Questions tagged [current]
Flow of electric charge - typically movement of charge carriers, such as electrons. Measured in amperes (A).
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list some low voltage(typical voltage as 3.3V) 3 to 8 decoder IC numbers and manufacturer [on hold]
I want to drive 7 LEDs using Attiny85 with different delays, using 3.3V and the light intensity is very important factor that I need to consider.
I tried with Charlieplexing, but when more than 1 ...
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2answers
63 views
Max startup current for Vacuum cleaner motor
We used the vacuum cleaner motor 2200W 220v in one dental device (vacuum former) as you can see here:
So now one of our costumers said when they used this device the power cable is warmed and when ...
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1answer
49 views
Inversely proportional current controlled voltage source
I need a circuit that senses a current and outputs a voltage, but in inverse proportion.
In my case:
When the current is around 0A, the voltage source should be around 18V (my Vcc).
And when the ...
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0answers
34 views
What is the “push” for vcc voltage [on hold]
What is the "push" for vcc voltage? For example, in a transistor, how is positive voltage applied to the gate? And what is the particle carrying the charge (electrons?)
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1answer
174 views
How does the Ring doorbell get powered?
The Ring doorbell is a pretty simple and useful product. I was wondering: how does the Ring doorbell get power without activating the chime? As far as I know, a doorbell works by shorting two wires ...
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2answers
122 views
Variable Current Source
simulate this circuit – Schematic created using CircuitLab
I need to build a variable current source that operates off a 36V supply, if possible using a single op-amp and a mosfet. I need to ...
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1answer
56 views
Do RCDs work for DC systems?
I'm designing a product powered by an alternator with a DC regulator that will provide me with 24 V DC and something like 100 A rated consumption. Do RCDs protects against earth leakage current in DC ...
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2answers
86 views
What is the peak current for CR, LIR and AA batteries?
I'm working on a project that requires low energy consumption. In standby mode, it will consume about 11uA. However, when it starts working (it will transmit data in RF), the current goes up to 121mA. ...
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66 views
Possible causes for the introduction of a sudden bias in the spectrum of a spectrometer
I have an ultraviolet-visible spectrometer. Recently, I changed the bulb of the current light source with an identical bulb. I immediately observed a change in the shape of the spectrum which is as ...
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1answer
51 views
Voltage controlled current source doesn't have constant current
simulate this circuit – Schematic created using CircuitLab
I have this circuit for a voltage controlled current source, but it isn't working.The transistor is a Darlington.The circuit is ...
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1answer
86 views
How does a capacitor affect the flow of the current?
I understand that the capacitor is like a secondary DC source when it's almost fully charged. What I don't understand is the way it behaves in a circuit.
It discharges itself when it's full or when ...
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2answers
87 views
Why the base current is zero in B part of this question?
In the B part of this question , i am not getting why the base current is zero. Everything seems to be fine but still not getting ...
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33 views
High power source and low power load (device) [duplicate]
Can we drive low power load on high power source? For example we have source power 12 volt 60 amp and load power 12 volt 5 amp. Do we need resistor between them? If needed, what value will it be and ...
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1answer
40 views
Voltage regulators in series
I'm trying to figure out if my power distribution setup is hurting my circuitry.
Below is a picture of the setup for one device:
The power supply is a wall adapter rated for 6VDC/900mA output.
The ...
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2answers
39 views
What is the current draw during load on the LM1117 3.3v
I am looking at using the LM1117 3.3v voltage regulator.
I would like to determine the current draw to power the regulator's function, during output of something near 650mA.
All I can find is ...
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2answers
73 views
What is difference between DC current from dynamo and DC current from battery? [closed]
Dynamo generate DC current and battery also gives DC current. Here my question is when I use inverter, it worked with battery however doesn't work with same voltage of current from dynamo. Why? ...
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1answer
68 views
Current consumption calculation + Full wave Bridge rectifier
I am facing to calculate the current consumption in a segment of a circuit as shown in the picture below.I have used the formula (showed in the picture) without considering the impedance of the ...
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1answer
83 views
Parallel connected LED and current problem
First of all, I don't have much electronic knowledge.
I am having trouble connecting the LEDs in parallel.I have two types of LEDs which have different power.Here are some current measurements:
The ...
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1answer
1k views
Short circuit detector (autoreverser circuit) using current sensor and switching relay
First of all I’m not electrical engineer. The original idea is described here.
It is a model railroad problem. The rails are carrying a power signal (DCC) 12-18 V. The frequency is ~17 kHz. It is a ...
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3answers
75 views
MT3608 gets very hot only handle 1A
In the datasheet they mention the MT3608 can handle up to 2A however in some stress tests with a load tester it gets already very hot at 1A. It is so hot, it is impossible to touch the board, all ...
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3answers
37 views
How can you visually model voltage vs. current?
I'm trying to wrap my head around Voltage and Current. I saw this analogy on a post from another site that seems to make sense:
For circuits I tend to mentally use a "plumbing" analogy. The voltage ...
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1answer
30 views
What is the maximum voltage that a RJ9/RJ10/RJ22 can carry?
I want to use a 4p4c modular jack for carrying isoSPI data and 12V at <1.5A and am not sure if the connector or cable could handle that
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1answer
49 views
Need help with 2 Transistor Current Limiter Circuit in LTSpice
I am new to LTSpice. I have attached a picture of my circuit below:
The goal of the circuit is to provide current to the R1 until It is too high. Then the BJT will activate, shutting the FET off.
...
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2answers
95 views
Measure volt, amps, watt and kWh of an external 12 V DC system
I saw online some cheap hardware ~10$ that can measure volt, amps, watt and kWh and display the results on an LCD screen.
I could buy and plug these on my 12 V solar panel system to monitor it. (5 of ...
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2answers
70 views
Will this circuit work? Using USB extension on a potentiometer
I have the following circuit. It is a simple Arduino project to read analog data from a potentiometer 10K. Click here for video link if you're curious.
The circuit shown above is tested and working ...
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32 views
Thevenin Termination Current Calculation and Iol/Ioh
I am calculating the current draw for a thevenin termination and am having issues with the Iol and Ioh from the datasheet.
From my understanding, when the source goes high (Voh), then Vtt (dest input ...
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7answers
1k views
How do batteries connected in parallel give more current than batteries connected in series?
Let's say we have three 1V batteries and we're connecting them to a 1Ω resistor. Connected in series, the voltage is 3V and since the resistance is 1Ω, that means that from Ohm's law, the current ...
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3answers
57 views
3hp motor contactor size 22A or 40A?
So my place has 2 contactor sizes of 22A and 40A. Now i know that both will be more than enough to power up a 3HP motor. To avoid oversizing in this case, would i need to provide additional fusing to ...
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1answer
53 views
Current rating vs duty cycle
Is there a rough relationship between the current rating of a device, say a connector, and the duty cycle? For example, I assume a connector rated at a continuous 5 amps isn't necessarily going to be ...
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1answer
39 views
Current source for high current LED driver- 24Vdc/max:16A
I am working on designing a current source for a LED driver, which can work up to max:16A, as long as stays On less than 500msec.
Actually, the leds circutry is a Dome-light which is divided in 4 ...
7
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2answers
1k views
How can I fix a dry solder pin in a BGA package?
I am facing problem in a 16-bit transceiver chip, 74LVCHR16245AZQLR, which is a 56-pin BGA package.
Its one data pin is not working as expected while all other pins are working OK. The problem pin is ...
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1answer
34 views
LED Strip - Voltage Drop when Wired in Parallel
please have a look at this chart:
I have a question on the calculation of voltage drop on each of the connection point between the wire and led strip. We are using 1.5mm2 wire and 24V led strip which ...
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1answer
68 views
How to find the current and voltage of this circuit?
I have this circuit with a Z-Diode in reverse.
Find U2 and I2?
I solved the fist circuit.
U1 = 0.7V, I1 = (15V-0.7V)/1kΩ)= 14.3mA
The results for are U2-8.2V I2=6.8mA but I just can't figure out ...
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0answers
39 views
Why does no current flow when GND of one battery is connected to VCC of other battery? [duplicate]
I have enough experience with electronics to design and solder working circuits. I never quite understood though why circuits must be closed for current to flow.
I alway understood electrical current ...
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3answers
85 views
Is a current varying output or voltage varying output for a 4-20 mA sensor more reliable for a rocket?
For the internal plumbing system of a rocket which is expected to reach 100 km above the ground, industrial pressure sensors with a 4-20 mA current output and a 0-10 VDC output are available. What ...
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2answers
91 views
Current carrying cable/busbar cooling ways in an aircraft
For an aircraft has an altitude 35000 feet, what'd it have to cool its cables/copper busbars up? High altitude means lower air density and it means lower oxygen, convection doesn't make sense and if I ...
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5answers
93 views
Voltage signal and Current Signal
Please give an intuitive explanation of difference between how a signal or data is carried using voltage and current?
I'm wondering even though current and voltage inevitability co-exist, why do we ...
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3answers
103 views
Why does my Inverter overload?
I have a battery pack consisting of 4 10 amp-hour 12 volt batteries wired in parallel. We recently bought a 2000 Watt rated HammerDown power inverter to run a 500 watt window air conditioner. The air ...
0
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1answer
78 views
Build a circuit so that you can determine the I-V curve of a diode
The question I have is: how can I design a circuit so that I can determine the I-V curve of a diode.
I've found this one:
But is that a smart circuit or can I find a better one? Thanks for any ...
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0answers
46 views
Understanding a ZVS Oscillator in-depth
For a project I've been building, I've been using the (overused) ZVS oscillator that can be found online. So far it's been working great transferring power wirelessly, but I'm interested in ...
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2answers
32 views
Series resistance for DC brushed motor with PWM drive
I'm looking for double-checking my math/assumptions, and if possible, a physical explanation of the "rising corner frequency" phenomenon.
When controlling a DC brushed motor with PWM, typically by ...
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0answers
39 views
LED Strip - Wire Size & LED Controller
First Question:
I bought a few rolls of high density 5M individually adjustable LED strips - 14.4 Watts/M @ 24V which equals to 0.6A per meter.
I was advised I could run up to 10M in series which is ...
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0answers
77 views
Peltier Cooling
I am trying to incorporate a peltier module on a relatively small space. Is there a way to incorporate a 40 x 40 mm heat sink (+- 10mm) to a 40 x 40 mm peltier module in such a way that it can run for ...
3
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3answers
688 views
What does the output current rating from an H-Bridge's datasheet really mean?
I bought the H-Bridge VNH7070BAS from ST because it would drive up to 15A, but when I test it, it only reaches 6A and then it shuts down.
What does that value really mean?
How can I get the output ...
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1answer
37 views
Current Consumption
I have a 3S LiPo as a power source for my circuit. My load consists of a peltier cooler module, a DC fan, and a water pump all running at 12V. Now, the question is: if i incorporate a DC fan that has ...
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43 views
Earth ground and return path [duplicate]
During a fault, how does current flow through the earth wire when the earth wire has no return path? Doesn't the earth wire in earth grounding terminate at a copper plate located deep underground, ...
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0answers
37 views
LED Matrix creation using resistors & MAX7219
I've been attempting to create my own LED matrix, but now I've plugged it all together I'm getting some unexpected LED's lighting up, it seems some are getting power when they shouldn't (not very ...
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2answers
67 views
what is the current range (amp) that could be drawn from the home electricity? [closed]
We always hear that home electricity has 220v (depends on country, maybe 110v or etc) voltage. But i cant find anywhere how much ampere we can get from it? So how much is the maximum current that we ...
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3answers
94 views
How to block reverse current from battery to charger (DC-buck CC/CV module)?
The set-up
For a project, I have a set-up where the power to the main load comes from either a AC-DC adapter input (24V) or a battery pack (12V to 16.8V - 4S4P 18650 Li-ion cells). The battery pack ...
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0answers
32 views
Is this schematic on the track to create a AC clipper voltage and current regulator?
Good evening
I'm trying to make a "clipper" circuit for an AC Voltage source that feeds 2 6V light bulbs rated at 10W and 5W.
Problem is that the generator at idle speed produces 4V and at maximum ...
