Activity for 2kind
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| 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) |
— | about 14 hours ago |
| Comment | Post #291384 |
I was thinking if a measurement is taken by a microcontroller (more) |
— | 3 days ago |
| Comment | Post #290357 |
I need comparator output to be +-12V, not 0/5V. (more) |
— | 5 months 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) |
— | about 2 years ago |
| Comment | Post #286211 |
Can you give a bit of background for x64 and x32 oversampling logic? (more) |
— | about 2 years ago |
| Comment | Post #286030 |
Not giving -1, but can you please include pictures in your questions rather than links? (more) |
— | about 2 years ago |
| Comment | Post #286020 |
How do you decide upon meaningful value? (more) |
— | about 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) |
— | about 2 years ago |
| Comment | Post #286007 |
What is the continuous current for 24V brushed motor you designed against? (more) |
— | about 2 years ago |
| Comment | Post #285458 |
How could 500V/125V ratio be achieved using 1:1 transformer? (more) |
— | about 2 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) |
— | over 2 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) |
— | over 2 years ago |
| Comment | Post #283361 |
Whoever downvoted, I would like to know the reason. (more) |
— | over 2 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) |
— | almost 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) |
— | almost 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) |
— | almost 3 years ago |
| Comment | Post #282127 |
I have a voltage source(35-60V range) and want to control the 12V/1.5A coil of the contactor without designing the 12V/2A buck solely for the purpose of contactor control. Moreover, 1.5A is enough for activating the relay, but I assume the holding current to be in the 300-500mA range. (more) |
— | almost 3 years ago |
| Comment | Post #281634 |
Thank you, Andy! Why would I care about ESR(dielectric+true resistance) losses at all and ignore the ESL when looking at AC? Impedance is something I should be caring about. The heck with ESR if ESL will kick into play(and it will at frequencies that are below and higher than the resonance one - plus... (more) |
— | almost 3 years ago |
| Comment | Post #281492 |
What might be the reason behind people recommending low-ESR caps put every 1m at the DC link cables for most of the RC stuff? I assumed it was because of the parasitic inductance with the input cables. Your analysis assumed pure ohmic cable characteristics. (more) |
— | about 3 years ago |
| Comment | Post #281478 |
"BLDC inverter" or BLDC motor controller. The unit takes DC input and converts it to a 3 phase voltage/current signal to control the torque or rpm of a motor. How to size the input capacitance of a BLDC motor controller taking input power cable length into consideration - mine calculation above doesn... (more) |
— | about 3 years ago |
| Comment | Post #281295 |
Thanks Olin! Is it usual to refer to "mechanical Hz" or "electrical Hz" when talking about V/Hz ratios? (more) |
— | about 3 years ago |
| Comment | Post #281294 |
How did you get 60? (more) |
— | about 3 years ago |
| Comment | Post #280927 |
Thank you Olin! By putting Q1 in common collector configuration, the role of D2 would not be needed because you could rely on opto’s diode reverse voltage. But I see why you have chosen common emitter. (more) |
— | about 3 years ago |
| Comment | Post #280893 |
It was a typo. Although I intended to have an opto on when input left floating because of no particular reason (more) |
— | about 3 years ago |
| Comment | Post #280900 |
Got it - it's a TVS. (more) |
— | about 3 years ago |
| Comment | Post #280900 |
If 36V is applied on the left terminal, "Vbr=36V" has no impedance to work against. A small resistor between the input and the Zener would do the job to keep it below max. power dissipation. (more) |
— | about 3 years ago |
| Comment | Post #280894 |
I can't see how is the MCU input high here when R1 is floating. (more) |
— | about 3 years ago |
| Comment | Post #280791 |
Everyone's right in one way. There is no way to close the question other than deleting it so I will leave it here unanswered. (more) |
— | about 3 years ago |
| Comment | Post #280791 |
I've been using 72V extensively and found that 60V was more common simply because it's in the "Low Voltage" category. It was battery-powered, though. Still, why 3.3V and not 3V? Most(every?) of the IC's accepting 3.3V could accept 3V so I assumed there is some historic reason behind the 3.3 value. (more) |
— | about 3 years ago |
| Comment | Post #280609 |
So you start with setting up the stator field to one of the six possible combinations and trust that the stall torque would be lower than the one you are creating with the field? (more) |
— | over 3 years ago |
| Comment | Post #279961 |
If we assume there is a forward based diode followed by a cap to GND on secondary. (more) |
— | over 3 years ago |
| Comment | Post #279961 |
Thanks, Andy! How does this current limit of 700mA RMS apply on a secondary when potential capacitor there acts as a "short" during the first pulse? If we assume pulse not exceeding 11Vus. (more) |
— | over 3 years ago |
| Comment | Post #279900 |
Only you could estimate the risk given the amount od data. Why connecting the opamp to +-15V when the rest of the circuitry could not grasp that? (more) |
— | over 3 years ago |
| Comment | Post #279816 |
@Andy Aka - Not sure I understood what you meant. I intended on using it instead of a relay so there should be no switching. Converting to push-pull and use gate transformer? In that case, I have no way to desaturate the core without using feedback. If I stay with flyback I have a lot of capacitance... (more) |
— | over 3 years ago |
| Comment | Post #279816 |
@Andy Aka I will ask a new question based on your comment. This goes beyond the scope. (more) |
— | over 3 years ago |
| Comment | Post #279819 |
@Olin Thanks, it’s clearer now what you meant! In the blog post you linked you claim:
“ Switching power supplies controlled by the pulse on demand scheme may have higher ripple compared to other control schemes. But they are simple, inherently stable...”, what is different in your circuits? Schemati... (more) |
— | over 3 years ago |
| Comment | Post #279819 |
Thanks as always! I've edited question with answers (more) |
— | over 3 years ago |
| Comment | Post #279728 |
"the FET is on" - I see what I wrote now - it should be "the FET is off". I wouldn't call this silly, especially when the load is motor. (more) |
— | over 3 years ago |
| Comment | Post #279733 |
Thanks for the comment @coquelicot. I made the mistake of not asking the question properly and thereby caused confusion. Will try to avoid this in the future as much as possible. Once again, sorry about that.
Now, the point was not how to parallelize the current flow on the MOSFETs but do's and do... (more) |
— | over 3 years ago |
| Comment | Post #279732 |
Thanks Olin! So for floating loads, low side switching + galvanically isolate communication interface could potentially be used instead of a high side switch? (more) |
— | over 3 years ago |
| Comment | Post #279728 |
@AndyAka The reason behind having two series MOSFETs is to prevent charging of the battery through the body diode when the FET is on. (more) |
— | over 3 years ago |
| Comment | Post #279010 |
Thanks Olin! You are right, the A1A is not connected correctly.
https://www.st.com/resource/en/datasheet/tsv324a.pdf
The data about ESD is very vague - it says it could withstand 2kV using Human Body Model, but for example, doesn't have a schematic of how the opamp is realized internally like s... (more) |
— | over 3 years ago |
| Comment | Post #279005 |
Thank you @Circuit fantasist. I am okay with the leakages because the thresholds for A1B and A1C would be set up conservatively.
Do you think the TVS between opamp inputs is needed for limiting the differential signal? (more) |
— | over 3 years ago |
| Comment | Post #278989 |
Thanks Andy. I've updated the question above! (more) |
— | over 3 years ago |
| Comment | Post #278989 |
It's "the TVS diodes". There is no TVS diodes on the schematic but I would like to put them in order to make the circuit ESD immune for both differential and common mode signals. (more) |
— | over 3 years ago |
| Comment | Post #278484 |
I guess you could tweak the "secondary" of the trafo and aim for aslightly higher voltage - then you simply put linear regulator and reduce the ripple. (more) |
— | over 3 years ago |