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

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2
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0answers
13 views

Reducing noise for a TDA8947J amplifier

I have an amplifier that produces a lot of background noise and I would like to cut it down a bit. I supposed the source of the noise is: 1. poor filtered power supply (it already has a 4700uF/35V ...
0
votes
1answer
60 views

How can the Vss or Vdd pins of a MCU handle sink or source current?

Today I was seeing the datasheet of STM32F103 MCUs and I came across with an interesting thing. assume I have an STM32F103RET6. it's a 64pin MCU of STM32 series. the pinout is this: It has 4 ...
0
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0answers
35 views

Current spikes when driving stepper motors

I am trying to figure out appropriate values for a timeout mechanism provided by the DRV8811 stepper motor driver. While doing my research I came across a website that conveniently has a write-up ...
1
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5answers
114 views

Does a led determine itself current load? [duplicate]

If I use a power source rated at 2.5v and 1 amps for power a standard red led , what should happen to led? Does it get burn for the high current value or not?
0
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1answer
27 views

Constructing a dc circuit with different input and output currents and voltages?

I am trying to answer this question (at the moment I am looking at part a) only as I still have not figured it out): But what I do not understand is how you can change the input and output of dc? I ...
0
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2answers
36 views

When a datasheet specifies output current is it per pin or aggregated for all pins?

When a datasheet specifies something like output current, as with the 74FCT244 or for example, is this referring to the aggregated output current between all pins or the capacity of a single pin ? ...
0
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2answers
46 views

Led Strip Heating Up

I have an LED strip with 7.2 Wattage/m and the strip is 3 meters long. The led strip has R,G,B,+12v inputs and I have connected a 12V DC 1000mA power supply to the +12v and attached transistors to ...
0
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2answers
41 views

Parallel of two shortcircuit

simulate this circuit – Schematic created using CircuitLab I have trouble finding value for I2 current. Would I1 go through NODE1 down and close the loop, so I2=0, or go to the left from ...
0
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2answers
74 views

How to reduce current

I need help reducing current in my motor driver. The chip is the L293D motor driver with output max 600mA. My stepper motors draw maximum 350mA per phase and operate at 12V, so I am concerned about ...
0
votes
1answer
37 views

Stepper motor current specifications - 12V/350mA, but draws more at lower speeds?

I have on hand a simple 12V/350mA stepper motor the datasheet is lacking, so I can only assume 12V is the maximum sustained voltage and 350mA is again, the maximum associated current. The datasheet ...
1
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2answers
66 views

Direction of current flow?

From the following diagrams: Are the current directions correct? Based on where the terminals are connected on both conductors?
1
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3answers
215 views

Max voltage vs current for LED

There's some basic flaw in my understanding of how LED's or diodes in general work so hope someone can help and forgive the simple question. So generally when one has an LED in series with a ...
0
votes
3answers
50 views

source indicator, dual schottky passive load transfer switch

A dual schottky diode powers a load from either battery or off-the-shelf power supply. How to indicate which sources are providing current to the load? None, one, the other, or both. Yet draw less ...
0
votes
2answers
59 views

how can i decrease the voltage of an AC-DC adapter without decreasing current (mAmpire)

i have an AC-DC adapter with 5volt 350mA (actually an old cellphone charger). i need to decrease it's voltage to 3volt. i tried adding a resistor in series & it worked, but it also decreased the ...
0
votes
3answers
107 views

Is the white wire carrying any electrons

I don't understand why neutral in 110v , does it carry any current ,does the load like the light reduce the current
0
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0answers
41 views

switching of mosfet using IC TL594

Switching of mosfet using IC TL594 I can't find the required circuit diagram switching of the MOSFET using an IC. Is it good to use the PWM method for switching ??
0
votes
1answer
71 views

Can electrical wires be ruined by overheating?

I have a friend that works with automotive mechanical sorts of things, and he told me that he had a pair of jumper cables that was ruined by too much current; it wasn't that the insulation melted: he ...
-1
votes
2answers
68 views

What does current draw mean for the [closed]

Does this mean that the battery only outputs current equal to the amount of current draw? I always thought that batteries outputted a constant output, but apparently after some research I found this ...
0
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3answers
83 views

Circuit Starving Question

I have a circuit where 2 DC motors are connected to 4 AA batteries and being controlled by an Arduino microcontroller. Whenever the motors start, they starve other components in the circuit and it is ...
1
vote
1answer
57 views

LM2678 Output Voltage Drop Under Load

I soldered up a LM2678 for a 5V 1A output with a 12 volt input (Input voltage and current from (12v supply @2A) like shown here. http://www.ti.com/lit/ds/symlink/lm2678.pdf It outputs a solid 5 volts ...
1
vote
3answers
174 views

Current Divider Formula Proof

Just recently, I was watching a video where the presenter used a current divider formula (I think he called it the "G" rule) to calculate the current flowing throw a resistor on a circuit with two ...
0
votes
1answer
43 views

Maximum surge current through short run of 24 gauge wire

I'm making a sequenced rocket launcher. I want to apply 5 amps for 3 seconds through a 12 inch run of 24 gauge wire. Since the launcher has four slots, I figured I could use cat5 ethernet cable. ...
0
votes
2answers
86 views

When does and when doesn't current flow to ground?

I was thinking about when current can and can't flow to ground. I came up with that current will only flow to ground when we have at least two grounds in the circuit, since then we have a complete ...
1
vote
1answer
58 views

how to calculate the current in this circuit ( opamp)

how to calculate the current in this circuit (show with the green arrow) Can someone explain with a bit of details. In the books i got from school, they dont come close to what this looks like.
2
votes
5answers
114 views

How do voltage, resistance and amperage work? (In DC circuits)

I have a (probably newb) question that I can't figure out. What I think I know is this: Voltage is electric potential (or rather a difference thereof) Amperage is the rate at which electrons move ...
2
votes
3answers
145 views

How does a flame sensor or thermocouple operate with just one wire?

I am learning electronics and I just got stumped. I was just looking at a flame sensor and it appears to have only has one connector. I thought sensors in general need two wires to form a complete ...
-1
votes
1answer
46 views

Li-ion Battery charging process [closed]

Why are constant current mode and constant voltage mode needed when charging Li-ion batteries? Why do we apply saturation charge even after the cell voltage reaches 4.2V? What exactly is 'I-sense' ...
2
votes
2answers
169 views

What does a parenthesized current rating on a switch mean?

I'm speccing out some switches for a project... is this some standard notation I've never seen before? Electrical Ratings: 12(4)A 250V AC What does the ...
0
votes
0answers
25 views

Current in op-amp rails [duplicate]

How can I estimate the current that an op-amp will sink/source from its power supplies? Will the current in the two rails be similar, or does their relationship depend on the output level? In ...
-2
votes
1answer
51 views

what is the value of resistor used for 4 digit 7 segment 12 pin display?

refer circuit http://www.instructables.com/id/Arduino-4-digit-7-segment-display/ .Here no any resistor is use is there any need to connect resistor for a b c d e f g .And is there any alternative for ...
0
votes
2answers
97 views

How to power a 12V6A peltier device with a 14.4V battery?

How to power a 12V6A peltier device with a 14.4V battery. My son is working on a school science project and unfortunately I have very little knowledge on electrical engineering. Please be patient ...
-1
votes
1answer
34 views

Why is the FLA current so much higher than the actual running current?

In most cases I should say, when user a motor the actual running current seems to be a ton less than the FLA, resulting in me feeling like I over sized my conductors by a long shot.
1
vote
1answer
58 views

Inrush Current Limiter for Torodial transformer

Just looking for some quick guidance or good sources. I have a 500VA toroidal transformer I am going to use with my UK mains outlet to step mains voltage down to 25V. I am using a 13A fuse with an ...
0
votes
0answers
32 views

Why is static electricity called static? [migrated]

They called it “static” because it doesn’t go anywhere. To create an static electricity, you have to rubbed the two different materials. At the moment you rubbed them, the electrons already moved. ...
0
votes
2answers
101 views

Capacitor bank for high powered appliance

I have a vacuum cleaner which draws a little too much current only when it's starting up. This causes the trip switch in the home circuit to trip. Is it feasible to use a capacitor bank to provide ...
-6
votes
1answer
113 views

Does current change when going through a DC voltage source? [closed]

Can you get the equivalent resistance of two series resistors if there is a DC voltage source between them
3
votes
2answers
362 views

Why is earth used for ground? Literally earth?

Noob question: I never considered earth to be particularly conductive. It's just dirt, after all. However, I've seen "earth ground" conductive stakes driven into the ground in order for electricity ...
2
votes
2answers
79 views

Is soldering extra wires to increase current capacity on a pcb trace good design?

I was working on a bunch of PC PSU organ donors and noticed that on lots of them through all the wires that lead the power to the outside there were wires soldered, and lots of solder added. This is ...
1
vote
4answers
327 views

PCB Tinning to increase current

How can I design a PCB in order for it to have this kind of PCB Tinning finish? I do know this decreases the resistance of the tracks and increases the amount of current it can handle however Do I ...
0
votes
2answers
74 views

How to run ATmega328P-PU using 3.7v Lipo 600mAh?

I want to run bare ATmega328P-PU using 3.7v 600mAh Lipo Battery. The Lipo is used to run Nano Quadcopter. The discharge rate is 20C. My Question is: 1. Will connecting Lipo to my atmega directly fry ...
0
votes
1answer
22 views

What's the difference between logic/if system and drive system of a display?

I've been looking at the current consumption of a display and the datasheet says the following: Can anyone tell me the difference between "drive system" and "logic/if system"?
0
votes
1answer
51 views

How Does Connecting a Battery in Series Affect Current Flow

Background: I am creating a circuit to run electronics and motors. The some of the electronics are 5V some are 12V and the motors are 24V. I have a small universal 12V battery for the electronics I ...
0
votes
1answer
63 views

Understanding benefit of higher watts on power bank

I have seen multiple lithium power banks offering 5000mAh. The Price can increase substantially for the same mAh but a higher output wattage. My understanding of a 5000mAh battery is that this power ...
3
votes
2answers
93 views

Using a transformer with 400 volt rated primary side with a 120 volt line

Is it possible to use a transformer rated for 360 to 400 volts on its primary side on a 120 volt line? Will it still perform adequately? And I would assume the turns ratios still apply? This is the ...
1
vote
1answer
83 views

How does this current monitor circuit works?

Can you please explain how can I analyze and equate its feedback? I have simulated it in LTspice as follows: I have tried for 0.5A and Vout is precisely 2, half of above, so it is working, ...
0
votes
1answer
86 views

How do I detect servo stall with an Arduino?

I am controlling a standard 5-volt servo with an Arduino with PWM. My objective is to rotate the servo until it physically gets stalled (feels resistance) and then stop. Then I want the Arduino to ...
0
votes
3answers
68 views

Limiting current draw on a camera battery charger

I have a camera battery charger which is driven from a 12V (measured 12.2) switched mode wall wart rated at 1A. All three items (charger circuit, wall wart and battery) are stock, but all three heat ...
0
votes
1answer
69 views

How to calculate electric current in this electric circuit?

Ok here is the problem. I have this circuit ( picture below ) and I need to design buck converter for it. I was told by my mentor that I should calculate electric current this circuit will consume. ...
0
votes
1answer
40 views

How would I properly develop a current rating for this system…?

I have a system that I have recently developed for in house (manufacturing) equipment testing. Transformers rated for 80VA (264V, .303A) are used in series and rectified using a full-wave diode ...
-1
votes
2answers
35 views

Can different sources with same voltage output can drive different amount of current through the circuit

I started experimenting with electronic devices. While I was doing that I connected a DC motor to output of arduino which provides 5V. It could not provide enough amount of current. But when I ...