hybridfree/eevblog-posts huggingface dataset:
Which chip is in this project .. ? - Page 1
Forum section: electronics / projects

author: wissa
author_rank: Newbie
timestamp: January 27, 2020, 07:18:17 pm
content: Hi, I came up with this product which I am interested in doing a similar one ... Do you have an idea which chip is in there or could you advise on a buck-boost converter with IN:1-30V and OUT:0-30V if possible with current cabability of 1-2A ??Here is the link of the producthttp://www.icstation.com/adjustable-step-step-down-power-supply-module-buck-boost-voltage-converter-p-13462.htmlorhttp://www.icstation.com/adjustable-step-down-power-supply-module-buck-boost-voltage-converter-p-13542.htmlRegards,

author: AE7OO
author_rank: Regular Contributor
timestamp: February 14, 2020, 01:05:22 am
content: Greetings,The controller is a Feeling Technology FP5139 which is used with a NCEPower NCE6075 NFet.There is also going to be a meter chip controlling the LED display, but those are fairly easy to come by.I've included datasheets for both chips,I found a review of board using the FP5139https://www.eevblog.com/forum/reviews/30w-sepic-dc-dc-converter-review-(5-35v-in-0-8-35v-out)/It's obvious from just the component selection alone that whoever "designed" it, did not have a clue. ON the other hand, it looks like whoever did the ZK-DP2 knew just a little bit more...Unlike the other board's 30W rating the ZK-DP2 only has a 15W rating, but it has a lot of adaptability and is not a design from the datasheet(I've only got two though)I've found out that yes, they still sell them and found an app note which I've also include now.
Which chips implement RSASSA-PSS ? - Page 1
Forum section: electronics / projects

author: 741
author_rank: Frequent Contributor
timestamp: April 14, 2023, 10:09:46 am
content: I'm looking for a part number thatUses an RSASSA-PSS signature (RFC 8017) schemeHas an RSA-2048 private key and SHA-256 hashHas some on-board NV memoryNot all data-sheets state the RSA algoritmn type. For instance,SLS 32AIA010MH/ uses "RSA SSA PKCS#1 v1.5 without hashing"SLB 9670 TPM2.0 contains no reference to "RSA"SLB 9673 (and NXP's SE050) do mention RSA, but do not state the algorithm.
Which component is causing the squeal and whine? - Page 1
Forum section: electronics / projects

author: carl0s
author_rank: Unknown
timestamp: June 29, 2018, 08:01:19 pm
content: This is a dimmer switch. It is WiFi contolled. I've removed the WiFi module in these pictures.Like most dimmers, theres a noticeable squeal and screeching, fuzzing noise. Not noticeable to all, but I am one of those hypersensitive tinnitus types.I'm hoping to be able to replace a cheap part with a better one. What is likely the be the source of the noise? The bt139 triac which could be fake? Or something else? There's no coil here to apply adhesive to :-((See attachments below. I'm posting from my phone)

author: carl0s
author_rank: Unknown
timestamp: June 29, 2018, 08:02:02 pm
content: Next pic attached..

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 29, 2018, 08:16:46 pm
content: Probably one of the ceramic caps. Unclear which ones, maybe the SMPS is badly compensated and that's where it's coming from.Tim

author: David Chamberlain
author_rank: Frequent Contributor
timestamp: June 29, 2018, 09:33:51 pm
content: Yes the caps. Ive had this before on a tantalum directly before it burst in to flames (i don't see any in your pics)Place a hard metal probe (screw driver or tweezers) on each package surface and give it a little presure. The sound will get louder when you've found the culprit because its conducting up the probe.Another method is, as above, but with an oscilloscope. The offending part should show the highest peek when your in contact with it. Somthing below 10kHz.[Edit : take care not to electrocute yourself while doing this. Use correctly insulated probes]

author: CopperCone
author_rank: Super Contributor
timestamp: June 30, 2018, 12:26:01 am
content: i built a little acoustic probe out of boredom. if you search my posts you will find it, I think its in the test equipment forum

author: wraper
author_rank: Unknown
timestamp: June 30, 2018, 12:31:05 am
content: Does it depend on brightness set?

author: DaJMasta
author_rank: Super Contributor
timestamp: June 30, 2018, 03:32:15 am
content: My guess is caps as well, and I think it's usually the bigger ones that exhibit more potential problems. There's a chance the transformer could do it too, but if it's that high pitched, I doubt it.A good starting point is powering it up and poking around with an insulated plastic/rubber probe on the potential problem parts. If it stops or changes, it's likely the culprit.

author: carl0s
author_rank: Unknown
timestamp: June 30, 2018, 08:55:26 am
content: Thanks guys I will get something rigged up :-)
Which connector is this? (14-pin connector on a bus ticket machine) - Page 1
Forum section: electronics / projects

author: Rjevski
author_rank: Unknown
timestamp: May 06, 2019, 12:59:46 am
content: Hello everyone!I'm trying to restore an AES Prodata bus ticket reader (the green one that was used on the Sydney bus network at some point, judging by the smell and the overall design it seems to be from the late 90s) and it's got the connector in the picture attached below - anyone recognize it? It's symmetrical, got 7 fairly heavy-duty pins on each side and 2 big steel alignment pins on either side. I can of course solder directly onto it but I'm trying to keep the machine original so I'd really love to just get the other side of this connector and solder to that instead.Thanks!PS: if anyone is interested in following the restoration of this machine let me know and I'll make a dedicated thread!

author: vk6zgo
author_rank: Super Contributor
timestamp: May 06, 2019, 02:03:51 am
content: I have no idea of the maker, but it looks vaguely like it may have come from Cannon, or perhaps Amphenol.These connectors were quite common in Oz back in the day.

author: reboots
author_rank: Regular Contributor
timestamp: May 06, 2019, 02:40:47 am
content: This looks similar to the Amphenol "blue ribbon" connector used on mid-20th-century Tektronix 500-series scope plugins. The Tek connector had more pins, however, and the vertical offset of the two alignment pins was reversed.That Amphenol line now appears to be produced, or at least licensed, by Eaton/CDM Electronics as their 26 series connectors. I do not see a 26-series part with fewer than 16 pins, and the alignment pins do not match. But take a look at their 26-4200-16S:https://www.alliedelec.com/product/eaton-cdm-electronics/26-4200-16s/70144704/If you can modify that part to clear the alignment pins, it may engage the "ribbon", leaving two extra pins unused. Best to start by checking the dimensions of your connector against the 26-series datasheet. No guarantees; it's a long shot.

author: Rjevski
author_rank: Unknown
timestamp: May 06, 2019, 04:06:30 pm
content: Thanks for your replies.> These connectors were quite common in Oz back in the day.This machine isn't specific to Australia though. It was manufactured by AES in Belgium, which then got acquired by ERG apparently (which then became VIX-ERG). Here's a datasheet for the successor of this machine:https://apps.fcc.gov/eas/GetApplicationAttachment.html?calledFromFrame=Y&id=57340> This looks similar to the Amphenol "blue ribbon" connectorLooks like it. In the datasheet you linked, one of the connectors (see attached screenshot) looks exactly like the one I've got (right down to the alignment pins which look the same and are in the same place), but has 2 extra pins... Does anyone know of any manufacturers who make similar connectors (hoping to find one that would fit roughly without having extra pins).
Which connector type for an Audio Frequency Induction Loop Outreach connection - Page 1
Forum section: electronics / projects

author: tggzzz
author_rank: Super Contributor
timestamp: November 27, 2020, 06:22:48 pm
content: Audio frequency induction loop amplifiers for the deaf have an "outreach connector" that allows remote microphones etc to be connected to the amplfier's input.What's the type of the connector?The pictures below show the external shell shape required. The pins are on a 5mm pitch. The connector latch into the socket. The outline connector shown probably has screw terminals to attach the wires.Thanks

author: 2N3055
author_rank: Super Contributor
timestamp: November 27, 2020, 07:18:52 pm
content: This type:https://www.tme.eu/hr/en/details/1-796634-0/pluggable-terminal-blocks/te-connectivity/There are similar connectors from other manufacturers.

author: tggzzz
author_rank: Super Contributor
timestamp: November 27, 2020, 07:56:46 pm
content: That looks right. Thanks for a quick helpful response

author: 2N3055
author_rank: Super Contributor
timestamp: November 27, 2020, 09:01:20 pm
content: Quote from: tggzzz on November 27, 2020, 07:56:46 pmGlad to help. I know because I use them a lot...
which definitively electronic components need some free air - Page 1
Forum section: electronics / projects

author: abdulbadii
author_rank: Frequent Contributor
timestamp: February 16, 2022, 01:47:25 pm
content: Would anyone list which electronic components need some (flowing) air and can't be 100% air tight?

author: thinkfat
author_rank: Unknown
timestamp: February 16, 2022, 02:30:20 pm
content: A speaker?

author: CaptDon
author_rank: Super Contributor
timestamp: February 16, 2022, 02:31:40 pm
content: Almost sounds like a troll question. Are you serious?Even a 2000 watt resistor doesn't need free air if it is only required to burn 2 watts. I'll let you think about that question. Why does any electronic component need air flow?TO REMOVE HEAT!!!! So to answer the question, ANY COMPONENT NOT RUNNING HOT ENOUGH TO REQUIRE COOLING AIR won't require air movement. All others will require heat sinking, whether that be free air, a big aluminum plate, an oil immersion bath, waterflow or a prediction from a ouija board, perhaps even being attached to the ouija board. I would say a 2 watt resistor burning 2000 watts would surely fit your description of requiring SOME free air.

author: TimNJ
author_rank: Super Contributor
timestamp: February 16, 2022, 06:35:28 pm
content: Generally, electrolytic capacitors need a little space just in case they vent (failure due to internal pressure build up). Same applies for lithium pouch cells (see: Samsung failures). But, I am not sure that's exactly your question.

author: magic
author_rank: Super Contributor
timestamp: February 17, 2022, 07:04:46 am
content: Quote from: TimNJ on February 16, 2022, 06:35:28 pmSome weird kind of homework?
Which ESD diode to use? - Page 1
Forum section: electronics / projects

author: hal9001
author_rank: Regular Contributor
timestamp: May 06, 2021, 09:13:09 am
content: How do you choose what ESD diode type to use? Specifically want to understand which to use for USB2.0 data but there are different app notes showing different diodes.Cheers

author: hal9001
author_rank: Regular Contributor
timestamp: May 07, 2021, 10:01:49 am
content: Does the speed of the bus determine which ESD/TVS to use? Can any one point me to more information for which one to use and why?

author: TimNJ
author_rank: Super Contributor
timestamp: May 07, 2021, 05:39:52 pm
content: Signal line ESD suppressors often need to be low capacitance. For high speed USB 2.0 data rates/edge rates, probably can get away with relatively high capacitance..maybe a few pF (~5pF) is okay. For higher speed buses like USB 3.0, you probably need sub 1pF or so.I am not sure if the semiconductor properties of the low-capacitance diodes have any disadvantages.Otherwise, to size a ESD/TVS diode correctly, you should consider the "energy behind" the ESD pulse. If the energy source is limited, you can use a a physically smaller diode. If higher energy source, need a physically larger diode to not melt it!

author: thinkfat
author_rank: Unknown
timestamp: May 07, 2021, 05:52:58 pm
content: What's wrong with just using an integrated standard solution? USBLC6-2SC6Y?

author: warpigs330
author_rank: Contributor
timestamp: May 07, 2021, 06:56:03 pm
content: Not the OP but wondering about the same thing. I am getting boards made by JLCPCB and am trying to reduce the number of extended components I need to pay for, so if I could replace this ship with basic diodes it would save a little money.

author: hal9001
author_rank: Regular Contributor
timestamp: May 07, 2021, 09:08:18 pm
content: Thanks all. To be more clear,I would want to know when to use which type of protection diode in the picture.Documents from companies like Wurth and Nexperia recommend different types for the same bus type(USB2.0 specifically). Are they interchangeable for ESD protection?

author: nctnico
author_rank: Super Contributor
timestamp: May 07, 2021, 09:30:37 pm
content: If it says USB protection diode in the datasheet then it is suitable for that purpose. Don't get too hung-up on the actual symbol. What is more important are the ratings for the amount of charge it can handle and what kind of requirement you have for that.
Which file to use for LTSpice? - Page 1
Forum section: electronics / projects

author: Wilson__
author_rank: Frequent Contributor
timestamp: July 11, 2024, 01:21:55 pm
content: This chip has many files.Which file to use for LTSpice version (x86) 24.0.12 (downloaded recently)? For voltage and current analysis of low speed high side power switch. P-MOSFET as high side switch of 4.2V power source. N-MOSFET to interface with MCU at 3V.Many thanks

author: Ian.M
author_rank: Super Contributor
timestamp: July 11, 2024, 02:09:08 pm
content: I assume you are referring to the Spice models fromhttps://www.vishay.com/en/product/62968/tab/designtools-ppg/The .txt and .lib files with the same root filename are (in this case) identical and contain the actual SPICE models. The .olb files are PSPICE symbols for the models and are useless to a LTspice user. This reduces it to three possibles:SiUD402ED_HS_Rev_ASiUD402ED_PS_RC_Rev_ASiUD402ED_PS_Rev_AUnfortunately the accompanying PDF doesn't give any usage details for the three models, and the headers in the model files are also notably uninformative. It is likely that the HS and PS in the model filenames refer to HSPICE and PSPICE, two well known SPICE modelling programs, not tied to any semiconductor manufacturer. They both accept standard SPICE3 netlist syntax but PSPICE extends this with its own proprietary syntax for certain devices which LTspice doesn't accept. HSPICE has the same issue, most notably with extra unnamed parameters for resistors which LTspice also doesn't accept.Comparing SiUD402ED_PS_RC_Rev_A and SiUD402ED_PS_Rev_A, they both contain *exactly* the same subcircuit model for the SiUD402ED MOSFET, but the _RC_ one also contains a cascaded RC thermal model for the device, to enable PSPICE to determine if it is operating within the SOA boundaries. LTspice hassimilar capabilitiesbut I expect you'd have to reverse engineer the PSPICE thermal model to wrangle it into a LTspice SOAtherm compatible format.Comparing SiUD402ED_HS_Rev_A and SiUD402ED_PS_Rev_A, the _HS_ file is similarly structured to the _PS_ file, but very different on a line by line basis. They appears to contain the same components (and values) and the same nodes, but the _HS_file has the problematic extra resistor unnamed parameters.I believe SiUD402ED_PS_Rev_A (either .txt or .lib) is your best bet. LTspice will give warnings in its error log for PSPICE specific named parameters it doesn't support, but they shouldn't stop the model running or gossly affect its accuracy.
Which glue for tie capacitors to PCB? - Page 1
Forum section: electronics / projects

author: lk.dgironi
author_rank: Regular Contributor
timestamp: February 10, 2023, 08:04:49 am
content: I'm wondering which kind of glue to use to tie capacitors (or others components) to PCB.I've used hot glue and the 704 glue.Wondering if there's something appropriate.Thanks!

author: wraper
author_rank: Unknown
timestamp: February 10, 2023, 08:12:44 am
content: 70x series silicone adhesives are fine. You will not get noticeably better than that. Hot glue is garbage which will fall off after a few years.

author: lk.dgironi
author_rank: Regular Contributor
timestamp: February 10, 2023, 08:17:28 am
content: Thanks!That is the confirmation answer I'll waiting for

author: xavier60
author_rank: Super Contributor
timestamp: February 10, 2023, 08:31:11 am
content: If available, Threebond TB1530C. It is clear, viscous and moisture curing, so it's self-leveling.

author: Hawaka
author_rank: Regular Contributor
timestamp: February 10, 2023, 10:45:46 am
content: In a company I use to work at we used Sikaflex 221. It works pretty good, but not sure about long term effect on electronics.Also I have looked in the past for some industry standard glue but never got a good answer…

author: lk.dgironi
author_rank: Regular Contributor
timestamp: February 10, 2023, 10:46:27 am
content: Thank you all!
Which handpieces work with Metcal RFG-30 power unit? - Page 1
Forum section: electronics / projects

author: duckduck
author_rank: Frequent Contributor
timestamp: February 18, 2024, 06:11:04 pm
content: Howdy. I was able to acquire a Metcal RFG-30 power unit for pretty dang cheap. Which handpieces work with this power unit? I think that a MX-RM3E handpiece will work. Is that right? Thank you.

author: Wolfram
author_rank: Frequent Contributor
timestamp: February 18, 2024, 06:23:04 pm
content: As far as I know, any 13.56 MHz one should work with the old RFG30. The only problems I've had are related to using older handpieces together with later stations, as they lack a resistor across the coupling capacitor, meaning no DC path which makes the station think that the tip has been removed.

author: scrofula
author_rank: Contributor
timestamp: February 20, 2024, 06:28:49 pm
content: I have this block in my collection. It is the smallest in power and does not have a boost when lifting the handle from the magnetic stand. the following handles and corresponding tips for them will fit it:CV-H1-AV,CV-H7-AV,MX-H6-HDTMX-H1-AV,MX-H7-SF,MX- RM3E,MX-RM6EMX-H2-UF
which impedance calculator to use - Page 1
Forum section: electronics / projects

author: hsn93
author_rank: Regular Contributor
timestamp: March 26, 2020, 08:13:35 am
content: hi,there are a lot of signals that need to be matched within 10%.say 50ohm impedance matching leaving you (45 - 55ohm) range.i got 3 calculators here :layer stackup and thicknesses:the first calculator saturn pcb:the second calculator excel made from various websites:the 3rd calculator altiumi set the solder mask thickness to 0 in case it affect the calculation as i didnt see others considering itand the impedance:i checked altium impedance equation:saturn pcb differ from excel calculator with around ~10% which is the limitand that is being said while im ignoring the pcb manufacturer PCB thickness +/- 10% ..altium is too far from that so which one so which one would you use ?=================i've seen this post beforehttps://www.eevblog.com/forum/altium/difference-between-altium-and-saturn-pcb-toolkit-impedance-calculation/in that post various experts states that you should tell pcb manufacturer what you want ..what if i dont want to i want to tell them but to take their stackup and do the design based on that ?in this case you cant control impedance within 10% ?
Which injection transformer for feedback loop measurements? - Page 1
Forum section: electronics / projects

author: jmw
author_rank: Frequent Contributor
timestamp: April 23, 2020, 05:57:52 am
content: I'm trying to follow the procedure inAN-1889for measuring the feedback loop gain in a power converter. A transformer is used to couple a function generator signal across a small resistor without passing DC, but I'm not sure what kind of transformer to use. The note says "There are special transformers for such measurements available, which offer a very flat voltage transmission over a wide frequency band." What kinds of commercially available transformers specifically fit this bill? I was browsing Digikey and thought maybe things under current-sense transformers or pulse transformers seem like they could work. Has anyone done this and have recommendations?

author: uer166
author_rank: Super Contributor
timestamp: April 23, 2020, 06:09:45 am
content: Got this guy at work not long ago, can't comment on how good it is, but it's designed for your application:https://www.picotest.com/products_J2101A.html

author: jmw
author_rank: Frequent Contributor
timestamp: April 23, 2020, 07:12:51 am
content: Did some searching, looks like this topic has come up before. Seems the options are that Pico-test unit or similarly priced, or homebrew it. Guess that's another project to put on the board

author: Mechatrommer
author_rank: Super Contributor
timestamp: April 23, 2020, 10:15:28 am
content: Quote from: uer166 on April 23, 2020, 06:09:45 am$525 can buy a lot of stuff... did the OP created this thread due to this thread?https://www.eevblog.com/forum/testgear/injection-transformers-bode-plots-application/?topicseenJay_Diddy_B uses much cheaper Wurth 744 229 Common Mode choke. ($2.46 USD Qty 1 Digikey) maybe testing and try and error with much cheaper transformer first can give us much lesson before we can spend anything near $500 bucks. if i want to do real life testing on this, i will start first with my function generator and/or if necessary wind my own HF transformer with available ferrite core in my stock. ymmv.
Which LCD technology would be best for custom segment design? - Page 1
Forum section: electronics / projects

author: AlanEB
author_rank: Newbie
timestamp: September 12, 2025, 02:28:55 pm
content: Hi All,I'm working on a project that includes a small custom segment LCD display and I'm looking for advice as to which of the LCD technologies/options would be best suited for the design. By LCD technologies I'm referring to TN, HTN, STN, FSTN, FFSTN, VA, and maybe others I've missed.Project details:- Driver part of the MCU (SiLabs EFR32BG26)- Driver includes a charge pump with an output between 2.4 V – 3.6 V- Power source: 3 V Lithium coin cell battery, CR2016/25/32Display details:- Approximately 24x20mm- 262 segments (dot-matrix area, 6 x 7-segment, and some icons)- 8 common, 33 segments- Transflective backing with an electroluminescent backlight intended to be used occasionally.Display requirements:- Wide viewing angle- High contrast- Decent response rate- Ultra low current draw (looking for multi-year battery life)Given the amount of segments, what would be the best LCD option that would guarantee a high quality viewing experience while using as little energy as possible? Once the segment design is turned into a mask, are manufacturers able to provide multiple versions of the LCD with different specifications for testing? Has anyone done this? Does anyone have any recommendations of manufacturers? Does anyone have experience with VA, this seems to be quite a new technology?I would greatly appreciate any help!Cheers,Alan
Which LED lighting for my van (internal illumination)? - Page 1
Forum section: electronics / projects

author: DTJ
author_rank: Super Contributor
timestamp: April 29, 2018, 12:03:33 pm
content: I've got a van set up for camping trips and I want to add some lighting in the rear compartment.It probably does not have to be bright enough to read by, but enough to say eat and do other things.I've not had any experience with LED strips - the ones that appear to be self adhesive and was thinking maybe one or two 2m lengths might do the job.Are they any good? The ones I have looked at on eBay don't seem to specify the current draw. Something like this:https://www.ebay.com.au/itm/4x-12V-Waterproof-White-1210-LED-Strip-Lights-Bars-Camping-Caravan-Boat-Car-1-2M/111703264251?epid=1789350541&hash=item1a02088bfbor thishttps://www.ebay.com.au/itm/2M-3M-5M-600-LED-Strip-Lights-Cool-Warm-Natural-White-12V-Waterproof-Car-Camping/262905244006?hash=item3d365fa966:m:mZ7_dmxbnl5qWqwye-v7TrQI'd be running the LEDs off a 7Ah to 12Ah 12V SLA battery. They'd be on for perhaps a maximum of 2 hours per evening.Any recommendations?

author: Audioguru
author_rank: Super Contributor
timestamp: April 29, 2018, 01:12:20 pm
content: Sellers on ebay know nothing about the cheap Unbranded/Generic junk they sell so the current needed and how long the LED strips last is questionable.

author: DTJ
author_rank: Super Contributor
timestamp: April 29, 2018, 01:39:31 pm
content: Quote from: Audioguru on April 29, 2018, 01:12:20 pmYep, there's plenty of junk on eBay but there's sometimes some gems. I was hoping someone here might have used some for bench lighting or something similar.

author: GerryBags
author_rank: Frequent Contributor
timestamp: April 29, 2018, 02:31:39 pm
content: Have a look at electroluminescent strip, wire and sheeting for internal lighting.https://lighttapeuk.wordpress.com/tag/electroluminescent/

author: Kjelt
author_rank: Super Contributor
timestamp: April 29, 2018, 02:36:54 pm
content: 12V led strips have resistors per 3 leds so you throw away 25% in to heat.Aren't there special 12V led bulbs in campershops or something like that?

author: mark03
author_rank: Frequent Contributor
timestamp: April 29, 2018, 05:54:34 pm
content: Quote from: GerryBags on April 29, 2018, 02:31:39 pmHow efficient are EL devices compared with good white LEDs? Assuming ideal drivers for each and a reasonably sized space being illuminated.

author: DTJ
author_rank: Super Contributor
timestamp: May 05, 2018, 09:41:55 am
content: For posterity....I ended up going with one of these:http://www.altronics.com.au/p/x3251-natural-white-12-volt-led-aliminium-strip-light-0.5m/With one of these dimmer switches:http://www.altronics.com.au/p/x3234-12-24-volt-led-strip-light-inline-dimmer-controller/It works well, the dimming is pretty linear etc.
Which Logic Buffer Should I Use? - Page 1
Forum section: electronics / projects

author: PsychedelicBreakfast
author_rank: Contributor
timestamp: October 31, 2011, 01:57:16 pm
content: Hello all,I'm using CPLDs to drive another CPLDs - essentially, a Serial In Parallel Out shift register (driving end) is connected to a Parallel In Serial Out shift register (receiving end) via some long (~10m) wires.After some advice from here and other forums, I think it's a idea to protect my outputs via buffers.However, should I use buffers on both ends of the wire i.e. at the output and the input?Today, I used a ULN2003 darlington array as a buffer. The weird thing was that the output voltage, when low, was 0.7V instead of the expected ~0V. I had a 1K pull up resistor between the collector and Vcc. Is 0.7V for low expected?The inputdidread everything okay - the 0.7V voltage was read as low, as expected.But should I look into using dedicated logic buffers? My requirements are to protect the device from ESD damage, reduce EMI and 3.3V operational voltage. Any suggestions?EDIT: wanted to add, the wires areexpectedto be short circuited. That's what I'm trying to detect! So, the buffers should be such that when a wire that's Low is short-circuited with a wire thats High, it should also become High.
Which micro controller would be suitable? (camera/wifi/PIR sensor)  - Page 1
Forum section: electronics / projects

author: mastermaw
author_rank: Newbie
timestamp: April 25, 2013, 12:21:59 pm
content: Hello all, I need some recommendations for microcontrollers. The project is a small security device, running on a single AA or button cell.A PIR sensor detects motion, which latches a relay, turning on a camera and WiFi.The camera takes a picture, saves it to storage and then emails the picture via SMTP to a preset recipient and deletes the image.Of course to conserve power the cam and wifi are always turned off unless motion is detected. Clearly a small button cell wouldn't last long powering wifi!So, I need a microcontroller with very low consumption, at least 1mb of onboard storage, a CPU capable of processing an image and firing off an email within 10 seconds, and reasonably simple connectivity with a WiFi chip and camera.Ideally, all the components should ultimately be available for under $40 - but for my project, it's not an issue. The components should also ideally fit in a 5cm2 box - but for a prototype, size isn't a problem.I know similar security devices exist but this is a fun project for me. The crucial thing here is that the device can run on a small battery - AA or perhaps a button cell. In which case, might it be sensible to have the PIR+controller separate to the cam/wifi controller?Does a suitable microcontroller spring to mind? I've played with arduinos but find the various shields a little clumsy and thought better options might exist. There are so many Atmel and TI options out there, it's a bit bewildering.Any advice much appreciated!Thanks.Maw.

author: nctnico
author_rank: Super Contributor
timestamp: April 26, 2013, 01:31:18 pm
content: If you are going for low power then the MSP430 from TI is the best choice. The MSP430 has been specifically designed for low power from the start.

author: eliocor
author_rank: Unknown
timestamp: April 26, 2013, 02:30:17 pm
content: are you sure regarding power requirements of your PIR sensor?To my knowledge they typically require from 0.5mA to 2-3mA (some rarer devices require only 100uA).I'm not so sure how long your battery will last (sensor must always be on)...
Which multiple satellite GNSS receiver has best fix under restricted sky view - Page 1
Forum section: electronics / projects

author: Wilson__
author_rank: Frequent Contributor
timestamp: July 12, 2024, 11:41:19 pm
content: Which brand and model GNSS receiver can recceiveALL satellites visiable in Europe.Able to givereasonably accuraceposition (10 to 15 meters) when sky view is restricted.Signal is weakin-door of Europe style 3 stories home (with little steel bar inside wall)Best isreveiver and antenna in one module. Cell energy limited, can work willlow wattage.Many thanks

author: uer166
author_rank: Super Contributor
timestamp: July 13, 2024, 02:39:28 am
content: I've had good experiences with UBlox M10S, it's multi constellation and optimized for low power. It is able to retain (but not aquire) a fix between 2 5-story concrete buildings in my tests.
Which of 3 SPICE models to use with LTSpice? - Page 1
Forum section: electronics / projects

author: 741
author_rank: Frequent Contributor
timestamp: May 29, 2022, 12:54:01 pm
content: Here (https://www.vishay.com/mosfets/list/product-62806/tab/designtools-ppg/) are 3 models for the SQJ407EP PMOS device.There are 2 'PSpice' and 1 HSpice' model.SQJ407EP_HS_REVA.TXTSQJ407EP_PS_RC_REVA.TXTSQJ407EP_PS_REVA.TXTMy guess is I use PSpice. The larger model seems to incorporate some temperature modelling (?)I am using this device as an on/off switch carrying 5A. The switch is used infrequently (on or off according to user selection), and so long as it switches fully on or off, I think I do not need to use the more elaborate model.

author: Ian.M
author_rank: Super Contributor
timestamp: May 29, 2022, 01:44:13 pm
content: SQJ407EP_HS_REVA.TXT uses the non-standard MOSFET CAPOP parameter which LTspice doesn't support. *AVOID* !!!SQJ407EP_PS_REVA.TXT appears to be a 'vanilla' SPICE3 subcircuit model consisting of four active parts (two level 3 MOSFETs, a diode and a unit gain voltage controlled voltage source), two fixed sources and a sprinkling of passives. Its likely to be your best bet for LTspice.SQJ407EP_PS_RC_REVA.TXT uses the obsolete voltage dependent current sourceCode:Gname node1 node2 VALUE {<expression>}syntax which is an alias of the behavioral current sourceCode:Bname node1 node2 I=<expression>LTspice *should* handle it but may misbehave if there's any sort of feedback loop in the thermal modelling subcircuit. Its also likely to be significantly slower.
Which ON/OFF controlled Offline Flyback is best? - Page 1
Forum section: electronics / projects

author: ocset
author_rank: Super Contributor
timestamp: December 27, 2017, 04:17:44 pm
content: Hello,The attached are two Offline (230VAC) , isolated, 15V,2W Flybacks.They both use ON/OFF control with the UCC28C44 controller.The feedback isolation is done by the digital isolator SI8710.Which Flyback would give the best Vout regulation?Do you agree that the one with the BJT current source regulation would give tighter Vout regulation?SI8710 digital isolatorhttps://media.digikey.com/pdf/Data%20Sheets/Silicon%20Laboratories%20PDFs/Si87xx.pdfUCC28C44http://www.ti.com/lit/ds/symlink/ucc28c44.pdf

author: station240
author_rank: Unknown
timestamp: December 27, 2017, 05:15:11 pm
content: One mistake in both circuits, you need to power VDD (pinon the SI8710 from the aux winding not the secondary. As it is you have a diode junction between primary and secondary halves, this defeating isolation.
Which op-amp/ADC driver after a high speed Mux? - Page 1
Forum section: electronics / projects

author: splin
author_rank: Frequent Contributor
timestamp: January 08, 2015, 05:54:35 pm
content: I'm looking for an amp to drive a 16-bit ADC which follows a mux operating at 10MHz. Given the ADC's 20ns S/H acquisition time and allowing 10ns for the mux to switch and settle, that leaves only 70ns to settle to 16-bit accuracy (.00153%). It will be operating at 3V but that could be increased to 5V if necessary. From an Analog Devices article on multiplexing, the BW would need to be 3.75 x the 5MHz Nyquist rate = 18.75MHz. The slew rate required is > 3V/70ns = 43V/us.The inputs are all low frequency AC signals but there are a lot of channels so it would be too expensive to provide the gain prior to the muxes and would have the problem that the gain errors over temperature would differ for every channel.To make things more difficult I'd like the amp to povide at least x20 gain and preferably x60. Is this realistic within a budget of less than $2 or $3 for the op-amp?One option would be to have two amps providing the gain prior to a final 2:1 mux feeding the ADC (or an amp driving the ADC) which would increase settling time to 170ns but still has the problem of gain variation between the two channels. Another would be to spread the gain over two amps in series but that would presumably require a track and hold between them at extra cost, complexity and gain errors.If the one amp solution is not feasible what about the two op-amp options?To get the best performance out of the ADC it needs to be driven differentially, so is single ended to differential conversion possible as well? Obviously it would cost more but again the settling time is the problem.I'm not sure which op-amp parameters, apart from slew-rate, settling time and noise performance are relevant for this application. In any case the settling times in the datasheets for high speed amps are typically at low gains of x1 or x2. Is there a simple way to calculate how it changes with gain?Can anyone provide any good app note/article references which discuss this issue?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 08, 2015, 11:46:25 pm
content: Knowing more about the nature of your signals and processing use might be helpful to figure out better things...Might be worth to try putting the mux switches within the op-amp loop(s), so the settling includes the switch. Otherwise you have the hard limit of capacitance + switch resistance (unless you want to try adding a peaking coil there or something).Tim
Which processor to use - Page 1
Forum section: electronics / projects

author: wigman27
author_rank: Regular Contributor
timestamp: April 17, 2014, 08:07:27 am
content: Hi all,I have a project coming up that will require me to have very simple IO capabilities and the main requirement will be to log information to a web server (via wifi) and also have an SPI or UART interface. I must confess that I have been an atmel fan up until now however I don't think they will be the best for this project.I have had a look at Beaglebone Black and it seems to be the pick for me at least but it is grossly overpowered for this project. It has also been suggested that I maybe able to use the STM32 processors.I must also confess, I am not a programming genius so any thoughts would be really appreciated on the best processor to use and where I can learn to code itThanksLee

author: hagster
author_rank: Frequent Contributor
timestamp: April 17, 2014, 08:34:55 am
content: Have a look at GHI Electronics boards. They run MS .net micro framework. And have WiFi, SPI, UART, SD cards etc as well as all the libraries needed to for IP protocols etc.Beagle bone black would do it, but it's overkill and slow to boot.

author: han
author_rank: Frequent Contributor
timestamp: April 17, 2014, 08:41:31 am
content: Simple answer: Buy cheap ruter and google: OpenWrt

author: gocemk
author_rank: Regular Contributor
timestamp: April 17, 2014, 09:15:55 am
content: Quote from: wigman27 on April 17, 2014, 08:07:27 amGo for the STM32. Buy the STM32F3 Discovery Board (around 20$) and you are good to go. STM32F303 has pretty much every peripheral you need, inlcuding SPI and UART. Also ST provides libraries for every peripheral on that chip, and they are extremely easy to use. For development you can use free tools such as CoIDE on Windows, or you can use Keil and IAR with code size limit up to 32KB.Hope this helps.
Which side to PWM in a H-Bridge, High side or Low side? - Page 1
Forum section: electronics / projects

author: mfeinstein
author_rank: Contributor
timestamp: November 19, 2012, 05:51:58 am
content: Hi,As the title sugests, I am working with a DC Motor, using a H-Bridge and I am wondering, is it there a better side to do the PWM? I believe the high side is better, because the current will flow through the lower part flyback diodes and TVSs in the Off cicle of the PWM, which means, the H-Bridge TVSs will help the MOSFETs diodes with the current circulation. Is there something else I am missing?Thanks!

author: Arlo1
author_rank: Contributor
timestamp: April 17, 2016, 06:42:33 pm
content: PWM both sidesUsing center aligned PWM you can make things heat up evenly. ON each side of the coil you do PWM.Say one side of the motor has PWM on the high side and the other side is PWM of the low side.1 PWM cycle will will look like this. M1 high side turns on then M2 low side turns on (current starts to increase) M1 High side turns off (current decreases) M1 turns back on (current increases) M2 turns off (current decreases)Using that method you get 1/2 the current ripple with the same PWM frequency you would use in a controller only running PWM on 1 side.When you PWM the High or Low side the opposite side will be responsible for the freewheeling currents.IE high side turns on then current flow starts then high side turns off and the current can't stop from the inductance in the circuit (mostly motor) and the Low side diode takes the current flow. BUT if you PWM the low side the current will ramp up in the opposite direction and when the Low side turns off the current will flow in the High side diode.synchronous rectification will turn the mosfet on that the freewheeling are flowing though briefly to reduce the diode heating.So to complicate things more...Here is what a PWM cycle will look like now.M1 High side turns on M2 low side turns on (current starts to increase) M1 high side turns off but after a small dead time to prevent a pass though M1 low side turns on to allow current to flow thought the low side mosfet rather then the diode.(current is decreasing) Then M1 low side turns off and after a dead time then M1 High side turns on again (current starts to increase again) The M2 low side turns off and M2 High side turns on after a dead time (current starts to decrease) then M2 High side turns off and M1 High side turns off.

author: sarepairman2
author_rank: Frequent Contributor
timestamp: April 17, 2016, 08:29:15 pm
content: by varying the phase shift to the top and bottom you can control power.
Which SMD tactile switch is the best? - Page 1
Forum section: electronics / projects

author: dusan
author_rank: Regular Contributor
timestamp: September 29, 2024, 11:14:36 am
content: Whichbearsmd tactile switch is the best? If you could have only one jellybean smd tactile switch?

author: tooki
author_rank: Super Contributor
timestamp: September 29, 2024, 03:15:57 pm
content: What is the purpose of a question like this? No one part is ever ideal for everything, so the "best" isthe one that fits the needs of the current project.

author: ataradov
author_rank: Super Contributor
timestamp: September 29, 2024, 03:21:14 pm
content: For basic buttons on the development PCBs where the button would be pressed directly, I personally use H everywhere. It has a nice tactile feel and biggest area of the moving part.If the switch is going to be pushed by something else in the design, then pick whatever fits the design requirements.
Which software was used to draw this diagram? - Page 1
Forum section: electronics / projects

author: Red_Micro
author_rank: Regular Contributor
timestamp: May 10, 2021, 03:49:09 pm
content: Does anyone know which software was used to draw this diagram I randomly found on the internet? (See attachment)

author: alexanderbrevig
author_rank: Frequent Contributor
timestamp: May 10, 2021, 04:16:41 pm
content: Looks hand drawn to me. GIMP og Inkscape (or equivalent) maybe?

author: voltsandjolts
author_rank: Unknown
timestamp: May 10, 2021, 04:21:01 pm
content: I would use inkscape for that sort of thing. It's well worth learning the basics of using it. And its free. (inkscape.org)But the fonts in the picture hint it might be something more microsofty, like MS Visio.

author: Nominal Animal
author_rank: Super Contributor
timestamp: May 10, 2021, 05:27:37 pm
content: I useInkscapeandDiato draw such diagrams. Examples:When I have textual data/database/CSV/program output I want to visualize into a graph/net/diagram, I useGraphvizto convert the node and edge descriptions to an SVG image, then either finesse it in Inkscape or redraw in Dia. For example:All of these are free and open source, and available (as both downloadable binaries as well as source code) for Windows, Mac, and Linux.

author: SiliconWizard
author_rank: Super Contributor
timestamp: May 10, 2021, 06:39:06 pm
content: If you're looking for open-source solutions, what has been mentioned above is pretty much it.I used to use Dia, but it hasn't been updated in years now and I find it pretty annoying these days. I now mainly use yED for diagrams:https://www.yworks.com/products/yedBoth can export to EPS and SVG, among other formats, so that's good for publishing.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: May 10, 2021, 06:57:37 pm
content: Don't forget if you want to install gigabytes of slow-loading and frustrating software, there's Libre Office Draw too.

author: Benta
author_rank: Super Contributor
timestamp: May 10, 2021, 07:13:28 pm
content: My first guess would be Powerpoint.

author: ajb
author_rank: Super Contributor
timestamp: May 10, 2021, 07:51:13 pm
content: That looks like it could have been drawn in just about anything from MS Paint to Photoshop.Quote from: SiliconWizard on May 10, 2021, 06:39:06 pmI will second this. yEd has been tremendously useful for me, though not without its quirks.
which solution has the largest outlet gasflow? - Page 1
Forum section: electronics / projects

author: daisizhou
author_rank: Super Contributor
timestamp: February 23, 2025, 04:53:48 am
content: Hallo everyone.I plan to make a gas source，I drew a sketch，At normal temperature and pressure, the medium is air,I want maximum gas flow at the outletquestion:1、Is solution 2 definitely better than solution 1?2、If I want to optimize solution 2,Where is the best place to move the turbine fan?(Move left or right?)3、If I want to optimize solution 2，Would reducing the angle between the turbofan and the ducting provide any real improvement?thanks help
Which Specs To Look For When Buying Differential Probe - Page 1
Forum section: electronics / projects

author: bostonman
author_rank: Super Contributor
timestamp: September 27, 2022, 06:07:44 pm
content: I'm looking to buy a differential probe and looking at a Micsig one but uncertain which specs are important.I've seen a few models, one is 700V and another is 1300V. Most likely going with 1300V will provide better safety, but the attenuation is more (50x / 500x).If I go with higher attenuation, this means I need to increase the scope V/div and may not see certain signals.My guess is three main specs are important: voltage, rise time, and attenuation.Is this correct or do other important specs matter too?

author: PartialDischarge
author_rank: Super Contributor
timestamp: September 27, 2022, 06:13:14 pm
content: The specs that are important depend on the application of the tool

author: bostonman
author_rank: Super Contributor
timestamp: September 27, 2022, 06:15:38 pm
content: True.... but for a universal diff probe that would be exclusive to AC circuits (and not exceeding 120) and non-grounded stuff.I don't see a future need to worry about rise time on digital circuits since those are usually isolated through the power supply.

author: jonpaul
author_rank: Super Contributor
timestamp: September 27, 2022, 08:38:09 pm
content: most importantCMRR common mode rejection ratio vs frequencyprobes and connectorspower supply isolationinput protectionWe used Yokogawa and Tektronix differential probes, but found these to be easy to damage physical or electronicly, and of very limited benefitsJon

author: bostonman
author_rank: Super Contributor
timestamp: September 28, 2022, 11:50:25 pm
content: Silly question, so if I go with the 1300V that is 50x / 500x attenuation, this means a 50v signal will look like 1V on the scope?If this is the case, then simple digital signals (0-5v) will need a scope that can have plenty of amplitude.
[Answered] Which style connectors are used on a Trueposition GPSDO board? - Page 1
Forum section: electronics / projects

author: rbm
author_rank: Regular Contributor
timestamp: November 10, 2018, 09:43:04 pm
content: I'm selecting pre-made cables for patching the antenna, and 10 MHz / 1PPS outputs on a TruePosition GPSDO board to panel-mount BNC connectors on my enclosure. I have the later model board with its part number beginning with 111603. I want to make sure that I am getting the right connectors, so anyone who has built this board into an enclosure, can you please confirm this information for me?[Updated Nov. 11] Received an answer through another channel.Late Model Board with Part Number beginning 111603Antenna:Takes SMB female plug to BNC female panel-mount jack10MHz outputs (2):MMCX-J male plug to BNC female panel-mount jack1PPS output:MCX-J male plug to BNC female panel-mount jackEarly model boards with Part Number beginning 0616220Antenna:Takes SMB male plug to BNC female panel-mount jack10MHz outputs (2):MCX-J male plug to BNC female panel-mount jack1PPS output:MCX-J male plug to BNC female panel-mount jack

author: cdev
author_rank: Super Contributor
timestamp: November 10, 2018, 11:13:55 pm
content: I don't know what they are but Ive successfully usedMCXconnectors with them "in an unsupported manner"

author: rbm
author_rank: Regular Contributor
timestamp: November 10, 2018, 11:30:17 pm
content: Thanks, cdev. I'm basing my list on info that was provided in the Packrat PDF file, but I have doubts. Don't get me wrong; It's a great document and I trust it. I just want to verify the information in it.

author: cdev
author_rank: Super Contributor
timestamp: November 11, 2018, 12:00:50 am
content: If you know the proper plug is right, get that.I just found the MCX, which I already had, worked okay- but itsnotthe proper plug.Its ugly, its very ugly, but its available and should last if you enclose the device and don't repeatedly remove/insert them.Because MCX connectors are really delicate. Not quite as bad as u.fl connectors but close.