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

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1answer
25 views

set one output high at a time when multiple inputs are high

I'm making a small circuit for detect water level of our home water tank .here is the diagram. when water level is low i want to turn red led when water level is max i want to turn green one on and ...
0
votes
3answers
62 views

How does charging a phone battery work?

For example, if a phone comes with a charger rated at 5V and 0.7A, when it's plugged in to charge, what dictates the current the phone draws, is it the resistance of the phone? If I = V/R, do phones ...
0
votes
2answers
42 views

USB power in Parallel, increasing the maximum current using a Y splitter idea[POWER ONLY]

When you connect batteries or power sources of the same voltage, in series, the voltage adds together. When in parallel the capacity of the two add together. Ive seen a few usb>sata cables in which ...
0
votes
3answers
75 views

Transistor feedback loop

In an attempt to create a single transistor flipflop I made this : The Idea : When the base is triggered by a pulse ,current starts flowing from collector to emitter . From the emitter it divides ...
0
votes
5answers
112 views

control multiple leds using only 2 connection wires

i want to control 5 led bulbs using just 2 wires .depending on some condition i want to turn a led with a specific color from 5 led set and only one led should on at a time. here is a small ...
0
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1answer
68 views
+50

How to calculate the induced voltage?

From the given diagram: Conductor(C) is the only movable part with given velocity (v), connected to a stationary terminals(top & bottom) and an exterior circuit with a load. Will current flow ...
0
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2answers
33 views

LED strip and current

I have an LED strip that uses around 2A from 12V DC (25W). I will probably use less than the full strip, so if I cut the strip, will it draw more current (the voltage will stay at 12V) or less? I want ...
0
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1answer
32 views

Generalized transistor equation for Collector Current including the reverse saturtion current?

44I am referring to Millman's Integrated electronics and there I came across and equation $$ \begin{equation} (I_c) = -\alpha(I_E)+I_{Co}(1-\exp^{V_C/V_T}) -->eqn(5.6) \end{equation} $$ where $$ ...
2
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0answers
125 views
+50

Calculating maximum power dissipation based on contact area between two metal conductors

I am trying to figure out how to properly calculate the minimum contact surface area based on the maximum required power dissipation. Let me explain.. I am creating a custom semi-circular metal tab ...
0
votes
1answer
63 views

Are Wire Current Ratings Different in AC than in DC?

Lets say I have a 1.5 mm^2 wire (between 14 and 15 AWG) and I have to use it in two different circuits, will the current carrying capacity of the wire change? One circuit is 240V AC and the other is ...
0
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1answer
49 views

need advice with LM317T current limiting circuit ,new alternative

i am using an LM317 as a Current Regulator for series LED similar to protecting LEDs From over current ( in time of short circuiting) for my LEDs and Mosfets, similar to this picture: the problem ...
1
vote
2answers
106 views

Is there a way to buffer current for high usage periods?

I am using a USB port as a power source(500-1000ma) for my latest design(Wireless Comms and lots of LED's) and most of the time things work perfectly. However at times I do get spikes where the ...
0
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2answers
125 views

How to plan my LED circuit, voltage, and resistor

The LED emitters in my outdoor lamps blew out and I need to replace them but I have to rebuild the emitter from scratch because replacement parts are not available. The whole lamp was made in China. ...
1
vote
2answers
63 views

Opamp AB Class Current Buffer

I am trying to design 100W (100V - 1A) Opamp Current Buffer with unity voltage gain. I will use PA441 or LT6090 opamp. Apex published a circuit for this amplifier. Please look at page 3 from the link ...
0
votes
1answer
32 views

feedback ammeter vs current probe?

Could anyone please let me know which one is better for low current measurement? I'm going to measure power consumption of MCU and camera module, But it seems I can't use shunt resistor, because ...
1
vote
2answers
231 views

What conditions could be expected to occur if one or both inputs of an op amp are left floating?

Question 1: Can an op amp work with both of the inputs floating? I assume that due to the input offset voltage if both the inputs are floating, the output would be +Vsat/-Vsat. Am I wrong? Question ...
1
vote
1answer
25 views

Minimum current draw of AC to DC converter at no load

I wanted to know if there is a minimum current draw on the AC to DC converters from the AC source when it is connected to an input voltage of 120V (60Hz), when no load is connected at the output of ...
1
vote
1answer
25 views

Choosing opamp with sufficient output current for Voltage Reference with high impedance load

I am designing a differential sensor that will be placed on the skin to detect biopotentials. Two inputs are fed into an instrumentation amplifier that has a reference set at 1.5 volts (VREF15 in the ...
1
vote
1answer
89 views

Current specifications for parallel circuit from two cross connected power supplies

I have two 24 volt DC power supplies (that each look like this - according to documentation). ...
-4
votes
1answer
68 views

ADC conversion using a Datasheet

Is it possible to find a corresponding digital value for an analog current value(Amps) using the ADC component datasheet? If yes, what are the parameters I should consider? Thank you!
-1
votes
1answer
96 views

All Possible Methods To Reduce The Current Without Reducing LED brightness

Am working on a project where in I had to control 169(13x13) LEDs, I chose ATMEGA 2560 processor for this task but it has absolute maximum Source and sink values as 200ma which was not sufficient. I ...
2
votes
1answer
230 views

Where to pull LED: VCC or GND? [duplicate]

I am going to blink with LED from MCU I/O port. Where do I need to connect LED: VCC ot GND? I think it might be a difference whether the current goes into the inside MCU (when the port is low level ...
0
votes
1answer
35 views

Which BJT-parameters need to be derated at raised ambient temperature?

I am designing a discrete MOSFET-driver stage based on BJTs in simple push-pull configurations and wondering, which of the values under absolute maximum ratings I have to derate at higher ambient ...
1
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2answers
46 views

Is there a virtual ground in this op-amp?

Consider an ideal differential operational amplifier whose circuit looks like this, Now in this circuit diagram it is given that, the negative terminal is at 0v. But if I give a sine wave as input ...
0
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1answer
39 views

in order to understand bldc motors and their working principle, I read a lot on the web, and I see them like a tripolar steppers, am I right?

I was told my previous questions were not well received by the community, it was never my intent to post a repeated question or a bad formulated one, and english is my second language, not my ...
0
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1answer
83 views

Questions about LEDs in a circuit [duplicate]

I read statements like ‘An LED has a fixed voltage drop regardless of the current running through it’, but looking at the following examples (using arbitrary numbers), can someone confirm that the ...
0
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1answer
28 views

How to interpret step-up output current with respect to input/output voltage

I have a Pololu 12V step-up converter (U3V12F12) that I'm powering with a 3.7V 6600mAh lipo battery. The idea was to use it to power a dev board that requires a 12V input. The dev board draws about ...
0
votes
1answer
44 views

Return Current Through Split Planes (1.5V, 3.3V, 5V)

If return path as GND plane, then return current/signal will be ended to GND pin of driver IC. Right? Similarly, if return path as POWER plane, then the return current/signal will be ended to VDD pin ...
0
votes
1answer
30 views

2 Questions regarding XTR105

The questions that I'm about to ask will likely "paint very broad a stroke" and open-ended, so feel freed to give whatever that may come to your mind, in full detail or with some rough ideas. XTR105 ...
0
votes
4answers
222 views

Placing just an LED in a circuit?

Kirchhoff's law states that “in any closed loop network, the total voltage around the loop is equal to the sum of all the voltage drops within the same loop” What would happen if you placed a LED ...
0
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1answer
99 views

How does earth ground complete the circuit?

I just started reading a book on electronics and currently reading some concepts of earth ground. I came across a section that mentions practices about grounding as follows: The ground terminal of ...
0
votes
1answer
42 views

How to safely connect the Arduino 5V Pin with a 5V wall wart and USB TTL converter for data transfer?

I'm currently developing a project that involves components with about 2A current draw. These are controlled by an AVR Atmega168 processor with Arduino bootloader over a CH340G USB TTL converter. The ...
-1
votes
1answer
45 views

5 mA DC Isolated Current Sensor

We are trying to measure the presence of ~ 0-5 mA of DC current in an isolated manner (no shunt resistors). Are there any commercially available solutions?
0
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2answers
79 views

Calculating voltage in a simple circuit

If I had a 12V battery and wanted to use an LED that used 2V and 20mA, then I need a resistor that will drop 10V and provide enough resistance to produce a current of 20mA. Therefore I would use R=V/I ...
0
votes
3answers
94 views

How can I be sure to supply enough current without increasing the voltage? [closed]

I have been trying to supply 5V into parallel-connected components which require a certain amount of current in total. If I wanted to increase the current from my supply, can I increase its current ...
0
votes
0answers
38 views

Pulse circuit current control

This is a simple circuit I'm trying to build. My aim is to supply a programmable pulse controlled by a microcontroller to drive a laser diode. The main 5V pulse signal is generated from the board ...
0
votes
3answers
154 views

What are coupling and decoupling capacitors?

I have come through many places stating capacitors as coupling and decoupling capacitors, but I can't understand what is meant by coupling and de-coupling capacitors? Can anyone explain me what they ...
4
votes
1answer
57 views

Current Ripple in Ceramic Capacitor Selection

I need to choose a ceramic capacitor (ESR<10mOhms, 5VDC) for my buck converter application, whose value should be around 300uF. The reason for going for a ceramic capacitor is the low ESR they ...
2
votes
1answer
130 views

Why inductors lose inductance when connected in parallel?

Generally I can't arrive due to why inductance lose inductance when connected in parallel. If two capacitors are connected in series, the distance between the plates of a capacitor increase and thus ...
0
votes
1answer
58 views

Why do we ignore parasitic capacitance in dc analysis of transistors?

Consider a transistor that has parasitic capacitance of the order of pico-Farads. Then at low frequencies, consider 10Hz $$X_C=1/(2\pi f C)$$ \$X_C\$ will be in the range of giga-ohms. ...
1
vote
1answer
217 views

Reducing magnetic field span, effects on induced EMF/current?

A conductor of known volume (V) passes a uniform magnetic field(B)with a constant velocity (v) the conductor is a source of induced EMF, a power source to a circuit. The induced EMF can be calculated ...
0
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0answers
24 views

current density vs voltage curve in OLED

What is a current density vs voltage curve? what could be an ideal white organic LED's plot? Can someone explain how to understand a J-V sweep?
2
votes
2answers
52 views

DC Forklift high current power supply

I have an old 36v DC battery hydraulic indoor forklift. The batteries are 23 years old, and no longer hold a charge for more than ten minutes, although they are a good counterweight. I have tried ...
0
votes
0answers
35 views

Multichannel voltage/current measurement device

I'm building a 4 channel voltage and current measurement device. 2 channels for voltage (ac 0-300V rms and dc 0-300V) 2 channels for current (ac 0-5A rms and dc 0-5A) There is a central ...
0
votes
1answer
65 views

How does a junction-less transistors work?

I have recently read in a book that in 2010,junction-less transistors were developed. I can't understand how a junction-less transistor can be used to amplify current or voltage with having any ...
-2
votes
0answers
28 views

EDLC Cyclic Voltammetry: Current peaks keep rising

I am running tests on some EDLCs using cylic voltammetry (sweeping from 1V to -1V) and for some reason the current peaks are gradually getting higher with every sweep. This doesn't make a lot of sense ...
0
votes
1answer
48 views

Headphones with dual jack, reduced volume

I recently built a pair of headphones and added an audio jack input to both the cans, for convenience of connecting. That would also serve another purpose of letting my girlfriend hear the same music ...
1
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1answer
59 views

Braking of Motors

Is an induction motor delivering or drawing mechanical power in the braking region? . according to the torque slip curve of an Induction motor,torque is positive and the motor continue to rotate in ...
-2
votes
2answers
59 views

Starting current of an induction motor

How to calculate the Starting current of an induction motor if I have the power in kilo watts and the voltage? I have looked up formulas , but I got confused. I calculated the full load current by ...
0
votes
1answer
66 views

DC motors in series to get 5 Volts?

I am trying to build a circuit that has wheels rotating that are connected to a motor. This motor will then generate 5 Volts to a battery which then charges lets say a cell phone. I have two wheels ...