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How can you calculate Peak Pulse Power for a Non-Rectangular Power Pulse

This is something of a non-answer, alas; but also the best possible answer? That's a bit contradictory, so let me explain. When the resistor is thermally limited, the problem is to avoid exceeding ...
Tim Williams's user avatar
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Building a hybrid ultra-capacitor and battery bank

There are hybrid supercapacitors to combine some of the advantages of both in one module. But for a system with both battery and supercap a very a basic arrangement could be something like this: It ...
Gos's user avatar
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1 vote

How can you calculate Peak Pulse Power for a Non-Rectangular Power Pulse

The same document explains this on item 4: So, you need to write the voltage's equation and solve the energy integral: $$ E = \int_{T1}^{T2}p(t) \ dt $$ If you have \$p(t)\$ put it directly. If you ...
Rohat Kılıç's user avatar
5 votes
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Should I connect a small DC motor directly to the mains without an isolation barrier?

Do NOT do what you are suggesting! You are planning to connect uninsulated motors, to the mains, with no safety barrier or protection. This is extremely dangerous. 12V & 24V power supplies, ...
colintd's user avatar
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1 vote

Sequential diode and capacitor - low vs high capacitance

Your diode has additional properties that can typically be ignored in most cases, notably, reverse recovery time and reverse leakage (frequency real slow, output capacitance real high, respectively). ...
MOSFET's user avatar
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1 vote

Why is it OK to separate a circuit in the process of simplifying it?

Placing a constant voltage source from one node to another isolates (decouples) all branches connected to the nodes from each other. Because the voltage across each branch is known, each can be ...
RussellH's user avatar
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3 votes
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What is the role of an MKP capacitor in the input of this SMPS? What happens if I remove it?

For reference, a typical schematic can be found on page 13 of this datasheet (similar but unrelated part); or on numerous appnotes, or schematic collection sites. https://www.onsemi.com/download/data-...
Tim Williams's user avatar
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3 votes

What is the role of an MKP capacitor in the input of this SMPS? What happens if I remove it?

That's an X2-rated capacitor. Those are intended to die by shorting (and in that way taking out a fuse), so you should check its resistance to see whether that is what it did. They usually buffer ...
user107063's user avatar
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1 vote

Need help with capacitor code

The Manufacturers Logo is International Rectifier, who's products are now part of Infineon. From the attached picture the part number is FS300<last character unreadable>. Are you able to get a ...
Chester Gillon's user avatar
2 votes
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DTR pin in the FT232RL working confusion

The reset pin of the ATMEGA328 is special. It can tolerate up to 13V. It can be used to enter the high-voltage programming mode although that is not triggered in this application. See the Absolute ...
Kevin White's user avatar
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1 vote
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Capacitor taping Vs straight leads

From Panasonic Packing specifications With taping means that the leads have outside bend in order to increase the pitch between them? Not directly. E13 (second row) has the same diameter (ø8) and ...
StainlessSteelRat's user avatar
2 votes
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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 ...
Russell McMahon's user avatar
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Circuit explanation with short circuit and independent current source

The 5 Ω resistor is shorted out hence, there will be zero current flowing through it.
Andy aka's user avatar
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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 ...
Andy aka's user avatar
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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 ...
Turbo J's user avatar
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1 vote

State space model of third order circuit

Rewriting your system of equations in matrix form yields $$ T\cdot \dot{x} = A\cdot x + B\cdot V_{in}$$ where \$x\$ is the state vector and \$T, A, B\$ are matrices of appropiate dimensions. Assuming ...
Yggdrasil's user avatar
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3-way switch with self-resetting toggle switches

What you need is an 'impulse' or 'ratchet' relay that changes state with a pulse input to its coil and reverts on the subsequent pulse. In other words, it changes state on consecutive pulse inputs to ...
vu2nan's user avatar
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3-way switch with self-resetting toggle switches

This should only be a problem if you can’t see if the lights are on or off from where the switches are. You can buy three way switches with indicator lamps that will tell you if the circuit is on or ...
GodJihyo's user avatar
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2 votes

Find a matching interference suppression capacitor

Values can be within a fairly wide tolerance; 2400pF is no problem. The current rating however must meet or exceed, which rules out #1. There should be an inductor in there also (hence the current ...
Tim Williams's user avatar
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1 vote

Why don't oppositely charged ends of separate batteries and capacitors produce current flow?

Current flows in circuits, closed loops. You are showing two open-circuit scenarios. Keep in mind, voltage is a potential difference between two points in circuit. The potential is across the battery. ...
MOSFET's user avatar
  • 303
1 vote

Why don't oppositely charged ends of separate batteries and capacitors produce current flow?

Current requires a closed circuit to flow. If you have a single battery connected to nowhere, no current flows. If you have a single battery connected to anywhere with one wire only, be it a load or ...
Justme's user avatar
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2 votes

Smoothing Capacitor value?

Load Current: 7A Frequency: 120Hz Ripple Voltage: 15V The ripple voltage in the equation from the web calculator you used $$C = \frac{I_{load}}{f \times V_{ripple}}$$ is "the peak-to-peak ...
Math Keeps Me Busy's user avatar
3 votes
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Smoothing Capacitor value?

As a rule of thumb, 1000 uF per amp, so you would want at least 7000 uF. You could come up with an approximation using constant current discharging a capacitor, i.e. \$ \Delta V = {i \ t \over C} \$ ...
qrk's user avatar
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5 votes

Is my washing machine board bad?

As others have said, those two cracked capacitors are bad and you should replace them with the same or higher voltage and capacitance rated caps. For example, the 470uF/35V can be replaced with 470uF ...
Edin Fifić's user avatar
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8 votes

Is my washing machine board bad?

Yes, those two caps (top left and the brown-ish one in the middle) are definitely defective. These types of electrolytic capacitors tend to fail in this way (crack open) after years of use. If you're ...
Patrick Fiedler's user avatar
1 vote

Is my washing machine board bad?

Yes, it's bad, due to bulging caps with electrolyte leaking out.
Justme's user avatar
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1 vote
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2A223J fixed capacitor immediately shows OL on resistance test

Resistances tend to be measured with limited current. If the current is near constant, voltage (and thus displayed resistance) will rise linearly in time, at a rate inversely proportional to the ...
user107063's user avatar
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3 votes

E series Components and Information

Resistors and capacitors are commonly given values according to an E series, as are inductors and zener diodes. Resistors can easily be made and are often required to percent tolerances, so all values ...
Neil_UK's user avatar
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3 votes
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E series Components and Information

There is a huge amount of information available on the E "preferred values" scheme available from a simple web search. Wikipedia has a very good article. The scheme defines spacings based ...
colintd's user avatar
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2 votes
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How can I find the steady state of current I with sinusoidal voltage source?

I'm looking at the book problem in the 9th edition right now: What they want you to think about is \$I=\frac{125\:\angle -60^\circ}{\mid Z\mid\:\angle \theta}=\frac{125}{\mid Z\mid}\:\angle\left(-60^\...
periblepsis's user avatar
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1 vote

How can I find the steady state of current I with sinusoidal voltage source?

You lose me a bit with the notation convention you're using in the line that start with "Now I=..." I believe if we use exponential form for the phasors (\$Ae^{j \theta}\$), everything will ...
Adam Q's user avatar
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1 vote
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Measuring capacitance with NE555 in astable mode

This is an oscillator, so you measure capacitance by measuring the frequency and then using the formula in NE555's datasheet or an online 555 timer calculator. A precharged capacitor within voltage ...
thegamebusterpl's user avatar
1 vote

Transient response of capacitor connected to current source with no resistor

Well, the voltage- and current relation in a capacitor is given by: $$\text{I}_\text{C}\left(t\right)=\text{V}_\text{C}'\left(t\right)\text{C}\tag1$$ So, when \$\displaystyle\text{I}_\text{C}\left(t\...
Jan Eerland's user avatar
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1 vote

Can I increase a capacitor's working voltage by putting two capacitors in series and doubling the uF value? I am dealing with a 0.1uf rated @1700VDC

I'm not totally sure from your question if you need a 0.1µF capacitor rated for 1700VDC, or a 0.2uF rated for 1700VDC. If it is 0.1uF, I found 3 on digikey (nb : make sure they meet all your ...
Sandro's user avatar
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2 votes

Can I increase a capacitor's working voltage by putting two capacitors in series and doubling the uF value? I am dealing with a 0.1uf rated @1700VDC

To a first order yes, but depending on style of capacitors you might need resistors to balance the voltages. Most film caps fine, but uneven leakage on electrolytic capacitors make stacking without ...
colintd's user avatar
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1 vote

Derating of C0G DC block capacitors with applied DC voltage

C0G/NP0 do not need derating due to voltage. C0G compared against other MLCC like the X7R, do barely dissipate any energy in AC mode in comparision. I've used C0G in 1000V boost converter to snub the ...
user103776's user avatar
0 votes

Transient response of capacitor connected to current source with no resistor

Start with the integral equation. The voltage across a capacitor is equal to the integral of the current as a function of time. If the current is a constant, it falls out of the integral. That ...
AnalogKid's user avatar
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4 votes
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Transient response of capacitor connected to current source with no resistor

A capacitor that is fed with a constant current will experience a constant voltage rise. $$\frac{dV}{dt}=\frac{I}{C}$$
Math Keeps Me Busy's user avatar
10 votes
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Derating of C0G DC block capacitors with applied DC voltage

There are two significant misconceptions from your colleague: Type 2 dielectrics, in general, need voltage derating, or some [fixed] ratio thereof. All ceramic capacitors, in general, need derating. ...
Tim Williams's user avatar
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4 votes

Derating of C0G DC block capacitors with applied DC voltage

C0G and in general class 1 dielectric ceramic capacitors don't derate neither with temperature not bias voltage, class 2 on the other hand do, the lower the number of that dielectric the higher the ...
diegogmx's user avatar
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4 votes

Derating of C0G DC block capacitors with applied DC voltage

Murata says in their ceramic cap FAQ that C0G caps have no DC bias characteristics. So either the caps need to be derated for other reasons, but at least they don't need derating due to capacitance ...
Justme's user avatar
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0 votes

Why are charge pumps only used for low current applications?

at least for low quantities, I need to do some calculations, buy specific cores and wires and wind the wire around the core myself. It's very time consuming. Instead, see what suitable fixed ...
Kuba hasn't forgotten Monica's user avatar
1 vote

Why are charge pumps only used for low current applications?

As pointed out in the comments of this answer, switched capacitor DC-DC converters, such as one built around an LTC7820, can be extremely efficient (99% efficiency claimed in that datasheet) and can ...
Math Keeps Me Busy's user avatar
0 votes

Discharging one side of a capacitor?

A capacitor is a device designed to contain a net zero charge by producing a very low energy electric field for a given charge difference. This is done by making the extent of the field very small ...
user107063's user avatar
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1 vote
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Capacitor at output of component followed by capacitor at input of another component

If you put them very close you can share the capacitor between them. Use whichever value capacitor is larger. However, if you're worried about noise to the point where you cascade an LDO after a ...
user1850479's user avatar
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1 vote

What could these mystery XX capacitor values in this schematic denote?

These are bypass capacitors (it says so at the top). usually this is not a critical choice. Find the data sheet for whatever parts are closes to the capacitors and see what value they recommend. 100nF ...
Jasen  Слава Україні's user avatar
2 votes

What could these mystery XX capacitor values in this schematic denote?

It could denote anything. It could mean they are capacitors drawn just in case they are needed, and the circuit was determined not to need these caps so they can be left out from the circuit. So it ...
Justme's user avatar
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6 votes

Capacitor and LDO voltage regulator gets really hot on circuit board

In addition to what the others said, I'll use another LDO (LDL1117) as an example. Thermal resistance junction to ambient is very high, this is the value to use for a layout like yours. However ...
bobflux's user avatar
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8 votes

Capacitor and LDO voltage regulator gets really hot on circuit board

@Spehro Pefhany probably found the problem. I just wanted to complete on your thermal calculations. You say (I haven't checked the datasheet myself) : R_th = 120°C/W P = 0.912W However, in your ...
Sandro's user avatar
  • 5,816
15 votes
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Capacitor and LDO voltage regulator gets really hot on circuit board

Looks like C1 is shorted, which is shorting out your 3.3V rail and causing the regulator to current-limit. Other pins on the chip appear to be shorted as well. Please inspect the board carefully for ...
Spehro Pefhany's user avatar

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