New answers tagged voltage
0
votes
I am trying to identify an smd 16 pin Linear Technology voltage regulator chip makes 5 volts with 6 volts dc in
I believe it to be this device: -
Image from here: https://www.analog.com/media/en/technical-documentation/data-sheets/3433f.pdf
- 437k
2
votes
I am trying to identify an smd 16 pin Linear Technology voltage regulator chip makes 5 volts with 6 volts dc in
Oh wait. That was easy. It's an LT3433.
- 88.7k
3
votes
Two switch flyback converter MOSFETs voltage stress
voltage source of 1000 V is applied to the primary side, does the high side and low side MOSFETs share the voltage (500 V +500 V) between them, like LEDs connected in series.
No, they don't.
Look at ...
- 27.5k
3
votes
Why can't I charge a capacitor using a N-FET as switch
Notice that you are getting femtoamps of current change which means the simulator isn't set up properly for what you want to see. You have a few options as shown below.
Use the UIC directive in the ...
- 7,709
4
votes
Accepted
Why can't I charge a capacitor using a N-FET as switch
If you look at the scale of your current graph, you'll see that the currents being predicted are less than one fempto-amp (\$\mathrm{fA}\$). That's \$10^{-15}\$ of an amp. The reason that you're ...
- 45.1k
0
votes
How is a differential impedance of Ethernet signals maintained without a ground plane
Two wires running in parallel in free space have a set differential impedance that's determined only by the geometry of the cross-section of the wire pair. No ground planes needed.
That's why it's ...
6
votes
How is a differential impedance of Ethernet signals maintained without a ground plane
Differential impedance can be achieved by referencing two lines to a common ground plane (so-called uncoupled lines) by referencing them to one another and a ground plane (so-called loosely coupled ...
- 15.2k
1
vote
How is a differential impedance of Ethernet signals maintained without a ground plane
Differential signaling means there's no ground reference by definition. You can have a grounded shield around the twisted pair, but if you ground a wire the differential signal becomes single ended.
...
- 238
0
votes
Question on orientation
Almost all RCDs will trigger on absolute leakage, not the leak's relationship to the phase of the supply. Direction should therefore be irrelevant.
- 4,022
0
votes
Finding the Thévenin and Norton equivalents for a circuit
First of all you have to choose the part of the network to which you want to replace the Thevenin equivalent circuit and which connects to the rest of the network via two terminals. Once this is done, ...
- 169
1
vote
Accepted
Polarity on Current Transformer
This is a Current Transformer. The current transformer is used to measure an AC current. This means there is no polarity as the current changes the direction in every cycle. The mechanical position of ...
- 720
1
vote
How does dB apply for non-linear components?
The first sentence of your question is already problematic. Decibels themselves cannot be used to express power, unless you also give what is the reference power, such as "power dissipated is 3 ...
- 130k
2
votes
Accepted
How does dB apply for non-linear components?
The definition of dB is 10log(P1/P2) where P1 and P2 are powers. The conversion to 20log(V1/V2) only applies when the voltages are across equal valued resistors. Often dB's are used in other ...
- 15.8k
3
votes
How does dB apply for non-linear components?
Think of dB as something like a comparison tool to compare one value to another (reference). One important point here is that the things to be compared should be of same type and unit.
This can be ...
- 27.5k
0
votes
Is my understanding of electronic ground correct?
Second answer. Different approach:
A major "issue" is that the question has essentially nothing to do with "ground". It relates to the flow of current between points at different ...
- 148k
0
votes
Accepted
How to calculate node voltage in this circuit
Thanks to a comment posted by @ThePhoton, I found a tutorial at All About Circuits on how to use Thevenin's Theorem to perform a DC network analysis. To do that, I re-drew my circuit (below) to ...
- 46
3
votes
Is my understanding of electronic ground correct?
"Ground" is just a name used for a convenient reference point.
It is often at or near local physical ground potential but this is not essential.
GROUND is just a convenient name for a ...
- 148k
0
votes
How to calculate node voltage in this circuit
From the datasheet ... Outputs are "Open Collector".
So, if you wire a resistor at output, it will respond ...
If my R2 = 22 kOhm (max), it will be ok.
- 11.3k
3
votes
Formula for R1 and R2 of a voltage divider bias
Some history
Before determining the resistances R1 and R2, it would be good to understand why these resistors are needed at all. We can do this best if we mentally go back two centuries to when Ohm ...
- 13.9k
2
votes
Accepted
Common-Emitter Amplifier
I find the problem given interesting in a few ways:
For questions I've seen here, it's unusual to see a specific mention of a "20%" variation in parameters. I take to mean ...
- 4,359
1
vote
What result does digital multimeter show when measuring filtered AC V? Is it Vavg or Vrms of the ripple voltage? What's the formula to calculate?
If the input is AC, most cheap meters will full wave rectify, average, then scale the result for the RMS of a sinewave, as that's cheapest. As the waveform changes from a sinewave, this method becomes ...
- 159k
6
votes
Why does an AC Voltage reading on a DMM decrease as the frequency is increased?
On a cheap meter the signal is AC-coupled, then rectified using a precision rectifier and then low-pass filtered yielding an average voltage, which is then (for display) (effectively) multiplied by ~1....
- 379k
6
votes
Why does an AC Voltage reading on a DMM decrease as the frequency is increased?
The oscilliscope is designed to display a wide range of frequencies accurately - from DC to 50 MHz or more, while a common DMM will usually only cover a much smaller frequency range - mine shows the ...
- 57.4k
2
votes
Common-Emitter Amplifier
However 'correct' Antonio's answer is, it has little didactic merit.
Power dissipation
You will notice there are no DC paths to ground. This means we can just take the power supply as 12 V.
...
- 159k
0
votes
0
votes
Accepted
Vb and Vbe of a transitor
You might be interested to know some more interesting details about this topic:
Since "voltage is a difference of two potentials", the voltage Vbe represents a "difference of two ...
- 13.9k
0
votes
Vb and Vbe of a transitor
Quote: "how is Vbe generated........and must the base voltage of a transistor be equal to 0.7 or can it exceed this value."
Yes - it must be externally generated with a DC value (bias ...
- 24.9k
3
votes
Vb and Vbe of a transitor
\$V_{XY}\$ is the voltage at node \$X\$ with respect to \$Y\$. Or in other words, the voltage across \$X\$ and \$Y\$ (X positive lead, Y negative lead).
\$V_X\$ is the voltage at node \$X\$ with ...
- 27.5k
1
vote
Vb and Vbe of a transitor
\$V_B\$ and \$V_{BE}\$ are only the same if \$V_{E}\$ is 0V; in other words, they are equal if the emitter is grounded. The \$V_B\$ voltage can exceed 0.7V (with respect to ground) if the emitter is ...
- 3,302
1
vote
Vb and Vbe of a transitor
Vb is the convention to state the voltage at base, compared to your 0V reference, which may or may not be emitter voltage Ve.
Vbe is the convention to state the voltage difference between base and ...
- 130k
1
vote
What's the potential difference across gap a and gab b
A capacitor cannot be modeled as a gap, and a gap cannot be modeled as a capacitor.
For analysis of a steady state system the capacitors can be removed but the voltages remain. as well, the inductors ...
- 12.9k
1
vote
What's the potential difference across gap a and gab b
It would be undefined if they were just gaps.
But in the circuit they are not gaps.
They are two identical 1F capacitors, so before flipping the switch, both are fully charged to 1/3 of 100V.
- 130k
1
vote
Accepted
What's the potential difference across gap a and gab b
Both are correct. Our at least, they're not wrong: if we actually model these things as gaps, their voltages are completely undefined. They might just as well be a=1099, b=-1033.
If we, however, model ...
- 88.7k
0
votes
Accepted
Calculate a voltage drop from power drawn (not current)
I'm trying to calculate the voltage drop by knowing not the current but the power of the device at the end of the line.
If the load is resistive, or has power factor correction (PFC), the ...
- 20.2k
2
votes
Isolation of Input signal and supply
More information is required on whether you need galvanic isolation.
If you don't, resistive dividers should be fine.
If you do, then I would be tempted to have the whole of the ADC circuit on the HV ...
- 4,022
1
vote
What is this IC with marking M7CK 825?
It's a MPS MPQ4460DQ step-down converter.
I can't find a picture of this IC, but I know that MPS uses this markings style. Here is a picture of a MPS IC with the marking ...
- 2,711
1
vote
Accepted
X-ray power input and power output Confusion
Assuming specs are right and based on other systems, a couple of things come to mind:
Is it 3-phase, so per phase current nearer 32A (and definitely under 63A, another common rating)?
10R resistor ...
- 4,022
2
votes
Accepted
Using a potentiometer to adjust a capacitor voltage
This does what you appear to want.
Note that you can acieve the same result by simply connecting the capacitor to the potentiometer wiper directly - however, for many capacitor values that will take a ...
- 148k
2
votes
Formula for R1 and R2 of a voltage divider bias
simulate this circuit – Schematic created using CircuitLab
First thing to do is draw a schematic - which you didn't do.
To solve for a standard voltage divider...
The current flowing through R1 ...
- 7,709
0
votes
LDO voltage regulator malfunctioning as passthrough after 24/7 usage
The actual current you can get from a regulator is usually dominated by power dissipation not the rating on the front page of the data sheet.
(5-3.3)*0.25=0.425W. Now this isn’t terrible and might be ...
- 474
0
votes
Convert [-24V,24V] range analog signal to [0V,3.3V] range for ADC
This schematic will kind of work, but with many caveats. For example, all the power supply ripple will go to the ADC and noise the input. Also, you need +24V line for the measurement, which is not ...
- 1,075
3
votes
Accepted
Powering ESP32-WROOM-32E using LM1117S-3.3 LDO voltage regulator
From: https://www.ti.com/lit/ds/symlink/lm1117.pdf
To generate 3.3V you must provide a battery that is at least 1.3V higher, so this will work as long as your battery is 4.6V or higher. A 3.7V ...
- 15.2k
4
votes
Accepted
X-ray filament and cathode connection
Is the filament connected in this manner with the cathode as shown below?
Yes
Now I know it isn't possible but I somehow connect an Ammeter at the battery end as shown below. Will I be able to get ...
- 159k
1
vote
Finding the Thévenin and Norton equivalents for a circuit
After finding the R(thevinen) you can find V(thevinen) by using the superposition theorem. Find the open circuit voltage because of each source saperately and then algebraically add them to find the ...
- 1,070
3
votes
Accepted
Finding the Thévenin and Norton equivalents for a circuit
I would really appreciate some help
Usually, these problems area easier to solve by converting the voltage to a current source: -
Then, because current sources play no role in the impedance it's ...
- 437k
0
votes
In a DC circuit with a battery and a capacitor how do electrons on the capacitor plate connected to positve terminal flow?
The negative plate of the capacitor is connected to the negative terminal of the battery and, the battery negative is a fairly unlimited source of electrons.
So, electrons "gather" at the ...
- 437k
0
votes
In a DC circuit with a battery and a capacitor how do electrons on the capacitor plate connected to positve terminal flow?
You forgot the electric field inside the capacitor.
The voltage source puts more electrons on the negative plate of the capactor and sucks some from the positive plate. This process stops once the ...
- 9,978
0
votes
Can I do voltage division for parallel resistors only?
Voltage division only works for series branches.
$$V_x = \frac {R_x} {R_T} \ V_T $$
where:
\$V_x\$ is the voltage drop of the target series resistance.
\$R_x\$ is the target series resistance.
\$...
- 7,896
0
votes
Interface between two different voltage levels
Not the best but you could try adding Q1 (Vgs < 3.3V) and R2 like this. However, this will flip the voltage logic.
- 48
2
votes
Can I do voltage division for parallel resistors only?
For resistors (or anything) in parallel, the voltage across them will be exactly the same ideally.
However the current through each will, in general, be different.
- 379k
Top 50 recent answers are included