New answers tagged capacitor
2
votes
Need delay circuit to pull IC pin low for 10 seconds
Here's a potential solution using three MOSFETs and a few peripheral components:
simulate this circuit – Schematic created using CircuitLab
The edge detector produces a 10ms low pulse at each ...
- 47k
7
votes
What's the point of low capacitance capacitors in circuits?
The regulator repeatedly pulses current through L1, delivering energy to it, then stands off while that energy is transferred to C2. The regulator does this as often as necessary to keep C2 "...
- 47k
18
votes
Accepted
What's the point of low capacitance capacitors in circuits?
The first misconception is that what you have in the picture is not a DC circuit.
It is an AC circuit that works at 1.5 MHz.
Sure it is a DC-DC converter but it switches the inductor to ground at 1.5 ...
- 172k
0
votes
Using a capacitor to mitigate voltage drop
I suspect the trips are caused by the heater resistance being too low when it is cold. If that is the case, then try a "soft-start" circuit connected in series with heater that limits the ...
- 5,830
0
votes
n Gate to source capacitor in gate drive?
It can help you with self-turn on problems as it is explained in https://toshiba.semicon-storage.com/info/application_note_en_20180726_AKX00074.pdf?did=59473 chapter 3. It will also demand more power ...
- 1
2
votes
Finding capacitor voltage in this seemingly simple rectifier circuit
This answer might not be what you are expecting, but I think the concept is very useful. It's based on a previous answer of mine found here:
What is the relation between NE555 voltage doubler output ...
- 5,469
1
vote
Finding capacitor voltage in this seemingly simple rectifier circuit
There is an analytical approach, but it is not simple.
The capacitor voltage will stabilize at a value for which the charge into the capacitor during a cycle equals the charge out. This is complicated ...
- 178k
1
vote
Finding capacitor voltage in this seemingly simple rectifier circuit
Update:
There is no simple formula for the Vdc out as this is a nonlinear circuit. I recall our Hammond power supply designer circa the mid-80s having elegant nomographs for all these and similar ...
- 148k
0
votes
Circuit capacitor debugging technique
Question: in order to test (with a multimeter or otherwise) a capacitor that's soldered onto a circuit, is it absolutely necessary to unsolder it off the circuit first, so it is isolated for testing?
...
- 23.8k
2
votes
Circuit capacitor debugging technique
Yes, to measure the capacitor alone, it must be removed.
Otherwise you are measuring both the capacitor and the circuit that connects to the capacitor terminals.
However there are tens of reasons why ...
- 172k
1
vote
How does nMOSFET conduct both ways in a DRAM cell?
You're thinking of 3-terminal FETs, where the body is tied to source. Yet, even with those the current can go both ways. To use them we have to just have to be mindful of the effect of the body diode ...
- 58.1k
2
votes
How does nMOSFET conduct both ways in a DRAM cell?
The body terminal will be connected to the substrate, which is at the negative supply voltage, usually ground. Or rather, as all of the FETs are made in the same substrate, their bodies are all the ...
- 23.4k
0
votes
Why do motor controller inverter sections use decoupling capacitors of a single value?
There's several reasons to use only one primary value.
0.1uF is 'good enough' for most applications
0.1uF hits a sweet spot for bypassing, doing a decent job in the 1-100Mhz region. More here: Where ...
- 58.1k
0
votes
Why do motor controller inverter sections use decoupling capacitors of a single value?
An inverter bypass application demands low impedance at up to modest frequencies, typically mid 10s of MHz. But it can extend up into the 100s MHz, particularly for modern transistors driven hard, or ...
- 45.6k
1
vote
Best way to design a PCB for frequent component switching?
Nothing beats 0.1" headers for practicality.
It is possible to solder 0805, 1206 or MELF components on the pins of a 0.1" header. The dimensions fit just right. You can solder a range of ...
- 81.6k
3
votes
Accepted
What harm can 9v do to common electrical components?
Pretty much all semiconductor components can be destroyed rather easily. For BJTs or LEDs, all it takes is a bit too much current and that's done.
This kit comes from a time when transistors were ...
- 81.6k
1
vote
What harm can 9v do to common electrical components?
What harm can 9V do to common electrical components
It depends where that 9V is coming from. If it is a series of 3 rechargeable AA-size or similar lithium cells, you get a fire if there's no fuse/...
1
vote
Accepted
How to calculate or select capacitor value for this H-bridge?
It depends on what you're doing with the motor.
If all the MOSFETs in the H-bridge are off, and the motor is turning, then it will act as a generator. The MOSFET body diodes will act as rectifiers, ...
- 81.6k
2
votes
What harm can 9v do to common electrical components?
If you connect a component right or wrong, what happens depends on what kind of circuit it creates instead of the intended circuit.
For example if you leave a resistor off by a mistake from a ...
- 172k
0
votes
What is this transformer doing next to this piezo buzzer?
Your underatanding could be correct or not. The MCU cannot sense the resonance so it might not be driven as LC resonance tank but simply some forced frequency set by the MCU. The piezo may be driven ...
- 172k
1
vote
Best way to design a PCB for frequent component switching?
While not a direct answer to OP's question about the best way to make it easier to replace a component multiple times, this answer provides a means to obviate that need.
Our power supply design team ...
- 11.1k
2
votes
EMI filter design for a DC-DC converter
Your EMI will be highly related to your layout, so start with that first and make provisions for filters on input and output side.
If you add parasitics to your schematic, you will be able to simulate ...
- 16.8k
4
votes
Best way to design a PCB for frequent component switching?
If you asked me to do it, I’d do it a bit differently. First, the opamp-based circuit would be replaced by an MCU or FPGA with ADC on the input side and a DAC on the output. The initial setup would be ...
12
votes
Best way to design a PCB for frequent component switching?
Nothing directly to do with design, but specify a superior PCB laminate (typically high-Tg) and invest in good soldering tools, including a tweezer type de-soldering tool if you feel flush.
Avoid lead-...
8
votes
Best way to design a PCB for frequent component switching?
For your prototype you can use a machined-contact DIP socket and 'fly-wire' it to your board to bring the components out.
This type of socket will accept 1/8W resistors and caps with 0.300" lead ...
- 58.1k
1
vote
Best way to design a PCB for frequent component switching?
You can allow multiple parallel pads to add SMD and not have to
change them often unless you overshot the target.
You can have jumper traces that may be cut to increase R.
I'm guessing you should ...
- 148k
5
votes
Best way to design a PCB for frequent component switching?
If you can afford a prototype board that is different from production, just stick a pot on there, like Sandro said. Once you have it right, measure it, and put a fixed resistor in that place for ...
- 5,806
6
votes
Best way to design a PCB for frequent component switching?
The traditional way was to use DIP headers holding the components and a DIP socket on the PCB.
Nowadays, there are much smaller board-to-board connectors that could be used to implement the same ...
- 178k
5
votes
Best way to design a PCB for frequent component switching?
If the frequencies in question is low, you can use a regular 2.54 mm pin header (female) and push the legs of THT resistors and capacitors in them.
- 16.8k
8
votes
Best way to design a PCB for frequent component switching?
If you have enough space, just use 3 potentiometers (or other variable resistances) : one 100k max, one 1M max, one 10M max in "parallel", with a jumper to select which potentimeter to use.
...
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0
votes
Is this a good schematic and did I choose the correct components?
With regard to the EP, the datasheet uses a different name:
The DAP (exposed pad) on the bottom of the WSON package is connected
to the die substrate with a conductive die attach adhesive. The DAP
...
0
votes
Is this a good schematic and did I choose the correct components?
There shouldn't be any issues using a resistor here, but if you aren't using the enable function, I would just tie it directly. One less component on your BOM. My best guess for why there's a resistor ...
- 38.5k
0
votes
Why this PMIC has Via between capacitor and PMIC pins?
The design likely has a plane for that signal/power rail, which also acts as a capacitor with the ground plane. Therefore it's a good practice to connect the pin to the plane as close to the pin as ...
- 3,704
0
votes
Accepted
RC circuit as a delay
Thank you @AnalogKid and @Michal Podmanický, but I found a different solution. I'm going to use this simple circuit:
I've taken the inspiration from the Art of Electronics. They use buffers, but NOT ...
- 33
0
votes
How to get the feedback factor of this system?
The feedback function is independent on the selected output terminal. The feedback factor is part of the loop gain which determines the stability properties of the circuit. Hence, also the R-C lowpass ...
- 28k
0
votes
How to get the feedback factor of this system?
How to get the feedback factor of this system?
It is the signal fed-back to the inverting input compared to the output signal, \$V_O\$: -
$$\dfrac{100\text{ k}\Omega}{100\text{ k}\Omega+400\text{ k}\...
- 473k
0
votes
RC circuit as a delay
If you are sure that the DRV ENN input is a Schmitt trigger, then what you have should work. In the switch-closed state, the DRV ENN signal will be over 0.8 V because of the two 20 K resistors ...
- 23.2k
0
votes
RC circuit as a delay
Since you work with small 3v3 voltage the diode has a huge impact how deep the cap is discharged and affects the timing. So I would use a transistor instead.
Here the discharging resistor is not ...
- 2,881
0
votes
Can you use many smaller trimmer capacitors in place of one big one?
It is not very practical but possible.
Define what tuner cap. specs you need and [where] to shop is the preferred approach.
- 148k
2
votes
Can you use many smaller trimmer capacitors in place of one big one?
You certainly can, and they do add, one consideration is that the minimum as well as maximum capacitance adds. So if you have a 5-20pF capacitor and parallel 10 of them you'll get 50pF to 200pF.
...
3
votes
Schottky Diode with High Frequency Signal
A diode can only drive the current one way. The only AC connection to discharge the parasitic capacitance on the load side of the diode is the parasitic capacitance of D7 itself.
Instead of unipolar ...
3
votes
Accepted
Schottky Diode with High Frequency Signal
The driving signal from the MCU is unable to pull the output low because of D7. D33 has a capacitance of 350pF according to the data, and is very high impedance, so there is no way for that 350pF cap ...
- 7,893
0
votes
USB communication keeps disconnecting because of power dip/spike
I had similar issue, the desktop built-in USB port connection was failing when turning the spindle off (a Dremel via opto-isolated relay). I tried isolating as much as I could, no luck. I tried the C-...
- 1
0
votes
LDO Output Capacitor Selection and ESR Consideration
I'm unable to answer all questions directly, but I suggest to:
stick to the output capacitor requirements given in the datasheet of your specific LDO.
test your design with load transients and check ...
- 171
0
votes
Why put a capacitor between VCC and a thermistor which is referenced to ground?
it's a cheap way to prevent really fast oscillations driving the micro crazy.
It's not a low pass filter but it acts as one for really high on-off but short bursts on the sensor side.
If the jitter ...
6
votes
Accepted
Why put a capacitor between VCC and a thermistor which is referenced to ground?
I would expect that the MCU puts the capacitor in a known state by driving P3 high- charging it through R13 (a relatively low resistance compared to 100kΩ), and then switches P3 to an input and ...
3
votes
The 3.3V Fixed Regulator was burned with 12V input
I agree with what @Hearth said. In addition, I would like to say that if the current values you need are high in the power domain you need and there is a high voltage difference between the input and ...
- 100
3
votes
understanding capacitor in a circuit 40106 Schmitt trigger
A simple way to look at it is capacitor plate area.
A capacitor with 10 times the capacitance has ten times the plate area (other things being equal) so it can store 10 times the charge (electrons) at ...
- 902
4
votes
understanding capacitor in a circuit 40106 Schmitt trigger
Q = I×t = C×U.
So it takes longer for the larger capacitance to charge up to same threshold voltage.
Larger capacitance at same voltage holds more charge.
Which is apparent from the RC time constant ...
- 172k
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