Activity for Pete W
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Question | — |
Humidity specs - is there typical reasoning for lower limit greater than 0? Question about relative humidity specification for electronics. Industrial automation, indoors, cabinet or instrument enclosure. The failure mechanisms at the upper limit are fairly intuitive. I'm wondering about the lower limit. Some devices specify 5%-95% RH - eg. Siemens S7-1500 PLC, which I... (more) |
— | about 1 month ago |
| Question | — |
What is sacrificed when buying cheaper oscilloscope probes (of same BW/cap/R/gain) I'm wondering if there are particular aspects of an oscilloscope probe's performance that tend to suffer, or failure points to look out for, if/when buying lower-end makes of oscilloscope probes (looking at the typical 1x/10x in 200-300 MHz BW range). (more) |
— | over 2 years ago |
| Answer | — |
A: Low-frequency PWM-controlled Mosfet heater circuit This answer is regarding the resonance issue that C2 is fixing, and how it could be done with a smaller cap. There are two aspects of it. To start, consider the 5.6uH vs the 10uF capacitors. It can be stopped from resonating with the addition of a series resistor. With the modest DC current (powe... (more) |
— | over 2 years ago |
| Answer | — |
A: Motor Controller - What might be the purpose of these resistors? I'd guess surge resistance and redundancy, rather than power dissipation. Looks like 10 stages of 5x parallel 2k going left to right?? So that's 10x400 = 4k. Perhaps used for parallel damping the DC link???? (the 6 subcircuits below would be 3phase half bridges??). Presumably then the DC link wou... (more) |
— | over 2 years ago |
| Question | — |
Is there a tool or trick for bending TO220 leads Small-shop question here. Is there a convenient tool for making the bend shown below, other than a pair of pliers that happens to be just the right size, and is it worth it for qty low 100's?  Not a huge deal, it i... (more) |
— | about 3 years ago |
| Answer | — |
A: Is there a particular type of lead-free solder that does not degrade soldering tips? PCB's and components are expected to be used with the common SAC solder, there's little reason to use SnPb, IMO. I learned on SnPb. After a brief transition for RoHS to re-calibrate the "feel" of it, never went back. Once or twice an oddball situation needed low melting point, used SnBi (also toxic I... (more) |
— | about 3 years ago |
| Answer | — |
A: Isolated Digital Input - Overvoltage protection UPDATED. based on clarification to original question. To be clear, just an idea, not tested for this situation! It is abusing the VIL margin on the 3.3V CMOS input, so series diode should be schottky... foo4 (more) |
— | about 3 years ago |
| Question | — |
What is causing this massive discharge traveling down a power line? []()What is causing [this [ABC-news video via Twitter]](https://twitter.com/ABC/status/1361393756067487744?refsrc=twsrc%5Etfw%7Ctwcamp%5Etweetembed%7Ctwterm%5E1361393756067487744%7Ctwgr%5E%7Ctwcon%5Es1&refurl=https%3A%2F%2Fwww.nakedcapitalism.com%2F2021%2F02%2F200pm-water-cooler-2-16-2021.html) spect... (more) |
— | about 3 years ago |
| Question | — |
Is a BJT 3-transistor Wilson mirror faster than a simple mirror? My question is trying to understand if there is an effect on the switching time, on both turn-on and turn-off, between the following configurations. A mirror set up to switch a current, and there is switching on the input side of the mirror input (for other reasons), meaning the simple mirror's ba... (more) |
— | over 3 years ago |
| Question | — |
MOV vs. TVS diode Simple thing that I realized I should know but do not -- when is an MOV preferable to a TVS diode (with some associated network to really make it work, in both cases)? Is it even something to routinely check as an option in e.g. 24V DC systems? (more) |
— | over 3 years ago |
| Question | — |
recommendation for chip programming connection (pogo?) Background: I have several microcontroller based projects with custom PCB that have been in very-low-volume production, but the quantities are starting to go up. (batch sizes now 100 and threatening to go to 1000). The economics here are such that part cost is a secondary concern. I don't feel re... (more) |
— | over 3 years ago |
| Article | — |
PWM Triangle Wave from two clocks What follows is a proposed concept of a simple (in principle!) way to generate a fixed-amplitude triangle wave, using two clocks, an XOR gate, and not using any processor cycles. It is practical in the low-mid-100-Hz ballpark, with typical mcu clocks. Motivating application is dither waveform for ... (more) |
— | over 3 years ago |
| Question | — |
is this too obvious for a post? I recently realized something blindingly obvious that I'd overlooked for a few years - that I can generate a servicable PWM triangle wave from a micro by using two PWM outputs with timers set to slightly different frequency. (i.e. no processor load whatsoever, no analog circuitry other than the filte... (more) |
— | over 3 years ago |
| Answer | — |
A: Is ESD overhyped? Real life example. The machine shop of the company where I work has HAAS VF2 milling centers. At 3.5 tons, you'd figure a big enough to warrant some care and respect. The favored method of data transfer is USB stick. On a winter day, the cnc programmer picks up enough static on the short walk ... (more) |
— | over 3 years ago |
| Answer | — |
A: Moving average that uses less memory? A bit of a tangent, but in mcu firmwares, higher order filters can also be implemented directly with biquad sections. More work to implement vs single pole, but very reusable. Although to be honest the benefit over cascaded single-poles is marginal, so there may be other topics, like loop stability, ... (more) |
— | over 3 years ago |