Activity for 2kind
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Comment | Post #292090 |
"You can inject short pulses of a few mA and a few 10s or 100s of µs and verify that you don't get corresponding changes in the difference between your internal reference voltage and the ground connection."
From the "recreated neutral" point? (more) |
— | 4 months ago |
| Edit | Post #292081 | Initial revision | — | 4 months ago |
| Question | — |
Circuit for earth conductor presence detection Reading a Tesla Wall Adapter installation manual , their brand of an AC EV charger, chapter about “Ground Assurance” and here is the quote from there: Quote from Tesla Wall adapter Although the equipment can work with L1 and L2 connected only, because of the safety reason I assume they require Ea... (more) |
— | 4 months ago |
| Comment | Post #291833 |
Check here. It’s from Analog but describes the principle irrespective of the IC itself https://www.analog.com/media/en/technical-documentation/application-notes/an88f.pdf
Note: i wouldn’t follow this if the input of the boost converter is being derived on the PCB where boost converter resides (more) |
— | 5 months ago |
| Comment | Post #291386 |
Does the orientation of the dots on the cmc matter here? If the dots were facing “source” side, would the circuit work as intended? (more) |
— | 7 months ago |
| Comment | Post #291384 |
I was thinking if a measurement is taken by a microcontroller (more) |
— | 7 months ago |
| Edit | Post #291383 |
Post edited: |
— | 7 months ago |
| Edit | Post #291385 | Initial revision | — | 7 months ago |
| Question | — |
Power Line Filter. Location of Cy and common mode choke. A circuit under question: filter with common mode choke Why are CY capacitors on the source side, and not on the load side? Henry Ott describes this with: > Because filter attenuation is a function of impedance mismatch, the role of the power line filter is to maximize the mismatch between... (more) |
— | 7 months ago |
| Edit | Post #291383 | Initial revision | — | 7 months ago |
| Question | — |
Standardized way of measuring AC line frequency In a general sinewave as below, is there a "right" way/"standardized" way to measure line frequency - and how do energy meters calculate that? - measuring pulse width of half-period, ie. time elapsed and then doing f=2/T - measuring pulse width of full-period, then f=1/T Is there a need to ave... (more) |
— | 7 months ago |
| Comment | Post #290357 |
I need comparator output to be +-12V, not 0/5V. (more) |
— | 12 months ago |
| Edit | Post #290354 |
Post edited: |
— | 12 months ago |
| Edit | Post #290354 |
Post edited: |
— | 12 months ago |
| Edit | Post #290354 | Initial revision | — | 12 months ago |
| Question | — |
Converting 5V to ±12V I would like to convert 5V rail I have on PCB to ±12V. Existing solution is using boost converter 5V to 12V, and a buck for 5V to -12V. This feels bulky for what it's needed - here are the requirements: - +12V and -12V rail shall serve for powering opamp only - Ripple of the ±12V rails is not of ... (more) |
— | 12 months ago |
| Edit | Post #287480 |
Post edited: reply to questions |
— | almost 2 years ago |
| Edit | Post #287480 | Initial revision | — | almost 2 years ago |
| Question | — |
Minimizing Common Mode Radiation - Separating Grounds There are various different methods to keep common mode currents off the cables, one of them being discussed on the site here and with Olin's decoupling caps post on StackExchange. Slight digression - this is for some reason, extremely hard to comprehend to 9/10 engineers. One of the approaches He... (more) |
— | almost 2 years ago |
| Comment | Post #286179 |
Erm I missed your comment. I understand what you are trying to say, but in this particular application it won’t be an issue. Implementing “IIR alike” filter in the ISR won’t take more than 3-5 cycles. Interrupting main thread every couple of hundreds of cycles for 3-5 is not critical.
In other us... (more) |
— | over 2 years ago |
| Comment | Post #286211 |
Can you give a bit of background for x64 and x32 oversampling logic? (more) |
— | over 2 years ago |
| Edit | Post #286179 | Initial revision | — | over 2 years ago |
| Question | — |
When do I need to put anti-aliasing filter in front of SAR ADC? Signal characteristics are: - 0 to 3.3V span - 0 to 100Hz range( there will be noise superposed on top with unknown characteristics) - Output resistance Rout=4700 ohm I want to sample that with a SAR ADC built in the MCU. ADC has following characteristics: - internal sample and hold c... (more) |
— | over 2 years ago |
| Comment | Post #286030 |
Not giving -1, but can you please include pictures in your questions rather than links? (more) |
— | over 2 years ago |
| Comment | Post #286020 |
How do you decide upon meaningful value? (more) |
— | over 2 years ago |
| Edit | Post #286025 | Initial revision | — | over 2 years ago |
| Answer | — |
A: PCB ground planes with isolated voltage You have a 6 layer design for controlling 24V brushed DC motor, galvanically isolated voltage rails(24V and the rest) and your question is how to separate them properly. There is no further reasoning why 6 layer design, why did you choose to isolate the PSU, is there something extremely noise sen... (more) |
— | over 2 years ago |
| Comment | Post #286021 |
If the SMPS is being fed by an ideal constant voltage source, adding an inductor would not have any value? Meaning, I am protecting against HF feeding my SMPS.
Is there other EMI aspect regarding having bigger input voltage ripple? (more) |
— | over 2 years ago |
| Edit | Post #286020 |
Post edited: |
— | over 2 years ago |
| Edit | Post #286020 |
Post edited: |
— | over 2 years ago |
| Edit | Post #286020 | Initial revision | — | over 2 years ago |
| Question | — |
How to choose the right value for input voltage ripple of an SMPS? Which important system design parameters need to be locked in order to estimate the maximum allowable level of the input voltage ripple of an SMPS? I have encountered ballpark figures of <1%, <1V throughout the various different designs and I wasn’t usually too worried about defining it - didn’t e... (more) |
— | over 2 years ago |
| Edit | Post #286012 | Initial revision | — | over 2 years ago |
| Answer | — |
A: Why are some PCB design software programs considered to be 'hobbyist' programs? I will try to cover additional aspects. Not eager on making changes - Big organizations are usually non very prone on changing their horse for the battle - sticking to their EDA choice from 20+ years ago. Doesn’t mean they would repeat it today. Pricing - I am yet to find the company which ... (more) |
— | over 2 years ago |
| Comment | Post #286007 |
What is the continuous current for 24V brushed motor you designed against? (more) |
— | over 2 years ago |
| Edit | Post #285849 | Initial revision | — | almost 3 years ago |
| Question | — |
Flyback transformer for Vout > Vin This question is asked in an addition to https://electrical.codidact.com/posts/276436 Here is a Flyback converter mentioned there: Flyback Design parameters are: - Input voltage `125 volts` - Output voltage `500 volts` - Load resistance is `10 kohm` - Transformer turns ratio `... (more) |
— | almost 3 years ago |
| Comment | Post #285458 |
How could 500V/125V ratio be achieved using 1:1 transformer? (more) |
— | almost 3 years ago |
| Comment | Post #285186 |
Having seen optocouplers with ATEX certification, not 100% sure you could use POE as an isolation. Is there a reliability calculation requirement? Likelihood of F1 not tripping when it should?
My other comment without reading the IS would be is there a req to solve the issue you described through ... (more) |
— | almost 3 years ago |
| Comment | Post #284304 |
Thank you, Olin!
"This is often done with rotor position feedback, like with Hall sensors. However, it can be done by looking at the back EMF generated, finding its zero crossings, and thereby finding where you are within the rotor's cycle."
If Hall sensors give you information where you are in t... (more) |
— | about 3 years ago |
| Edit | Post #284282 |
Post edited: |
— | about 3 years ago |
| Edit | Post #284282 |
Post edited: added detailed explanation |
— | about 3 years ago |
| Edit | Post #284282 | Initial revision | — | about 3 years ago |
| Question | — |
Driving PMSM machine as an AC induction machine Is it possible to drive a PMSM motor - here I am referring to an AC motor with permanent magnets(stator wounded, rotor with PM) - in a way that there is no externally mounted rotor position sensor(no hall, encoder, or resolver) using the scalar VFD method(V/f (Volts per frequency)) as one would typic... (more) |
— | about 3 years ago |
| Comment | Post #283361 |
Whoever downvoted, I would like to know the reason. (more) |
— | over 3 years ago |
| Edit | Post #283361 | Initial revision | — | over 3 years ago |
| Question | — |
Motor Controller - What might be the purpose of these resistors? I was looking at the video of the Tesla Model 3 motor controller(400VDC, 500A) disassembly and noticed a resistor network as in the picture below. They are 2k resistors(SMD code 202). See the picture below: Model 3 Inverter I was wondering what might be the reason for putting these resistors... (more) |
— | over 3 years ago |
| Comment | Post #282151 |
Thanks Coquelicot. Yeah, I could utilize micro that I have onboard, but agree that your circuit could be utilized in a lot of applications. (more) |
— | over 3 years ago |
| Comment | Post #282139 |
Thank you Olin, like always. First circuit makes sense for PCB mounted relay where I can keep high dv/dt nodes on PCB. (more) |
— | over 3 years ago |
| Comment | Post #282139 |
Thanks, Olin. Makes sense, I could try flipping L1 and C1, adding a PCB inductor instead of L1(contactor coil), and connecting the contactor coil in parallel with C1. Then the contactor coil would be the "load" of the low-side switched buck converter. Hmm, don't know whether this is feasible. (more) |
— | over 3 years ago |