Design products for many industries
- Out-of-spec problem with a long tail
- A very good story... illustrating several aspects of engineering - and problem solving- we are faced with. Well done! recap: - Specs rarely tell the whole story on a part. (Today it is apparent with errata sheets!) - "there is more than one way to skin a cat" (gross but accurate) - We are rarely given ALL the variables... but as engineers are expected to provide solutions without error. Ah.. the grey areas of "life"... (when is a product "over engineered?")
- "Old-school" tech still does the trick
- "...not considered legal documents"..... Blanket statements about legal matters is asking for trouble... see: https://www.netcredit.com/blog/are-faxed-legal-documents-legal/ Sorta like: legally taping phone conversations, burial laws, etc.. the answers "depend".
- Simple SSR has zero-cross on/off switching
- Need to watch the details on the circuit's load... I ran across a 3 phase contactor (Big relay) with embedded controls for reducing it's holding current...(nice idea). The leakage from snubber (R2 100 ohm/ C1 0.1uf cap) across the output of the smaller drive relay was enough to keep the Load relay closed (on) when everything else was off/removed... I wasn't expecting that.. Had to remove the snubber for the circuit to work correctly.
- EDN at CES 2015: No news, just an inside look at the electronics---The Zano drone
- This product appears to be marketed as a device intended for personal use .. not professional/Commercial use. Which would make the (hoped for) legislation/FAA rulings.. .moot. It will be interesting to see how well they resolve their manufacturing / volume production issues through their Kick starter funds.... and what the final pricing will be. The latest available pricing you can get from their campaign is 318 Sterling ($481 US). BTW .. the Lantronix xPico Wi-Fi module shown dimensions... are the width and thickness only. They are 24 to 30 mm in length, depending on the version. A significantly larger area than implied.
- The myth called "ground"
- Electrons... they don't have any illusions to over come when addressing their physics. People .. it's another story. Cop: " Do you know how fast you were going?" Response: "Relative to what?" (the sun?, the center of the universe?, the other people in the car? in which axis?) "Don't play dumb with me.. " (I thought I was doing the opposite of that...) Oddly enough, when explaining grounding issues (loops) to installation techs.. I often get an emotional response very similar to the cop's response! The Cop? .. mmm....OK. To be expected. The tech?... it IS relevant to doing their job correctly! Why so many fall back to galvanic isolation (additional expense) when often it isn't required. Too time consuming to convince others to think.
- Tale of two thermostats: Nest teardown
- I thought the review was lacking. Technical but not much depth. Reviewing packaging? Something I expect to find in a consumer review - not in a EDN break down comparison. Nothing to indicate any real info about reliability differences. (gotta work ? yes!) Nest has obviously done a better job of selling it's product as "designed"... (a'la Apple ideals of design). This is a big deal for marketing to the consumer directly. But as MWagner_MA has pointed out, this doesn't impress the professional installer much. But there is nothing keeping Honeywell's design from making improvements to match or exceed any features on the Nest design (it's second gen .. could have a people movement detection - if that is really the selling feature being significant) .. There is much to question about "savings".. that either of these products will provide over a simple thermostat. http://www.getrichslowly.org/blog/2011/03/21/do-programmable-thermostats-really-save-money/ At the point a building has enough IoT devices to be consolidated to provide a truly integrated experience (building automation).. .do I really expect the thermostat to be tying it all together? Optimizing power consumption, maintenance, security, lighting, etc..? Do we expect the normal home owner / maintenance guy to tie everything together? For a significantly more comfortable house or cost savings, it takes more than one or two points of measurement for temperature and humidity... and continually changing the set points. My point: I am not convinced either product is worth their cost or effort. or any product that presents itself as a "silver bullet" improvement to most homes.
- Glossing over lossy capacitors
- I am also annoyed with poorly thought out specs... (often the result of marketing / sales people being lazy) And I smiled reading your joke (Pious, gotta remember that one)... Still... I am aware that many instruments are actually wired into during the testing they perform on a system. So this requirement MIGHT be valid .... Not all "probes" are held in place with a human hand - especially logic probes (got 16 hands?) Most standard avionics and military products are tested @-55 to +125C.
- Quick-Turn PCB shop review project: Step 1, the PCB
- Very interested in seeing the results of this experiment. I understand that many here will never "get serious" on the pcb design work and want to spend zero for their development tools. But EDN isn't really a hobbyist forum.. it was intended for electronic engineers As a engineer, I wouldn't want to spend ANY time learning a tool that I would quickly become limited by. I simply don't have the time. I would recommend any professional system that had: - a zero cost evaluation version, - was usable at work - was easy to use (doesn't require daily use to remain proficient) - interactive links between schematic and pcb layout - integrated well with other tools (most important- mechanical 3D, then simulation tools) Numerous products meet these requirements. At present I am using Cadint. (works with fine with Wine) (cadint.com) Only complaint: documentation is weak Greatest strength: user interface on pcb and schematic is consistent and easy. While it has nice 3D features.. I really love how easy it is to export pcb assembly into IDF formats for work in Solidworks.
- When I was making Thick film hybrids back in the 80s.. we (micro-electronics processing engineers) had to address the rheology of pastes being screen printed. We were printing gold, platinum, silver, etc.. layers and firing on to ceramic. Wire bonding the raw IC die to the conductor patterns. Still an issue when screen printing solder paste on SMT assemblies. The pastes "recovery" (of viscosity) time VS the printing (shear) speed being used. Today, most SMT production people just "know" the first few prints of solder paste are questionable (image of solder paste on pads - not ideal) - till an equilibrium is established between the two characteristics of the paste. Break a rhythm in printing? start all over again. Rheology... ( bigger scope of thixotropic related issues).. an important thing to know about.
- Too little of a bad thing
- OK ... Where did you find "good" money? Of course, if they will take "Bad" money for their MOSFETs .. why care? And then there is that "money being the root of all evil" thing..... (go ahead .. smile! it won't hurt much) Regardless, you are correct. "max" in a specification should mean "max" (under specified conditions).
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