terminal and it was 12ma. Next I connected 3 LEDs to separate 16ma 9volt ...
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### How many LED's can a TLC5940 16-Channel LED Driver power?

A TLC5940 can sink up to 120ma per channel. I am having difficulty finding the max current for the entire chip on the Datasheet. Is there one, or is there another limiting factor for this chip? ...
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### Input power rating on power supplies - how does max amp draw apply to 220V

If a power supply says the input power is 100-240V, ~1.5A, I'm assuming that the "1.5A" draw would be at 100V, not at 240V, right? I.e. would the total max watts be 150W regardless of the input ...
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### Current flow through inductor (large inductance) in AC circuit

I fail to understand why does the current flow in one direction only initially at t=0 in an AC circuit.. also when inductance is increased the time take for the current to stabilize and move in equal ...
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### Some questions about current and reading electrical characteristics from a datasheet

I'm trying to understand the concept of drawing current. I read in a site(method 10) that Arduino (ATmega328P) can be damaged if i set ten I/O pins to be high and draw 20mA from each one at the same ...
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### voltage to current Module [closed]

I want to output signal in current form (4ma - 20mA) from arduino. I plan to use DAC to get high resolution analog signal 0-5V, but how to get convert if from Voltage form to Current form is not clear ...
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### Can we feel sinusoid? [closed]

If we have a signal of 1 or 2Hz, can our skin receptors feel that sinewave, if that sinewave has aproppriate voltage level?
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### Do power MOSFETs have significant disadvantages over normal MOSFETs?

I have noticed that many power MOSFETs are cheaper, have a much greater $I_{D}$ and $V_{DS}$, and have comparable $R_{DS(on)}$ and $V_{GS(th)}$ values to normal MOSFETs amongst other ...
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### RC circuit How does the current vary after the switch is closed?

in the image below : a quiz from the book "physics for scientists and engineers" in chapter 28 dicussing direct current circuts and RC circuits i need an explanation for the answers for this quiz ...
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simulate this circuit – Schematic created using CircuitLab Currently there is an extension cord that runs from the wall with 10kA. The current on the cord says 10 amps, 125 volts, and 1250 ...
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### How do I calculate maximum current that each pin of PC8575 is able to sink?

http://www.nxp.com/documents/data_sheet/PCF8575.pdf Can somebody tell me which parameter one should look for while looking for calculating maximium Current source/sinked by a pin.
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### Question regarding specifications of power bank for a laptop [migrated]

I'm not sure about how it suits the forum of electronics here on stackexchange, but I hope I'm at the right place. if not, please forgive and explain. So the case is that I own a high-end laptop (...
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### Is a neutral wire necessary between 2 circuits

Suppose I have 2 circuits with their own individual power supply. Circuit 1 needs to send some sort of signal to circuit 2. Would I need to carry the current back to circuit 1 after the signal has ...
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### DAC controlled constant current source

Was given the task of creating the simplest constant current source that can supply up to 50 mA with an ~700 ohm load. I can use any IC's out there. I stumbled across the chip here from linear tech: ...
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### I can't find the values of the currents

The picture below is on page 7 of the datasheet of TL497, it is a switching regulator that I use as an inverting regulator (it has an inverting mode) to generate -24V from 12V in input, in the first ...
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### Minimum Switching Current in Boost regulator Datasheet

I am planning to use TI TLV61220 in one of my designs. My design will be in sleep most of the time & the current in sleep mode is 10-20 uA. In active mode, it wil take max 10mA. The device is ...
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### Pickit3 overcurrent protection

The reason for these questions is I'm using these programmers to test a circuit boards with test firmware so I'm trusting the pickit3 to report programming failures without damage to the USB port and ...
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### Cause of skin effect: eddy current inside conductor

We all know very well that due to eddy current (back EMF) generation within an AC carrying conductor, "skin effect" occurs. Eddy current density: Highest at center of conductor core Lowest at ...
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### Can you only lower the breakdown threshold voltage of solid insulators once with high-voltage?

For example, insulator Z has a threshold voltage of 1000V. After exposing insulator Z to more than 1000V, its breakdown threshold voltage is now 800V. Can I lower the threshold voltage further with ...
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### Input and output relation of ACS712 Hall effect current Sensor

ACS712 works by the use of the hall effect principle. When i went through the datasheet, i found out that the relation between input current and output voltage is varied largely ie. 66 mv/A to 185 mv/...
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### Mosfet keep circuit closed (vape mod)

Hello i made circuit with IRLB3034 mosfet for using vape mod with low current rated button, but i have problem - mosfet is firing itself when i plug battery in and its overheating (coil is 0.5ohm). I ...