# Tag Info

### Why, when conductors are connected in series, their current strength is equal?

The current through the conductors is going to be determined by the total resistance, which you get by adding together the resistance of each conductor. Moreover, what we see using Ohm's law, is that ...
• 8,855
1 vote

### Why, when conductors are connected in series, their current strength is equal?

Because the electrons have nowhere else to go. If you think about electricity as the physical movement of electrons, then in a DC circuit all of the mobile electrons enter at one end of the two joined ...
• 21.2k
1 vote

### Why, when conductors are connected in series, their current strength is equal?

Perhaps a water pipe analogy is in line. If you have two pipes with different diameters connected in series, will the flow rate (liters/minute, gal/minute) be different in each section if there are no ...
• 10.2k

### Why, when conductors are connected in series, their current strength is equal?

1 amp is equal to 1 colomb's worth of electrons passing a given point in a second. 1 coulomb is about 6x10¹⁸ electrons. If the two wires are in series, then the current in the two must be the same. ...
• 19.5k
1 vote

### Why, when conductors are connected in series, their current strength is equal?

Not only conductors. This logic applies to anything: insulators, vacuum, plasma, whatever. The reason lies in the conservation of charge, which is a principle deeply rooted in physics. The charges ...
• 22.4k
1 vote
Accepted

### Distribute power from one battery to multiple devices

All these components on that system, works in certain amount (range) of voltage, right? Right. how can I create a system - above the main system - to distribute power correctly Do not power the ...
• 22.8k

### Should I replace my stepper driver since my motor is acting up?

If it worked well for such a long time, and changing the driver to a new one doesn't help, then I doubt it's the problem. What comes to my mind is that the vibration from the motor caused a solder ...
• 11

### Why is a push-pull transistor configuration asymmetric?

Each transistor is responsible for passing current in two different parts of the input/output waveform, between which current in the load changes direction. The upper transistor is allowing current to ...
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### Why is a push-pull transistor configuration asymmetric?

Everyone has already pointed out that one of your transistors is arranged incorrectly. So I won't belabor it here. Sufficient that you know it won't work. The phrase ...
• 11.1k

### Why is a push-pull transistor configuration asymmetric?

Your circuit is invalid. Try something like this. It can operate from a single-ended power supply. Reference the amp to 6-volts. Circuit reference https://circuitdigest.com/electronic-circuits/push-...
• 652

### Why is a push-pull transistor configuration asymmetric?

But that's not a valid push-pull circuit to begin with. You have the PNP transistor upside down. Even if it were correct, for negative output you would need a negative supply and you don't have one. ...
• 158k

### Why do I measure different resistances in the same wire at different current levels?

My first comment would be regarding your poor measurement configuration that will surely not give very accurate results. The voltage taps (I guess these are the crocodile clamps) position is not well ...

### Voltage and current on two identical TVS diodes in parallel during a voltage spike

With 2 identical TVS diodes, surge current will be shared equally and, the clamping voltage will be dictated by the current flowing through either of the 2 devices (it will be somewhat less than the ...
• 464k
1 vote
Accepted

### How to measure battery voltage during charging?

Will I read battery voltage/charger voltage/intermediate voltage between 15V and 12V. No. If the meter probes are placed across the battery, you will measure the sum of the battery voltage and the ...
• 16.8k
1 vote

### How to measure battery voltage during charging?

If your battery is 12V and charger is 15V then connecting the charger to the battery should show 12V or something very close to 12V as the battery voltage cannot jump instantaneously as it needs ...
• 158k
1 vote

### How to measure battery voltage during charging?

the battery voltage or the charger voltage or some intermediate voltage. Yes, yes, and kind of yes. By definition, the battery voltage and the charger voltage are exactly one and the same because ...
• 22.8k
1 vote

### How much current will a BJT transistor draw through its base?

There are two primary viewpoints for the BJT: the DC operating point and the AC behavior around that DC operating point. You must keep these ideas totally separate in your mind. The connection between ...
• 11.1k
Accepted

### How much current will a BJT transistor draw through its base?

Shouldn't $i_B$ be the full current we'd get between base and emitter if we simply had a diode? If it's not, then how do we predict what $i_B$ is? It is. But you need to remember that $V_{BE}$ ...
• 175k

### How much current will a BJT transistor draw through its base?

The transistor will draw more current from the base if you disconnect its collector. Yes, the BE junction behaves like a diode but here its cathode follows the anode, so the current is too small. You ...
• 17.5k
1 vote
Accepted

You made two errors: your KCL equation did not conform with arrow direction. The sign of one or more of the amounts did not conform with arrow direction, leading to a situation which is physically ...
• 38.3k

### Powering on a laser diode that exceeds PSU max current

To make a quick test of that power laser diode, put a small resistor in series, and a moderate size capacitor across the output of the power supply. In the diagram above, a 1µF cap charged to 10 or ...
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### Powering on a laser diode that exceeds PSU max current

Edit: See also comment by DrMoishe Pippik If pulsed operation is fine (as it is here), you can get away with a capacitor, inductor, Power MOSFET and a signal generator. The idea is to convert the 10A ...
• 209

### Why is the power conserved in a phone charger?

I don't understand because in a generator or a battery, when the voltage increases, the current also increases according of the resistance in the circuit because U=RI. Why does the current increase in ...
• 3,449
1 vote

### Why is the power conserved in a phone charger?

Why is power conserved? Why does the increase of voltage not increase current? Because we choose components, topologies and, designs that attempt to conserve power as much as we can. It's a vital aim ...
• 464k

### Why is the power conserved in a phone charger?

why is power conserved? The Nature just works that way. That means: our Universe happens to have this power conservation property. It follows from more basic laws, but that's how it is. Power cannot ...

### Why is the power conserved in a phone charger?

You are right, U=R*I is always true for a pure resistive circuit (where only DC is involved!) When a transformer (or switching regulator) is present, you have 2 circuits, one on the primary side and ...
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### Do we need MPPT in grid synchronization and string inverters?

As stated by Dave Tweed we use an MPPT only when we have a large sink that can consume a huge amount of current. At times of synchronizing and load providing in string inverter the load is limited and ...
• 669
1 vote

I didn't watch the video (don't have time) but I have measured large voltages on the external conductive surfaces of various electrical equipment many times. It does not necessarily mean the voltage ...
• 5,307

### Why does a battery have a limit for current in amperes?

The electrochemical reactions in the battery can only take place so fast. With some batteries the current should be artificially limited to protect the battery from self-destruction. It may be able to ...
• 407k

### Why does a battery have a limit for current in amperes?

An ideal voltage source can supply whatever current the load wants, unlimited. But a battery is not an ideal voltage source. So, it can't. A battery can be modeled as a voltage source plus a series ...
• 22.8k

### Trying to T-tap wires of different gauges. Do these t-connectors even exist?

A busbar should be a better choice than taps. Something like this will get you 20 connecting points and is rated at 50 A. If you put two LED modules on each screw you could use two busbars per side, ...
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### Trying to T-tap wires of different gauges. Do these t-connectors even exist?

Assuming your proposed solution it to use IDC taps (where the main wire is not cut at each tap only its insulation is pierced) then yes that could work. There's a fairly large wire gauge difference, ...
• 34.5k
1 vote
Accepted

### Trying to T-tap wires of different gauges. Do these t-connectors even exist?

There are not a whole lot of elegant ways to split out that many taps from a single feed, but I've had success with buying plain copper bar stock (or silver plated if the budget allows) and drilling/...
• 20.2k
1 vote

### Why does a 230V 16A socket supply only the needed current to loads?

If I connect a 150W laptop charger to a socket that supplies at home 16A 230V, it will only draw the necessary amperage needed for the laptop charger at 230V. Why? The definition of electrical power ...
• 5,307

### Why does a 230V 16A socket supply only the needed current to loads?

Your socket rated at 16A does not know how many hundred or thousand amps are available from your electricity provider and it also does not know how much your laptop needs for charging. If you connect ...
• 158k

### Why are the 10A inputs on many multimeters unfused?

I'll provide a reason why it may not be such a bad thing after all to have an unfused input. I have blown a multimeter fuse on the 10A input several times. At first, I didn't understand what happened ...
• 1,752

### Why in a inverter DC to AC 12V et 220V when I increase the voltage, the current decrease to keep the same power?

A transformer or DC->AC inverter passes Power, not just Voltage or just Current. Power is Voltage times Current, so if the transformer or inverter increases the voltage, it must also decrease the ...
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### Why in a inverter DC to AC 12V et 220V when I increase the voltage, the current decrease to keep the same power?

Amps (A) is voltage (V) divided by resistance (R): A = V/R. Correct - for a resistor. I have a step up inverter that steps up voltage... So it would be logical that more voltage pass on the out side ...
• 177k
1 vote

### Why in a inverter DC to AC 12V et 220V when I increase the voltage, the current decrease to keep the same power?

Unlike simple passive loads, an inverter uses active electronics to switch connections on and off as needed to provide its designed output. When the input voltage is higher, these connections don't ...
• 35.1k
1 vote
Accepted

### Designing Eddy Current Sensor?

Having previously designed Eddy current sensors for UXO, you really didn't give enough information to narrow down what changes you need for a target sensor; however, ESTCP has more than enough ...
• 3,284
1 vote

### Two formulas for defining RMS and average of a waveform through a diode

RMS is, by definition, about power. For current or voltage it is about finding the equivalent that would dissipate the same power in a resistor if administered as a DC level. Since power is ...
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### Designing Eddy Current Sensor?

The general principle of eddy current sensing is to read the impedance of a coil (coupled to some workpiece) as a complex impedance, the real part of which corresponds to resistivity of the material, ...
• 39.2k
Accepted

### How to make this high side current limiter more predictable

The regulation needs to kick in fast. The 48 V might sag down to 40 and the load impedance is unstable Q1 and Q2 should be a dual matched transistor like BCM857. These dual transistors have pretty ...
• 79.5k
1 vote

### RMS of sine wave curve defined between two points

Could someone explain for the following attachment (waveform image) how were exactly the values of "RMS" and "average" determined this way (for that curve of sine)? RMS Fact: a ...
• 464k

### RMS of sine wave curve defined between two points

Well, the general formula for the RMS-voltage is given by: $$\text{I}_\text{RMS}=\sqrt{\frac{1}{\text{T}}\int\limits_0^\text{T}\text{I}\left(t\right)^2\space\text{d}t}\tag1$$ Where $\text{T}$ is the ...
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### RMS of sine wave curve defined between two points

The RMS value of an entire cycle of a sine wave (in relation to the peak) is the same for a 1/2 cycle or even 1/4 cycle starting at 0. You should be able to see that from symmetry and the fact that ...
• 407k

### How to make this high side current limiter more predictable

Perhaps this might help. I have a working high current 12-volt power supply. I have used the design in roughly 50 DC power supplies with voltage and current limiters replaced with this LDO regulator. ...
• 652
1 vote

### How to make this high side current limiter more predictable

Your first circuit doesn't work the way you want because you lack a precision reference - Vbe is not a precision voltage reference. Your second circuit has the same problem as the first, but this time,...
• 4,830
1 vote

### How to make this high side current limiter more predictable

You need an op-amp and reference voltage, not a current amplifier. The amplifier is fixed-gain, which sets output current in terms of Vgs(th), which is poorly defined. In both cases, you likely need ...
• 39.2k

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