Activity for Elleanor Lopez
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Edit | Post #296284 | Initial revision | — | 3 months ago |
| Answer | — |
A: Is it allowed to skip a pin to increase creepage distance? Olin's answer lead me to look for illustrations and I found a reference around creepage definition in IEC 62368 to another IEC norm, namely IEC 60664-1: "Insulation coordination for equipment within low-voltage supply systems". Within this norm, chapter 5.3.3.6 "Creepage distances split by floati... (more) |
— | 3 months ago |
| Comment | Post #296269 |
Just seeing it done by others and repeating it does not make it compliant, that is my concern. (more) |
— | 3 months ago |
| Comment | Post #296270 |
Yes, we do have several signals around 40V. To determine exact voltage 0.635mm allows I would have to do linear interpolation, but it would be between 32V and 40V.
I really like the suggestion of arranging signals by voltage level, I have to check if they are static and/or toggled at the same ... (more) |
— | 3 months ago |
| Comment | Post #296269 |
Do you have any reference for the claim that it counts? It contradicts the definition of creepage being between 2 conductive elements. (more) |
— | 3 months ago |
| Edit | Post #296267 | Initial revision | — | 3 months ago |
| Question | — |
Is it allowed to skip a pin to increase creepage distance? From IEC-62368 for signals below 30kHz the creepage distance for pollution degree 2 and material group IIIa,IIIb (FR-4 boards are IIIa) at 40V is specified to be 1.1mm. We have a connector that has many BGA pads, and the copper-to-copper distance is 0.635mm: Imagealttext Putting a slit betwe... (more) |
— | 3 months ago |
| Edit | Post #295804 | Initial revision | — | 6 months ago |
| Question | — |
Assembly challenges for shared pad between mounting hole and resistor Hi, I was watching Many EMC Tips to Help You Design Better PCB Boards (with Keith Armstrong) and at 1:01:30 timestamp he talks about bonding reference plane to chassis and emphasizes that the connection has to be low-impedance and very close: screenshot from a Youtube video My question is ... (more) |
— | 6 months ago |
| Edit | Post #295334 |
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— | 8 months ago |
| Edit | Post #295334 |
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— | 8 months ago |
| Edit | Post #295334 | Initial revision | — | 8 months ago |
| Question | — |
Rigid-Flex vs Flex with stiffeners - What is the practical difference? Looking at Flex-Rigid PCB technology vs Flex PCB with added stiffeners under sections with components I struggle to see the advantage of Flex-Rigid for low layer counts, as it seems more complex to manufacture and is more expensive as a result. There is a lot of information online explaining w... (more) |
— | 8 months ago |
| Comment | Post #295255 |
If you downvote the answer, can you comment on what you don't like in the answer? (more) |
— | 8 months ago |
| Edit | Post #295184 |
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— | 9 months ago |
| Edit | Post #295184 | Initial revision | — | 9 months ago |
| Question | — |
Is inductor winding insulation rating important for a high-voltage application if the voltage is not across inductor itself? In many hobby and even commercial designs, people use generic wire-wound inductors or common-mode chokes that do not have a specified insulation or hipot voltage rating. Drum-core inductors are sometimes used as well. Example circuit that generates more than 0.5kV based on switching duty cycle... (more) |
— | 9 months ago |
| Edit | Post #295163 | Initial revision | — | 9 months ago |
| Answer | — |
A: Back-EMF in bipolar stepper motor seems inconsistent with torque graph I got an answer regarding the back-EMF number in the datasheet. The back-EMF voltage waveform is a sine and the listed value is the peak value. What this means in practice is that energy can still be pushed into the winding before and after the peak, once the back-EMF is below the driving voltage... (more) |
— | 9 months ago |
| Comment | Post #294958 |
Appnote makes it clear, thanks! (more) |
— | 10 months ago |
| Edit | Post #294947 | Initial revision | — | 10 months ago |
| Question | — |
ADE7933 layout guidelines - Lazy Y capacitor? ADE7933 contains an isolated DC-DC converter (Page 82). The control uses 1MHz PWM signal with unknown rise time, but assuming something like 10ns, most of the energy would be contained in the 35MHz band based on: $f{\text{max}} \approx \frac{0.35}{tr} \approx \frac{0.35}{10 \times 10^{-9}} = 3... (more) |
— | 10 months ago |
| Comment | Post #294931 |
Yes, once we acquire the motor we can set it in a lathe/drill of fixed RPM and measure phase voltage. At the moment we just don't have it yet. Manufacturer, has been contacted, waiting for response now. (more) |
— | 10 months ago |
| Edit | Post #294929 |
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— | 11 months ago |
| Edit | Post #294929 | Initial revision | — | 11 months ago |
| Question | — |
Back-EMF in bipolar stepper motor seems inconsistent with torque graph In the AM2224-1000 datasheet for the '1000' model the following parameters are given: Nominal voltage per phase: 1.4V Back-EMF amplitude: 3.8V/k step/s There is also torque/speed graph present for different voltages: Imagealttext However, it seems that the graph does not correspo... (more) |
— | 11 months ago |
| Edit | Post #294380 | Initial revision | — | about 1 year ago |
| Question | — |
Current path in GPIOs protected by clamping diodes The typical GPIO protection circuit can be seen here: diagram if a typical GPIO protection circuit In most articles online this type of protection just boils down to 'excess current is dumped into the VDD rail'. However, where does it actually go? If the situation is modeled with ideal voltag... (more) |
— | about 1 year ago |
| Comment | Post #294345 |
@#36396 I never quite understood the tangible difference between noise filtering using inductors vs capacitors. If you have local decoupling capacitors that have low impedance in high frequency band, why would there be a need to add a ferrite in series before the capacitors? Instead of shunting t... (more) |
— | about 1 year ago |
| Comment | Post #294328 |
@#52935 Differential driver lines, 0 to 5V with 2.5V midpoint. (more) |
— | about 1 year ago |
| Edit | Post #294328 |
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— | about 1 year ago |
| Edit | Post #294328 |
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— | about 1 year ago |
| Edit | Post #294328 | Initial revision | — | about 1 year ago |
| Question | — |
Does preventing CMOS latchup with a diode in VCC path prevents protection diodes from working? I want to use ADG726 multiplexer for an application where the multiplexer inputs could have potential on them before ADG726 is powered up. Seeing that ADG726 is a CMOS device, it seems it might be susceptible to latchup. One way to prevent it according to theory is to put a diode in series with t... (more) |
— | about 1 year ago |
| Comment | Post #294246 |
Hey I have noticed that a lot of questions lately have been getting downvotes without any explanation as to why. Consider giving some kind of feedback, otherwise how can OP fix whatever you are dissatisfied with? (more) |
— | about 1 year ago |
| Comment | Post #294124 |
@#36396 I want you to know I appreciate this a lot. I will update the post once I have tried out your suggestions! (more) |
— | over 1 year ago |
| Edit | Post #294122 | Initial revision | — | over 1 year ago |
| Question | — |
Geophone amplification circuit behavior This is an expansion on Biasing a differential opamp input post. Olin pointed out that gotchas can be in the implementation, so I will provide the circuit and design specifications as well as my research so far. The geophone is HG-6 B coil, shunt for 0.7 damping is specified to be 9090 ohm. ... (more) |
— | over 1 year ago |
| Comment | Post #294083 |
@#36396 I separated them now and added a datasheet link. The part is a yellow blob because it is autogenerated from .lib file I found for the spice model, I tried re-making the part using opamp symbols but it was throwing errors and after an hour I decided yellow blob will do. (more) |
— | over 1 year ago |
| Edit | Post #294083 |
Post edited: Separated schematic from simulation, added datasheet link |
— | over 1 year ago |
| Edit | Post #294083 |
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— | over 1 year ago |
| Edit | Post #294083 |
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— | over 1 year ago |
| Edit | Post #294083 | Initial revision | — | over 1 year ago |
| Question | — |
Biasing a differential opamp input I have a differential signal source and a single source amplifier. The source has 2Vp-p signal. I wanted to center the differential signal around 2.5V, so I came up with the following circuit: Imagealttext Simulation results: Imagealttext The opamp used is INA188 Simulation does what I w... (more) |
— | over 1 year ago |
| Edit | Post #293778 | Initial revision | — | over 1 year ago |
| Question | — |
Matching network considerations for STM32WB55CEU6 Hi, I am designing a system using STM32WB55CEU6 and I want to use the RF functionality. Looking at evaluation board I see that there is a matching network for the output pin. The datasheet does not specify the output impedance, but an ST employee posted their empirical measurements: Imagealtt... (more) |
— | over 1 year ago |
| Edit | Post #293402 | Initial revision | — | over 1 year ago |
| Question | — |
Tesatronic TTD20 DGND AGND unconnected The TESATRONIC TTD20 is a precision length measuring instrument used in various industrial and laboratory settings. On the backside it provides a 15 pin interface for reading out signals: Imagealttext I wanted to use this interface to connect to an external measurement PCB. Before designing i... (more) |
— | over 1 year ago |
| Edit | Post #292898 | Initial revision | — | almost 2 years ago |
| Question | — |
OPA2211 datasheet discrepancy Looking at Texas Instruments opamp OPA2211it mentions GBW of 80MHz at a gain of 100, and 45MHz at gain of 1: screenshot of the 1st page of a datasheet Looking at the bandwidth graph from Figure 10 in datasheet: chart It looks like 80MHz is unity gain bandwidth, and at a gain of 100 the ... (more) |
— | almost 2 years ago |