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

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28 views

Can you power a LED with a lower tension but the right current [duplicate]

Can you power a 50w LED that by the datasheet needs 30v and 1.5A with less than 30v but 1.5Amps?
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0answers
30 views

i want to heat up NiChromide 80 40awg with a dc power supply need help plz [on hold]

Ok so UK what I want to heat up. Ive been doing some research and ive read that the amps is how hot the wire get, and the volts is how much of it will heat it. Well I want to heat up about 3 inch's of ...
-3
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2answers
37 views

Is it better to have a larger resistor or a smaller one?

What resistor would be needed before two LEDs in series? I asked how much resistance was required before two LEDs in series. After a response, on how to do it, i worked out that i needed. I have ...
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0answers
50 views

What resistor would be needed before two LEDs in series?

I was wanting to use the lowest amount of amps in my project because it contains around 60 LEDs. http://www.rapidonline.com/pdf/55-2484.pdf : The technical description It has a max current of ...
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2answers
68 views

Why do we need to find the current?

I am beginner in electronics. What i came to know until now is that mostly we have to find the current in a circuit in our text books. I wonder what useful work we do after finding the current, dc ...
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2answers
1k views

What is the dual of a diode?

A diode has an exponential I-V curve. To a first approximation, it will pass whatever amount of current is required to keep the voltage across it constant. Is there a passive component that will ...
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0answers
40 views

Burning air pressure switch [migrated]

I use a 12 V air compressor at my car for air suspension which I understand is draining around 30-35 A. The problem what I have is overheating and eventually burning the pressure switch and ...
0
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1answer
41 views

max current drawn from an IC or a circuit [on hold]

how do i find the max current drawn from a simple circuit with an IC, few resistors and caps. if it's taken from the datasheet, what current rating i should be looking at exactly? or should i be ...
0
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0answers
28 views

Why output is zero in TIP 31 as CC mode [duplicate]

I am using an Arduino Uno board and R-2R DAC to obtain a signal which should vibrate a transducer connected across R19 of common collector amplifier using TIP31C. I need about 300mA of current to ...
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0answers
45 views

Force voltage, measure current

When using a power supply, they often come with a standalone mode and a FVMI mode. FVMI apparently stands for "force voltage, measure current". What does that exactly mean and how is it different from ...
-3
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0answers
30 views

Definition of cross current

What is the definition of cross currents? An example would be great. I have also heard the term cross conduction and I am not sure if this is relevant. ...
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1answer
46 views

Bipolar Voltage to Current Converter

I need a circuit or component which converts bipolar voltage to bipolar current. I have found the XTR111 from Texas Instruments and the 1B22 from Analog Devices. However, they only convert 0-10 V to ...
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1answer
39 views

current flow from positive to positive between batteries?

If you have two batteries with different voltages, let's 12 and 9 volts and you connect the negative terminals while you put a LED or whatever between the positive terminals, there will be current ...
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1answer
63 views

Working on a high current USB charger

Title says it: I'm working on building a high current USB charger for my devices so that I can integrate USB ports into my headboard. However, I'm having a few glitches. When I plug in a device, the ...
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2answers
26 views

KCL sign and negative result

So by using KCL to solve for a node voltage Vds (branch consisting of only a resistor Rds -> Ids = Vds/Rds,) if I obtain a negative answer for Vds, does this mean that the sign I used for the current ...
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0answers
22 views

Solving for a voltage using KCL w/ multiple current sources

I'm solving for Vds(s). I'm somewhat unsure about how to write the KCL equations for this circuit. Shouldn't Vds(s) be equal to the current provided by the dependent current source on the same branch ...
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0answers
1k views

Got shocked by a native dell laptop charger outputting 19.5 V 6.5 A DC. It was REALLY uncomfortable, but was that dangerous? [migrated]

Okay. My laptop was running out of battery. I grabbed my charger (outputting 19.5 V 6.5 A DC) which was plugged into the wall, and as I touched the end of the charger I got some electric shock going ...
0
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3answers
68 views

DC Motor consuming too much current

I'm trying to use an H-bridge, which is connected to a wall power supply, to power a DC motor. The motor was originally powered by a 12V battery pack in a toy. Now my motor is consuming too much ...
3
votes
2answers
53 views

capacitor ripple current in buck converter

I designing a step-down buck converter and i'm a little bit worried about ripple current which flows through the output capacitors. In my research on internet i found that ripple current essentialy ...
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2answers
48 views

What does battery charger's current rating mean? [duplicate]

I am basically a software engineer but have some interest in electronics so this is probably a very basic question. I understand theoretically a battery or power source can provide as much current as ...
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votes
3answers
30 views

current or voltage what is imp to run a load [duplicate]

recently i took a power supply fan which says 12 V and maybe 0.15 A to run.So which is the priority that i should follow to make it run should i go for 12 v supply or should i go for 0.15 A secondly ...
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2answers
56 views

How do I limit the current supplied to a boost converter

I have a power supply that can supply up to 20 amps at 12 volts, I want to give a boost converter a maximum of 4 amps. I tried using a 3 ohm resistor but the resistor burned up. I want to use the ...
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0answers
44 views

There is thermochromic pigment. Is there a magnetic variety of pigment?

I can mix thermochromic pigment with transparent epoxy resin into a brightly colored paste which changes colors when it detects a temperature threshold in the surface it is applied to. Is it ...
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1answer
94 views

Transistor - Control current flow

simulate this circuit – Schematic created using CircuitLab I am having trouble finding how to limit the current flow from the collector to the emitter of a transistor. (Is it possible? I ...
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1answer
210 views

Why does this zener diode fix the voltage to the LEDs?

I am just getting started working with small electronics. I have soldered together a few kits and recently converted a car stereo into a home stereo. With all of this soldering, I found this ...
7
votes
4answers
674 views

What is the difference in meaning of a voltage signal and current signal?

This might sound like a crazy bad question. But I'm wondering even though current and voltage inevitability co-exist, why do we use the term for one concept(current or voltage)? If there is a signal ...
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1answer
59 views

Do force-sensing resistors draw current?

I know that a resistor in a series and parallel circuit would draw a certain amount of current. However, would a force sensing resistor wired with a 10k pull-up like in a typical microcontroller ...
2
votes
1answer
67 views

what is the collector gain of a transistor?

I was wondering what exactly collector gain is for npn transistors, or more specifically if there is some sort of equation for getting it, and if its value changes as you change the input ...
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0answers
28 views

Over current detection using INA300

I have built A H-bridge driver circuit which is controlled by a pic micro-controller. To detect the event of over current i have incorporated the INA300 current sense comparator which has a 10us ...
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2answers
76 views

Why collector current is inwards to transistor in an NPN?

In this page, the following model is given for an NPN BJT. simulate this circuit – Schematic created using CircuitLab Also, it is stated that I(e) is outwards from the transistor, I(b) ...
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5answers
120 views

Why does a resistor reduce voltage if V=IR? [duplicate]

I'm sure this is a very simple question, but I have been confused about this topic for a while now. According to Ohm's law, resistance varies directly with voltage. This means that if resistance ...
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2answers
65 views

35W 6V, what wall wart max current needed

If I have a load of 35W at 6V. (5.8A). How would I scale up the current to 230v UK mains voltage? I am doing this to decide what wall-wart to use (and what max current specification to choose)
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2answers
78 views

Direction of current in inductor

simulate this circuit – Schematic created using CircuitLab Can the Direction of current in an inductor in a closed circuit change instantaneously. The circuit is in steady state for ...
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2answers
45 views

Can I drive a led light with help of a CT clamp

If I have a 230V wire with alternating current and a load in the far end, drawing current. Could you "steal" energy with a CT illustrated in the image, to for example drive a led light? BR Chris
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1answer
59 views

Ohms law applications [closed]

As you change the value of resistance of the resistor,how does this change the current through the circuit and the battery voltage?
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3answers
771 views

Do all components obey Kirchhoff's Current Law?

Kirchhoff's Current Law states that the net current through a node is always 0. AFAIK this derives from conservation of charge principle. My question is, is KCL applicable to any electrical component? ...
0
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1answer
76 views

Design challenge: Detect finger-to-finger touch with nothing in between

I'm trying to build something quite challenging and seem to be getting nowhere. Maybe you'll help. I'd like to detect a touch of two naked fingers with no materials or sensors in between (simple ...
0
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0answers
58 views

Microcontroller (Arduino) issues detecting mains AC power

I've been trying for a while to find a simple yet accurate way to measure power through a mains cable 240VAC I've seen online methods using hall effect sensors. Could someone please help me to ...
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2answers
153 views

long wire kickback voltage problem

the long wires acts as inductor which shutdown and sometimes damage my microcontroller(IC1), for the AC part ill be implementing an optoiso along with triac and snubber circuit (lemme know if you ...
0
votes
3answers
60 views

Current flow in a specific scenario

I'm pretty new to electronics and came across a fact I don't quite understand. If you have the below circuit, there are 2 situations: The switch is not pressed: Lamp 1,2,3 and 4 will glow. The ...
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3answers
104 views

How to measure small currents using current to voltage converter?

The battery voltage = 12 volts. In the first circuit The op amp works as a current to voltage converter and its output equation is: Vout = - I * R I choosed R to be 20 ohm so that each 50 mA will ...
0
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1answer
65 views

How do I calculate, or measure, all values in a simple A.C. circuit?

I'm trying to figure out how all the formulae fit together regarding A.C. currents. Given this circuit and equations: I figured out the following: ...
0
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1answer
35 views

Using multiple wire/rings to provide more current in Slip Ring connector

I'm going to use a slip ring connector (such as this one) to power 6 servos on the other end of a rotary. This slip ring is rated for 2A of current per wire/ring. If the 6 servos share a common +6v ...
0
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1answer
45 views

30 Ohm Thermistor blown

This is a follow on question from a previous one about a blown fluorescent UV ballast. I have discovered that the in-rush current thermistor is blown. Question 1 is whether it is worth changing it, ...
0
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1answer
83 views

How much current used in 20 LEDs circuit?

If I have 20 LEDs (red) and I want to connect it in parallel and series. Which circuit need more current? and how much? *And what happen if I use a source that can provide current both less than and ...
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2answers
49 views

Current step to LC circuit

An inductor is a device which adjusts its voltage to keep the same current flowing through. However, the current exponentially decays when there is no source any more. Similarly, a capacitor is a ...
0
votes
1answer
26 views

LTC1153 current trip off IC

I am using an LTC1153 IC, with an IRLML6346 MOSFET. I am supplying a 3.3V rail. Now, the output is being fed to an arduino board and the supply works. The Gate pin gives out about 7V (in conformance ...
0
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1answer
64 views

Difference between controlled current and constant voltage charging

Modern charging of lithium and nickel based batteries starts with a constant current, until a certain voltage and then a constant voltage until the current falls to some level that indicates end of ...
0
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1answer
89 views

How to choose the correct inductor for my application

I am planning on using induction to power some game pieces in a project I am building. My plan is to use identical coils in board and piece, so they will be small (2" max diameter). My problem is ...
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1answer
40 views

Need 300mA current to drive a transducer

I am working on a project in which I need to use a preloaded value to vibrate a transducer. So loaded required values into Arduino Uno, converted into analog values using R-2R DAC and buffered values ...