hybridfree/eevblog-posts huggingface dataset:
TTF: Ultra tiny micro DC 2 pole connectors - Page 1
Forum section: electronics / projects

author: Kjelt
author_rank: Super Contributor
timestamp: January 01, 2017, 06:26:07 pm
content: Hi all,Someone asked me to add led lighting to his Lego and other train hobby buildings.I am using the 0,25mm teflon wire and soldering them directly to smd leds that I glue stuck.But now I am trying to find very very tiny DC connectors with requirements:DC 24V2 pole100mADimensions around 4mm or smaller.Wire to wire connectors not to pcbTo be used with the teflon wirewrap wire?Anyone has a tip? , preferably available through ebay, farnell or tme.

author: jpanhalt
author_rank: Super Contributor
timestamp: January 01, 2017, 06:49:59 pm
content: 4 mm is not all that small. Two conductor standard hobby connectors are on 2.54 mm centers, such as these:https://hobbyking.com/en_us/jst-series-connector.htmlOUtside might be a little over your 4-mm criterion.JST (and others) make connectors that are 2 mm on center or smaller and are considerably smaller outside dimension. This one is 3.8 mm outside dimension:http://www.jst-mfg.com/product/pdf/eng/eSFH.pdfJohn

author: Kjelt
author_rank: Super Contributor
timestamp: January 01, 2017, 09:22:55 pm
content: Yes I really would like it to be as small as possible.Thanks but that eSFH connector is way overkill with 4A and 130VDC

author: jpanhalt
author_rank: Super Contributor
timestamp: January 01, 2017, 09:41:24 pm
content: I was trying to urge you to use the parametric search for your favorite vendor. As you get smaller and smaller, the difficulty of assembling by hand gets harder. Here is a partial parametric for you to try:http://www.digikey.com/products/en/connectors-interconnects/rectangular-connectors-free-hanging-panel-mount/316?k=connectors&k=&pkeyword=connectors&pv89=170&pv89=109&pv89=108&FV=fff40016%2Cfff802f5%2Cffe0013c%2C1600002&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=500Note, some of those connectors are quite small. 0.6 mm is about the limit for me to hand assemble, but there are ones even smaller.John

author: Kjelt
author_rank: Super Contributor
timestamp: January 01, 2017, 09:54:49 pm
content: Thanks, I was curious if there were members that also had experience with small model electronics and if they used certain "standard" connectors. It does help me to get the requirements more specific such as that the connectors should be wire to wire and to pcb
TTL-controlled bipolar precision current source? - Page 1
Forum section: electronics / projects

author: awallin
author_rank: Frequent Contributor
timestamp: June 10, 2013, 01:22:31 pm
content: Hi all,From an AD-converter for bridge-applications (e.g. AD7195) I get a TTL logic-signal for AC-excited measurements.In a 4-wire measurement for an RTD temperature sensor (pt100) I want to use this TTL logic-signal to push either +500 uA or -500uA through the RTD (exact current value TBD).I have a positive voltage reference (either +2.5V or +5.0V) and with a unity-gain inverting op-amp also -2.5V reference.The AD-conversion will be done ratiometrically, i.e. we push the same RTD-current through a reference resistor that gives the reference-input for the ADC - which somewhat relaxes the precision requirement on the current source, but I'd still prefer it to be quite stable.What is the easiest way to do this?My initial idea was to use a simple op-amp circuit with either a high-side or low-side (does not matter much afaik) sensing resistor. Then the problem is how do we use the TTL-signal to easily switch between the +2.5V and -2.5V reference at the op-amp input? (without sacrificing the precision of the reference)TIA,Anders

author: ve7xen
author_rank: Super Contributor
timestamp: June 10, 2013, 06:45:20 pm
content: An analog switch should be all you need. They have some series resistance, but it should be negligible for your use with high input impedance.I suppose you could also put a switch in the current path, with two independent feedback loops etc. and just switch in the appropriate current source. Then your feedback loop would compensate any switch effects.

author: awallin
author_rank: Frequent Contributor
timestamp: June 11, 2013, 08:58:43 am
content: Thanks! should have thought of thatHere's what I have now:http://www.anderswallin.net/2013/06/pt100-frontend/comments?
TTP223B Touch Sensor IC - Large Area Detection - Page 1
Forum section: electronics / projects

author: kolbep
author_rank: Frequent Contributor
timestamp: July 01, 2019, 09:04:11 pm
content: Hi All,Busy with another strange one, and my google-fu is not too strong today.I have a Transparent Perspex Panel (Acrylic for the Non-Yanks)(Approx 900mm x 450mm x 5mm), on that perspex panel i have a 'chrome' sticker. It is not a metallic sticker, just a shiny one. (I tested - It is non conductive).I would like for a person to be able to touch the 'Chrome' part of the panel, and the RPI responds to that touch.So I ordered some TTP223B Modules. (Man those things are Tiny).I tried putting it on the rear of the acrylic, and it would not detect touch through the acrylic, but a touch on the Modules board itself did detect.Is there a way to expand this modules sensitivity and area, so that a touch anywhere on the panel (or even a decent sized area of the panel) will trigger, or is there another way for me to go about this.Thinking to myself, maybe use a Piezo Transducer, but then i have to tell them to knock or hit the panel. Ideally I would prefer the Cap Touch, but whatever the best solution isThanksP

author: vintagemaniac
author_rank: Newbie
timestamp: July 01, 2019, 09:44:35 pm
content: To increase the sensitivity you should reduce (or remove completely) the 30 pF cap on the board.

author: Microcheap
author_rank: Frequent Contributor
timestamp: July 01, 2019, 10:00:54 pm
content: To increase the sensibility of the TTP223B try to use a larger sensor pad connected to pin 3 of the IC (I used a cooper foil pealed off from a PCB clad, soldered a wire to it and then I insulated with kapton tape).As pointed by @vintagemaniac, a capacitor from pin3 to ground will reduce the sensibility of the sensor.
Tube Guys, What Is Going On In This Mesa Amp? - Page 1
Forum section: electronics / projects

author: Cyberdragon
author_rank: Super Contributor
timestamp: March 20, 2021, 02:46:08 am
content: This circuit is nuts, I'm not sure he's 100% drawn it correctly though. There is a tube in there who's only connections to the system are a capacitor to the grid and a resistor to the cathode both tied to the input, and a capacitor and resistor in series on the plate as output. That it, 0 DC bias at all. Both sides ultimately tie to ground though resistors so the only source of voltage even on the other side of the caps seems to be resistor drop, which can't be very much since the cathode side ends up positive, and the anode side negative in terms of where the resistor dividers terminate (as he says similar to a cathode follower, but even that has to have plate bias).Has anyone seen a circuit like this before and how does it even work?

author: floobydust
author_rank: Super Contributor
timestamp: March 20, 2021, 07:26:05 am
content: I've worked on the Mesa, the schematic is incorrect (on purpose), I have it redrawn somewhere.They have a mystery wire called a "radiator". It's a wire connected at one end to an O/P tube's plate and 220k resistor. At high output power, the plate-wire radiates due to the high voltage AC and causes positive-feedback via capacitive coupling to make the amp wail and have other special fx. I wonder if he noticed it.

author: Cyberdragon
author_rank: Super Contributor
timestamp: March 20, 2021, 06:17:07 pm
content: Quote from: floobydust on March 20, 2021, 07:26:05 amOk so the circuit is still really weird but at least it has a proper power supply.No laws of physics are being violated.By "radiate" do you mean like RF? Corona discharge? Heat?

author: floobydust
author_rank: Super Contributor
timestamp: March 20, 2021, 06:51:07 pm
content: I'm not sure if it's common knowledge but it had me stumped for a bit to find a wire from a plate simply ending near the pre-amp section, connected to nothing.That's what they are called because the wire "radiates" like 400Vpp at audio frequencies, as a gimmick capacitor with HF rolloff due to the 220k series resistor, in proximity to the sensitive pre-amp section.Normally it does nothing but as soon as amplitude goes up and waveforms are a bit more square, there is some positive feedback and the amp's sound goes to a new dimension.The video I'm not clear about what is the odd circuit he found, you don't need formal grid bias if you use "space-charge" instead. It's likely doing that, and when the adjacent triode upsets the space-charge then you get extra effects.Musicians want a unique sound and get their amplifiers modded so no one else can sound like them.
Tube Preamp Cathode Follower help.  - Page 1
Forum section: electronics / projects

author: darkness_electro
author_rank: Contributor
timestamp: August 21, 2015, 09:23:43 pm
content: Hello, i am building this circuit, and i need something to drive a cable and the input impedance of the amplifier.http://diyaudioprojects.com/Schematics/7025-12AX7A-Tube-Phono-Preamplifier-Schematic.htmI was thinking to add something like this.http://diyaudioprojects.com/Schematics/7025-12AX7A-Tube-Phono-Preamplifier-Schematic.htmIs there any simpler way to make a cathode follwer, one that doesn't have so much gain?Regarding the first circuit how clean the dc must be? Is a 2 stage rc filter going to be enough?What rectifier tube shall i use? I have a 250v transformer and i was thinking about a hybrid rectifier. The chinese 6z4 is ok?Thank you.

author: Andy Watson
author_rank: Super Contributor
timestamp: August 21, 2015, 09:37:12 pm
content: Quote from: darkness_electro on August 21, 2015, 09:23:43 pmUse a FET.QuoteA cathode followerwillhave a gain of unity (or slightly less).

author: darkness_electro
author_rank: Contributor
timestamp: August 21, 2015, 09:40:09 pm
content: Indeed, i want a cathode follower with a gain of 1. Actually, it's a bit under unity. I just didn't find a complete schematic with elevated heaters. Can you suggest one. I try to have a full tube design, but for testing purpouses a fet like irf840 may work.
Tube quartz oscillator EF80 - Page 1
Forum section: electronics / projects

author: Simon123
author_rank: Regular Contributor
timestamp: August 05, 2014, 05:24:35 pm
content: Im making tube-EF80 transmitter, but there is no carrier frequency.Schematic is something like this:http://www.rfcafe.com/references/popular-electronics/images/after-class-crystals-april-1960-popular-electronics-5.jpgThe accelerator grid is connected threw audio transformer, resistor to +160VSupressor grid isnt connected.Thing doesnt oscillate, what should i do?Control grid Voltage with respect to ground is about -0.5VDC

author: N2IXK
author_rank: Frequent Contributor
timestamp: August 05, 2014, 06:23:46 pm
content: What frequency are you trying to make? Do you have a fundamental or overtone crystal? Are your L and C values consistent with the desired frequency?

author: Simon123
author_rank: Regular Contributor
timestamp: August 05, 2014, 06:35:51 pm
content: I am trying to have 6.5536Mhz with fundamental frequency.LC circuits aren't perfectly tuned (10uH,47pf+25pf TRIMMER), because i have multiturn trimmers and am intending to tune it, when it will work.

author: PA0PBZ
author_rank: Super Contributor
timestamp: August 05, 2014, 07:07:13 pm
content: Quote from: Simon123 on August 05, 2014, 05:24:35 pmYou can't do that, it will be charged by the electron beam, earth it.Also, the accelerator grid should be earthed for HF, so put a cap of say 100N to earth from there.

author: Simon123
author_rank: Regular Contributor
timestamp: August 05, 2014, 07:22:59 pm
content: Ok, il ground it with 100n(accelerator), but why should i ground it(supressor)?How will current go to quartz and energize it?http://nmwilliam.tripod.com/el84.html

author: PA0PBZ
author_rank: Super Contributor
timestamp: August 05, 2014, 08:46:10 pm
content: If you don't ground the supressor it will be charged by the electron beam and repel the beam flowing to the anode.In an EL84 the supressor is internally connected to the cathode so there is no need to connect it to ground:The quartz will be energized by the electron beam randomly hitting the control grid... it's a bit of a mystery

author: Simon123
author_rank: Regular Contributor
timestamp: August 05, 2014, 08:58:04 pm
content: Thanks, gonna do that.Did that, still not working.By the way, why do i have -0.5VDC on controll grid?I think i solved it.I rewired quartz as pierce oscillator.http://www.rfcafe.com/references/popular-electronics/after-class-apr-1960-popular-electronics.htmThanks for help!
Tube radio help! - Page 1
Forum section: electronics / projects

author: Deactivated-1
author_rank: Frequent Contributor
timestamp: September 11, 2019, 02:04:08 pm
content: I broke the inductor for this radio and I don't know what value it is. and is there a way to bypass it?

author: trevatxtal
author_rank: Contributor
timestamp: September 11, 2019, 03:54:29 pm
content: Your circuit diagram appears to be a Audio stage of a radio.You do not indicate what inductor is broken Values of all components appear to be on the diagram.Please add more information.

author: schmitt trigger
author_rank: Super Contributor
timestamp: September 11, 2019, 05:11:57 pm
content: Air core or ferrite core?If it is air core, with the number of turns, diameter and length, there are online calculators which would allow to estimate its inductance.A photo would help.

author: schmitt trigger
author_rank: Super Contributor
timestamp: September 12, 2019, 01:45:45 pm
content: You mentioned there are two in series? Measure the good one.You will require a LCR meter. This may be the perfect excuse to get one if you already don't own one. Nowadays, you can find many low cost devices on Ebay or Alibaba. True, they are not precision instruments, but I don't think the inductor value is very critical.In the position it is attached it appears like a high frequency rolloff. The key factor here is that it should be able to sustain a DC current without saturation. Likely 10 mA or less. That is the reason it is a rod core one.

author: cvanc
author_rank: Frequent Contributor
timestamp: September 12, 2019, 02:30:02 pm
content: Can you simply re-wind the bad one?One of the two is broken, and the other one is OK, correct?Do they appear identical?How is the broken one damaged?Can you just unwind the broken one while counting the turns of wire? Then measure the diameter of the wire with calipers and determine the correct replacement gauge. Buy what we over here call 'magnet wire' but it might have other names elsewhere.More photos would help.
Tube Single-Ended and Push-Pull power stage calculator - critique invited - Page 1
Forum section: electronics / projects

author: basinstreetdesign
author_rank: Frequent Contributor
timestamp: February 28, 2022, 01:19:54 am
content: I worked up a spreadsheet which will draw SE and P-P plate curves for a pentode or triode tube used in single-ended or push-pull configuration. Once loaded with points on the plate current curves, including max plate dissipation power, it will take into account the bias voltage used the screen voltage used and create the I-V charts for it.I have created versions for four tubes so far and plan to add more.So far there are 6L6, KT88 (non-ultra-linear), KT88 (ultra-linear) and 6550 versionsThey can be found here:https://www.trisweb.com/files/tim/Click EDIT DOCUMENT to change it from read-only to usable form.I invite anybody to critique this spreadsheet and post comments here regarding any shortcomings or possible additions or corrections that may be make it better. Feel free to suggest tubes for which you would like to see entered into the calculator. The cells which are to accept tube data from the user are the GREY cells. All others are calculated.The dependence of the curves on screen grid voltage, the plate curves are adjusted from the entered raw data from published/measured plate current curves according to the voltage given on the screen grid. A voltage higher than that on the original curves will make the curves swell upward. A lower voltage will make them shrink down. The amount of this growth/shrinkage is determined by a 2nd order-polynomial that is found by interpolating data also given in the published charts.This calculator is given under the Attribution, Non-commercial, Share-alike license. Of course, should the calculator be copied, distributed or used for a derivative work I want the Basin Street Design name and its copyright message preserved.
Tube sockets nomenclature - Page 1
Forum section: electronics / projects

author: fabiodl
author_rank: Frequent Contributor
timestamp: March 18, 2018, 11:06:03 am
content: Hello, I am looking for tube sockets (9 pins, radius seems to be 6mm, and they look 36 degrees apart).Searching for sockets I found many variantsGZC9-BGZC9-C1GZC9-FGZC9-AGZC9-Y-3and many more. What do the trailing letters stay for?See for examplehttp://www.mableaudio.com/uploadfile/Download/201309221521001040.pdf

author: fourtytwo42
author_rank: Super Contributor
timestamp: March 18, 2018, 11:21:44 am
content: If you look at the pictures below the listing you can see the differences, there is no standard for this it is vendor dependant, it would also identify the base material e.g. ceramic vs plastic, not so clear in the pics but then they have provided you with an Email address!

author: Richard Crowley
author_rank: Super Contributor
timestamp: March 18, 2018, 11:22:46 am
content: 7-pin and 9-pin miniature tube sockets are standardized. As you have discovered dozens of manufacturersmakemade probably hundreds of different sockets that will connect to a standard miniature tube. The entire part numbers you refer to appear to be manufacturer's (or vendor's) arbitrary part numbers. Perhaps they have some meaning internal to the manufacturer. But this late in the evolution (lingering death) of firebottles, you are probably lucky to even find tube sockets at all, regardless of what they are called.

author: DBecker
author_rank: Frequent Contributor
timestamp: March 18, 2018, 07:11:56 pm
content: It's amusing how many things still use tube sockets.I was recently dealing with gas sensors. They have internal heaters and sometimes use a flow-through air passage. They are designed around an open-center tube socket.Just glancing at my desk I see two cheap (free with coupon from Harbor Freight) multimeters that appear to a use tube socket for the transistor test.

author: drussell
author_rank: Super Contributor
timestamp: March 18, 2018, 10:09:27 pm
content: Quote from: Richard Crowley on March 18, 2018, 11:22:46 amThey're still being manufactured, though perhaps not by too manydozensof manufacturers.

author: Cyberdragon
author_rank: Super Contributor
timestamp: March 18, 2018, 11:16:46 pm
content: You can get tube sockets from instrument amplifier shops (provided they sell parts).

author: fabiodl
author_rank: Frequent Contributor
timestamp: March 19, 2018, 10:06:31 am
content: Thank you everybody!
Tube vs Tray for Design for Manufacture - Page 1
Forum section: electronics / projects

author: qbradq
author_rank: Newbie
timestamp: November 20, 2013, 03:40:52 pm
content: I am choosing between two different packages of IC, one offered in tube and one in tray. I am designing the product with volume manufacture in mind. In general, are tube packs or trays preferable? Or does it depend on the assembler? The part is not available in tape without a 100% price increase even at volumeThank you,QBRADQ

author: reagle
author_rank: Unknown
timestamp: November 20, 2013, 03:51:39 pm
content: It depends on the assembler and the machines they have. In general trays may take more feeder slots than vibration feeders used for tubes, and tubes take more space than reels.So in the end it's the total number of feeders slots your board needs versus what they can fit on the machine. If it does not all fit, now you are either hand placing larger parts or settinp up multiple machines

author: Alphatronique
author_rank: Regular Contributor
timestamp: November 21, 2013, 03:13:37 am
content: Hiask you assembler but most of time it traytube feeder was unreliablehere what we do is to transfer from tube to tapeBest regard

author: JoeyP
author_rank: Frequent Contributor
timestamp: November 21, 2013, 03:21:23 am
content: Trays will almost always be preferred. Most assemblers have plenty of component capacity (unless your board has a very large BOM or the CM is very small), so you don't have to worry too much about number of feeder slots.Trays always feed more reliably than tubes. Nothing causes more grief to a CM than parts which must be fed out of a tube. The vibratory feeders they use for tube parts "just" work when properly adjusted, and if you have two different parts with significantly different mass or tube size then it can be impossible to get the feeder to feed both parts reliably.

author: qbradq
author_rank: Newbie
timestamp: November 21, 2013, 02:29:42 pm
content: Thank you all for the replies and insight! It is very helpful to get some advice from those with experience before my first run.
Tubular extruded heatsink manufacturer - Page 1
Forum section: electronics / projects

author: OgreVorbis
author_rank: Newbie
timestamp: June 13, 2019, 03:23:36 am
content: Hi,I'm looking for a company that sells heatsinks like this:https://www.fischerelektronik.de/web_fischer/en_GB/heatsinks/D02/Miniature%20cooling%20aggregates/$catalogue/fischerData/PG/LAM4/search.xhtmlI would go with fischer, they just don't have the length I need and I'd like the raw stock anyway.I don't know the exact term to describe this other than tubular extruded heatsink.Let me know if you know any manufactures for this.Thanks.

author: soldar
author_rank: Super Contributor
timestamp: June 13, 2019, 06:16:41 pm
content: Interesting concept. I have never seen those in the wild. Maybe the purpose is to exhaust the hot air into ducts and then take it away? Otherwise I cannot think of a reason to use them.Maybe you can askhttps://www.boydcorp.com/thermal/heat-sinks/extruded.html

author: Benta
author_rank: Super Contributor
timestamp: June 13, 2019, 06:50:46 pm
content: Why don't you call Fischer?I'm pretty certain that the extrusion tool is their property, but that doesn't mean they won't sell the profiles in full length.

author: wraper
author_rank: Unknown
timestamp: June 13, 2019, 06:53:26 pm
content: Quote from: soldar on June 13, 2019, 06:16:41 pmThey are common in electronic loads and system PSUs. You can mount a lot of devices on both sides, and all hot air gets straight out from back of the case. Great for dissipating a lot of heat.

author: thm_w
author_rank: Super Contributor
timestamp: June 13, 2019, 09:05:35 pm
content: If you are making a lot of these, its not too expensive for a custom die. But if 40x40mm works thats quite a standard size so you should find something that works.https://www.aliexpress.com/i/32821793383.htmlhttps://www.aliexpress.com/i/32780223588.htmlhttps://www.aliexpress.com/i/32904858135.htmlhttps://www.aliexpress.com/item/1-piece-4CM-fan-radiator-Aluminum-profile-cooling-tunnel-40-40mm-Length-can-be-customized-free/32913499568.html

author: OgreVorbis
author_rank: Newbie
timestamp: June 13, 2019, 10:52:59 pm
content: Quote from: thm_w on June 13, 2019, 09:05:35 pmThanks so much. That's the exact size I'm looking for.I called fischer and they gave me a quote for custom and the price wasn't as bad as I expected.
Tuning fork motional resistance - Page 1
Forum section: electronics / projects

author: GK
author_rank: Super Contributor
timestamp: June 17, 2012, 02:18:26 am
content: .

author: ejeffrey
author_rank: Super Contributor
timestamp: June 17, 2012, 09:35:20 am
content: The data sheet says -0.034 +- 0.006 ppm/C^2, so I think that is a pretty good estimate.Edit: Sorry, I realize now you are worrying about the resistance, not the frequency. I don't think you should have to worry about that over the operating range. Are you planning to use some odd circuit?

author: ejeffrey
author_rank: Super Contributor
timestamp: June 17, 2012, 01:34:40 pm
content: Hmm... yeah, that is pretty far outside the target use of these devices. You might look for information on tuning fork AFM. They use the same tuning forks but they care a lot more about all the details of the electrical properties. I can ask a few people next week to see if they have any idea, but I suspect that popping it in a toaster oven or heating it with a hair dryer is the easiest way to go. Sometimes an hour in the lab can save a day in the library, at least if you already have a setup to test the performance.

author: SeanB
author_rank: Super Contributor
timestamp: June 18, 2012, 04:05:40 pm
content: Simplest is to solder them all to a grounded copper trace and cover the top and bottom of the board around them with a thin polystyrene sheet to make them all track thermally. No need to heat them, just keep all at the same temperature, and make sure all are from the same production batch, which probably will mean ordering 50 or so and matching them for resonant frequency using a simple oscillator. May take a while to find the 5, as they will have to be kept in an isothermal enclosure and tested individually whilst not heating or cooling them.
tunnel gun supply di-hvs 01, what is that ? - Page 1
Forum section: electronics / projects

author: oz2cpu
author_rank: Frequent Contributor
timestamp: March 19, 2022, 11:09:06 pm
content: what is this ?tunnel gun supply di-hvs 01looks like a dual high voltage supplysomething with kV and uA in one part.and V and mA on the other part.what is this used for ?google dont know this ?should i do a teardown video ?just power it up ?or open it first ?
Tunnel gun supply DL-HVS 01 4.7kV High-voltage 1990 Teardown and Repair - Page 1
Forum section: electronics / projects

author: oz2cpu
author_rank: Frequent Contributor
timestamp: March 20, 2022, 10:49:52 pm
content: really funny design and manufacture quality is a little bit variablefrom super duper nice, to breadboard and prototype level other places :-)it is from 1990 written on one of the PCBdont know exactly where it was manufactured but the text on the label is in czechhttps://youtu.be/dfxF4nhGVQcmore is comming up soon.. so maybe bookmark the playlist
turbo jet fan - feedback appreciated - Page 1
Forum section: electronics / projects

author: cyberdog
author_rank: Newbie
timestamp: July 16, 2025, 04:31:49 pm
content: I decided to build turbo jet fan (enclosed), with a lot of help from chatGPT.Can you help me with feedback on this one?LiPo batteries are expensive and hard to integrate in smaller form factor.Motor is bit too powerful, but I can dial it down.I am looking for feedback compatibility of component and safety.components:- motor + ESC + controller; 40mm=460W MAX in 16,8V; 29,8A, working voltage 7.4-16.8Vhttps://www.aliexpress.com/item/1005006184419940.html- battery 4x Samsung 21700 INR21700-45T Li-Ion 3.6 V 4500 mAh 50 A- BMShttps://techfun.sk/produkt/bms-modul-pre-litiove-baterie-3s-4s-5s-100a/- Charging boardhttps://www.aliexpress.com/item/1005008974402419.html?spm=a2g0o.productlist.main.12.1a58214caz1Mnu&algo_pvid=b046c3f8-b461-4fe4-98dc-c896d83c7992&algo_exp_id=b046c3f8-b461-4fe4-98dc-c896d83c7992-8&pdp_ext_f=%7B"order"%3A"31"%2C"eval"%3A"1"%7D&pdp_npi=4%40dis%21EUR%2114.50%2114.06%21%21%21117.28%21113.72%21%40211b81a317500128196712421ee1ed%2112000047426810193%21sea%21SK%210%21ABX&curPageLogUid=wICzV5Vlpn9m&utparam-url=scene%3Asearch%7Cquery_from%3A- battery indicationhttps://www.aliexpress.com/item/1005005727166588.html-amp meterhttps://www.toolkitrc.com/product/wm150/-nickel strips 0,2mm x 10mm (6 layers between each battery connection - spot welded)-copper strip 0.2x10mm alternative for 6L nickel (sandwich of nickel (bottom), solder(center), copper(top) spot welded on battery)-XT60 connectors-21700 Battery Terminal Insulator Rings-heat shrink tubing-Kapton tape-car fuse 40 amp-Balancer connector (JST-XH 5-pin (male +female)-case 3D printed by friend-High-temp silicone rubber cable (e.g. 200 °C rated)[somehow in metric part of this world the silicone cables are also categorized by "AWG" size]---------------------------------------------------------wired connection Current Wire Size (mm²)Battery to ESC ~30–50A 4.0 mm²ESC to Motor ~30A 2.5 – 4.0 mm²Charging leads ~5–10A 1.0 – 1.5 mm²Balance wires <1A 0.14 – 0.25 mm²wiring scheme straight out of chatGPT:the last image is little bit "sus"

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: July 16, 2025, 09:50:07 pm
content: That's a ducted fan, not a turbojet.

author: thm_w
author_rank: Super Contributor
timestamp: July 16, 2025, 10:01:08 pm
content: That schematic is garbage, are you able to draw your own instead?For less than the cost of your parts you can buy a fully assembled unithttps://aliexpress.com/item/1005008672886992.htmlBut I'm not sure what your goal is here: to learn, to make one with long battery life, etc.Quote from: Alex Eisenhut on July 16, 2025, 09:50:07 pmIt is the same fan they use on handheld turbo blowers, which is what the OP is talking about.

author: Benta
author_rank: Super Contributor
timestamp: July 16, 2025, 10:26:14 pm
content: It's still a ducted fan, not a "turbo-jet".
Turbomolecular pump driver PSU - Page 1
Forum section: electronics / projects

author: ChristofferB
author_rank: Frequent Contributor
timestamp: March 21, 2020, 10:26:54 pm
content: Hey all! I'm delving into some ultra high vacuum projects, and I'm currently trying to build a vacuum system controller based on my Edwards EXT255H turbo pump.It comes with a controller doing all the motor drive/speed monitoring stuff, but this controller needs a REALLY oddball 70-85 VDC in... at 2.2A maxHow does one accomplish 70-85V 2.2A easiest? Here are the two options I have considered so far:-serial connected 24V + 48V SMPS modules (=72V, and all control and vacuum gauges and relay logic needs 24V too)-230->50VAC transformer, then rectification to give roughly 70V.Using switchmode modules is easier, but I'm unsure if they actually CAN be put in series like that. Also, it might not be ideal to also power relay inputs, buttons, gauges and so from the motor PSU.Using a linear PSU has the same drawback it always has: heavy and expensive. Also If I could minimize the amount of mains voltage work I need to do I'd be happy.thanks in advance!--Chris

author: langwadt
author_rank: Super Contributor
timestamp: March 21, 2020, 10:33:45 pm
content: Quote from: ChristofferB on March 21, 2020, 10:26:54 pmhttps://www.west-l.ru/uploads/uf/2a0/2a088acbd4731817651179f5b54b7aa0.pdf

author: ChristofferB
author_rank: Frequent Contributor
timestamp: March 21, 2020, 10:41:26 pm
content: Good resource, thanks! Switchmodes it is, it seems.

author: Zoli
author_rank: Frequent Contributor
timestamp: March 22, 2020, 02:39:14 pm
content: Quote from: ChristofferB on March 21, 2020, 10:41:26 pmCareful with the pre-made SMPS's: some of them has the ground hardwired to the minus.If you connect two of those in series, the lower unit output will be shorted - always get a proper and detailed datasheet.
Turingy Mini Power supply  - Page 1
Forum section: electronics / projects

author: Marduk
author_rank: Newbie
timestamp: January 25, 2013, 02:59:42 am
content: hello out there.. i have was Davis video about the turingy liPo battery and ended up get 2 of them. i want to make a mini power supply out of them to power random stuff that i need. and come up with this design. but then when i got the battery i found out that they have not protection or anything. so i was just going to add it to the design but i can't find anything good out there to use.. and seeing that i don't want to blow up my lab i want to see if anyone here would look over and get me a hand or an idea.

author: gregfox151@gmail.com
author_rank: Contributor
timestamp: June 08, 2013, 05:24:04 pm
content: The attached circuit will not only shut down when the bat gets low, but uses a single push button for on/off.
Turn Normal Relay into Latching Relay - Page 1
Forum section: electronics / projects

author: Kedar264
author_rank: Regular Contributor
timestamp: May 17, 2015, 05:25:29 pm
content: Turn normal electric relay into latching relay only using neodymium magnetJust open the relay and stick an neodymium magnet on to common terminal and that's all.....!You can use this latch as memory, switch, etc.This Modified relay doesn't need continues power ,input pulse is sufficient to latch the relay in one of the two states.See the videohttps://youtu.be/SxRl7rMPGRk

author: SeanB
author_rank: Super Contributor
timestamp: May 17, 2015, 05:36:50 pm
content: Nice mod, just will be a little vibration sensitive. If you use a larger relay ( plug in type) you might be able to do it and put the cover back on as well.
Turn your face tanner into a pcb UV lamp - Page 1
Forum section: electronics / projects

author: heliosoph
author_rank: Newbie
timestamp: March 02, 2014, 07:22:48 pm
content: Hello all,this is my first post in the EEVblog forum, so I first want to introduce myself a little: I was doing electronics since the 80s where I was building a Z80 system among other projects. My hobby electronics activities ceased for many years and in 2012 I began again with an Arduino and some related stuff and I began writing my ownblog. Not very big at the moment but growing. What I want to show to you today is my latest project. I bought a face tanner for use as a UV lamp for making PCBs. The built-in time switch was too coarse for my usage so I replaced it. There is nothing special on it and this is why I want to show it to you: Everything I did is just plain standard and not a lot of work to do. And I got my problem solvedIf interested, look at:http://heliosoph.mit-links.info/face-tanner-pcb-uv-lamp/heliosoph

author: Zepnat
author_rank: Regular Contributor
timestamp: March 02, 2014, 10:50:38 pm
content: Hello and welcome from another newbie! Where did you get the lamp? it looks really powerful you wouldn't catch me near that thing.

author: heliosoph
author_rank: Newbie
timestamp: March 03, 2014, 06:36:37 am
content: The lamp was from ebay. It cost me 8.50 € incl. shippingAnd yes, it is very powerful. I recommend very much using sunglasses or other eye protection while using it.heliosoph
Turnigy Charger Regenerative Discharge on server PSU? - Page 1
Forum section: electronics / projects

author: iamdarkyoshi
author_rank: Frequent Contributor
timestamp: February 01, 2016, 06:45:22 pm
content: I have one of those turnigy reaktor chargers with regenerative discharge. It allows you to discharge the battery under test up to 20A into the source power supply, as obviously, that power has to go somewhere. However, when using a server power supply (like I do) the regenerative discharge will not work. IS there some sort of circuit I can build using some nichrome "springs" and a fan as a high power resistor, and make it so the charger discharges into that load instead of the power supply, but the power supply does not discharge into the load?

author: Siwastaja
author_rank: Super Contributor
timestamp: February 08, 2016, 04:06:41 pm
content: Simple comparator comparing the voltage to an adjustable setpoint, driving a MOSFET which turns the resistors on. Adjust the setpoint above the PSUs idle voltage. When the batteries discharge, the DC link voltage rises until your comparator thing works. Beware of oscillations, though.
Turning Images of Layers into Gerber, Drill Files, Etc. - Page 1
Forum section: electronics / projects

author: sacherjj
author_rank: Frequent Contributor
timestamp: March 17, 2012, 10:06:30 pm
content: If there an easy way to convert images of various PCB layers into files needed to order them.I'm asking, because the I2C Bus book that Dave showed in the Mailbag episode arrived. I decided to build most of the projects. However, $100 for boards is ridiculous. For the same amount, I could get 10 of each board. If I can convert the PDF they provide into orderable files.

author: Unknown
author_rank: Unknown
timestamp: March 17, 2012, 10:18:12 pm
content: Not that I'm aware of. You could etch them yourself if they're single layer. I believe some PCB manufacturers accept image files instead of Gerbers for an extra fee (no idea how close this it to $100). Most PCB design packages will allow you to import an image as background, so you can trace it. Not sure if your time is cheap enough to warrant the labor, though.

author: FreeThinker
author_rank: Frequent Contributor
timestamp: March 17, 2012, 10:24:39 pm
content: Just a pure guess but I suspect that you will not be able to. PDF's are basically a picture format and Gerbers a text based format

author: mariush
author_rank: Super Contributor
timestamp: March 17, 2012, 11:29:22 pm
content: I would probably start off by vectorizing the image and saving it into SVG. This is basically a text format, so I could later on write a script that would convert the svg to gerber .... the Gerber is a very simple format.I just tried to vectorize a pcb gif I had around and the SVG file was relatively close to the image.. I used an evaluation vector of TotalVectorize but looking in the SVG to see how hard would be to write a script for conversion to Gerber, I saw a comment there saying "Created by Potrace Professional 1.0c" so apparently they licensed the open source package protrace that's available here:http://potrace.sourceforge.net/If you have pdf files, you can basically export the images from it, they should be inside at least at 100 dpi, should be good enough for 0.5mm pads, give or take a few mils.

author: sacherjj
author_rank: Frequent Contributor
timestamp: March 18, 2012, 03:40:27 am
content: Thanks all, that is about what I thought. I wish Elektor would charge reasonable fees for these, so this wasn't necessary.
Turning Nokia hhd into precision motors for micro camera gimbal - Page 1
Forum section: electronics / projects

author: avb284782235
author_rank: Newbie
timestamp: September 03, 2023, 07:08:16 am
content: Hello, I am trying to build a micro gimbal that can stabilize ultralight cameras, yet retain higher precision that standard servo gimbals of these gimbal’s design. The pico analog 5V camera that some company’s offer weigh about 1.4 grams, and if I double the weight as a capable of two cameras with one as backup, the gimbal would have to carry at most 3 grams. I would want to use the hhd out of the Nokia 91, and use a rotary encoder so I can turn it into a rudimentary brushless motor.I was wondering if anyone knew if any rotary encoders that are size of the components in the spinning axle part of the nokia 91 hhd, pictured here:https://www.aliexpress.com/item/1005004080808553.htmlSecondly, beside building a diy rotary encoder of this scale, or purchasing one, I have one more issue to solve. Does anyone have any links for sliprings of the scale of hhd? I am trying to find the smallest sliprings available, they only need to have power ground, and one third (wire analog for video). Building one could be an option, however I was wondering what the available, that have miniature form factor, and are very light weight.Any product selection recommendations or advice would be appreciated, thanks.
Turning off Mosfet results in spikes, with slowest setting (6EDL7141) - Page 1
Forum section: electronics / projects

author: eTobey
author_rank: Super Contributor
timestamp: December 13, 2024, 07:32:59 am
content: Can anyone explain, why there are those spikes in the current? I already have setup the driver to drive the gate with 10mA, and that is the slowest setting possible.The resistor after the inductor is 0.1 Ohm, held in place by alligator clips. The inductor is actually a stator, with just using 2 of the 3 connections.The turning on of the mosfet happens faster, and looks good.Datasheet of driver:https://www.infineon.com/dgdl/Infineon-6EDL7141-DataSheet-v01_20-EN.pdf?fileId=8ac78c8c8e7ead30018ec7bd6aac46f3Datasheet of Mosfet:https://www.vishay.com/docs/76233/sir180dp.pdf

author: jwet
author_rank: Frequent Contributor
timestamp: December 14, 2024, 05:17:40 pm
content: Its a bit difficult to understand your scope plots- I can't tell the magnitude of these spikes, it looks like there on a math channel thats reading out in webers? I think the problem is that at these very slow rise times, you're getting through conduction. The driver has dead time insertion between hiside and lowside but it kind of breaks down at these very low speeds. Do you really need to operate at these levels? Another possibility is running out of dynamic range in the current measuring- isn't there a low side current sense below the fets? (CSNA etc.). These can also be tough measurement but if your high speed stuff works ok, you probably have a decent test setup.I have a question for you. I just bought a Siglent scope (SDS120x HD), what are you using for a current probe?. I have one for my old Tek buts it only for that scope with the smart interface stuff. I haven't bought an I probe in a while, they've gotten really pricey.

author: Andy Watson
author_rank: Super Contributor
timestamp: December 14, 2024, 06:39:16 pm
content: Spikes? Looks like oscillation to me. To get from On to Off the mosfet must transition through a linear region. The longer the transistion, the greater the chance of dwelling in that "sweet spot" where oscillations can build-up. The inductive nature of the load probably does not help.If turn-off (and on) time is not important to you, try spoiling the "Q" of the gate circuit with a resistor (10-200\$\Omega\$) placed close to the gate lead.
Turning off the high side power mosfet without disrupting circuit functionality - Page 1
Forum section: electronics / projects

author: electronx
author_rank: Regular Contributor
timestamp: November 29, 2024, 02:32:44 pm
content: I have a voltage clamp circuit like this. I want to turn the power mosfet on and off with the mcu, but I don't want the clamp functionality of the circuit to be damaged. What are your suggestions in this case?

author: mtwieg
author_rank: Frequent Contributor
timestamp: November 29, 2024, 04:14:45 pm
content: Simplest way I can see is to pull down the base of Q1 (or the cathode of the 6.2V zener) with an open-drain FET/BJT, controlled by the MCU. This will turn off Q1 regardless of the output voltage. May want to add something to protect Q1 from base-emitter reverse breakdown though.
turning on rackmount 12V PSU - Page 1
Forum section: electronics / projects

author: horvat.kamca
author_rank: Contributor
timestamp: December 12, 2021, 04:01:41 pm
content: Hi,a friend of mine got a few rackmount 12V SPAFFIV-03G powersupplies and asked me for help how to turn them on. I've found description of PSU output connector inhttps://belfuse.com/resources/datasheets/powersolutions/ds-bps-fnd300-series.pdf.Unfortunately, there is no PS_ON pin.Do you know what standard this power supply is compliant with and how to turn in on ?PIN SIGNAL NAME DESCRIPTION1-3, 13-15 V1 RTN V1 Output Return4-6, 16-18 V1 V1 Output7 - Not Used8 - Not Used9 PF Power Fail10 I2C Voltage Input/Output11 SDA Serial Data Line12 SCL Serial Clock Line19 - Not Used20 - Not Used21 LSB Address Input Line22 RSD Power Supply Remote Shut Down23 PS_PRSNT_L Power Supply Present signal24 Fan Fail Fan Fail signal

author: ledtester
author_rank: Super Contributor
timestamp: December 12, 2021, 04:09:16 pm
content: It looks like it is meant to be controlled via an I2C bus:https://www.i2c-bus.org/This is a very common bus used with microcontrollers but you'll need more documentation on what I2C messages to send to the unit to control it.I would contact Bel tech support to get the I2C protocol documentation for the device:

author: NiHaoMike
author_rank: Super Contributor
timestamp: December 12, 2021, 09:39:53 pm
content: I would suggest starting with pins 22 and 23. Check what voltage they are to pin 1 (output ground) with input power applied. A pin that has about 3-5V open circuit probably needs to be pulled to ground and a pin with no voltage probably needs to be pulled up. (There's a reference to the enable signals being active when pulled to ground, try that first!) 100 ohm resistors are good for avoiding damage if those pins aren't what you were expecting. Also check the voltage of pin 10, that appears to be aux power and might be useful for pulling up signals.

author: horvat.kamca
author_rank: Contributor
timestamp: December 14, 2021, 07:10:53 am
content: NiHaoMike> Thanks, I've sent the suggestion to my friend. Only instead of 100 ohm resistor, it's better to use 1k resistor. Another datasheet from BellFuse describes how Power Supply Present PIN should be treated in a little bit more detailOUTPUT CONNECTOR DESCRIPTION:Power Supply PresentTYPE:Resistor (1 kΩ) connected to logic GNDLOW LEVEL/ HIGH LEVEL:Open/Pull upV MAX/ I MAX: 10 V/10 mAhttps://belfuse.com/resources/datasheets/powersolutions/ds-bps-fnp1500-1800-series.pdf

author: TomS_
author_rank: Frequent Contributor
timestamp: December 15, 2021, 01:05:43 pm
content: Yeah, there will have to be some kind of standby power supply coming out of them, otherwise there would be no way to power the off-board control circuitry, and thus no way to ever turn them on fully.Seems common to pull one of the signals down to get the main output to turn on. Fans may also spin up at that point if it has any. Ideally they will have an on-board fan controller to bring the speed of them back down to something less jet-enginey.
Turns in antenna feed transmission line... it's okay, right? - Page 1
Forum section: electronics / projects

author: shadewind
author_rank: Frequent Contributor
timestamp: October 14, 2011, 07:00:45 pm
content: This might seems like a stupid question, but it is okay to route antenna feedlines (CPWG or microstrip) in anything other than a single straight line if you keep the characteristic impedance and avoid stupid things like 90 degree turns, right?
Turntable remote operation - Page 1
Forum section: electronics / projects

author: abhi1981
author_rank: Regular Contributor
timestamp: January 30, 2024, 07:39:54 am
content: HelloI have a Yamaha TT400U RS turntable which has a remote start/stop feature. The remote terminal is a 3.5mm mono jack, which activates a 12v solenoid plunger. The plunger mimics the function of the start/stop button. I don't have a matching amplifier with remote output. I tested it by manually feeding a 12v pulse to it and it worked perfectly. The first 12v pulse will drop the tone arm and another 12v pulse will lift the tone arm and stop playback.Just for fun, I am planning to use this feature with an Alexa smart plug. So, I want to make a circuit which will send a 12v pulse when the mains power is on and another pulse when mains is switched off. I will say "Alexa, drop my needle" and playback will start ( just like Tony Stark in Iron Man 3)Please help me with the circuit design. I'm a newbie when it comes to designing circuits.
turret terminals AWG rating - Page 1
Forum section: electronics / projects

author: coppercone2
author_rank: Super Contributor
timestamp: March 10, 2021, 08:47:59 am
content: Does anyone know how to define turret terminals wire capacity in AWG for reliability connections?Like, if you measure the wire wrapped around the terminal in proportion to the terminal diameter and the diameter of the little plates/rings, what should these values be? Exactly what is too large for a chirstmas tree turret terminal?And also, is there a table of wattage of soldering vs gauge of wire soldered?
Tutorial: ESP8266 SoC, Blynk App, Arduino and Internet of Things - Page 1
Forum section: electronics / projects

author: Hugoneus
author_rank: Frequent Contributor
timestamp: December 07, 2015, 05:48:34 pm
content: You can watch the video here: [30 Minutes]youtu.be/76hsxHBn00kMore videos at The Signal Path:http://www.TheSignalPath.com

author: Hugoneus
author_rank: Frequent Contributor
timestamp: December 08, 2015, 02:22:13 am
content: I have now updated the site with the Arduino code.