hybridfree/eevblog-posts huggingface dataset:
F-Parts: My new component organisation program - Page 1
Forum section: electronics / projects

author: Rager
author_rank: Contributor
timestamp: March 08, 2017, 09:53:09 am
content: Hey everyone!I looked al over the internet and could not find a good component organisation program. So after quite some time I desided to Do It MyselfI think that it turned out quite well and I put a lot of work and time into it. For that reason I think it would be a waste to not share it:https://github.com/RFgermany/F-PartsI hope you like it!Florian

author: Zom-B
author_rank: Regular Contributor
timestamp: March 08, 2017, 06:08:55 pm
content: Funny, because yesterday I was discussing about component inventory programs with a coworker.There are some (e.g. partkeepr), but they all have in common that every part is exactly tracked, like if you have 457 of a resistor, you'd enter 457 and hope everyone updates it dutifully (not gonna happen). Moreover we experiment a lot so often parts are tried and put back, or not put back, or left on the tables until a cleaning round and then into the trash because they're cheaper than chopsticks.What would be better than exact count would be a metric like: [none, very few, few, plenty, too much]. Then each part would have a flag 'keep stock' or something, and the program could compile a BOM of all 'keep stock' parts that have <= 'very few' in stock. As for feedback:Cool feature of adding files. Haven't thought of that before.Add context menu for categories/tree editing instead of buttons,Allow add/remove columns, because I won't need Vmin/Vmax but would like 'Package',Add SearchAdd Ctrl+F shortcutAdd Parametric filterAdd a picture column that shows as a micro-thumbnail and zooms when clicking (see image of a program I once made). Kudos if it automatically finds missing images on common shop sites.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 08, 2017, 07:36:50 pm
content: Hmm, interesting....But with a name like that, why didn't you go for simply: "Farts"?Tim

author: Rager
author_rank: Contributor
timestamp: March 08, 2017, 09:36:45 pm
content: Hey there and thanks for the feedback!It is the first time for me to program something like that, so there is l lots of room for improvements. Maybe I find time to implement some of the ideas 😄 By the way. Columns ( properties) can be added, removed our renamed with the add, remove, rename properties buttons. And parts can be filtered by the search bar I the upper right cornerBest regards,Florian
F5152-1 info - Page 1
Forum section: electronics / projects

author: nonsuchpro
author_rank: Contributor
timestamp: November 24, 2014, 08:02:33 am
content: Hello all.New to the forum. Been watching the videos for about a year now. Great stuff!!I've acquired a component that I can't find any info for. It's has 6 pins and is labeled F5152-1 on all of them, all the other numbers change. Anybody have any idea what it is? I'm thinking an op-amp or some kind of darlington but have no clue.Thanks in advance!Rob

author: philpem
author_rank: Frequent Contributor
timestamp: November 24, 2014, 12:58:02 pm
content: The "F" looks like a manufacturer's logo. Fuji Electric or Fairchild perhaps? Have a look at a semiconductor manufacturers' logo website and see if you can match it up.http://www.elnec.com/support/ic-logos/?method=logomight be worth a try, orhttp://www.siliconinvestigations.com/logos/logos.htmorhttp://www.classiccmp.org/rtellason/logos/semiconductorlogos.html.That leaves 5152-1 as the part number.Given the 3:3 pinning, my bet is that they're dual matched transistors, possibly JFETs. If you've got a semiconductor analyser (Peak Atlas DCA or similar), you could try connecting the sets of three pins in turn (first the set on one side, then the other). If they're FETs, they should read similarly."225" and "227" (read on a few of the parts) is probably a date code, but I can't remember how to decode the old 3-digit codes. It's either YWW or WWY (year-week or week-year) and the year is the last digit of the year. Realistically, YWW is most likely, and I'm guessing 1980s, which would put them at the 25th and 27th week of 1982. That's just a guess though!

author: SeanB
author_rank: Super Contributor
timestamp: November 24, 2014, 06:15:00 pm
content: Logo is Precision Monolithics, now Analog Devices.Can't find the 5152, probably well obsolete now, but try to look here for datasheets for similar devices.http://www.analog.com/en/special-linear-functions/matched-transistors/products/index.html

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 25, 2014, 03:11:46 am
content: What was Ferranti's logo..?Agree, looks like a dual transistor; if nothing else, you can ohm it and see. Likely candidates: NPN, PNP, N-JFET.Tim

author: SeanB
author_rank: Super Contributor
timestamp: November 25, 2014, 07:45:19 pm
content: I have some 2N2223 transistors in the same package. the pinout should be the same, so you can just use this to check them as individual transistors.

author: nonsuchpro
author_rank: Contributor
timestamp: November 29, 2014, 12:48:51 am
content: Thanks for the replies, much appreciated!
facepalm patents - Page 1
Forum section: electronics / projects

author: madires
author_rank: Super Contributor
timestamp: February 20, 2017, 02:01:07 pm
content: While looking at CLDs I came acrosshttp://www.google.de/patents/US8766548which is about using a bridge rectifier and CLDs for driving LEDs from mains. What an ingenious invention!Can you top this?

author: CatalinaWOW
author_rank: Super Contributor
timestamp: February 20, 2017, 05:19:27 pm
content: I once spent time reviewing corporate patents and doing prior art searches. There are so many stupid patents. It is demeaning to those who actually have a clever idea.Patents on using a chimney to clear smoke from a flaming device.A patent on putting handles on a wheelbarrow.The patent on the personal computer (Imagine, taking a cpu and adding a storage device and a display device. Who could have thought of that?)

author: JPortici
author_rank: Super Contributor
timestamp: February 20, 2017, 07:27:34 pm
content: Quote from: madires on February 20, 2017, 02:01:07 pmnot electronics, but my dad's new byke has a ring bell with "patent pending" written on it. i think i can provide a photo

author: Siwastaja
author_rank: Super Contributor
timestamp: February 22, 2017, 09:08:21 am
content: Practically all (or 99%) of the patents. This shouldn't be surprising, really.Patents are exactly used for this - purely for blackmail and trolling, and to keep lawyers in business. This has been the only real usage for patents for at least 40-50 years, if not longer.We all have the eye opening moment when we first come into realization of this. For me, as a kid, it was reading the Microsoft patent covering double click.So, from a designer viewpoint, patents only serve one purpose: they are a sanity lithmus test. When you meet a potential business partner who starts talking about patents in a serious sense that they serve some other purpose than what I stated above, you know they are totally and utterly clueless about anything, and you need to run before they accidentally destroy everything in legal shit they don't understand.
FACP(Fire Alarm Control Panel) interface, phy, ideas - Page 1
Forum section: electronics / projects

author: flodins
author_rank: Contributor
timestamp: March 16, 2013, 10:56:27 pm
content: Hello,I'm looking for any information about interface, phy in double loop addressable fire alarm systems. Can anyone help?This interface has two wires. Aensors are powered and comunicate by voltage modulation and current pulses in one cable. They are addressable.

author: SteigsdB
author_rank: Contributor
timestamp: March 17, 2013, 12:38:35 am
content: Check with the folks over onhttp://cocoontech.com. There a few guys there that are really ace with this stuff.
Faded e-ink display - Page 1
Forum section: electronics / projects

author: Kemme
author_rank: Contributor
timestamp: October 25, 2024, 12:54:00 pm
content: I have nrf 52DK evaluation board connected to Waveshare e-paper shield and 2.66 inch Waveshare e-ink display.Everything worked fine and suddenly everything I try to display looks faded.1. I made no changes in program2. I have 2 evaluation boards and 5 displays so and they all act the same so I believe that the problem is somewhere else.3. The problem seems to be the e-paper shield. I measured all the connections, resistors and caps and I struggle with finding the reason of this behaviour.Here's a short video. As you can see during the refreshing for a split second the screen looks clear but after the refresh it's faded again. Have you got any idea?https://streamable.com/xo3eq3

author: aldi
author_rank: Contributor
timestamp: October 26, 2024, 10:02:26 am
content: Check the power supply (driver module) with a scope, maybe the voltage dips during this stage of the refresh.
fail to replace nikon EN-El14a battery cells - Page 1
Forum section: electronics / projects

author: wawinfo
author_rank: Contributor
timestamp: December 10, 2023, 07:24:00 pm
content: I have 2 Nikon EN-EL14a battery that I decided to change their cells instead of buying new clone ones. First I checked every battery output and they were about 8 volts but their capacities are very low. then I replaced their internal cells with new Nokia BL5B battery that is equal in size and can be placed in battery enclosure. but after soldering pin correctly there in no output. I am sure that pins and soldering is OK and have checked that many times. My question is : Can anyone confirms that this can be done? or is there any possibility that may battery has some protocol for detect original cells? or is there any trick that must be done for this replacement?Tanks a lot.
Failing Surge Immunity test where TI's TIPD126 design passes - Page 1
Forum section: electronics / projects

author: yashrk
author_rank: Frequent Contributor
timestamp: November 20, 2020, 03:48:52 am
content: Hey everyone,We are having issue in passing surge immunity test. I am using XTR117 in transmitter product by referring TI's CerTIfied design TIPD126.We have used same component as shown in the TI's design but we were failing the surge immunity test. After the failing at 500V surge we tried using two SMBJ40CA (TVS diode) in parallel this helped us pass the 500V test but still we weren't able to pass the 1KVor 2KV test. The diode is failing short, protecting the XTR117 and rest of the circuitry. We are working with 24V DC input. We are using XTR117's internal voltage regulator to generate 5V and external LDO for the 3.3V rail.We are not sure what is going wrong.Our schematicTI's schematicEdit: 2kV test is not applicable just up to 1kV

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 20, 2020, 06:13:44 am
content: SMBJ40CA is rated 9.3A maximum peak pulse, 10/1000us surge. For two in parallel to survive at 500V surge, implies a generator impedance above (500 - 64.5V) / (2 * 9.3A) = 23.4Ω. This seems improbably high (20 ohms is typical for TNV circuits?), and shows you have no hope of passing 2kV with this strategy.Does that include common mode, by the way? Is your circuit isolated, or is there protection elsewhere..?Have you considered an SMDJ or 5.0SMDJ series part (or any mfg equivalents)? Have you considered a lower voltage rating? Have you considered a snapback device (SIDAC or GDT)?Or a MOV, with additional steps taken to protect the transistor and IC from the higher clamping voltage.Tim

author: yashrk
author_rank: Frequent Contributor
timestamp: November 20, 2020, 11:56:25 am
content: Thank you for your answer Tim.Quote from: T3sl4co1l on November 20, 2020, 06:13:44 amYes our circuit is isolated we only have +24V and GND from isolated power supply. Also mistakenly I mentioned that we tested at 2kV but we only need to go to 1kV for Surge and 2kV for EFT.We need some resource to properly size our TVS diode. The voltage rating seems right as we didn't damage the XTR117 IC. Also, as you mentioned the impedance seems low as per the standard we should have 42ohm impedance for signal lines (4-20mA being the signal line).The question remains then why TI's design passed the test?Quote from: T3sl4co1l on November 20, 2020, 06:13:44 amAs this my first design which is going through the EMI/EMC testing I didn't wanted to do anything different apart from the things mentioned in the application note. So I didn't considered any other protection device.
Failure in buck switching voltage regulator (LM2574) - Page 1
Forum section: electronics / projects

author: alek
author_rank: Newbie
timestamp: May 15, 2017, 06:52:11 pm
content: Hey guys and gals,I was prototyping a buck regulator circuit (per reference circuit shown in a datasheet for an LM2574-3.3http://www.ti.com/lit/ds/symlink/lm2574.pdf) and had it fail after several turn on cycles. I did diverge from the ref. schematic by using a larger output cap (1000u instead of 220u - had them lying around) and by using an 1N4148 instead of the suggested 11DQ06 (once again, what I had lying around and I am only drawing 100mA of current).While I was playing around looking at its turn on transients, the LM2574 failed - so now I'm trying to figure out what was the culprit. For your reference the input is unregulated 35VDC (rectified and filtered 24VAC) and the circuit was being tested unloaded. I think I actually captured the turn on cycle at which it failed. I had the scope hooked up to LM2574 output pin on single shot. That time instead of many pulses, I just had it saturate to somewhere around 20-30 V over several milliseconds. Cycled the power again and then there was no pulses coming out of the LM2574. Output voltage was then 0.5 V. I checked the diode and it's still functional. Checked the output cap and it's still good. I even hooked up a 3.3V supply to the output to see if anything would fail catastrophically - nothing, PS was outputting 3.3V at 1mA.Any ideas? Any help would be greatly appreciated - I'm somewhat lost here.

author: Niklas
author_rank: Frequent Contributor
timestamp: May 15, 2017, 07:15:46 pm
content: It could be due to too low switching speed of the diode. It is fast for low currents, but slower with higher current. When the regulator turns off the switch transistor, and the diode is not fast enough to turn on, then the inductor can create a voltage transient high enough to breakdown the switch transistor. The input voltage is already close to max, so your safety margin is low.Google "diode induced failure linear". Linear has both an appnote and a video clip illustrating this issue.

author: alek
author_rank: Newbie
timestamp: May 17, 2017, 08:23:25 pm
content: After replacing the diode with an appropriate one and blowing yet another regulator I found my rookie mistake of the week: over-voltage due to inrush current in a hefty 24V transformer (attached).Looks like I need a bigger cap + TVS on input.
Fairchild 1F30SD data sheet - Page 1
Forum section: electronics / projects

author: IconicPCB
author_rank: Super Contributor
timestamp: March 07, 2019, 10:53:22 pm
content: Looking fo a data sheet or any information at all on a Fairchild 1f30sd.Tried google... no joy any references to 1f30sd point to distributors of old and obsolete gear with offers of data sheet upon request... however i do not need to purchase materials.. am trying to understand what the component is.ON semiconductors, the new owners of Fairchild , are as useful int his regard as the tits on a bull.

author: amyk
author_rank: Super Contributor
timestamp: March 08, 2019, 02:26:08 am
content: Could you post a picture?

author: IconicPCB
author_rank: Super Contributor
timestamp: March 08, 2019, 02:45:13 am
content: Certainly... it is the SMD component located between two ferrite core transformers on either side , a blue electrolytic capacitor and axial power resitor in the right half of the image.

author: amyk
author_rank: Super Contributor
timestamp: March 08, 2019, 01:02:19 pm
content: SMD markings contain date/batch codes too, so you are unlikely to get results by searching for the full mark.

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 08, 2019, 04:25:51 pm
content: Yeah, no datasheet to be found... and yes I doubt any of those brokers will send you a datasheet unless you place an order (and I'm not even sure they really have one for this).I'm just guessing that it's probably a diode (single or dual). You could try and confirm this with some simple testing.
Fairchild 777 dualbeam scopen info - Page 1
Forum section: electronics / projects

author: PA4TIM
author_rank: Super Contributor
timestamp: December 13, 2012, 02:24:46 pm
content: I'm restoring a Dumont/Fairchild 777 4 plugin, dual beam 100 MHz scope from the late 60's.I found manuals for some of the plugins but not for the psu / display unit ( or mainframe as you like)It looks a bit like a solid state version of the Tek 556, it is allmost as big but then modtly silicium and nuvistors.The PSU looks like the one in a 766 but this one has three adjustments the 766 does not have. -50, +50 and +100 balans. And I have no clue how to adjust them and their purpose.Problems found now is a few totally dead filter caps ( electrode ripture) and as a result no stable -50V Vref and a huge ripple.One vertical plugin is dead. No respons on vertical position, beamfinder or input but that should be rather easy to fixbecause i have the manual from that plugin.Does anyone has info ?

author: PA4TIM
author_rank: Super Contributor
timestamp: December 19, 2012, 06:12:35 pm
content: Is this scope realy so rare that no one knows it ?
Fake ST SGS Thomson Part (GS-R405S) - Page 1
Forum section: electronics / projects

author: andybarrett1
author_rank: Regular Contributor
timestamp: January 25, 2019, 03:25:40 pm
content: Looking for a little help.We have purchased some GS-R405S from a reputable seller here in UK.I have the feeling with have both been duped by his seller.(1) There is a label with the makers details on the top of the device ... Not screen printed !(2) The tolerances are miles out for the pin spacing etc. Over 3mm(3) A couple have bounced back on me now as well as a fail on the bench(4) Have seen china sellers on ebay selling same batch / date code on ebay again on the labelJust looking to see what others thinkThank you for readingBRAndy

author: TrickyNekro
author_rank: Frequent Contributor
timestamp: January 25, 2019, 04:04:31 pm
content: You know that´s an obsolete part so as supplies are getting low...The problem is also that´s it´s potted... not going to be easy removing all that...But it might be parts that were indeed marketed for the Chinese market and are just reappearing, try to save non-function-critical costs isn´t that crazy,especially if they try to sell in a competitive market.About the tolerances, are you absolutely sure it´s the same variant? It could be the same part but not the same variant.Try to de-pot the failed one! The devil is in the details, meanwhile contact your seller, things like that happen all the time.
Fan controller with over heat warning - Page 1
Forum section: electronics / projects

author: oliver602
author_rank: Regular Contributor
timestamp: April 28, 2015, 11:49:13 pm
content: This is a replacement for an 'alarm unit' that went faulty in a 97 Honda Fourtrax ATV.I made a simple circuit which takes the input from an oil temperature sensor. One comparator for controlling a fan and one for an overheat light. This was made from parts I had to hand. If I was to design this again I'd perhaps use a quad comparator instead of the two op amps and 555. My knowledge on such parts is very limited.If you were designing this from scratch which parts would you use.I'm particularly interested in what you would do for input protection and filtering. Supply is pretty noisy.Is it normal behaviour for a 555 in one shot to trigger once on power up? I'm using this behaviour too test the light bulb.

author: oliver602
author_rank: Regular Contributor
timestamp: May 02, 2015, 04:21:16 pm
content: rev b
Fan induction motor ON/OFF modulation - is it OK or Harmfull for motor ? - Page 1
Forum section: electronics / projects

author: Miyuki
author_rank: Frequent Contributor
timestamp: May 14, 2019, 06:33:06 pm
content: Hi folks,I have here air system fans and need to regulate them (simple induction motor with run capacitor)Question is can I use slow speed ON/OFF modulation and what frequency is best. Control system can go up to 10Hz. But full phase control is not achievable, without external hardware, now they are connected with SSR controlled by logic signal.At 5Hz fans run steady even at low 10% duty and make little audible switching noise but produce some shaking to mounts as they are relative strong 80W radial fans with big inertiaNoise is not a problem but I'm afraid of that vibrations can it damage motor and bearings ?

author: capt bullshot
author_rank: Super Contributor
timestamp: May 14, 2019, 06:40:20 pm
content: I've done this control scheme for water pumps in the central heating system - never noticed any issues. Afaik, for some time this was the "state of the art" method to control these pumps. They also were induction motors with capacitor. For the same concern as you have (movement and vibration), I had manually adapted the modulation scheme to avoid obvious mechanical resonant points.

author: james_s
author_rank: Super Contributor
timestamp: May 14, 2019, 08:10:43 pm
content: The only concern I'd have is if they're the type of induction motor that has a centrifugal starting switch, you don't want it slowing to the point that the starting switch is repeatedly cycling and activating the starting winding. You also might want to check the current draw, many types of motors draw considerably higher current while trying to accelerate up to speed than they do steady state. Otherwise it shouldn't be an issue.
Fan life at 4 deg C - Page 1
Forum section: electronics / projects

author: Circlotron
author_rank: Super Contributor
timestamp: May 09, 2019, 01:38:10 am
content: Back on 2nd November 2002 I put a 90mm Sunon ball bearing fan inside the refrigerator, aimed at the evaporator panel for the purpose of improving the heat transfer. That, and a pair of fans at the bottom of the condenser behind the fridge improved the compressor duty cycle from 60% to 31%. Halved the power consumption. But that's another story. The point is, the fan inside the fridge is still going just fine after 144,768 hours 24/7 in a 4 deg C ambient as of today. We did some life tests of fans at work some time ago and at 70 deg C some would only last a few months. Temperature sure seems to make a difference!

author: wraper
author_rank: Unknown
timestamp: May 09, 2019, 01:44:25 am
content: In hot environment sleeve bearing fans will often fail within a few weeks. On the other hand I use 120x38mm 230V Sunon fans with ball bearings in a place with above 60oC temperature. They run fine for 5+ years 24x7 then bearings start emitting noise. Stupid manufacturer for some reason used Sunon fans with sleeve bearings, they don't last even a year.

author: OM222O
author_rank: Frequent Contributor
timestamp: May 09, 2019, 01:24:35 pm
content: You might want to look into maglev fans. they use a magnetic field to levitate the blades so there isn't a real bearing to speak of. corsair has some but I believe other manufacturers have also made similar ones.

author: wraper
author_rank: Unknown
timestamp: May 09, 2019, 02:15:07 pm
content: Quote from: OM222O on May 09, 2019, 01:24:35 pmWhatever they claim, ball bearing fans are more reliable, especially at higher operating temperatures. Also, they don't levitate blades. It's just a fancy sleeve bearing. All magnet does is pulls shaft to one side so it does not bounce and move depending on fan orientation.https://strawberry-linux.com/pub/VapoBearingMaglevTechnology.pdf

author: wraper
author_rank: Unknown
timestamp: May 09, 2019, 02:18:26 pm
content: There is also fluid (hydro) dynamic bearing type. Also fancy sleeve bearing. Shaft has grooves to keep lubrication in.https://www.nidec.com/en-NA/technology/capability/fdb/. However it's really good if done properly. That's why they are used in HDD.
fan on/off control methods on a sailboat  - Page 1
Forum section: electronics / projects

author: jmeredith
author_rank: Newbie
timestamp: August 01, 2019, 01:23:07 pm
content: hey guys, I have a few Caframo fans (https://www.caframolifestylesolutions.com/product/marine/sirocco/) with single pushbutton power (and a timer circuit) that have been acting up... I opted to pull the guts out of one and just throw in a simple toggle switch to allow power to the fan motor... on the second, I'd like to see if I can use the existing PCB items to make the on/off momentary switch work as on/off... I have seen several examples of how this can be done with a few 2N3904s and a mosfet. on the fan's PCB there is KIA65N06, a 10uf cap, 47uf cap, 2 SS36 diodes, DA3664 voltage regulator, and a gaggle of SMD resistors (511s, 2701, 2702, 105, 101, 103, 104) a few SMD caps and a micro-controller (text on it is too small to read and I don't have anything other than a jewelers loupe on the boat! so the question i pose to the geniuses in this blog are: can I use a KIA65N06 with any of the items listed to make a soft latch power switch for a 12VDC fan motor that stays off when the circuit is charged?thanks in advance for helping with my fun weekend project!-J
Fan PWM control using a signal generator. - Page 1
Forum section: electronics / projects

author: drummerdimitri
author_rank: Frequent Contributor
timestamp: May 14, 2019, 10:06:24 am
content: I would like to control the speed of a fan by supplying it with 12V DC and using a PWM signal from my function generator to control its speed.I have tried using a 25 KHz switching frequency and started at 30% duty cycle with 1V RMS but was not able to control the speed.Should I connect my generator's ground to the black lead on the fan and the positive side to the blue cable?Also, is it ok to leave the yellow (tach) cable unused?

author: ogden
author_rank: Super Contributor
timestamp: May 14, 2019, 10:10:17 am
content: You can't put 1V RMS AC sine into 12V DC fan and expect it to rotate. Voltage is insufficient and fan will not like reverse voltage as well. Your signal generator shall supply12V DC pulses.

author: drummerdimitri
author_rank: Frequent Contributor
timestamp: May 14, 2019, 10:19:49 am
content: Quote from: ogden on May 14, 2019, 10:10:17 amWhat is the purpose of the Blue PWM cable in that case if I only need the red and black ones for PWM?

author: ogden
author_rank: Super Contributor
timestamp: May 14, 2019, 10:24:32 am
content: Quote from: drummerdimitri on May 14, 2019, 10:19:49 amThird wire (in your case blue) is output signal from FAN - to measure fan speed (RPM). You shall PWM-modulate supply voltage of the fan, 12V (red wire). As corrected later - you have 4-wire fan which means that blue wire is fan PWM control (logic) signal indeed.

author: OM222O
author_rank: Frequent Contributor
timestamp: May 14, 2019, 12:21:32 pm
content: connect the output of the function generator to a BJT or a FET, which then drives the motor from a 12V supply. you're feeding it very little voltage at it's output!

author: drummerdimitri
author_rank: Frequent Contributor
timestamp: May 14, 2019, 01:51:34 pm
content: Quote from: ogden on May 14, 2019, 10:24:32 amYou're incorrect.Blue is for PWM signal and yellow wire is for tachometer (rpm reading). So if I only need the black and red leads so send a 12V PWM signal, what exactly does the blue wire do?

author: ogden
author_rank: Super Contributor
timestamp: May 14, 2019, 02:36:05 pm
content: Quote from: drummerdimitri on May 14, 2019, 01:51:34 pmUps. Completely forgot about existence of 4-wire DC fans. Blue wire is PWM control indeed. It needs logical signal 5V or 3V. Thank you for correcting my
Fan sensor output measurement? - Page 1
Forum section: electronics / projects

author: pacmann
author_rank: Contributor
timestamp: July 19, 2025, 06:32:52 pm
content: I want to measure the fan speed from a 4 pin SanAce fan. I assume the sensor is open collector? I put 10K and then 1K pull up but the signal is only ever at ground with small 20khz spikes that don't change with speed of the fan. I try with 2 new fans and see the same thing. Do I need to do something else to measure the sensor output?

author: Uunoctium
author_rank: Frequent Contributor
timestamp: July 19, 2025, 07:11:35 pm
content: The specs from SanyoDenki = SanAce fans for their pulse sensors:https://www.sanyodenki.com/archive/document/product/cooling/San_Ace_M0011876.pdf

author: pacmann
author_rank: Contributor
timestamp: «Reply #2 on:Todayat 05:54:22 am »
content: The fan in question is 9wv1212p1jd003, part of SanAce120W family. I wrote to Sanyo to get the pin out (black, red, blue, yellow wires) but they tell me the fan is custom made for a customer and the pin out is a secret.I bought 9WV1212P1J001 (almost the same p/n) on digikey with known pin out but different color wires (black, red, yellow, brown). Brown is control andyellow is sensor feedback. I connected a 10k pull up resistor to yellow and get a square wave as expected. The yellow for 9wv1212p1jd003 looks to becontrolas I can change fan speed with a 20KHz square wave on yellow. If I connect the same 10k pull up to thebluewire, the fan holds the wire low the second it gets power and there is no waveform.Blue resistance with gnd is 10 megaohm.What else can the blue wire be??
Fancy PCB Cutout (HP Easter Egg) - Page 1
Forum section: electronics / projects

author: TradieTrev
author_rank: Contributor
timestamp: September 23, 2012, 07:25:01 am
content: G'day guys,Curious to know "what were they thinking" after designing this HP Laptop expansion pack. Functionally it's a simple sata + data connector, practically I can see many hours of unwanted and wasted effort.What do you see?- Trev

author: T4P
author_rank: Super Contributor
timestamp: September 23, 2012, 07:35:22 am
content: I have seen loads of easter eggs on HP consumer equipments

author: rollatorwieltje
author_rank: Unknown
timestamp: September 23, 2012, 08:30:04 am
content: Maybe they had a minimum size requirement for easy assembly and the designer tried the "shape to board outline" feature of his CAD tool? It doesn't exactly look like wasted hours, more like half a lunch break.Too bad easter eggs are not allowed at the company I work for

author: EEVblog
author_rank: Unknown
timestamp: September 23, 2012, 08:31:42 am
content: Quote from: rollatorwieltje on September 23, 2012, 08:30:04 amIf you tell them, you're doing it wrongDave.

author: amyk
author_rank: Super Contributor
timestamp: September 23, 2012, 09:10:46 am
content: It's a "conveniently shaped handle for easy removal and installation"

author: rollatorwieltje
author_rank: Unknown
timestamp: September 23, 2012, 10:42:49 am
content: Quote from: EEVblog on September 23, 2012, 08:31:42 amI didn't, I was caughtNothing serious happened, we just had a laugh and decided to remove it. It was a little easter egg in the user interface.I did manage to sneak it into a development tool instead

author: TradieTrev
author_rank: Contributor
timestamp: September 23, 2012, 12:28:09 pm
content: Thanks for the input! My first easter egg find makes a nice keyring, we'll see how long it lasts lol
Fancy small enclosure options with card cage? - Page 1
Forum section: electronics / projects

author: MajorEE
author_rank: Contributor
timestamp: March 28, 2024, 02:07:54 am
content: Can anyone recommend some nice looking enclosures with a card cage?Ideally half rack size, 2-3U tall with handles.Elma and nVent have some nice full size boxes but I am hoping for a half rack size not a full 19". Something like this takachi (photo attached) but with a card rail for example.Thanks!

author: Swake
author_rank: Frequent Contributor
timestamp: August 04, 2024, 02:31:43 pm
content: Did you end up finding something?

author: squadchannel
author_rank: Frequent Contributor
timestamp: August 04, 2024, 02:43:45 pm
content: My recommendation is to get an old hp measuring device that is broken, unpopular, or about to be thrown away.The hp enclosures of the time were solidly constructed frames covered with diecast aluminum frames.A little sheet metal work would make a very good enclosure.However, sometimes (e.g., models with low selling prices) a cheap sheet metal frame that is not a diecast frame is used (later models of the hp 3478A). Careful selection is necessary.

author: tooki
author_rank: Super Contributor
timestamp: August 04, 2024, 02:50:39 pm
content: You can also just choose whatever enclosure you like and install card rails… For some enclosures, dedicated ones are sold, but otherwise generic ones are easy to get.
Fanless UPS - Page 1
Forum section: electronics / projects

author: JacquesBBB
author_rank: Frequent Contributor
timestamp: March 01, 2015, 02:46:02 pm
content: I have a Pinnacle plus 1000 UPS, that is suppose to provide 700w of power for a short time, usually used for computer backup.There are 3 12V, 7.2 Ah batteries, that is about 200 wh of backup power.I wish to use it for a very small power (20 w max) for a long time ( up to 10 h). Up to here, no problems.The problem is the fan. I want to get totally (or nearly) rid of it as it makes a huge noise. I could use a more efficient fan, but I have the idea that the fan is mostly necessary at full power. Unfortunately, it runs permanently.I intend thus to monitor the fan by putting a temperature sensor on the main radiator that holds all the power components.What would be the maximum temperature of the radiator at which I should start the fan ?Thanks

author: SeanB
author_rank: Super Contributor
timestamp: March 01, 2015, 02:56:27 pm
content: 50C would be a good starting point, as it is likely the existing thermal switch there is an 83C one which turns it off if the fan fails. I would not like to run the unit hotter, better to have a cycling fan than burning UPS.
Fans and cooling - methods and calculations? - Page 1
Forum section: electronics / projects

author: Corporate666
author_rank: Unknown
timestamp: February 04, 2015, 11:36:26 am
content: I am working on a custom project that requires a light be enclosed fully in a polycarbonate tube (industrial system where the protection is required per jobside requirements - tube is straight, no bends).For clarity, let's just imagine the tube is 100mm interior diameter and the light installed inside is a 50mm square aluminum extrusion acting as a heat sink with LED's on one of the 4 sides. If a fan were to be used on either end (one pushing, one pulling), what is the method to calculate the fan requirements for appropriate airflow for cooling? Fans I've seen are rated for flow and static pressure... how is that translated into the cross-sectional area available for airflow and length of the tube?I've seen some information online from various sources but thought there might be some simple engineers rules of thumb that folks use in these cases?
Far distance magnetic rotor rotate detection - Page 1
Forum section: electronics / projects

author: poturbowany22
author_rank: Newbie
timestamp: April 26, 2023, 09:44:36 am
content: Firstly I want to say Hi to all of You, I'm new on this forumWe have a magnet inside a titanium rod, rotating that magnet with electromagnetic coils let us to change length of the rod. We want to get any feedback about that the magnet was rotated and with this information and some calculations get know about changed length of the rod. I'm looking for some solution how to deal with that task. Till this day I've tested some of GMR and TMR type sensors, but with poorly results. I've found some research about hall type sensors and focusing magnetic field with ferrite rods, that can help with detection from long range. The radius of distance that sensors can be located is something about 100 mm.If you have any experience with a similar issue I would greatly appreciate your help.Also any other "out of the box" ideas how to detect rotation of this magnet will be very helpful.BR,Carl
Farmers joining up to use RTK and FOSS rover software to automate agriculture. - Page 1
Forum section: electronics / projects

author: cdev
author_rank: Super Contributor
timestamp: July 30, 2017, 12:52:32 pm
content: http://diydrones.com/profiles/blogs/matthew-reimer-s-pixhawk-powered-tractor-makes-the-wall-street-joMatt Reimer's robotic tractor projectis a good example of how "necessity is the mother of invention" !There is an amazing piece of high accuracy GNSS/GPS software,RTKLibwhich has made this explosion in affordable precise movement possible.It's a stable and robust tool, that enables high accuracy positioning with a rapidly growing list ofraw-data capableGNSS receivers.Tomoji Takasu's (RTKlibs's author) list ofsupporting resources.RTKLib'smain Github project is here.A good, new GPS-GNSS blog specifically highlighting RTK ishere.OpenStreetMap's wikihas a page on RTKLibTheFOSS-GPS listalso has a lot of info on RTKLib.
Farnell pulse generating system dual module set 1968 - Page 1
Forum section: electronics / projects

author: oz2cpu
author_rank: Frequent Contributor
timestamp: April 22, 2025, 08:09:21 am
content: we have seen pulse generators many times before, it was a huge thing in 1980-90 with themI think they where used for data communication simulating testing and such,today i play with this oneFarnell pulse generating system dual module setit is from about 1968, all transistor, dual ?? why ?? cant be stereo ? must have been some kind of other dual idea ?it is also compleetly modular, see the plugs and cables for power and signals between the installed modules,anyone can tell more ??here is a little video about my unithttps://youtu.be/OtiEWZL1hLI
Farnell TM 2 Finished - Page 1
Forum section: electronics / projects

author: M0BSW
author_rank: Frequent Contributor
timestamp: October 26, 2012, 06:51:20 pm
content: I've really enjoy bring this back to a standard I like, you can see from the picture then & now, key things and worrying, front panel screws missing postcode from the college it came from, and beaten up generally,sort of project I like. First thing I took it to friends of mine at a calibration centre to see what was what, eveything was spot on so didn't need any adjustments, took it home deep clean, 4 new machine screws , removed postcode, printed new instructions for zeroing the meter, nex perspex ,polished up up the bright work & panels Some switch spay on all wafers switches, & pots, put it all back to together, made a couple of new stickers one for SC,and the other on the top to hide a mess ?bad handling at college gave it. So now it's going to have a good life here in my Radio amateur shack. looking on E-Bay for next project:)Paul
fast 1/2 ch. quadrature decoder A/B+index, RP2040, Arduino - Page 1
Forum section: electronics / projects

author: mino-fm
author_rank: Regular Contributor
timestamp: March 13, 2024, 09:49:46 am
content: With its PIO units, the RP2020 installed on the Pico board offers the possibility of implementing one or two 4-fold quadrature decoders with a high count rate, so that signal changes of up to 1 x 10^7 edges/s can be recorded. Furthermore, the index pulse can be evaluated by position or rotary encoders, which sets the internal counter to 0 or a freely selectable default value.The circuit consists of the finished RP2040 pico board, to whose inputs GPIO10 and GPIO11 for channel 0 the two phases A/B of the encoder signal are connected (GPIO14+15 for channel 1). The index pulse is expected at GPIO12 (GPIO13 at channel 1) and is active with a '0' level in the program shown. If '1' level is required, the GPIO pin can be reprogrammed with 'set_index0_pol(1)'.If the encoder signals deliver levels > 3.3 V, voltage dividers or at least protective resistors must be inserted into the signal lines.The demo program ‘Pico-qcnt.ino’ shows examples for two channels 'init_qcnt0(0)' and 'init_qcnt1(0)', is written for the Arduino IDE and outputs the current counter reading when changed via the USB interface. The .uf2 file can be written directly to the Pico board in boot mode without using an Arduino IDE. The program module 'pio_qcnt0.c' or 'pio_qcnt1.c' can be transferred to other IDEs. If the file extension is renamed to '*.ino' for reasons of compatibility with Arduino, 'rp2040_arduino.h' must be used to avoid duplicate definitions.http://mino-elektronik.de/progs/RP2040/Pico-qcnt.zip

author: MarkT
author_rank: Frequent Contributor
timestamp: March 14, 2024, 09:00:17 pm
content: Ah, handy... Thanks for sharing.

author: mino-fm
author_rank: Regular Contributor
timestamp: March 18, 2024, 11:30:47 am
content: 2024-03-18: Expansion to 1 - 4 channelsIn the program shown previously, the function for the second channel was implemented by simply copying from PIO1_SM0 to PIO0_SM0. It was quick, but not particularly efficient.In order to have PIO0 freely available again for other applications, PIO1_SM1 is now used and two additional channels using PIO1_SM2 and PIO1_SM3 are activated. A total of four quadrature decoders are available: Pico-qcnt4x.zipChannels 2 and 3 are reduced in function as examples. This eliminates the need for an INDEX signal, which saves one input pin, and only uses one DMA channel for data acquisition. The retriggering of the DMA_TRANS_COUNT is done via software.Basically, this could be achieved via an interrupt after 2^32-1 changes have expired, here it is done by resetting the counter with each function call 'get_qcnt2()' or 'get_qcnt3()'.For demonstration purposes, the maximum clock frequency was also reduced to 1/10. Like the GPIOx and DMA_CHx used, you can set this differently as you wish.http://mino-elektronik.de/progs/RP2040/Pico-qcnt4x.zip
Fast, bidirectional current sense amplifier - Page 1
Forum section: electronics / projects

author: Siwastaja
author_rank: Super Contributor
timestamp: March 11, 2016, 01:06:04 pm
content: Hi,I'm using INA213 to amplify current sense resistor signal in a bidirectional power converter. The key points:- Bidirectional: shunt voltages vary from -30 to 30 mV in a bidirectional DC/DC. INA213 has a reference voltage input that biases the output at zero current.- 80 kHz bandwidth - it's inside the current control loop, so I had to design the DC/DC to run at less than 80 kHz, and still the reaction to overcurrent is not perfect.- High-side, good CMRR.- It has a proper buffered voltage output, so high-speed interfacing with ADC doesn't require external buffer.I'd like to replace the INA213 with anything else with similar specs, but a bit more BW. I need:- Bidirectionality (that really works)- Gain between 25-75. INA213 has 50, which is kind of optimal.- Small signal BW of at least 150 kHz (-3dB), preferably 200 kHz or more. INA213 has 80 kHz.- Input common mode range at least 2 - 5V. Many possible replacements start at 3 or 4V, rendering them unusable.- Buffered output that can be directly connected to ADC. This is not an absolute constraint, I can use an external high-speed opamp as a buffer, but would like an integrated solution.- Low or mid cost, < $3-4/pc @ 100 pcs.I have spend several hours and have gone through dozens of parts. INA21x series is the only I can find, but the BW is no good.Any suggestions? Parts I'm missing? Other ideas?

author: jeroen74
author_rank: Frequent Contributor
timestamp: March 11, 2016, 01:15:14 pm
content: LTC6104 or LT1999. The latter one is faster but only available in fixed gain versions, and 50 is one the possible gains.

author: RobK_NL
author_rank: Frequent Contributor
timestamp: March 11, 2016, 01:21:07 pm
content: MAX4069-4072 or MAX9929
fast buffer/driver for logic pulse? - Page 1
Forum section: electronics / projects

author: awallin
author_rank: Frequent Contributor
timestamp: February 15, 2014, 02:05:47 pm
content: Hi all, I'm experimenting with this pulse stretcher circuit based on the LT1711:http://www.planetanalog.com/document.asp?doc_id=527407and I got some OK results:http://www.anderswallin.net/2014/02/pulse-stretcher-v1/However as such the LT1711 is quite sensitive to output load impedance. With a 50 Ohm load on the output the output will not swing as high as with 1 MOhm load, and thus the latch pin will not charge/discharge the same, and the output pulse length suffers.Any suggestions for a buffer circuit that could drive both 1 MOhm and 50 Ohm loads that I could add to this circuit?Ideally the buffer should not add much propagation delay (now 4.5ns) and not degrade rise/fall times (2ns per the datasheet, I haven't actually measured them)EDIT1: single-supply 5V operation would also be much preferred!EDIT2: or is in fact the behavior I've seen (pulse length shortens with 50Ohm load on output) because my +5V supply can't handle the current required? Fixed with better/larger voltage regulator and/or more decoupling capacitors for the LT1711?thanks,AW

author: dannyf
author_rank: Super Contributor
timestamp: February 15, 2014, 02:54:54 pm
content: Put a follower on it.

author: Marco
author_rank: Super Contributor
timestamp: February 15, 2014, 03:18:23 pm
content: Isn't that a bit overkill for a one shot? AFAICS a fast flipflop with reset input can meet those specs at a fraction of the cost.
Fast current source - Page 1
Forum section: electronics / projects

author: blueskull
author_rank: Unknown
timestamp: January 27, 2016, 06:12:02 am
content: I'm in the process of a double pulse MOSFET tester project, which conventionally uses an inductor to regulate current through DUT, as shown below.First, the DUT turns on for a given time, charging the inductor to a certain current, then turns off and on fast, hence the name of double pulse. Since the current of an inductor won't change (drastically over short time), I can get pretty stable current during the double pulse testing, and this circuit is used as industrial standard to test power MOSFET switching characteristics.I'm thinking if I can use a pulsed MOSFET current source to do the test, so to eliminate the need of an inductor. This will make my design more flexible and programmable, like this.Do you think this design will work? LTSpice says okay, but I've never built this. I intend to pulse 6 parallel connected 25mR SiC MOSFET devices (each device gets 167A) rated at 250A surge capability. By calculation, these devices can do higher current, but due to ohmic voltage loss, current regulation will be worse.
Fast data aquisation with FPGA with visualization on the computer, need advice - Page 1
Forum section: electronics / projects

author: asgard20032
author_rank: Regular Contributor
timestamp: June 10, 2016, 05:27:01 pm
content: The FPGA send data at very high rate to the computer (almost fill up a 10/100 interface). The data contain 16 to 1024 channel of data, 24 bit each channel. Will send many frame per second to the computer (a frame include all channel data). I then need to do a real time plot of the data. The plot will have as horizontal axis the time, vertical axis the channel, and the color or greyscale = the value of the data. What technology (language, library...) should I use?

author: CM800
author_rank: Frequent Contributor
timestamp: June 10, 2016, 05:45:33 pm
content: Sounds like you want to have a closer look at PCI possibly or handling more of the grunt-work on the FPGA / hardware before passing it to the computer in a more compact form.

author: asgard20032
author_rank: Regular Contributor
timestamp: June 10, 2016, 05:52:58 pm
content: Why? the data is not encoded, it is just many 24 bit value following each other... one vertical line in my chart will be a whole frame....

author: Marco
author_rank: Super Contributor
timestamp: June 10, 2016, 05:59:49 pm
content: Just use whatever language your comfortable with and find a good data plotting library, it's not a lot of data in the grand scheme of things considering the purely linear memory access patterns.You could do this in javascript (please don't).

author: uncle_bob
author_rank: Unknown
timestamp: June 10, 2016, 10:49:20 pm
content: Quote from: asgard20032 on June 10, 2016, 05:27:01 pmHiWell, there's a lot of range in your numbers...Filling up a 10 Mb ethernet isn't a lot of data. Filling up a 100 Mb interface is ...errr ... 10X more.1024 channels of 24 bits each would be 24Kb per frame or 3 KB per frame. Without jumbo frames on the ethernet, that's three packets of data per frame including overhead.To fill a 10 Mb pipe you would be in the 200 to 400 frames / second range. That's 600 to 1200 packets. Most modern PC's are not even out of sleep mode that point.Bob