hybridfree/eevblog-posts huggingface dataset:
TPS92411 100V Floating MOSFET Switch - Page 1
Forum section: electronics / projects

author: Terabyte2007
author_rank: Frequent Contributor
timestamp: October 22, 2014, 02:44:42 pm
content: Has anyone here used the Texas Instruments TPS92411 100V Floating MOSFET Switch in a LED lighting design yet? If so, your thoughts? Is it really effective in replacing traditional flyback/boost type drivers?
Trace width in analog circuits - Page 1
Forum section: electronics / projects

author: crispytato
author_rank: Regular Contributor
timestamp: October 06, 2014, 06:47:53 am
content: Hi there everyone,I'm posting this in the projects subsection because I fear the PCB/CAD section doesn't get much traffic comparatively.I'm making some final tweaks to a design, a high performance headphone amp based on LME49720/LME49610 and have a problem that I don't have the experience to answer definitively.Basically, it involves traces carrying signals in my design, which will be seeing small, but significant current. The rest of the design is very "belt and braces" and I don't want to have piddly little tracks be limiting my performance with excess parasitic inductance/impedance. The output devices will generally not be exceeding a few hundred milliamps, and I've used 0.5mm traces for anything that will be carrying a decent amount of current. I've also linked all of my bulk capacitance and power traces using 1mm tracks. The total input power is around 25vac (rms) and 600ma when driving a sine wave at high volume (likely much more than it'll see in real life operation).Looking at the board after doing this, there is still room to flood fill areas between the caps, and from the ac input. I was wondering whether in this situation, there would be any advantage to doing so. It's at no cost to do so or not, but it'd be a bit more work to replace all of these traces with a nice flood fill instead, so I'd rather not if it doesn't serve any positive purpose. I've also used larger than usual traces for input signals, to minimize parasitic losses, is there any reason not to do this?Along these same lines, I've avoided using thermal relief on my vias/through hole leads, except in places where it will actually make soldering them easier, to avoid excess parasitic losses. I've only used a single via (1.27mm outside/0.7mm inside) in the few places where power goes through the board to the other side, making sure to bus the power tracks as continuously as possible. Is this all sufficient for the application? Is there a reason I shouldn't go for the largest traces and over rated vias in this circuit? I've always thought, bigger is better, but sometimes these things aren't entirely intuitiveThanks for taking the time to read this. I can post some pictures to illustrate my design choices if anyone thinks it'd help them understand my questions better.Peace!-Chris

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 06, 2014, 06:59:00 am
content: I pour both sides and stitch religiously as a matter of practice, doesn't matter the bandwidth.Tim
Trace width rules for high-speed analog? - Page 1
Forum section: electronics / projects

author: Pack34
author_rank: Frequent Contributor
timestamp: October 12, 2017, 01:07:38 am
content: I'm evaluating an analog design that needs to be as low-noise as possible. Some of these are 6 mils wide that run for a couple inches. The overall swing can travel the full 2.5V over the end ADC where 30 raw counts can matter. That's about 1.2mV.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 12, 2017, 01:10:25 am
content: What bandwidth? What nearby EMI sources?I don't see how a trace that wide could possibly affect noise, on its own. You'd be looking at noticeable amounts of noise (0.1nV/rtHz?) for extremely narrow (um?) traces in that length.Tim

author: Pack34
author_rank: Frequent Contributor
timestamp: October 12, 2017, 01:22:43 am
content: All linear regulators on-board but a 50MHz clock to the sensor. 8 clocks to resolve one pixel on the sensor. Output for that pixel is only stable for two of those clock cycles.

author: Marco
author_rank: Super Contributor
timestamp: October 13, 2017, 03:47:45 pm
content: So you want to reduce received emi by reducing trace impedance? Why not shield the trace instead?

author: DaJMasta
author_rank: Super Contributor
timestamp: October 13, 2017, 04:15:10 pm
content: I don't think this will be as much of an issue as you may be expecting. It's on the lower end of frequencies where impedance matching could be a big issue, and your noise allowance is not really going to be impacted by thermal noise related to the width of the traces. With wide traces close to a ground plane you do get some added capacitance, but it's not so much noise as it is just a low pass filter (which could actually take out any very high speed noise).So specifically designing for low noise, I would look towards other things than trace width. Can you keep the routing away from other signals/digital logic? Do you have analog and digital ground planes separated? Do you have local linear regulation for analog parts (with maybe some LC filters on them for extra rejection)? Can you bury the trace between ground planes and stitch around it? Is it so low current that surface leakage is an issue? Would external shielding from other parts radiating be valuable?I guess if noise really ends up being an issue and you can't route around interfering signals, you could also swap over to a differential signal and gain the noise rejection benefits of using them over whatever track length you end up with.

author: Rerouter
author_rank: Super Contributor
timestamp: October 13, 2017, 08:55:29 pm
content: In this appraoch, seeing as a single count is only 40uV and your tolerance is to less than 30 counts,I would say follow best practices. Put a ground trace between any switching signals and your analog signal. To act as a fence for the noise on your board. Keep the distances short. And unless capacitance is a big issue. Maintain a clean return path under the signal as the ground return path can contribute to noise pickup if you cross breaks in planes or if large DC currents have a path of least resistance that directly crosses under it.
Tracing a signal through UHF circuit - Page 1
Forum section: electronics / projects

author: Raff
author_rank: Regular Contributor
timestamp: December 19, 2013, 01:43:57 am
content: G'day all,Im trying to repair the power amplifier module for a UHF repeater.It looks like most if not all the semis have been destroyed as it has very low power output, it should put out around 75 watts at 470 odd megahertz, but its down to around 2 or 3 watts at best.My question, what method do people who work on these things use to trace the signal through various stages to confirm the replacement parts are doing their job?I have worked on audio gear and up to HF and VHF gear, and with those Ive used a signal generator and the trusty CRO, but my CRO goes to 200MHz.I have a humble home setup, Ive go a demodulator probe but suspect its not up to the job at 400 plus megs, its a rather old "B and K" one.I thought perhaps I should try and make a new demod probe with a higher spec diode in it?Thanks guys and gals,Raff

author: KJDS
author_rank: Super Contributor
timestamp: December 19, 2013, 08:08:45 am
content: Solder a 390 or 470 ohm resistor onto the end of the center conductor of a length of coax. One end of the coax to a spec ana, the other with the resistor is the probe. Fairly flat to over 1GHz, 20dB loss, however that's only for a 50ohm point.I've worked on power amps where the device input impedance has been a fraction of an ohm. What's there isn't readily measurable, though there is usually enough there for something to be visible.

author: Raff
author_rank: Regular Contributor
timestamp: December 19, 2013, 11:37:10 am
content: Thanks for the suggestions KJDS but unfortunately I don't have access to a spectrum analyser. I would love to have one thoughI passed up one at a recent HAMFEST for $250, I'm still kicking myself about it.Regards,Raff
tracing building power circuits - Page 1
Forum section: electronics / projects

author: calzap
author_rank: Frequent Contributor
timestamp: October 12, 2024, 02:07:29 am
content: We recently inherited a second house, which will be a rental for a while. I have no information about wiring in the house and have been sleuthing with reasonable success. However, it’s come down to 3 outlets that have no power and no obvious source of power. None is a GFCI outlet, but all should be GFCI-protected … 2 are outside, 1 is in the garage. No breakers are tripped and all GFCIs that I discovered are not tripped and function normally. There are no wires in panels that are not connected to circuit breakers. All wiring is in walls or ceiling spaces.I have several 2-piece circuit tracers. One part plugs into a socket and injects a high frequency signal. The other part has a detector for the signal and can detect wires or breakers where it is present. The catch is the outlet into which the signal generator is plugged must have power.I’m considering using output from an isolation transformer connected to a powered circuit to put power into the unpowered circuit under test. I could do this with a suicide cable or use a cable with a plug on one end and lugs on the other end fastened to power connections of a socket of the circuit under test. The signal generator would be plugged into a different socket of the circuit under test. I’ve checked that the high frequency signal of the signal generator cannot pass through the isolation transformer. I'll have an ammeter attached to the connection cable. If there is any significant current, I'll disconnect.Does anyone see any big problems with this scheme?Mike

author: Kim Christensen
author_rank: Super Contributor
timestamp: October 12, 2024, 02:29:20 am
content: There is a risk that if the wire is unterminated/cut inside the wall, and the leads are barely touching, creating just enough resistance to spark a fire.Unlikely, but still possible. I wouldn't rely on my own slow reaction time to pull the plug if 15+ amps flows for even a second. Putting a low amperage (1A or less) fast acting fuse between the isolation transformer and the circuit under test would reduce this risk.A better option is to use a signal tracer with it's own built in power source. Like those used to trace telephone wires. (Though these can get damaged if you put the toner on a live AC circuit)

author: calzap
author_rank: Frequent Contributor
timestamp: October 12, 2024, 06:41:51 am
content: Good idea to use a 1 A fast acting fuse rather than me watching an ammeter and pulling the plug. I’m aware of signal tracers for dead circuits, but don’t want to spend US$150 for a decent one for a one-off use. However, if the fuse blows, I'll do it.Mike
Tracking down a Datasheet: Omron g4d-287p-bt2 5V - Page 1
Forum section: electronics / projects

author: jiggles
author_rank: Newbie
timestamp: January 12, 2014, 05:04:36 am
content: Can anyone point me in the right direction or even just some info on a relay I have found? Its a Omron g4d-287p-bt2 5V. Google comes up with nothing at all!Seems a fairly old relay to the point that Omron have nothing about it on their site!Thanks in advanced!

author: calexanian
author_rank: Super Contributor
timestamp: January 12, 2014, 06:37:15 pm
content: http://www.ebay.co.uk/itm/5x-Omron-G4D-287P-BT2-PS-3-6VDC-2-pole-change-over-3-6v-/150596011434From the picture on the top it looks to be a double pole double throw pretty standard relay. It has been discontinued. There is the pinout so it should not be hard to find something close enough to bodge in.

author: jiggles
author_rank: Newbie
timestamp: January 12, 2014, 07:54:37 pm
content: I know the pin out I was just wanting to know the current draw of the coil and such.

author: calexanian
author_rank: Super Contributor
timestamp: January 13, 2014, 12:16:48 am
content: g4d series I believe were 5 amp contact depending of the plating type. But its been a few years (15) since I have looked at those. We use Hasco KSD series relays. Relays kinda fall into standard pinout/package/current categories so the Chinese may copy them easier!
Tracking down pinout for an unknown 16x4? char display - Page 1
Forum section: electronics / projects

author: brian4120
author_rank: Newbie
timestamp: May 30, 2016, 10:20:39 pm
content: Hello to the EEVBlog forums!I've been looking through google trying to find more information about a display I picked up in the surplus section local electronics shop for cheap, presumably because they ran into the same issue as I did.The label on it reads:EG-X84320ER9601E1Epson JapanUnfortunately variations of searching this presumed model number have come up empty. The only information I can gather is the IC on back, a SED1503F 16x1 dot matrix driver.http://www.vetco.net/datasheets/VUPN6337/SED1500_series_datasheet.pdfSince there are 4 ICs and it looks like you may be able to do a master/slave type setup I am guessing this is a 16x4 character display. I am hoping someone with better google-fu may be able to find a pinout for this display. I may end up having to swing by the shop again and buying a few more of these displays (Only about $3) and sacrifice them for some reverse engineering.If anyone has a suggestion or can find a pinout that would be most helpful!Apologies if I am missing something obvious, I've been tinkering around with electronics for years but I won't say that I am completely knowledgeable.

author: Andy Watson
author_rank: Super Contributor
timestamp: May 30, 2016, 10:33:39 pm
content: "Mostly compatible to EPSON EG 84320 display"http://new.qscomp.cz/download/batron/BT_84320_dm.pdfAt least is gives the pin-out of the module. It should be possible to figure-out the command set from the driver chip information.

author: brian4120
author_rank: Newbie
timestamp: May 30, 2016, 11:15:14 pm
content: Thank you! Now that I have a little better idea of what I am working with I am going to try probing the pins to see what they correspond to on the IC. Based on some info I found on the SED1503F one IC will be master and the other 3 are slaved to it.http://www.datasheetarchive.com/dl/Scans-005/Scans-00116587.pdfI'll have to do some research to figure out how to properly drive this thing but at least I know what I am dealing with. Much appreciated!
tracking pre regulator doesnt track! - Page 1
Forum section: electronics / projects

author: xReM1x
author_rank: Regular Contributor
timestamp: July 14, 2015, 10:55:22 am
content: hi, I'm using EEVBLOG tracking pre regulator design and it works great only when there is the tracking pre regulator, but in my work in progress psu it doesnt work! what the heck?here is the output of the pre regulator, the pre regulator doesnt track. also there is oscilliation.

author: void_error
author_rank: Frequent Contributor
timestamp: July 14, 2015, 10:35:14 pm
content: Try adding some resistors around Q3 like I did for Q1 below. That worked for me.You can also safely leave out C6 & C9 (in parallel with V1) as V1 modeled as an ideal voltage source.

author: xReM1x
author_rank: Regular Contributor
timestamp: July 15, 2015, 09:52:55 am
content: Quote from: void_error on July 14, 2015, 10:35:14 pmthanks, I think it works but the simulation takes alot of time... so I'm still not sure. (and it just happend that im going to use simple switcher also to pre regulate. I have 20 LM2576 that I got from ebay.)also, is the schematic maybe for dc electronic load? just assuming because of the current sink and all the other things.

author: DanielS
author_rank: Frequent Contributor
timestamp: July 15, 2015, 01:47:13 pm
content: Quote from: xReM1x on July 15, 2015, 09:52:55 amThe current sink is not connected to the output, it is connected to the high-side current sense and since the high-side amplifier is powered from the output, it needs a constant current source to keep its voltage relatively constant regardless of what the output voltage is without overloading the LMV431.

author: xReM1x
author_rank: Regular Contributor
timestamp: July 15, 2015, 10:03:50 pm
content: Quote from: void_error on July 14, 2015, 10:35:14 pmwell, i tried it and it works on constant voltage, when I'm entering constant current it doesnt drop the voltage.I set the current to 0.1V = 0.1A and put 1R resistor, so the voltage at output of the post regulator is supposed to be 0.1V. but its not, the output is the same voltage as the pre regulator feedback.
Traco DCDC with large capacitive load - Page 1
Forum section: electronics / projects

author: Amper
author_rank: Frequent Contributor
timestamp: July 24, 2020, 11:43:25 am
content: Hi!Im buildng a full sized segway clone and have an issue with my powersupply solution.Since the Motors are industrial bldc servos the inverters need 24V for their control side of things. My Battery is 48V however and the simple solution is to use some traco dcdcs, in particular TEN6-WINseries devices. Sadly the inverters have >1000uF of input capacitance that im stuck with, this causes the converter to fail starting up. Having inrushlimiting helps but it seems a bit dodgy.Is there some proper way of doing this to the spec of the parts?
Traco Power - Power Supply design - Page 1
Forum section: electronics / projects

author: ElectricGuy
author_rank: Regular Contributor
timestamp: November 26, 2015, 10:52:39 pm
content: Hi;Does anyone worked with this power supplys before tha can give me some hints?http://www.tracopower.com/products/browse-by-category/find/tmp-tmpm/3/http://assets.tracopower.com/TMP-TMPM/documents/tmp-tmpm-datasheet.pdfMy questions is, does this kind of supplys needs any external components, like capacitor and TVS on the output, and capacitors and fuse on the input?I searched on the datasheet, and i don't see anything about that.In other power supplys like this one, the designer must add some external components, for instance, this one;http://docs-europe.electrocomponents.com/webdocs/117d/0900766b8117dee1.pdfor this one;http://docs-europe.electrocomponents.com/webdocs/117d/0900766b8117dee0.pdfThank you!

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 27, 2015, 05:46:02 am
content: "External input fuse required:" (near top, p.2).You could add surge protection, more filtering, etc. But probably not a big deal.Obviously, having uninsulated parts, it needs an enclosure, but otherwise it meets UL/IEC 60950 (a safety standard), and all the other things needed to sell something.BTW, EMC approvals are helpful, but not sufficient for selling a final product -- you still have to test, in case you've added things, or managed to make existing clean parts dirty somehow.

author: ElectricGuy
author_rank: Regular Contributor
timestamp: November 30, 2015, 03:19:59 pm
content: Quote from: T3sl4co1l on November 27, 2015, 05:46:02 amThank you T3sl4co1l;This is not for a comercial unit, it's a 1 or 2 units production, and it will be enclosured.I will try it out!Thanks

author: Pjotr
author_rank: Frequent Contributor
timestamp: November 30, 2015, 03:28:14 pm
content: I have used the Traco units al lot >= 10W. These are ok and reliable. But although class-II they have an EMC cap build in between mains and SELV side. So if you use more units together watch the total safe leakage current.

author: ElectricGuy
author_rank: Regular Contributor
timestamp: November 30, 2015, 04:28:33 pm
content: Quote from: Pjotr on November 30, 2015, 03:28:14 pmThank you. I only need the 4W. Only one unit per/equipment will be used.

author: Kjelt
author_rank: Super Contributor
timestamp: November 30, 2015, 05:56:19 pm
content: Anybody know of a teardown of such a traco powerbrick? Would like to see what's inside if it is just a simple design or real fancy stuff.

author: ElectricGuy
author_rank: Regular Contributor
timestamp: November 30, 2015, 05:58:21 pm
content: Quote from: Kjelt on November 30, 2015, 05:56:19 pmYes, that would be great!
TRACO TMSB 2 vs. CUI VSK-S1 - Page 1
Forum section: electronics / projects

author: Ice-Tea
author_rank: Super Contributor
timestamp: August 18, 2016, 12:28:17 pm
content: So, I'm considering these two modules for AC/DC duty on a POC board. The CUI datasheet clearly states some external components are still required and offers some examples. The TRACO? Not so much. So either the TRACO is entirely self contained (ie. attach mains and you're good to go) or...?Anyone got any experience with this?
Trade name for wire to pcb wire ends? - Page 1
Forum section: electronics / projects

author: StarquestMan
author_rank: Newbie
timestamp: November 17, 2016, 06:41:22 am
content: Ive been searching for over an hour online trying to find a part with no luck. what are those little ends that get crimped on to a pice of insulated wire before being soldered to a pcb in through hole fashion (im sure there must be a trade name for them). im repairing an old B&K 467 and all it has is insulated solid strand wire soldered through hole to the pcb which is giving me nothing but problems with random wires breaking off whenever i dismount or move the pcb and i would like to ad them as strain relief to the insulation.

author: trophosphere
author_rank: Frequent Contributor
timestamp: November 17, 2016, 06:50:32 am
content: Something like abootlace ferrulewould be my guess to your description.

author: StarquestMan
author_rank: Newbie
timestamp: November 17, 2016, 08:20:30 am
content: Quote from: wilfred on November 17, 2016, 07:47:27 amthese look like what i need however i cant seem to find a supplier, i will have to do some digging. where did you do that search you compiled? ebay didn't turn up any results and the only google results i found were to molexes website. i checked mouser and i couldn't find those VSR series terminals listed i will have to check digikey in the morning. to tired to come up with a good search that eliminates all the crappy spade terminal sets like you find at your local auto parts store

author: rollatorwieltje
author_rank: Unknown
timestamp: November 17, 2016, 08:46:51 am
content: Quote from: StarquestMan on November 17, 2016, 08:20:30 amThose Molex parts are available at Digikey, just paste the product number in the Digikey search. I.e.http://www.digikey.com/product-detail/en/molex-llc/0002092105/WM9120CT-ND/6165646

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: November 17, 2016, 09:24:02 am
content: "board-in connector"

author: StarquestMan
author_rank: Newbie
timestamp: November 17, 2016, 08:00:58 pm
content: thanks guys. "board-in connector" really brought in some more results. some things are just impossible to find if you don't use the right key words in the right order. i went ahead and ordered 50 of each of these.http://www.digikey.com/product-search/en?keywords=WM3298CT-NDhttp://www.digikey.com/product-search/en?keywords=WM3633CT-NDill try em both out and see which one works best for me.

author: Mattylad
author_rank: Regular Contributor
timestamp: November 20, 2016, 10:47:03 am
content: OH bring back catalogues with pictures in them!When we could thumb through them looking until we found the right pictures, now its all having to know the exact search term and having zero results if you get it wrong, no browsing.
Trade-off between LDO max Iout AND PSRR - Page 1
Forum section: electronics / projects

author: promach
author_rank: Frequent Contributor
timestamp: May 16, 2020, 05:48:29 am
content: PSRR is inversely proportional to output impedance of LDO.But Iout_max of LDO is proportional to width of output mosfet (M20) , Rds of M20 is inversely proportional to width of M20.Given that output impedance is a parallel impedance configuration between Rds of M20 and (R1+R2), so Iout_max is proportional to output impedance of LDO.If I need Iout_max = 3A, then my PSRR result looks very very bad.
Tradeoff between noise coupling from DC/DC to ADC and impedance of PDN - Page 1
Forum section: electronics / projects

author: gperoni
author_rank: Contributor
timestamp: February 28, 2023, 03:05:22 pm
content: I have what I consider to be a very silly question, but yet, I can't answer it myself.I have some sensitive chips, like clock gen and ADCs. They are powered through multiple, properly filtered switching regulators. Here are my two tradeoffs:1) Keep the switching regulators close to the sensitive chips. Like 1 cm / half an inch apart, separate from ground sticking vias and the shield made by the CNC-milled enclosure. Magnetic coupling between the two should be eliminated by the solid metal of the enclosure, and I get all of the advantages of having a super short power distribution network.2) Meh the PDN, move the switching stuff far away from the sensitive circuitry. The CNC enclosure is still there, mostly for power dissipation reasons, but maybe it's not as critical, and maybe I can sell a cheaper version without it.What would you do? Optimize for PDN inductance or for physical separation between switching regulators and ADCs? The main reason I'm doubting myself is the CNC enclosure, if it wasn't for that, I would go for maximum separation and add extra capacitors close to the sink.

author: ejeffrey
author_rank: Super Contributor
timestamp: February 28, 2023, 04:06:36 pm
content: Option 2. A short PDN isn't really needed. Capacitors provide local bypass and ground/power planes or wide polygons provide a low impedance connection to the regulator output filter.The only real downsides to a longer PDN are higher DC resistance and the possibility of high frequency parallel resonances involving the PDN inductance. But you can have resonances from the capacitors regardless of the PDN length anyway as well and in either case they can be damped with RC snubbers if really necessary.

author: David Hess
author_rank: Super Contributor
timestamp: March 01, 2023, 12:09:20 am
content: The self inductance of a longer PDN solution helps filter out the high frequency switching spikes.

author: donmr
author_rank: Regular Contributor
timestamp: March 01, 2023, 05:48:45 pm
content: It used to be common to initially regulate to a slightly higher voltage and then use a linear LDO regulator near the sensitive chip for final filtering.

author: David Hess
author_rank: Super Contributor
timestamp: March 07, 2023, 12:24:34 am
content: Quote from: donmr on March 01, 2023, 05:48:45 pmThat is required to reduce low frequency noise, but linear regulators are much less effective removing switching noise.

author: jonpaul
author_rank: Super Contributor
timestamp: March 07, 2023, 02:34:45 pm
content: What is a PDN?

author: brumbarchris
author_rank: Regular Contributor
timestamp: March 07, 2023, 08:51:51 pm
content: Power Distribution Network
traditional stepup or autotransformer for 'split phase' - Page 1
Forum section: electronics / projects

author: Nitrous
author_rank: Newbie
timestamp: May 25, 2023, 06:53:52 pm
content: Hi folks,I'm in the process of winding a 120vac to 240 volt 'split phase' transformer but on further thought, I wonder if a better way might be to use an autotransformer.I have a 120vac inverter that I'd like to split into 120v - N - 120v split phase. Is an autotransformer the better way to go, or is a standard primary/secondary CT transformer. If this is relevant, I'm using a toroidal core.For that matter, since at this point I'm likely just wanting to offset AC electricity to PV, would a simple step up be best since it would be able to isolate as well as step up... I just thought I'd ask those who likely knowThanksDoug

author: richard.cs
author_rank: Super Contributor
timestamp: May 26, 2023, 08:01:44 am
content: Is there a reason you are winding one rather than buying one? Especially a torroid, hand-winding those for low frequencies is a horrible job.This doesn't sound like an application needing isolation, so an autotransformer would be a good plan, smaller for the same power, or lower impedance for the same size. A 1:1 isolating transformer could also be used as an autotransformer here.What power rating do you need?

author: Ian.M
author_rank: Super Contributor
timestamp: May 26, 2023, 09:32:37 am
content: Unless you know for certain your inverter has a grounded Neutral, or that grounding its Neutral is permissible, you need a real transformer, 120V to 120V-0-120V

author: richard.cs
author_rank: Super Contributor
timestamp: May 26, 2023, 09:56:38 am
content: Ah yes, I'd forgotten a lot of smaller inverters effectively give two phases at 60V, (and sometimes with the centre voltage DC offset 80V above battery ground, urgh). If you have one of those then an isolating transformer is needed to create a conventional supply. Can you post your inverter model number or a datasheet?
Traffic light circuit with 556 timer: UPDATE! - Page 1
Forum section: electronics / projects

author: phennessey
author_rank: Contributor
timestamp: January 03, 2020, 07:50:01 pm
content: Original thread:https://www.eevblog.com/forum/beginners/traffic-light-circuit-with-556-timer/Well...after much ado, here's my first functioning traffic light circuit! I tried (and failed) to build this circuit with a 556 timer. I was only getting two LEDs to blink. Hopefully, SmokeyTheElectrician can weigh in on this. I think my schematic was wrong, despite being told it was correct. Perhaps someone can take a look at my old schematic?https://www.eevblog.com/forum/beginners/traffic-light-circuit-with-556-timer/?action=dlattach;attach=895598;imageSince I just wanted to make the damn thing work, I used an Attiny85 for now. Here's the result:Code:#include <avr/io.h>#include <util/delay.h>int main(void){while(1){DDRB= 0xff;// set all pins to outputPORTB=0b00000001;// set pin 1 high_delay_ms(3000);// delay 3 secondsPORTB=0b00000010;// set pin 2 high_delay_ms(1000);// delay 1 secondPORTB=0b00000100;// set pin 3 high_delay_ms(3000);// delay 3 seconds}}

author: Wimberleytech
author_rank: Super Contributor
timestamp: January 03, 2020, 09:12:02 pm
content: Excellent!

author: ebastler
author_rank: Super Contributor
timestamp: January 04, 2020, 01:45:19 pm
content: And you have some pins to spare, so you could make a traffic light for both directions of an intersection. (With proper delays/safety times between the green phases for either side.) Or use one pin as an analog input to adjust the cycle time. Or cater to European tastes and implement a "red, red/yellow, green, yellow, ..." cycle. Or use two pins as a sensor input and a trigger output for a red-light camera.Microcontrollers are neat; loads of flexiblity in small, simple and cheap packages.
TRAIC switch OFF at opposite Polaity - Page 1
Forum section: electronics / projects

author: anishkgt
author_rank: Frequent Contributor
timestamp: December 08, 2016, 06:24:42 am
content: i am trying to switch off a triac at the opposite polarity after it switches on. The project of for a dual pulse spot welder. The first pulse which is about 50ms seems to be sitching off the opposit polarity but the some second pulse are not. As in the attached.Is it the Time delay after the ZC that needs to be adjusted ? My Mains are 240VAC @ 50Hz and the delay i'v set after zc is 5630.Any help would be appreciated.
TrailCam/GameCam Circuitry Design.. - Page 1
Forum section: electronics / projects

author: IdahoMan
author_rank: Regular Contributor
timestamp: June 06, 2016, 06:26:22 am
content: Anybody have an interest in surveillance, CCTV or any type of detection/recordingandlow power consumtion over long periods of time (Ex:Trail Cameras AKA Game Camera)?Anyone who has used a TrailCam knows their benifits:Long battery life (Ex: almost a year on 12 AAs)Fire on detection (Ex: PIR)Fast trigger time (under 1-2sec)The problem with TrailCams is their physical shape/size: They are a brick, and it's hard to place a brick covertly in many areas such as urban settings, indoors, in a vehicle, etc.. or even in the woods. There are many CCTV products out there sold for covert surveillance (DVRs, Cams, Mics, Batt. Packs, etc.) that can be connected, shaped and arranged to fit the situation, but they seem to be lacking in the benifits that make a TrailCam usefull: Battery life and trigger time.Imagine if there was a digital-recorder PCB you could buy (kind of like amini-DVR) but with the benifits of a TC listed above. You could then decide on your own power-source (Mains, Batt.), triggering device (PIR, Seismic, Sound, Door-switch, etc.), recording device (camera, FLIR, microphone, radio reciever, etc.), and an output for an illuminator or alarm ("Alarm Out").Long battery-life and fast trigger-time. Anybody interested in this?IM
Trailer brake controllers, hard to custom build? - Page 1
Forum section: electronics / projects

author: Apothus
author_rank: Contributor
timestamp: November 14, 2016, 12:58:13 pm
content: Working on a robotics project. I am planning on using electronic trailer brake hubs as brakes (not much of a hack there). However I want more control than a conventional brake controller that just works off the tail lights. I have hopeful I could do something proportional.My expectation is that these brakes are just a coil in a field. Hopefully A basic H-Bridge circuit can controll them with some form of proportional PWM control.Has anyone done anything with these before or even laid their hands on a pair? I dont want to shell out for parts i may not be able to control.

author: firehopper
author_rank: Frequent Contributor
timestamp: November 14, 2016, 01:26:16 pm
content: most trailer brakes are a electromagnet that attracts to the drum, its attached to the brake shoes via a mechanism, as the wheel turns it rotates the mechanism and that applys the brakes, the controllers I've seen are connected via brake line or another method, and is usually proportional too

author: Apothus
author_rank: Contributor
timestamp: November 14, 2016, 01:59:16 pm
content: Thanks firehopper for your patience. I should have just read the wiki page before posting here. Silly me that had all the answers
Training problems - Page 1
Forum section: electronics / projects

author: SSTC
author_rank: Newbie
timestamp: July 11, 2010, 12:04:07 pm
content: Hey there..do anyone know a web page like thishttp://projecteuler.netjust with electronics problems??

author: DJPhil
author_rank: Frequent Contributor
timestamp: July 12, 2010, 05:35:05 am
content: Wow, that's an amazing system!I don't know of anything offhand that's like that anywhere, for anything. The closest thing I can think of is the chapter exercise sets in The Art of Electronics which are treated separately in the student guide. I wonder if the larger electronics community (including the newsgroup folks, for example) would participate and support a similar venture.A close second would be answering questions on forums, anywhere you can find them. If you wander back through my post history you'd see a lot of, "I'm just guessing, but this might help" and "I'm not sure, but these links might get you closer." I'm new to the vast majority of electronics and by researching the problems people post about I learn a great deal about a broad range of things. I've also been blessed/cursed with abundant free time, so I can leverage that into research that anyone with a normal-ish life wouldn't have the time to do. It works well for me, I just have to remember to lay on the disclaimers thickly so nobody mistakes my advice as certainty gained from real experience. No complaints so far.

author: EEVblog
author_rank: Unknown
timestamp: July 12, 2010, 06:22:08 am
content: The problem with electronics questions is that the majority of the time there is almost always insufficient information presented by the poster in order to get anything but an "generally speaking..." type response.It's a bit of a catch-22 actually. You need sufficiently deep knowledge in order to ask the right question, and then in which case...And given that many areas of specialties exist in electronics, it is often better to ask a question in a specific focus group.For example, if you have a question on how a specific instruction on a PIC micro works, you will get a much better response on the Microchip forum than say the sci.electronics.design news group.Dave.
Tranilamp transformer - other uses? - Page 1
Forum section: electronics / projects

author: armandine2
author_rank: Frequent Contributor
timestamp: March 24, 2022, 08:54:16 pm
content: Courtesy of a control panel disposal I have a handful of (electrician rejected) old Tranilamp transformers - had a quick look on-line and they seem ubiquitous, yet don't seem to get re-purposed.I wonder if there are any ideas, previous projects etc, out there on what else you could do with these things.

author: moffy
author_rank: Super Contributor
timestamp: March 24, 2022, 09:38:44 pm
content: A couple of questions first:1. What do you mean by "electrician rejected", are they in any way damaged or sub par?2. A little bit of detail as to what their input and output voltages are as well as power rating would help.

author: Gyro
author_rank: Super Contributor
timestamp: March 24, 2022, 09:46:21 pm
content: Irrc, Tranilamps are small panel mounted transformers with integral bulb holders, allowing torch bulb type filament lamps to be used as mains indicators. If so, they probably put out something like 4.5 to 6V at around 1W max.Photos would help.

author: armandine2
author_rank: Frequent Contributor
timestamp: March 24, 2022, 10:51:42 pm
content: Quote from: moffy on March 24, 2022, 09:38:44 pmso the items were removed from a previously working panel compartment - as its previous use is now obsolete. "Electrician rejected" just means if the electricians wanted them I would not have them. (think of copper busbars)

author: armandine2
author_rank: Frequent Contributor
timestamp: March 24, 2022, 10:57:15 pm
content: Quote from: Gyro on March 24, 2022, 09:46:21 pmhttps://www.radwell.co.uk/Shop?source=GoogleShopping&IgnoreRedirect=true&ItemSingleId=32798895&gclid=EAIaIQobChMIgLvt1-vf9gIVGuvtCh0WFwV-EAQYAiABEgKv-vD_BwEI doubt itRadwell sell them for next to nothing

author: moffy
author_rank: Super Contributor
timestamp: March 24, 2022, 11:38:51 pm
content: Thanks for the info, so 240V input and 6V@300ma output.

author: james_s
author_rank: Super Contributor
timestamp: March 25, 2022, 04:06:58 am
content: They're cool in their original form. I've used some of the similar Allen-Bradley indicators and buttons for their originally intended purpose.
Transceiver Protocol - Page 1
Forum section: electronics / projects

author: Left_Jab
author_rank: Newbie
timestamp: July 16, 2011, 11:24:11 pm
content: Hi,I would like to know which protocols are being used nowadays with the transceiver HopeRF RFM12 (not 12b). I intend to use it in a wireless mesh network.Also, please let me know whether SNAP (Scalable Node Address Protocol) is still a popular choice or whether it has become obsolete now.Thanks!

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: July 17, 2011, 10:28:35 am
content: Who cares what's popular or not - use what is most appropriate for your application.

author: Left_Jab
author_rank: Newbie
timestamp: July 17, 2011, 09:05:49 pm
content: Thanks for the reply.I was also tempted to come up with my own protocol, but the thing is I would like my system to be compatible with other devices (i.e. there should be interoperability).In my previous question, I did not mention the specifications of the device I am using: it runs on 433 MHz and uses FSK. So I'd like to know whether a protocol exists for any device having these particular specifications.

author: Mechatrommer
author_rank: Super Contributor
timestamp: July 17, 2011, 11:04:33 pm
content: maybe a good starting point...1)http://lmgtfy.com/?q=HopeRF%20RFM12%20datasheet2)http://lmgtfy.com/?q=radio3)http://lmgtfy.com/?q=fsk

author: Left_Jab
author_rank: Newbie
timestamp: July 17, 2011, 11:25:34 pm
content: I already had the datasheet. It says nothing about the protocols being commonly used today.

author: Mechatrommer
author_rank: Super Contributor
timestamp: July 18, 2011, 03:00:17 am
content: you have to make international poll on that.Quote from: Left_Jab on July 17, 2011, 11:25:34 pm
Transceivers question - Page 1
Forum section: electronics / projects

author: amij
author_rank: Newbie
timestamp: December 26, 2011, 11:23:59 am
content: hello allI'm new here and i hope you could help me.I'm working now on a project that involves wireless communication.I have a field of sensors and the information need to be delivered through some MCU to some transceivers,who will send the information according to our algorithm for sending order.My question to you is which transceivers would you recommend me to use?I'm just want to test my algorithm so i don't really care about the distance, or sending rate.thx john

author: Psi
author_rank: Super Contributor
timestamp: December 26, 2011, 11:40:29 am
content: sparkfun have some RF modules, as do oatley electronicsDepends if you want a module that has built in smarts for error correction (so like a serial pipe) or a raw RF module.
Transconductance amp....connect v source to its output directly? - Page 1
Forum section: electronics / projects

author: Faringdon
author_rank: Super Contributor
timestamp: July 19, 2022, 11:19:36 am
content: Hi,Can you connect a volt source (eg output of an opamp buffer) directly to the output of a transconductance error amplifier?(eg to the VAO transconductance amp in UCC28070A)?UCC280780Ahttps://www.ti.com/lit/ds/symlink/ucc28070a.pdf?ts=1658228370989&ref_url=https%253A%252F%252Fwww.google.com%252F(Sorry i lost my other overly long-winded post about this, which wasn't ensconced with +ve responses)

author: David Hess
author_rank: Super Contributor
timestamp: July 19, 2022, 06:32:53 pm
content: Yes, it would have the effect of overriding the output of the transconductance amplifier.

author: TimFox
author_rank: Super Contributor
timestamp: July 19, 2022, 06:36:18 pm
content: In a simple model, it's equivalent to loading the output of a voltage source with a current source.If both are within their operating limits (maximum current for the voltage source and compliance voltage for the current source), the resulting voltage will be determined by the voltage source, and the current flowing in or out of the voltage source will be determined by the current source.
Transconductance opamp set up as "Voltage follower"?....Boost PFC battery charge - Page 1
Forum section: electronics / projects

author: ocset
author_rank: Super Contributor
timestamp: June 15, 2020, 10:53:09 pm
content: Hello,We have special batteries which are pretty much always 400V +/-5V no matter what the state of charge.We want to charge them with a non isolated “controlled open loop” BCM Boost PFC converter as attached. (we’ll be careful). PDF schem and LTspice sim as attached.This involves setting up the internal transconductance error amplifier in an LT3799 (Boost BCM PFC) IC as a simple buffer as shown...Then one simply adjusts the charge current by adjusting the voltage into the CTRL3 pin of the LT3799 controller as shown. (“iterative set and check algorithm”)Can you see any problems with this? That is, the connection of the internal transconductance opamp as a "voltage follower" as shown.Datasheet: LT3799 BCM Boost PFC controller IChttps://www.analog.com/en/products/lt3799.html

author: NiHaoMike
author_rank: Super Contributor
timestamp: June 16, 2020, 02:05:04 am
content: You still want voltage feedback as a failsafe mechanism to stop charging. Actually, you'll want several of those mechanisms since such a large battery can fail in a very dramatic way.

author: ocset
author_rank: Super Contributor
timestamp: June 16, 2020, 10:25:36 am
content: Thanks, yes...we will have a FET switch in series with that battery (not shown in top post) , and if its voltage goes too high, we'll switch it out.Do you think maybe we'll need to connect inputs and output of the OTA together, then apply the control voltage to that? (instead of the way we've done it in the top post)?After all, if inputs of OTA are the same, then its output current is zero...and so its output impedance must then be highest, which is probably good for our situation where we want to "Inflict" an external voltage onto the OTA output? (in order to control the power throughput of the Boost PFC stage)

author: David Hess
author_rank: Super Contributor
timestamp: June 16, 2020, 11:56:04 pm
content: It should work but I suspect there are better ways albeit probably not as inexpensive.Quote from: treez on June 16, 2020, 10:25:36 amThat is going to be a problem. Protection against open circuit faults require the output to conduct 2% of the output current which is done with some type of shunt, like a zener diode.QuoteThe application notes show the control inputs connected to the positive reference to disable them but I do not see where it matters.
transfer function - Page 1
Forum section: electronics / projects

author: electros6
author_rank: Regular Contributor
timestamp: October 07, 2013, 11:30:43 am
content: Please somebody tell me the transfer function of an amplifer. Also please tell me the transfer function of a the bench power supply that designed by DAVE,( only analog part)

author: Jebnor
author_rank: Regular Contributor
timestamp: October 07, 2013, 01:40:54 pm
content: The way this is phrased, we can't answer your question. Work through it and provide details of where you are having troubles. Then we may be able to help. At the moment it sounds like "What is the answer?"
transfo rewind - Page 1
Forum section: electronics / projects

author: p.larner
author_rank: Frequent Contributor
timestamp: October 18, 2023, 03:34:42 am
content: i have a transfo ie core with a 240v pri,its about 2kg weight,it has the secondary removed,if i rewind the secondary using 1.25mm copper enammeled wire,how many amps at say 30v be ok for output wise ish?.

author: soldar
author_rank: Super Contributor
timestamp: October 18, 2023, 07:18:27 am
content: Quote from: p.larner on October 18, 2023, 03:34:42 amThe output volts are a function of the number of turns. How many turns do you need in order to get 30V? Knowing that number you can calculate what wire diameter you can use. Maybe 1.25 mm may not fit. Or maybe you can fit higher diameter.If you have 1.25 mm wire and want to use that and it fits without problem then the amps you can get is a matter of temperature and many variables are in play but the simplest way is to test it and measure temperature. A transformer can stand higher current for a short time.As a permanent load I would start with 3 A and go up from there. You can probably get 5 or 6 A but it depends very much on the construction of the rest. A lot more information is needed.

author: p.larner
author_rank: Frequent Contributor
timestamp: October 18, 2023, 10:16:17 am
content: can i not just feed current thru the wire and measure the amps untill it starts to get hot?,at least to give me an idea,the transfo has bags of room,its a hefty unit.

author: Ian.M
author_rank: Super Contributor
timestamp: October 18, 2023, 10:38:55 am
content: Define 'starts to get hot'! Do you know the temperature rating of the primary insulation and its thermal resistance to ambient?How many VA was it originally? Expect 20% - 30% less due to difficulties rewinding it with the same packing density in the core aperture area. If you can strip it down and put the bobbin on a coil winder mandrel, maybe 10% less.

author: Roehrenonkel
author_rank: Frequent Contributor
timestamp: October 18, 2023, 11:23:28 am
content: Hi p.larner,Quote from: p.larner on October 18, 2023, 10:16:17 amNo. Okay you can, but why should you?And you need to measure the tempreture inside the winding.Usually 2.55 A/mm² is good for transformer-windings with CuL (coated copper).Search for current-density in transformer-wires for further details.Good luck.