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

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26 views

Circuit error: Possible reverse current in the circuit

Imagine the system: 1. Power supply connects to CAN EGSE 2. Through DC/DC converter, EGSE provides converts 28V to +15, -15, and 5V outputs 3. The outputs go to the module Note:EGSE provides CAN ...
0
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1answer
64 views

Circuit similar to current divider

This is a circuit with a general, unspecified logic gate fed by a battery. The series \$ L \$ and \$ R \$ represent the wire which carries the current from the battery to the logic gate. ...
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2answers
96 views

Is the current gain value constant for a single BJT ?

hfe of a npn bjt transistor is given by collector current / base current so to calculate hfe you need to know the collector current and base current (which can be set using resistors) . I have to ask ...
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1answer
27 views

Circuit for controlling 3 DC motors

I have a simple 3 motor robot arm. Without much experience or knowledge, I put together a circuit for controlling it. Circuit is below: Now the circuit actually works and I can program the Arduino ...
0
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1answer
33 views

How to properly compute device need and set of a Universal adapter for powering said device [duplicate]

So, I just blew the fuse in my 17" monitor using a universal adapter with the settings Input: 100-240V 1.5A(1.5A) 50/60hz Output: 15/16/18.5/19.5/20/22/24V (max of 70w) I want a clarification of ...
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1answer
29 views

Calculate DC pulsed Current going into Inverter

Have created a DC battery monitor for a Narrowboat. All the sensors work as exspected except the one measuring the current to the Inverter, which I cannot get to show the correct value. I have tried ...
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0answers
28 views

Motional EMF and Electrons

Here is a typical description of motional EMF: "The figure below shows a conducting rod of length L being moved with a velocity v in a uniform magnetic field B: The magnetic force acting on a free ...
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1answer
39 views

12volt LED used with 12 volt, 6A power supply.

Thank you for reading and thinking about this: there is some unknown factor here. I need to use an LED to light an area of a device. The device has a 12v, 6A power supply. I was expecting to have to ...
0
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1answer
69 views

PCB Board drawing high current when little bit of liquid gets into it. How to debug the board?

I am new to circuit design and debugging them. I have recently helped in building a PCB with certain kind of circuits on it which includes opamp, boost converter, microcontroller and accelerometer. ...
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0answers
32 views

The real flow of electricity [duplicate]

Let's say I have a battery labeled "+" and "-". It is unclear to me which of the following is true: "+" and "-" actually represent the negative and positive terminals respectively, and thus current ...
0
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3answers
103 views

What happens to voltage source if I take out both volt and current with separate circuit using diodes and then combine both separate circuits?

I have 3.8V and 1.2Ah battery. I will use a step up circuit that gives 5v and 200mA output using 2v in (from my battery). Then I will use blocking diode to take voltage only(5v) and I don't need ...
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1answer
36 views

PSU with dc stepdown buck

I want to connect different LEDs that have these parameters (the LEDs I am using are just generic LEDs I got from ebay.): Led 1: 6.4V - 7.2V @ 0.7A Led 2: 2.9V - 5.6V @ 1.9A Led 3: 8V - 12V @ 3.4A ...
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0answers
11 views

How to interpret the spectroscopy, electro-chemical analysis and efficiency data related to OLEDs (Organic LEDs)?

Can someone help me understand and interpret the characterization results of OLEDs? I am new to this field and I have little background in this field. Can anyone explain the external and internal ...
0
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1answer
28 views

Holding current of a thyristor

What is the anode to cathode voltage that corresponds to the holding current?And is the forward conduction current extremely large?I see no limitation besides the forward resistance of the device.
1
vote
1answer
43 views

Is there any wearout mechanism for a relay simply from current flowing?

How will the wear of a relay be affected if the current through the relay is brought to zero before the relay is operated? I'm thinking about having a solid state relay in series with 3 mechanical ...
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4answers
260 views

Why does temperature modify the characteristics of a diode?

Everyone knows that temperature affects every semiconductor device you can think of, and diodes are no exception. From the below graph, we can see that the temperature has marked effects on pn ...
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2answers
42 views

The optimal way of MCU power consumption measurement

I'm trying to measure the power consumption of various MCUs(AVRs and STM32). For this measurement, a power supply and oscilloscope will be used. Because I want to plot the power usage vs time just ...
1
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1answer
52 views

led voltage and current relationship via a driver

I am trying to understand what happens to the voltage supply to a high power LED when using a Constant Current LED Driver. Things I (think I) Know: -An LED has a certain range of operating ...
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3answers
43 views

Matching appropiate current value for components

I was looking around the site and I encountered an intresting answer.The one who posted it said that:"If you supply too much current to a device,it will draw as much as it needs" and also that if you ...
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1answer
44 views

Ac to DC conversion

In a battery charger (ex.laptop charger), the ac voltage of 120volts is converted to a DC voltage to charge the batteries in the laptop. But, the maximum current available from a 120v socket is 15 ...
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2answers
48 views

Connecting a 20 amps battery charger to an 18 amps source [on hold]

I have an inverter with a 20 amps DC battery charger (AC to DC ). I need to a connect the ac Generator output to the ac input of the inverter. The thing is that the generator can provide a maximum ...
0
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2answers
32 views

Losses in wire with varying cross section along its length

Say I have 5 meters of thick wire (10 sqmm), and for the last couple of centimeters, I have to use a piece of 2.5 sqmm wire for mechanical reasons. When sending a large amount of DC (say, 30 A) ...
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1answer
20 views

CD4017BE output pin question

I am designing a circuit which uses a CMOS decade counter to activate and deactivate pairs of transistors in turns.The problem is:will the IC be damaged if the current of one of the outputs(activated) ...
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2answers
91 views

Measuring very low current

I have asked here a month ago regarding measurement of very low current. I was told that Amper-Meters today has this resistance in series that will cause a voltage drop, hence you can't measure a very ...
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1answer
52 views

Easy PCB trace width calculation

I've tried this question and this and several other possible duplicates of this question, but I still can't wrap my head around this. I'm using OSHPark for PCB production. They support a minimum of ...
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4answers
108 views

Does electrical current flow from positive to negative or negative to positive?

When you listen to people wiring up a DC circuit they seem to mumble about the electricity flowing from positive to negative. However in school I was always taught that DC electricity flowed from ...
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1answer
37 views

voltage mode vs current mode motor

I wanted to ask question regarding voltage vs current mode for a feedback control motor . Will operating in current mode have any effect on our torque values provided that we are keeping the speed ...
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2answers
39 views

Deactivating NE555P with a latch

I wish to use a two gate latch to control a 555 timer.The goal is to turn off the output by shutting down the IC.Will this happen if I disconnect the positive supply or the ground so there will be no ...
0
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1answer
27 views

Reading Current Transformer using Arduino

I want to be able to read current using an Arduino. I have purchased a Hobut Current Transformer from Farnell (Element14): ...
2
votes
1answer
59 views

How much current does a Android phone USB port supply?

this is my first post on here, so bear with me. I know that a USB 2.0 port delivers 500mA and USB 3.0 delivers 900mA. Is this any different on a phone, because it is a smaller device? I was thinking ...
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1answer
49 views

High Current Split Supply

I am looking for a way to construct a 1 A, ±15 V split-supply. So far, I've seen a number of designs for split-supplies (http://tangentsoft.net/elec/vgrounds.html), but they are all low current (i.e. ...
0
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1answer
47 views

About Fly back diodes and motors

so here's the situation, i have a motor and i am controlling it with a bunch of transistors and an arduino, so i think i need a flyback diode to protect the transistor and my arduino, problem is i am ...
-1
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1answer
54 views

How to deal with inrush current tripping circuit breakers?

I have a temperature controller supplied with 230VAC via a 0.5A circuit breaker curve C. The thing is, the MCB trips as soon as power is turned on. I have measured the inrush current profile without ...
0
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1answer
57 views

Is potential difference is sufficient for charge/current flow?

Suppose there are two points A and B. A is having fewer electrons than B. That is,it is positive with respect to B.If these two points are connected by conductive wire will the current flow? If this ...
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1answer
41 views

step down switching frequency

If I have a power supply that outputs 32V,7A and I need to power an LED that requires 24V-2.8A, can i use this step-down module to power up the LED? ...
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1answer
60 views

Heating Nitinol while driving LED

Edited in my LED module current requirements, fixed needed resistance and added a schematic to better illustrate what I'm trying to do. Thanks Tom and asmydolf. Okay, it might seem like a dumb thing ...
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0answers
35 views

Does connecting different solar panels in parallel affect total current? Are there any dangers? [duplicate]

I've posted this question on another forum as well but got no usable replies. I've done a lot of research but only found info about batteries in parallel, which says higher voltage will charge lower ...
0
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1answer
50 views

switching power redundancy

I have a load (LEDs) that draws 36V, 5A. The circuit is made in this way: Power Supply (AC-DC) -> LED Drivers (5 in parallel) -> LEDs (5 strips). What component I need to install if I want to add ...
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3answers
52 views

finding angular frequency when current is maximum in circuit

A series of ac circuit consist of an inductor and capacitor. The inductance and capacitance are 1 henry and 25μf. The current is maximum in circuit, then what will be the angular frequency? The ...
0
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1answer
30 views

Does wire gauge significantly impact the charging rate of smartphones?

This article claims that wire gauge in USB cables significantly impacts the charging rate of smartphones: USB cables have a data wire and a charging wire within the cable itself. Most USB ...
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3answers
62 views

Solid State Relay operation

A solid state relay specifies a trigger current of "7.5mA/12V". How much current does it draw at 5V? This is the relay. I'm controlling it with an Arduino which has a maximum current draw of 40 mA ...
3
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1answer
192 views

How many ohms do you need before you need a resistor?

Okay, I'm rather a bit confused here now. I am trying my first real circuits, for some LED lighting. I tried making a little circuit last night, matching two LEDs in parallel on 4.5v of battery. ...
11
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3answers
706 views

Why does the intensity of light in LEDs not increase with current after a particular value?

I read in books that light intensity from an LED does not increase beyond a certain value of current. The amount of light emitted depends on the combination of holes and electrons. If so, then as the ...
-1
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0answers
51 views

Would this power supply work for this config?

I have looked around on the forum but could not find an answer specific to this issue. I have 8 parallel LED strips, each works at 30-33V and requires a constant current of 0.7A. I have a power ...
7
votes
2answers
148 views

Eliminating micro current flow

I've built a RAM expansion cartridge for my VIC-20 computer. It uses the CY62256L 32KB SRAM chip. It has been working fine except there's a quirk. If I power off the computer, but leave the ...
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0answers
77 views

State Equations

Please can you help me in finding the state equations for the circuit below? My problem is the two capacitors. How will we cater for the second capacitor? I only know problems with 1 capacitor and 1 ...
1
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2answers
156 views

Reasons for a voltage follower introducing voltage gain?

I'm using a 3130 op-amp as a voltage follower (unity gain buffer amplifier). However it is introducing voltage gain. It is wired the following way: This is then just fed into a simple low pass RC ...
0
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1answer
59 views

Testing Amps And Resistance On PC Case Fan

Context: I'm wanting to tinker around with some mini solar panels to power some old PC case fans I have laying around. I know that case fans are generally 12v so I was thinking of running some 3v ...
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2answers
109 views

How to increase current of a circuit? [closed]

Hello everybody please help me. I want more output current in my circuit. How to increase current in a circuit? For any instance my circuit output is 5V and 1.2A but i want 2A keeping fixed 5v. Is ...
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2answers
29 views

Estimating battery capacity remaining from SLA connected to motors

I have an SLA battery, at say 10 Amp-Hours, connected to 3 high power motors. Each motor can draw up to 10 Amps each (worst case / max power). Using Q = It as an ...