hybridfree/eevblog-posts huggingface dataset:
good saftey design tip for HV power supplies - Page 1
Forum section: electronics / projects

author: SArepairman
author_rank: Frequent Contributor
timestamp: August 25, 2014, 03:16:59 am
content: Put a neon bulb oscillator on your high capacitance HV rails, next to the bleed resistor. This PSU I am taking apart from a dynamic signal analyzer has a neat little neon bulb blinker on its 170V rail, that stops blinking at ~50V. I have put regular neon bulbs on my HV stuff before.. I might reverse engineer the circuit if anyone cares. The higher the voltage the faster it blinks.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: August 25, 2014, 03:50:18 am
content: Relaxation oscillator, eh? Can you still get decent NE-2s these days?

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: August 25, 2014, 03:53:14 am
content: Whoah, who knew?"Neon lamps have been historically used as microwave and millimeter-wave detectors ('plasma diodes' or GDDs- Glow Discharge Detectors) up to about 100 GHz or so and in such service were said to exhibit comparable sensitivity (of the order of a few 10s to perhaps 100 microvolts) to the familiar 1N23-type catwhisker-contacted silicon diodes once ubiquitous in microwave equipment. More recently it has been found that these lamps work well as detectors even at submillimeter ('terahertz') frequencies and they have been successfully used as pixels in several experimental imaging arrays at these wavelengths."http://en.wikipedia.org/wiki/Neon_lamp

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 25, 2014, 04:41:03 am
content: My favorite is a 100k or so resistor and a blue LED in series. The blue LEDs need very little current to give a bright glow.

author: TerraHertz
author_rank: Super Contributor
timestamp: August 25, 2014, 10:19:04 am
content: Quote from: SArepairman on August 25, 2014, 03:16:59 amNot much circuit required. The neon is acting as both the level sensing trigger and discharge part. Besides the neon there'll be one or two resistors and one capacitor. One high value resistor from HV to the cap. Other side of the cap is ground. The neon either paralleled to the cap (short blinks), or the neon plus series resistor paralleled with the cap. That resistor extends the blink duration.Neons exhibit resistance hysteresis. The cap charges up till the neon fires. Neon then discharges the cap down to some lower voltage then goes high impedance again. Firing voltage typically around 50V; I vaguely recall they can be obtained from around 30V to 80V. Neons were often used as overvoltage protection crowbars in CRT supplies.
Good score or not? - Page 1
Forum section: electronics / projects

author: 404 Not Found
author_rank: Newbie
timestamp: September 01, 2017, 06:31:36 am
content: So I got a Macbook pro "A1278" and 2 Sony Vaio PCs + 1 Dell dimension 4700 all free with issues.The desktops are working and I'm waiting on a charger for the Macbook, is this a good score for free?

author: Jeroen3
author_rank: Super Contributor
timestamp: September 01, 2017, 07:14:32 am
content: You misplaced this thread? It should be inrepair.You know where you bought it from, if the issues have been looked at and given away for free, they might be BER.
Good SDR dongle as simply  SA & SG  - Page 1
Forum section: electronics / projects

author: Emi
author_rank: Contributor
timestamp: November 23, 2016, 10:02:54 am
content: Hi, another foolish questionAre usb SDR dongles like AirSpy, RSP1/2, and similar suitable for an "almost decent" hobbystic Lab SA?Could Lime SDR and Hack RF be used as basic wide band signal generator too ?Forgive my strange questions but i'm quite tweaking oriented guy

author: Scrts
author_rank: Frequent Contributor
timestamp: November 23, 2016, 04:33:07 pm
content: Well Red Pitaya was created for this purpose. I believe hackrf or any other SDR could be used if that is sufficient for your needs.

author: PointyOintment
author_rank: Frequent Contributor
timestamp: November 24, 2016, 10:27:36 am
content: SmartScope too.

author: phil
author_rank: Regular Contributor
timestamp: November 24, 2016, 11:18:29 am
content: A HackRF can be a powerful tool if you know your way around GNU Radio Companion.However, as with other SDRs, you have to know its limitations and work around them.For example, the output power level (when used as SG) is not flat over frequency and not calibrated. You have to tweak it by manually setting IF and RF gain in your GRC flow graph. That means you need a power meter or some other device to actually measure output power at the frequency you are interested in. Using another SDR has the same problem: You need to calibrate it first.You *can* use a HackRF for simple RF-work, but you need a way to measure its performance first. Meaning, you need access to a decent SA/power meter and SG at least once.My particular HackRF needs 8dB IF gain and 16dB BB gain to get "accurate" power level readings. Beware: Its easy to saturate the IF/BB amps, you need some input attenuators.If you plan on doing serious RF work, don't buy a HackRF. Go for something like the VNWA 3.I do, however, use my HackRF quite often for filter analysis where absolute output power matters little.

author: Emi
author_rank: Contributor
timestamp: November 24, 2016, 01:43:59 pm
content: Thanks guys, Phil, you've been really clear ..I was a little optimistic in fact...And i'm not a GNU guru too..

author: tggzzz
author_rank: Super Contributor
timestamp: November 24, 2016, 04:40:43 pm
content: With a little imagination and understanding, the $15 SDR dongles can - within their limitations - be surprisingly useful.I've noted how I've used one to make a 1.5GHz spectrum analyser, 1.5GHz scalar network analyser, measure 650ps risetimes, and a TDR that can resolve discontinuities 4cm apart.FFI including the utilities I created, seehttps://entertaininghacks.wordpress.com/category/frequency-domain-analysers/
good textbooks detailing wave soldering and SMD oven soldering (industrial) - Page 1
Forum section: electronics / projects

author: SArepairman
author_rank: Frequent Contributor
timestamp: May 11, 2015, 02:35:17 pm
content: I would like to better acquaint myself with the nitty gritty of reflow and wave soldering.What are some good resources for this? I assume I should take a youtube college thermodynamics class first.I can probobly cobble something together by reading a buncha diff resources, but I thought a text made a an author that specializes in the subject might be helpful. This is not for toaster ovens/small scale etc, I am interested for the industrial overview, for medium size production.

author: woodchips
author_rank: Frequent Contributor
timestamp: May 12, 2015, 08:27:25 pm
content: Some years ago books by Electrochemical Publications seem to cover this.Might be just too old, my copies date from the 1980's.

author: SArepairman
author_rank: Frequent Contributor
timestamp: May 21, 2015, 06:12:02 pm
content: Quote from: woodchips on May 12, 2015, 08:27:25 pmthanks, ill check them out
good types of interconnects for chassis wiring? - Page 1
Forum section: electronics / projects

author: sarepairman2
author_rank: Frequent Contributor
timestamp: January 31, 2016, 07:03:50 pm
content: What are your favorite kinds of interconnects for chassis wiring.I have grown fond of wago din rail mountable stuff myself. But I wonder if there might be other fancy options out there.

author: dom0
author_rank: Super Contributor
timestamp: January 31, 2016, 07:24:34 pm
content: What kind of chassis / setting are you talking about specifically?DIN rail suggest something like a distribution box? Or more like inside a device?

author: sarepairman2
author_rank: Frequent Contributor
timestamp: January 31, 2016, 10:13:21 pm
content: A box that might have various stuff in it. Pump, circuit boards, transformers. Instrument Chassis. And on the inside of rack mount equipment. With custom made racks that interconnect a bunch of different things that does a fairly complicated function.

author: dom0
author_rank: Super Contributor
timestamp: February 01, 2016, 12:02:05 am
content: Okay, in that kind of setting Wago DIN rail blocks are as good as it gets.Inside 19", 10" and similar rack mount equipment, well, there are some DIN/ISO/IEC standards used for those, at least here. They are basically a system of standardized connectors that fit exactly in 1/2/3 U of a 19" or 10" wide rack case and allow to just push cards / modules into a common backplane.These things are called subrack (Baugruppenträger, literal translation: assembly carrier), the standards are IEC 60297-3, many manufacturers mark their products with compatibility with that IEC standard. The most common kind is 19" wide and 3 U height with a total depth of 200 to 260 mm (designed for 100x160 mm "eurocard" PCBs). They can be had very cheaply, because lots of industrial gear is built into those things. Units with insides installed are a common sight on scrapyards. Since they are standardized with just a few common variants they are easily repurposed. New they cost about 50 € per unit.+ Common+ Sturdy construction+ Common types are quite cheap, even new+ No worries connector systemThe connectors are IEC 60603-2 or more commonly DIN 41612. They are, like the BGTs, available from many manufactures, common types cost about 3-4 € for one connection (two connectors) with typically 96 or 128 pins. Mixed connectors with high-power contacts and signal contacts are possible. They are available for 1/2/3 U heights (6 U backplanes are usually split in two 3 U backplanes and use 3 U connectors). Backplanes with 1:1 interconnections are available commercially.One can use smaller (1U or 2U) connectors with a custom backplane and offset them vertically from each other, encoding individual plugin slots, where the wrong plugin cannot be inserted. Normally all slots use the same 3U connectors, hence plugins can be inserted wrong, if the connectors don't have all the same signals and pins (like in a VXI bus).+ Large selection available+ Mixed contacts+ Common types are cheap+ Most types compatible with 2.54 mm protoboard
Good USB2 webcam for wide color gamut/sharpness? - Page 1
Forum section: electronics / projects

author: cdev
author_rank: Super Contributor
timestamp: July 17, 2017, 09:49:40 pm
content: I'm looking for a good quality USB webcam that's not too expensive, has a sharp manual focus lens, and nice looking colors. I'm hoping to use it in computer vision.It would be especially great if it had a standard screw for mounting on a tripod if necessary.Does anybody have any suggestions?

author: Fraser
author_rank: Super Contributor
timestamp: July 17, 2017, 10:24:45 pm
content: The Thermal camera sub forum may not be the best place to ask about a webcam ?Fraser
good video showing performance of solder composition types? - Page 1
Forum section: electronics / projects

author: coppercone2
author_rank: Super Contributor
timestamp: September 19, 2018, 10:30:16 pm
content: Is there a good high quality youtube video that shows the performance of various solder compositions in a side by side comparison with explanation, microscope shots, expert comments, highlights where they fail and excel, etc?I would like it to be specific for electronics assembly, or focused on it, but showing stuff for aluminum, steel, etc would be interesting too.. there is more about soldering structural stuff, but no neurotic electronics videos.I only use the eutetic lead/tin one, but people defiantly have their preferences.If I saw something that knocked my socks off in a video I might want to buy other kinds, but I am happy, or maybe complacent, with the eutectic.The closest video I find is this:But its not solder-nutty enough for me.
Direct connect 12V SLA to 12V SLA with overtemp/current protection - Page 1
Forum section: electronics / projects

author: Psi
author_rank: Super Contributor
timestamp: July 25, 2025, 12:00:55 am
content: Has anyone got any ideas, or a schematic, for a nice simple way to connect one 12V SLA to another 12V SLA so that one charges the other in a safe way. Current at least 4A, 6A would be best. I know you can buy off the shelf things to do this, but I need to build this into a new product i'm working on.It can be linear, since under normal situations the voltage difference will be almost nothing. And will come up to meet the other battery pretty fast if not the same. It obviously needs to reduce charge current to keep itself at a safe temp when/if there's a big voltage drop to burn off. And it needs to switch off to block any current flowing the other way.It doesnt need to care about the in/out voltage being safe for charging, it can assume the source SLA is always at a safe voltage to charge the destination SLA.I'm thinking just 2 series FETs operating in linear region with some temp and current control. Unless anyone has any other better ideas?

author: mtwieg
author_rank: Frequent Contributor
timestamp: July 25, 2025, 07:20:02 pm
content: A properly selected PTC resettable fuse will probably do what you want.

author: Psi
author_rank: Super Contributor
timestamp: July 26, 2025, 02:59:25 am
content: Quote from: mtwieg on July 25, 2025, 07:20:02 pmGot any recommendations for selecting a PTC for this purpose. I was under the impression they don't like repetitive use like that.
Goog...... Raspberry Pi Glass - Page 1
Forum section: electronics / projects

author: DomesticHacks
author_rank: Regular Contributor
timestamp: August 15, 2013, 07:13:05 pm
content: After hearing Dave talking in the "Amp Hour" about making a project for the Maker Faire, I thougt it would be a good idea to show you my project i build for the first Maker Faire in Germany.I build a wearable Raspberry Pi which can be printed out with a 3D Printer.You can find further details and all the 3D models on Thingiverse:http://www.thingiverse.com/thing:127800I also made a YouTube video (German language) tearing it apart (because i hadn't the time filming while building it):It would be cool to get some feedback.

author: Erwin Ried
author_rank: Regular Contributor
timestamp: August 15, 2013, 08:44:44 pm
content: Pretty neat! specially the plastic color, it really looks extracted from the last bioshock

author: nctnico
author_rank: Super Contributor
timestamp: August 16, 2013, 06:21:54 pm
content: Resistance is futile...

author: Alana
author_rank: Frequent Contributor
timestamp: August 16, 2013, 11:39:52 pm
content: Reminds me of pip-boy personal computer from Fallout game series

author: DJ_EAS3
author_rank: Newbie
timestamp: August 17, 2013, 12:12:00 am
content: ^ YES!
Google Chromecast audio/portable speaker earth noise solution - Page 1
Forum section: electronics / projects

author: moodymoo
author_rank: Newbie
timestamp: November 22, 2017, 08:13:07 pm
content: Hi,Using the Google Chromecast Audio with most battery portable speakers is an absolute nightmare when the chromecast device is powered by the usb out port of the speakers. (really bad noise and distortion)I'm told this is a "floating earth" problem and I am wondering if there is a simple very small circuit that will clear this up.Powering the chromecast from either a separate portable battery (current solution) or the mains seems to be the only current solution.Does anyone know any elegant (small) decoupling solutions out there that will work without affecting the quality ?thxian

author: Someone
author_rank: Super Contributor
timestamp: November 22, 2017, 10:05:30 pm
content: Its the opposite of a floating earth, connecting the power and audio to the same device creates an earth loop.
Google glasses have come on a long way - Page 1
Forum section: electronics / projects

author: chris_leyson
author_rank: Super Contributor
timestamp: December 04, 2022, 01:11:35 pm
content: I was watching "Click" on BBC today and they showed how Goole glasses where being used to help blind people. You can ask the glasses to describe what they see for example or you could call a friend and ask them to describe what the glasses see. They will also read text and speak it back to you.Decades ago a design for glasses to help the blind was published in Wireless World. They used a pair ultrasound transducers and fed tones into a pair of earpieces to help blind people navigate. I can't remember exactly how audio interface worked and I'm not sure if a working product was ever developed.It's nice to see that Google are making significant progress in a niche electronics application.

author: tooki
author_rank: Super Contributor
timestamp: December 04, 2022, 03:31:50 pm
content: Yeah, that’s been out for a while, and I think that’s a fantastic application for the Glasses tech.Now, while I applaud all progress with respect to accessibility, Google is far from a leader in this regard. By all accounts, Apple’s accessibility support is far better than Android’s.Apple has tons and tons of accessibility features built into their devices and software. Yesterday was the International Day of Persons with Disabilities, and leading up to that, they posted another video showing off the built-in accessibility features in use. Forbes’ accessibility writer did an interesting write-up about it:https://www.forbes.com/sites/stevenaquino/2022/11/30/apple-releases-accessibility-centric--short-film-the-greatest-highlighting-disability-in-tech/Sure, the Glasses are a great use, but it’s $3500. There’s a lot to be said for the robust accessibility features built into every iPhone for $0.

author: Marco
author_rank: Super Contributor
timestamp: December 04, 2022, 11:49:53 pm
content: Our gyroscopes are in our head, it's charity so they have to be happy with what they get but an iPhone is a terrible form factor for the blind compared to a head mounted camera.

author: tooki
author_rank: Super Contributor
timestamp: December 06, 2022, 02:44:16 am
content: Sure, but not everyone has, or can afford, a head mounted device, whereas everyone has a smartphone. As I said: there’s a lot to be said forbuilt-inaccessibility features that don’t require any additional hardware or software. (Ditto for robust, built-in support for assistive hardware, without having to buy expensive software to go with that.)

author: bidrohini
author_rank: Regular Contributor
timestamp: December 06, 2022, 06:36:41 am
content: How much is the accuracy of that glass? How helpful is it to the blind people in real life?
Google Nest Mini Wifi Antennas - Page 1
Forum section: electronics / projects

author: nAyPDJ
author_rank: Contributor
timestamp: February 09, 2020, 12:58:09 am
content: So I was taking apart a Google Nest Mini (I'm not actually gonna turn it on ha), and this thing is really nice on the insides. In particular, check out the antennas in the attached picture!I'm no RF engineer, but it looks like they've computer-optimized these antennas somehow! Really cool stuff, I'd love to hear if anyone knows more about this thing.The little white thing on the left antenna isn't a cap, it's a resistor I knocked off while desoldering. 1/400 isn't too bad.
Goop to attach PTC to heatsink - Page 1
Forum section: electronics / projects

author: AcHmed99
author_rank: Contributor
timestamp: March 06, 2014, 02:21:26 pm
content: What do you guys use to attach say aTO92package to a heatsink?

author: ElektroQuark
author_rank: Unknown
timestamp: March 06, 2014, 02:43:39 pm
content: You can use a pressure-heatsink (sorry, I don't know the correct name):

author: poorchava
author_rank: Super Contributor
timestamp: March 06, 2014, 03:00:41 pm
content: Or drill a hole with 6mm drill bit and epoxy the bastard inside.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 06, 2014, 03:21:26 pm
content: TO92s are not designed to be used where they would require a heatsink. If it's for a thermal sensor, I either glue or clamp it to the surface to be measured.

author: georges80
author_rank: Frequent Contributor
timestamp: March 06, 2014, 04:25:02 pm
content: I've attached thermistors into recesses in copper 'slugs' to measure their temperature. I've used Arctic Alumina 2 part thermal epoxy.cheers,george.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 06, 2014, 06:25:59 pm
content: Super glue or any generic epoxy works well for that application. The high thermal conductivity epoxies are not necessary.

author: Christopher
author_rank: Frequent Contributor
timestamp: March 06, 2014, 07:19:40 pm
content: Loctite Output is a good thermal conducting quick-activating gloop

author: SeanB
author_rank: Super Contributor
timestamp: March 06, 2014, 09:27:39 pm
content: Any metal epoxy like Araldite rapid, in either white or metal will work. I have used it as a heatsink epoxy.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 06, 2014, 10:48:52 pm
content: JB Weld will survive very high temperatures (up to 600F or so) and I have never had any issues using it to attach heatsinks to chips.
Goose chase: Discover & replace TFT panel w/ touch screen help - Page 1
Forum section: electronics / projects

author: mkiijam
author_rank: Regular Contributor
timestamp: January 18, 2024, 05:00:11 pm
content: Hi Guys,So I have this very expensive audio mixer (Digico S32) that has a cracked 10.1" TFT LCD / touch screen assembly that only comes from the factory as an entire faceplate to the tune of >$6KThe thing is probably junk, but as I long shot and for a bit of learning, I thought it might be fun to try and replace the screen / touch screen. Where to start?Really the only thing I have discovered so far is the by reading the numbers on the flex cable going to the touch portion of the screen. "HSD-101297, CG"http://m.hsdtp.com/projected-capacitive-touch-panel-commercial-gg/10-1-inch-capacitive-touch/10-1-inch-industrial-capacitive-touchscreen.htmlThe numbers on the LCD screen itself didn't bring back any results.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 18, 2024, 05:28:00 pm
content: this pdf should be close HSD is normally Hannstarhttps://cdn-shop.adafruit.com/datasheets/HSD101PWW1.pdfhttps://eurotech-lcd.com/productView.aspx?no=HSD101JHW2-A20%20&view=4128https://www.twscreen.com/en/lcdpanel/8070send a email to Hannstar since they make them, or a more recent revision ?? maybe you could find a subst ....the problem would be to get an capacitive touch screen overlay ... it depends on how many wires you have 5 6 8

author: mkiijam
author_rank: Regular Contributor
timestamp: January 18, 2024, 06:06:56 pm
content: Could I just place / paste a new touch screen over the existing one? I believe they are "optically bonded" together, whatever that means...

author: mkiijam
author_rank: Regular Contributor
timestamp: January 18, 2024, 06:15:06 pm
content: Quote from: coromonadalix on January 18, 2024, 05:28:00 pmIt looks like 8 for sure

author: coromonadalix
author_rank: Super Contributor
timestamp: January 18, 2024, 07:02:02 pm
content: normally they are glued or dual side adhesive on the lcd edges, i could change the lcd and recover the touch panel overlay if its not damagedor with a very sharp blade at a given lenght, just slide it under the overlay gently

author: p.larner
author_rank: Frequent Contributor
timestamp: January 19, 2024, 12:03:55 pm
content: i would imagine its like replacing the digitiser on a phone screen?.

author: mkiijam
author_rank: Regular Contributor
timestamp: January 19, 2024, 05:42:36 pm
content: It's kinda like a phone screen. But I'm hoping to find a complete touch screen / LCD assembly that interfaces with the connector types and the language?
Gopro hero2 housing waterproof + want usb power - Page 1
Forum section: electronics / projects

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: August 23, 2015, 01:17:08 am
content: GoPro Hero 2.Have you guys got any suggestions on how I might use a waterproof gopro housing and supply power via the usb port and retain water-proofiness?All ideas welcomed. Doesn't need to be water submersible, just rain proof. Purpose is all day time lapse.

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 23, 2015, 01:45:32 am
content: What about wireless charging kits?

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: August 23, 2015, 03:47:42 am
content: Quote from: NiHaoMike on August 23, 2015, 01:45:32 amNot available for that model afaik.

author: amyk
author_rank: Super Contributor
timestamp: August 23, 2015, 01:34:15 pm
content: I suppose you could do something involving a drill, the neck and cap of a small bottle, and some epoxy...

author: m98
author_rank: Frequent Contributor
timestamp: August 23, 2015, 03:28:21 pm
content: Maybe something like that:https://www.adafruit.com/products/1407

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: August 23, 2015, 11:32:52 pm
content: Cool.But I'm after more mechanical ideas to waterproof the usb cable. Preferable without gluing the whole thing permanently.
Got a lesson in Flame Proof vs Flame Retardant resistors - Page 1
Forum section: electronics / projects

author: pilotplater
author_rank: Newbie
timestamp: January 06, 2020, 11:00:31 pm
content: Hobbyist hereSeems obvious reading the listings and datasheets after the fact, but not digging into the details I didn't think much about the term flame retardant before placing some orders. Flame retardant meaning they won't sustain a flame once heat (power) is REMOVED.Having dealt with self-extinguishing 3d print plastics normally this is well good enough, overkill even, but given a resistor is the heat source, it will sustain a flame while overloaded.My very non-scientific tests to assess the short-circuit behavior of two resistors I got. A flame proof Yageo part, and a flame retardant coated stackpole part. Suffice it to say, don't want to let it get this far in-circuit. This is way beyond the rated spec obviously:https://photos.app.goo.gl/aeMLaQYQAbZmiqmi9

author: thm_w
author_rank: Super Contributor
timestamp: January 07, 2020, 01:23:06 am
content: Quote from: pilotplater on January 06, 2020, 11:00:31 pmhm you'd hope that would be the case with all modern resistors, although they may not wish to guarantee it.Good demo.
got a surprise project today that I slam dunked. - Page 1
Forum section: electronics / projects

author: Tranan
author_rank: Contributor
timestamp: October 08, 2013, 05:34:05 pm
content: Sat in the "Office" and minding my work on a high voltage wire model. When a Interior designer storm in cause he had problem! Oh dear a arty guy with a math problem. He has a room 18X12X3,5 meter and his contractor has stipulated that at 0,8m there must be 100 to 150 lux as a mean value. We call it hallway lighting. This was at 10:00h.After dragging my calculator out of its casing and turned it on. I did some math. I used n=(E*A)/(¤*N). thats the normal efficiency formula. E= desired lighting condition in lux A= area in square m ¤=flow of lamps N= number of lamps. Shake the formula then I got this N=(E*A)/(¤*n) I got th info that they wanted a lamp with ¤=6000lm and at least 40% efficiency and the room is 216m2.dunked that in and got that I needed 8 pieces of fixtures.So I punch that in to my 3D render and placed the room and fixtures and gave them a report. If they follow my plan then they got 115lux as a average light at 0,8m.Did a short report and some economic calculation and wiring plan and material cost estimate and mailed that to them at 14:00h.Math is good. I think I can get a reward and a treat fore that!Engineers is ruling the world.

author: JackOfVA
author_rank: Unknown
timestamp: October 08, 2013, 05:42:29 pm
content: Do you have to worry about uniformity of lighting and analyze the radiation pattern of the individual light fixtures or is the light sufficiently diffused by the fixtures that the pattern near the floor is uniform?

author: Tranan
author_rank: Contributor
timestamp: October 08, 2013, 05:54:04 pm
content: Quote from: JackOfVA on October 08, 2013, 05:42:29 pmI mead a analyses in the 3d render and I got the light to a some what uniform pattern got a EAvg=115 Emin=23 and a Emax=189 that gives a Emin/Emed=0,197 And that gives a somewhat of a patten. but if I had given them a 10 fixtures the it had been to bight fore the specs given and 9 fixtures no I like 8. I believe they want spots on the wall fore artwork and so on but I don`t know. the got their 100-150 lux and it is going to cost them 4,3kWh a day.

author: GoatZero
author_rank: Regular Contributor
timestamp: October 08, 2013, 07:40:50 pm
content: Quote from: Tranan on October 08, 2013, 05:54:04 pmWhat software are you using to render that kind of simulation?

author: Tranan
author_rank: Contributor
timestamp: October 08, 2013, 07:49:59 pm
content: Quote from: GoatZero on October 08, 2013, 07:40:50 pmDIALux 4,11
Got bored...  ATX PSU & E-Load build up. - Page 1
Forum section: electronics / projects

author: Skimask
author_rank: Super Contributor
timestamp: October 18, 2014, 03:26:39 am
content: Got bored this week. Took an old ATX PSU, turned it into an extra bench supply. Also, re-watched Dave's video on electronic loads. Built one of those up too. It ain't perfect, it probably ain't accurate, but it's good enough for me.

author: dr.diesel
author_rank: Super Contributor
timestamp: October 18, 2014, 01:03:05 pm
content: Quote from: Skimask on October 18, 2014, 03:26:39 amCan't wait to see what next week brings!

author: nuno
author_rank: Frequent Contributor
timestamp: October 18, 2014, 11:40:30 pm
content: So, how did the PSU performed under load?

author: chickenHeadKnob
author_rank: Super Contributor
timestamp: October 18, 2014, 11:57:03 pm
content: Hi skimask, I have a question, a stupid question. How does that e-load shed the heat? kinda small lookin'

author: nctnico
author_rank: Super Contributor
timestamp: October 19, 2014, 01:05:56 am
content: Quote from: dr.diesel on October 18, 2014, 01:03:05 pmLook, it's my kid! (yellow label saying: 'Kick has happy fun time super sweet baby')

author: Skimask
author_rank: Super Contributor
timestamp: October 19, 2014, 01:13:10 am
content: Quote from: chickenHeadKnob on October 18, 2014, 11:57:03 pmoh, there's no plan for getting rid of heat.that's the beauty of it all. Built it up. Sweat the small stuff later.but ya, there are small holes for air and the fet is on a large heatsink inside.
Gould 4074 extreme teardown - Page 1
Forum section: electronics / projects

author: Noopy
author_rank: Super Contributor
timestamp: July 28, 2019, 08:30:33 pm
content: On more project I want to share with you.I´ve begun to publish a huge teardown project regarding the Gould 4070 series (4072, 4074, 4082, 4084, 4072A, 4074A, 4090, 4092, 4094, 4096):https://www.richis-lab.de/Gould407X.htmIt will take some time until it´s finished. But it can not be ruled out that it is an endless project, so I will update the report part by part.Text is german...Sorry...Have fun!Best regards,Richard

author: coromonadalix
author_rank: Super Contributor
timestamp: July 29, 2019, 01:38:50 am
content: thks, one heck of a report and findings

author: Noopy
author_rank: Super Contributor
timestamp: July 29, 2019, 03:19:18 am
content: Thanks!Wait until it´s finished! For the 4074 hardware I have more than 300 pages left to review...
Gould os4000 dual beam not functioning! (HELP!!!!!!) - Page 1
Forum section: electronics / projects

author: crashandburn_ds
author_rank: Newbie
timestamp: August 25, 2013, 10:32:48 am
content: I Recently came into possession of a Gould 0S4000 CRT DSO, unfortunatly i can only get ch2 to display. I can trigger off of ch1 so im assuming that there is an issue with the Beam Selection or Assosciated hardware, My Knowledge is still rather lacking. I am still yet to check voltages as someone ran of camping with my multimeter but i have been tring to locate the issue with the service manual (Heres a copy it wont let me upload it, its to big)http://www.kevinchant.com/uploads/7/1/0/8/7108231/os4000manual.pdfAny help would be greatly appreciated as i am now making it my lifes work to fix this, i can see it laughing at me already.
GW Instek GPC-3020 fan replacement: Has anybody attempted it yet? - Page 1
Forum section: electronics / projects

author: cdev
author_rank: Super Contributor
timestamp: August 16, 2017, 01:14:16 am
content: A few months ago I bought a GPC-3020 and its getting a lot of use. But, theres one problem and its noise. The fan is very noisy. Has anybody replaced their GPC-3020s fan yet?I am sure all of us who own one would like to.The case has such tiny ventilation holes- its not well designed. It seems to me that opening up some more ventilation would likely make the existing fan quieter, because right now its airflow is constrained by the tiny vent holes.That likely is a big part of the noise problem right there.The steel in the case is very thick, though and doesn't seem very likely to be easy to cut to add additional air flow. So maybe the first attempt for me will simply be to find a quieter fan and see if that supports adequate cooling, see if its temperature rises under load conditions.I was just wondering if anybody else had already done this.
GPIB end device - Page 1
Forum section: electronics / projects

author: davorin
author_rank: Unknown
timestamp: June 17, 2014, 04:38:47 pm
content: There are many open source projects on the web, mostly with Microchip controllers to control GPIB enabled devices....I also use one self built successfully with my instruments...But has anyone stumbled across a project where a microcontroller is used as a GPIB device?All my instruments can be remotely powered via an IP switch. Much more convenient to finger around the back and looking for the power switch (o;My idea is now to have the power switches modified so they can be controlled via GPIB as well....
GPIB Streamer Project complete - thanks to EEVblog - Page 1
Forum section: electronics / projects

author: Ment11
author_rank: Contributor
timestamp: May 08, 2013, 07:12:43 pm
content: Just wanted to thank Dave and everyone else on this forum for helping me out before, without EEVblog, I would not be able to finish (and probably even start) my project. I have been working on this project for the last 2 years at work, and it's finally complete!Quick summary about it - its a GPIB spy/streamer that is designed to capture the GPIB data off of a mass spectrometer without interfering with instrument or the control computer to enable it to stream data in real time (the control computer runs MAC OS9 so its ancient).Here are a few pics for your enjoymentThank you again to Dave for amazing videos, and everyone who helped me out on this forum.
GPIO Schottky Diode Clamping Circuit with Battery and Low Quiescent Current - Page 1
Forum section: electronics / projects

author: lukegalea16
author_rank: Newbie
timestamp: March 02, 2025, 06:39:38 am
content: Hi,I'm testing a typical schottky diode clamping circuit with a resistor before the external input and schottky diode pair.When testing this with two bench power supplies where Vcc was set to 3V6 and the external voltage applied was 6V, the Vcc attempted to start rising.Considerations and improvements to keep in mind:1. The quiescent current of the board is micro amps. Some noted that the lack of high constant current will make this circuit not work properly and VCC will rise.2. The circuit will be powered via a 3V6 Li-Soci2 battery or a 3V6 LDO.3. A zener diode clamping circuit might be a good alternative but apparently if the microcontroller is off the absolute maximum ratings will obviously change.4. I read about using a PMOS voltage clamping circuit as an alternative.My thoughts here for the circuit not working is because of the low quiescent current or the bench power supplies not being able to sink the excess current.What are your thoughts on this?

author: ahsrabrifat
author_rank: Regular Contributor
timestamp: March 08, 2025, 05:37:51 pm
content: When the external voltage (6V) is applied, the Schottky diode forward-biases (since 6V > 3.6V + Vf) and conducts current into Vcc. A Zener diode to ground (e.g., 3.9V Zener for a 3.6V system) will clamp the voltage more effectively.However, Zeners tend to have higher leakage and may not behave well in ultra-low-power systems.
GPS 1pps how to fanout - Page 1
Forum section: electronics / projects

author: rakeshm55
author_rank: Regular Contributor
timestamp: January 21, 2019, 10:46:11 am
content: Hi,I would like to use XM1100 GPS module in one of my project. It has a 1pps output.I would like to distribute this signal to two separate modules. Which buffer should I use for this purpose??IF i use an ordinary buffer with wont is affect the jitter characteristics of ipps.Are there sophisticated buffers available which can have very low propagation delay across o/p pins.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: January 21, 2019, 11:07:40 am
content: Simple approach.... 74HC04D if you can afford 12ns (Feed input into one gate and use it's output to drive the others)

author: rakeshm55
author_rank: Regular Contributor
timestamp: January 21, 2019, 12:40:08 pm
content: For 3.3V wont it be 50ns approx (24ns + 24ns ) ....http://www.ti.com/lit/ds/symlink/sn74hc04.pdfHow did you arrive at 12ns

author: TomS_
author_rank: Frequent Contributor
timestamp: January 21, 2019, 02:31:01 pm
content: Quote from: rakeshm55 on January 21, 2019, 12:40:08 pmYou wont want to use HC logic parts for 3V3 operation, 3V3 may only barely meet the logic HIGH threshold if at all. LVC (Low Voltage CMOS) which is intended for use with lower voltages would be better.74LVC04 has a typical propagation delay of 2.5ns at 3V3, if that matters.e.g.http://www.ti.com/lit/ds/symlink/sn74lvc04a.pdf

author: awallin
author_rank: Frequent Contributor
timestamp: January 21, 2019, 04:21:17 pm
content: For 1PPS I've used IDT 5PB1108https://www.idt.com/products/clocks-timing/clock-distribution/clock-buffers-drivers/5pb1108-18-v-33-v-18-lvcmos-high-performance-clock-bufferif you tie a few (4-5) outputs together then it drives around 2.7V into a 50R load. It has internal 50R series termination, so connecting outputs together reduces the output impedance from the ideal 50R - a trade-off to pay for the 2.7V into 50R...
GPS 35mm ceramic patch antenna - Page 1
Forum section: electronics / projects

author: GigaJoe
author_rank: Frequent Contributor
timestamp: December 31, 2021, 12:35:50 am
content: Hello,i did purchased 35mm patch ceramic antenna , amp on back. Due to my ex. exp , i de-solder a metal screen:https://i.ibb.co/NFGT1Zk/DSCN3897.jpgIn my understanding left side of coax are input power feeding, it appears: D1 - 0.911V (zener) ; R5 - 0 Ohm ; R1 - 300 Ohm.Questions:Why R5 == 0 Ohm , ( it should be some resistance along with zener)AT2659S - nominal supply 2.8 V min 1.4V , not even close to 0.9Vcan anyone identify Q1 (label 10U) on top ? , May I assume it an additional amplifier or it filter ?( should I re-do power feeding ? , I'm expecting up to +5V to feed the antenna, it seems will burn everything)Thanks a lot in advance, everyone

author: lordium
author_rank: Regular Contributor
timestamp: December 31, 2021, 01:39:43 am
content: Are you sure D1 is not broken? 0.9V zener seems unlikely. Any markings on it? Hard to tell from the image.(better desolder for measuring, or disconnect other parts of circuit)Q1 = CKRF3509MM34 or similar amplifier

author: GigaJoe
author_rank: Frequent Contributor
timestamp: December 31, 2021, 02:44:14 am
content: D1 - de-soldered , ( label was D5 or F5, not so sure , due to size)0.911 one way , 0.537 another R5 - indeed 0 OhmYes ! CKRF3509MM34 == Q1 , labeled 10U , and V rating 2.7 min 3.0 opt 3.3 max and 15ma .so def. need LDO on 2.8 V well well ....( but it great , i did ordered a few weeks ago 2.8 sot ldo ; total consumption around 20ma, and zener ... ldo 5 cents . I'm wonder if inductors in filter, just a random thing, a good thing i ordered with 1.6G freq.)

author: lordium
author_rank: Regular Contributor
timestamp: December 31, 2021, 03:42:35 am
content: Diode probably something like MMSZ5230B.should work fine without it, but can replace with another diode 4.7V or so ( >3.3 should be fine I guess).

author: GigaJoe
author_rank: Frequent Contributor
timestamp: December 31, 2021, 03:54:52 am
content: i have 2 dead 25mm with AT2659S , it got fry with 3.5V , so i spent some time to figureout feeding schematics parts etc, arrived recently , so will do modding
GPS, BLE, 9 axis IMU part suggestions - Page 1
Forum section: electronics / projects

author: GeorgeJr
author_rank: Newbie
timestamp: January 11, 2024, 11:59:46 pm
content: Looking for some suggestions for parts.Main custom PCB Board has a STM32F401 MCU with connectors to add a Hat.3.3v with I2C and UART and likely will have SPI available for the hat off the main board.What am I doing with this hat: Hat is for 3mph or less rocking vehicle to provide heading and speed adjustments. Looking to average 10-15-30 sec of data and make correction if outside acceptable speed or heading tolerance. Clear visibility for GPS. Sensors are for heading and help with low speed where GPS isn't as accurate. 1/10 mph speed tolerance for speed adjustment or so is desired and heading 5 degrees or so either direction (adjustable if more deadband is needed for both).GPS was looking at SAM-M10Q also Quectel L89 (Dual band L1&L5) or ? Wondering what others like/dislike from hardware to using data in code.IMU: Was looking at 9 axis but seems many are 6 axis. Any suggestions on parts? Starting looking at ICM-20948 but would need to shift the output. BNO085 was another one I was looking at but looking for suggestions here on what works well. Minimal calibration would be a plus as controller might not be easy to access. Also any issue mounting vertical vs horizontal?Bluetooth: App for iOS and Android future state and would like to have enough flash to update the firmware in the future. MGM240PB32VNA3 from Silicon Labs or a Nordic chip or ?Thanks for any suggestions. Will build and test first but long term would be larger run say 500 boards so some cost will come down with larger order.
GPS Comm software - Page 1
Forum section: electronics / projects

author: raptor1956
author_rank: Frequent Contributor
timestamp: May 11, 2018, 09:43:11 pm
content: I want to connect my Garmin GPSmap 60CSx to my PC and have the live data available to my PC -- not just upload/download waypoints etc. I want to be able to log the data to do averaging to refine the accuracy of the fix. No, I don't expect the same level of accuracy as a surveyor grade GPS instrument but by averaging for a few hours the +/-10m error should be reduced to a couple meters and if the averaging is longer the fix might be better than 1m.I did some checking in the internet and a program called EasyGps pops up but as best I can tell it's really only an upload/download utility so not what I want.Years ago I had a Garman GPS50 that had an RS232 interface with a NMEA protocol and I was able to use a terminal program to capture the live data then used VisualBasic to log and process the data. The 60CSx uses a USB interface but I don't have VisualBasic anymore nor a terminal program to talk to the GPS.So, any software out there that can be recommended for my application?Brian

author: AustinR
author_rank: Newbie
timestamp: May 12, 2018, 12:01:03 am
content: My background is in systems in agriculture, so if I make incorrect assumptions, I apologize.I am fairly certain that programming is still being done via RS-232, looking at cables on Garmin's website for your device.If they program via RS-232, they could, in theory, transmit via RS-232 as well. And, if it can communicate via PC, it probably doesn't even need a null modem adapter to do it.So, It's likely that Pin 2 or 3 of the DB9 connector can output RS-232 still. Baud rate may be tricky, but for rough positioning, it's probably 9600 at 1 Hz.Once the device is configured via software to output NMEA, a PC should be able to read it with a cable from Garmin.Just checked, yup. The power data cable from Garmin is what you need to export GPS. Otherwise, all you need to do is export GPS and figure out which pin is RS-232 TX, then connect that to either Pin 2 or 3 of your DB9 connector on your PC.Page 75 of the latest Owner's Manual has a basic page with this info.

author: AustinR
author_rank: Newbie
timestamp: May 12, 2018, 12:02:17 am
content: Link to Garmin Website:http://static.garmin.com/pumac/GPSMAP60Cx_OwnersManual.pdf
GPS module strange TXD problem - Page 1
Forum section: electronics / projects

author: Roy-DH
author_rank: Newbie
timestamp: March 03, 2021, 09:41:31 pm
content: Howdy folks, my first post to this forum, tho' I have been reading for a while. I thought the eclectic collection of big brains might be able to help me.I have a few gps modules, bought from Amazon because the price was right. Specifically -https://www.amazon.ca/Geekstory-Antenna-Supports-GLONASS-Compatible/dp/B07ZR8R17Q/ref=sr_1_15?dchild=1&keywords=gps+module&qid=1614806415&sr=8-15I am using these modules in a custom GPS-DO project. They work very well and give me the 1PPS signal I need for timing.However, I could never get the TX data from the module to display.I should mention that I am using the module as a stand alone device, with wires attached to the appropriate points on the board for 1PPS, TXD, VCC and GND.I tried plugging the module, via it's USB connector, into a computer and running gps software.The U-blox Connect program identifies the module as a M8/8 device and it seems to perform properly. No doubt it is a Chinese knock-off but since I don't need to write any data to the module it would suffice.As soon as I selected the right comport in the software my scope showed me data on the TXD line and the software also showed all the expected NMEA data.I found that when I closed the program the data would stop on the TXD line.I experimented with various pull-up and pull-down schemes on the RXD line to try to trick the module into thinking the computer was there, but no joy. Since there are only two data lines from the computer to the module, TXD and RXD, I'm at a loss.I have never seen this behavior in any other gps module I've used, including other M8 modules.Any ideas would be appreciated.regards, Roy
GPS Project - Page 1
Forum section: electronics / projects

author: cksa
author_rank: Regular Contributor
timestamp: December 08, 2019, 07:39:34 am
content: Hi,I am thinking of interfacing the MAX2771 (https://www.maximintegrated.com/en/products/comms/wireless-rf/MAX2771.html), up to a FPGA, and building a GPS receiver from the ground up. What other features should I integrate onto this project? Ultimately, I want to be able to have 2x of these receivers for dual-band GNSS, but not for the first phase.Anything I should watch out for? Any other interesting chips in this space?I'm quite familiar with FPGA development, but haven't done an RF project before. I spent the whole of yesterday reading through this book --> A Software-Defined GPS and Galileo ReceiverA Single-Frequency Approach (https://www.springer.com/gp/book/9780817643904)