hybridfree/eevblog-posts huggingface dataset:
Commonly appearing numbers - Page 1
Forum section: electronics / projects

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: January 01, 2021, 05:28:22 pm
content: I once saw a web site where you could enter a number and it would return constants and other applications where that number appeared. It was extensive in its coverage, with thousands of entries. Never been able to find it again. Does anybody know of that site?

author: mathsquid
author_rank: Frequent Contributor
timestamp: January 01, 2021, 05:45:24 pm
content: I doubt this is it, but maybe the online encyclopedia of integer sequences?http://oeis.org

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 01, 2021, 05:47:27 pm
content: Wikipedia has entries for most small numbers. Some are dates, some have mathematical facts, many don't exist (you can help by expanding this list).Not sure about a more dedicated site. Probably there's a few dedicated to math facts?Tim

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: January 01, 2021, 07:31:30 pm
content: That sequence site is good- thanks. Turns out WolframAlpha does a pretty good job, though I don't know if that's the site I once found.

author: Renate
author_rank: Super Contributor
timestamp: January 02, 2021, 02:15:15 am
content: Ah, what you are looking for is "Plouffe's Inverter".It doesn't exist anymore and the various replacements don't seem active either.You could put in "0.7071" and would tell you sqrt(2)/2See:https://oeis.org/wiki/Plouffe%27s_Inverter
Communicating with RND Labs power supply over LAN - Page 1
Forum section: electronics / projects

author: Ron68
author_rank: Newbie
timestamp: April 10, 2022, 06:01:54 pm
content: Hi all,I just got the RND 320-KD3305P programmable 3 channel DC power supply at 150W, and thought I should make a little program to control it.Using an ethernet sniffer (Wireshark) I found most of the commands, except the tracking information.Taking a chance, I ask for STATus?, a rather typical SCPI command, and then I do get 8 bits encoded in ascii back, and it does indeed seem like the 4 least significant bits indicate tracking status as they vary with the tracking modes.But then - guess what? - when I turn ON any of the channels, the device gets a hiccup, resets the tracking and turns off all channels, behaving like nothing really happened at all. Groundhog day syndrome?Well - at least there is a response. Better than nothing, I assume.It is amazingly easy to control these devices over UDP, using separate client and server components, and the communication is fast.I am using Delphi.But isn't this behaviour quite strange? Maybe "STATUS?" is interpreted as an input command, but the questionmark should ideally override that, well - depending on the "intelligence" at the other side, i.e. the coding in the device.The proprietary software was not that much to write home about, but the unit seems to be working well.

author: H.O
author_rank: Frequent Contributor
timestamp: April 11, 2022, 12:18:53 pm
content: They call it programmable but they make it quite hard to find how to actually program it. Did it come with a CD and if so, have you checked if there's aditional documentation on it?Anyway, that's a rebranded Korad supply. I managed to find a Korad manual for the KA3300 series, it's not the same supply but it does havesomeinformation on the commands it accepts:https://familab.org/wiki/images/1/11/Korad-KA3305P.pdf

author: Ron68
author_rank: Newbie
timestamp: April 11, 2022, 02:25:18 pm
content: Your suspicions were correct - I found the programming manual on the CD-ROM...have almost forgotten that they even exist these days.Yes, it seems to be a Korad unit, some modification of KD3305SP but without the memory buttons.I query the voltage and current of both channels in a loop, but when doing the status query something goes wrong, as the unit will not properly turn on.The STATUS? command is clearly for output.Thanks for the link, I found that the other day and it did offer some clues.

author: tooki
author_rank: Super Contributor
timestamp: April 11, 2022, 07:20:16 pm
content: Quote from: Ron68 on April 11, 2022, 02:25:18 pmHuh? It’s a completely standard KD3300 series:http://www.koradtechnology.com/product/13.html(Not sure which model you’re saying it’s a modification of; KD3305SP doesn’t exist.)
Communication Protocol Analysis via Microcontroller Board - Page 1
Forum section: electronics / projects

author: demi1773
author_rank: Newbie
timestamp: December 26, 2020, 05:07:00 pm
content: Hi there,I hope you are doing well,I have an idea for my master thesis. So, i want to make a communication protocol analyzer and monitor the datas on PC via software i codedFor the first stage, i need a kind of data acquisition system like below(or in the attached files):Communuciaton bus i am interested in has 2 mbps bitrate, and manchester coding (±5V differantial voltage).But i have no experience about high speed communcation signal processing. What do you suggest for? Should i use some kind of ADC/tranceiver or process the data directly via microcontroller with high sampling rate? In that case, is there any microcontroller you could propose with high msps?Edit:By the way, writing ADC may cause misunderstanding. Scope of my evaluation ismanchester-high,manchester-lowandnon-data(means no 1 or 0).Thanks in advance,

author: NiHaoMike
author_rank: Super Contributor
timestamp: December 26, 2020, 06:30:34 pm
content: Easiest option would be a Cypress FX2 and Sigrok. Then use some fast comparators to interface to the bus.
Compact 250Vac fuse array - Page 1
Forum section: electronics / projects

author: Jester
author_rank: Frequent Contributor
timestamp: December 22, 2023, 12:06:54 pm
content: I need to distribute 220Vac (10A fuse in both legs) for distribution to 4x servo driver modules, so 8 fuses in total, 4 on each phase.I'm trying to conserve space in the enclosure, so I'm looking for a compact fuse holder and in a perfect world something easily gang-able into 2 x 4 configuration.There will be upstream HRC fusing to deal with maximum total fault currentDIN mount is one possibility?Suggestions please.

author: nightfire
author_rank: Frequent Contributor
timestamp: December 22, 2023, 12:50:07 pm
content: When you ask for DIN mount- would a solution be able to incorporate standard RCCB breaker switches that are designed to switch single phase+N?I might remember that Schneider manufactured some slim line stuff at least for standard single phase RCCB that were only using half width of the size of other breakers...

author: themadhippy
author_rank: Super Contributor
timestamp: December 22, 2023, 02:03:54 pm
content: imo do sevral din rail fuse holders for glass fuses ,thers a few to chose from in the SCF range ,or maybe the the ERF4 .

author: nightfire
author_rank: Frequent Contributor
timestamp: December 23, 2023, 09:49:17 pm
content: Something like this maybe?https://www.wago.com/de/reihenklemmen/2-leiter-sicherungsklemme/p/282-122
Compact banana plug to female pin header adapter - Page 1
Forum section: electronics / projects

author: Zbig
author_rank: Frequent Contributor
timestamp: April 08, 2020, 07:54:09 pm
content: Stuck at home, getting bored out of my mind, I came up with this silly little thing:It could come handy in situations like:powering breadboarded projectsconnecting instruments' remote voltage sensingsticking through-hole components (almost) straight into the multimeter

author: Ian.M
author_rank: Super Contributor
timestamp: April 08, 2020, 08:36:53 pm
content: To make it more robust, drill out the banana covers to the diagonal dimension of the Dupont F. pin housing so you can recess that within the banana cover.However, if the banana sockets are in proper binding posts, you really don't need the adapter. Where it comes into its own is if you are hooking up to a DMM or similar that just has shrouded sockets, no posts.
Compact Led dimming - Page 1
Forum section: electronics / projects

author: electron_misfire
author_rank: Contributor
timestamp: March 18, 2015, 09:10:54 am
content: Hi guys.I've been enlisted to make props for a theatre production. Currently i'm working on little plastic blocks with pulsating leds inside them.My plan is to just conect an led to an attiny micro with 2 button cells as power. So my only worry is that the attiny won't be able to do this for some strange reason.Thanks for any help,electron_misfire

author: Corporate666
author_rank: Unknown
timestamp: March 18, 2015, 12:19:39 pm
content: Quote from: electron_misfire on March 18, 2015, 09:10:54 amWhat exactly are you worried about? Can you give some more details?In theory, it should be fine... the ATTINY can be run from a voltage that should be fine to also run your LED's, and assuming we're talking normal (not high power) LED's, the TINY can sink the current directly and you can PWM the output for dimming.

author: Kjelt
author_rank: Super Contributor
timestamp: March 18, 2015, 12:28:09 pm
content: And what do you mean with "pulsating" is that slowly on and slowly off to normal led currents like 20mA or do you want to flash the leds by for instance applying 100mA for 100ms per second? This last application requires an extra transistor or fet.

author: daveatol
author_rank: Regular Contributor
timestamp: March 18, 2015, 12:59:17 pm
content: I assume that pulsating refers to something similar to the "breathing" pattern of sleeping Mac/PC power lights. If this is the case, it's been done here:http://thecustomgeek.com/2011/06/17/breathing-sleep-led/andhttp://web.cecs.pdx.edu/~gerry/class/EAS199A/topics/pdf/breathing_LED_code.pdfand I believe there is code available at both.
Compact Power Supply Debug & Thermal Behavior – Field Notes from a Recent Projec - Page 1
Forum section: electronics / projects

author: camello
author_rank: Newbie
timestamp: August 05, 2025, 03:51:20 am
content: Hi everyone,Just thought I’d share some findings from a recent project I wrapped up — a compact, low-noise power supply module intended for sensor interfacing in a constrained enclosure (around 60x60x25 mm).The PSU was based on a buck converter topology, switching at ~600kHz, followed by an LDO for cleanup. On the bench, everything looked fine: stable rails, good ripple performance, load response within spec.The twist came when I mounted it inside the actual enclosure.Thermal behavior changed dramatically. A linear reg that barely reached 38°C on the bench went over 70°C after 10 minutes in the box. Ambient buildup, reduced airflow, and copper pour behavior made a bigger difference than expected.To track down the issue, I used a compact thermal camera I’ve been evaluating recently — it’s a small module that plugs into a phone (USB-C), and while not as precise as a FLIR Txxx or SeekPro, it was enough to spot hotspots and thermal gradients in real time.This helped me identify an unoptimized ground plane that was acting as an unintended heat trap near the LDO.I redesigned that section with better thermal paths and more spacing from high-dissipation components — issue solved.I’m curious:How do you usually approach thermal validation in tight enclosures?Do you rely mostly on simulation (e.g., SolidWorks Flow, ANSYS ICEPAK), or do you jump straight to physical measurement?Anyone here using mobile thermal tools for rapid diagnostics?Happy to share more details if anyone’s interested.
Compacta UniBoard  6809 SBC - Found the schematic! - Page 1
Forum section: electronics / projects

author: intabits
author_rank: Frequent Contributor
timestamp: October 08, 2018, 07:55:17 am
content: Maybe this belongs in the retro-computing section, but I've put it here since a similar topic was placed here not long ago:-https://www.eevblog.com/forum/projects/6809-single-board-computer-project/And I think those that read that, would probably want to see this.In the above thread, I showed this Compacta Uniboard, a 6809 SBC.I thought I'd lost the documentation, but I've found the schematic for those interested.Picture and schematic are on Imgur, as they are too large for here, while keeping full resolution, 4MB-5MB.(They're the sizes I uploaded, but they "save image as" to smaller sizes?!)

author: W0MJ
author_rank: Contributor
timestamp: October 15, 2020, 04:55:59 pm
content: I have the documentation for the Compacta Uniboard if anyone needs it. And a running board!contact me for info, if you need it.Thanks,w0mj@arrl.net
Comparator excites op amps in sensitive radiation detector - Page 1
Forum section: electronics / projects

author: MarcinWachowiak
author_rank: Newbie
timestamp: September 16, 2018, 08:32:04 pm
content: Hello,I have encountered a problem while trying to assemble semiconductor radiation detector that I described here:https://hackaday.io/project/159909-gamma-pin-semiconductor-radiation-detectorThere were some problems at the beginning with the 3- stage op amp, because the gain was set too high - 1000x an there probably occurred a crosstalk that excited it all.I reduced it to 100x and now it behaves fine.While trying to assemble the comparator segment I found out that it gets excites and affects the op amps even after a single pulse.The first three op amps serve to amplify the signal then the last one is designed as a subtractor to lower the upper noise level just below 0V/ground so that the pulses from radiation are easily distinguishable above the "floor". The comparator has little hysteresis and is supposed to detect positive pulses, but instead after a single detection it goes on a rampage and generates a square wave which causes the signal to go full sine from rail to rail.I will increase the caps in the three op amps to 100pF, and the hysteresis loop to 10mV, but I have no further idea what else may be causing the oscillations.I have a different design already in mind with a layout consideration, but I would like to make this one work too...Can you advise me, please?

author: iMo
author_rank: Super Contributor
timestamp: September 17, 2018, 08:06:09 am
content: I did it with 3 transistors in past getting 10-300mV pulses from a single PIN diode. The 10 diodes in parallel - the total capacitance must be great.. You can hardly get a pulse out of it.. Over-engineered, imho.I would advice you to make a simulation (ie LTSpice) with your string of opamps and comparator. Increasing the capacitors in the feedbacks may affect the amplitude and shape of the pulses you want to measure.I would not use the TL3016 "ultrafast 7.6ns comparator" with 47k/1ohm feedback. The pulses are generally "slow" (when talking their frequency and edges). An old LM311 would be ok there, imho.

author: iMo
author_rank: Super Contributor
timestamp: September 17, 2018, 01:57:14 pm
content: Here is an app note from Maxim re pin diode gamma detector:https://www.maximintegrated.com/en/app-notes/index.mvp/id/2236

author: ConKbot
author_rank: Super Contributor
timestamp: September 17, 2018, 08:54:50 pm
content: Try adding more decoupling. A single 100n probably isn't enough to properly supply 6 different ICs, which include relatively fast opamps, fast comparators and the like.
Comparator with above window output: Detecting tristate or Logic - Page 1
Forum section: electronics / projects

author: BurnedResistor
author_rank: Regular Contributor
timestamp: May 08, 2017, 06:11:17 am
content: Hello All,I am working on a demonstrative project which includes a tristated busses (A total of 48 lines). I thought it would be neat to have two leds for each wire to indicate it's state: one to light up if it is tristated, and one indicating its logic state (on if high, off if low, off if tristated). Detecting tristating is easy enough with a window comparator and equal pull ups and pull downs to hold the bus at 2.5 v. However, because of the large number, it would e great to have this functionality within a single chip.I found a Linear Technology Part:http://cds.linear.com/docs/en/datasheet/1042fa.pdfIt is a window comparator with an output that goes high if it is within the window, which would be my tristate led, and an output which goes high if it is above the window, which would by my logic led.However, it is not available in a small smd form factor, nor is it available at mouser. At prices of one euro per part it is also rather expensive.Anybody know of any other similar chips which could do this? Speed is not very important, as it is only really used at low frequencys where the change in LED is visible. 5V Supply, and would be great if it could drive an led by itself!

author: BurnedResistor
author_rank: Regular Contributor
timestamp: May 08, 2017, 06:44:31 am
content: Because it is split up on 4 different busses, I might only need one window comparator per bus, and have only one tristate led per bus.Maybe hook up the window comparator to one of the lines, and then leds directly to all of them. The output of the comparator could sink all the the leds, so when it is high (tristated), all of the LEDs are off. Might need some buffers as sinking 16 leds in one comparator is not that good of an idea!

author: danadak
author_rank: Super Contributor
timestamp: May 08, 2017, 01:26:10 pm
content: Possibly PSOC, one part to do all the detection, see attached tool shot,and another for LED driving.PSOC code should take ~ 30 - 40 lines of code max, and a serial componentto drive LEDs, a serial to parallel converter chip. Could use another PSOC if drivecurrents did not exceed PSOC total allowed per port Vddport current. Couplethem using I2C component.AN72382 is pertinent application note on total allowed current limits for GPIO.Code can setup amount of hysteresis.Regards, Dana,
Comparator with delayed output - Page 1
Forum section: electronics / projects

author: 84750Erik
author_rank: Contributor
timestamp: January 20, 2022, 03:55:53 am
content: Purpose of this design: detect light variation at low intervals (>1 second, up to minutes).The detection works independent of ambient light.What I do need is a delay on the output when LDR is uncovered, ie when the voltage on the non-inverting input recovers to a high level.The left design uses two comparators and works well. I would however like to reduce this to a design with one comparator only, if possible.I am in a bind how to introduce a delay circuit for the voltage on pin 9 (non-inverting): voltage going up on that pin needs to be delayed.

author: moffy
author_rank: Super Contributor
timestamp: January 20, 2022, 11:23:18 pm
content: I would keep the delay as a separate function just as you have it. All I would alter is:1. Add some hysteresis around the detection comparator.2. Increase the values of R1, R4 to conserve some current, also makes the hysteresis easier.3. Why is R7, 300k, seems high?

author: Terry Bites
author_rank: Super Contributor
timestamp: January 21, 2022, 06:32:43 pm
content: A capacitor from the comparator input to ground will slow the response time. As pointed out, you need to apply hysterisis on all of the comparators or you will have problems.

author: moffy
author_rank: Super Contributor
timestamp: January 21, 2022, 11:23:02 pm
content: Yes hysteresis, as you suggested Terry Bites, should be applied to all the comparators. The delay unfortunately is asymmetrical because of the NPN open collector nature of the comparator output. So moving the cap to the input would delay both +ve to -ve and -ve to +ve transitions.
Comparator with rail-to-rail inputs? - Page 1
Forum section: electronics / projects

author: Clear as mud
author_rank: Regular Contributor
timestamp: September 19, 2013, 03:32:11 am
content: The last couple of days, I have been designing a LED light bar indicator for current consumption. It would be for a display on a power supply circuit, used instead of a panel meter to indicate how much current is being used (much less accurately, though). So, I put a sense resistor on the high side of the input voltage, with a 2.5 volt reference IC (I found some for less than 25 cents each on goldmine-elec-products.com) to generate a reference voltage 2.5 volts below Vin. Using the reference voltage, a couple of op-amps can generate a power supply any fixed amount I choose below the Vin (as long as it is still higher than ground). Then I was planning to use a resistor network to divide the Vin - Vref into several ranges, and each node between resistors would have a comparison with Vout (the downstream side of the sense resistor), to decide if the corresponding LED should be lit. After I did this much of the design, I realized there's a reason not to design things with reversed polarity from the way everyone else does it. There don't seem to be comparators that can operate on input voltages near the positive rail.Anyone know if a comparator like this exists? Four in a package would be good.Oh, I just found it I think: LMC6762. I searched for quite a while earlier, but just realized I had been searching for "LM6762" without the C. I couldn't find it for sale anywhere, and the one datasheet I found indicated that it is a deprecated design. Now that I am searching for the correct part number, I found several listings on Mouser and they don't indicate "NRND," so I think this is OK to use. The only thing is, this is only a dual regulator, and quad ones would be useful, but dual is better than single and much better than nothing. The other nice thing about the LMC6762 for this design is that it has enough output current to drive the LEDs directly.I realize that this circuit could probably be designed more easily by putting the sense resistor on the output of the regulator, and driving the comparator + voltage from the input voltage. That way, inputs near the positive rail would not be required. But I wanted to also complete the design I am working on because it seems to be better for modularity, that is, it could be re-used in various situations where a higher voltage may not be readily available.
Comparing avalance ratings on mosfets - Page 1
Forum section: electronics / projects

author: eTobey
author_rank: Super Contributor
timestamp: December 03, 2023, 09:22:15 am
content: Hi,i am trying to compare two mosfets: TPH2R608NHhttps://toshiba.semicon-storage.com/info/docget.jsp?did=15733&prodName=TPH2R608NHand SiR180DPhttps://www.vishay.com/docs/76233/sir180dp.pdf. I found this very good video about this:https://www.youtube.com/watch?v=6CQj5s_cc5I.When i calculate the Eav for the TPH (with the formula from the videos at 6:12), it does give me 58 mJ, but in the table in the Datsheet it says 149mJ. The datasheet for the sir has values as expected.Is this a simple calculation error in the datasheet, or do they use tricks to make things look better?

author: MarkT
author_rank: Frequent Contributor
timestamp: December 03, 2023, 11:33:05 am
content: Do not ascribe to malice that which can be adequately explained by incompetence - probably a mistake.I don't understand why anyone would ever rely on such a figure, avalanche breakdown in a MOSFET is never a good thing! Especially the "single pulse" figure...

author: Terry Bites
author_rank: Super Contributor
timestamp: December 05, 2023, 10:23:29 am
content: Yes, its more a measurement of a fault condition and not a normal operating paramater.Its a conditon that you need to protect against with good layout and snubbing circuits.

author: eTobey
author_rank: Super Contributor
timestamp: December 05, 2023, 12:44:53 pm
content: I have thought about it. I came to the conclusion, that my mosfets in my BLDC driver never get into that state, because of the diodes of the complemmentary msofets.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 05, 2023, 05:44:50 pm
content: Notice the condition in note 5, VDD = 60V. The inductor provides 57.6mJ of booston top ofthe 60V supply. We need to know the actual breakdown voltage to calculate this, which isn't easy to know: only a minimum (75V) is given, and it varies during the pulse anyway. Using 90V as a SWAG, then the inductor would deposit 57.6mJ at 90 - 60 = 30V, but the device sees 90V therefore the total was (57.6mJ * 90V / 30V) = 172.8mJ.Alternately, we can use the same argument to measure the average breakdown voltage. Since they give the 149mJ figure, evidently Vbr is even higher, (60V) * (149mJ) / (149mJ - 57.6mJ) = 97.8V.Which sounds like a generous safety factor, but there are multiple reasons to avoid operating continuously above the rated 75V.The energy figures match up much more closely in most datasheets, where a lower VDD is used (for example, 10V supply into a 600V MOSFET); it is peculiar that they used such a high value here.Tim
Comparing performance of semi-rigid cable based on cross section dimensions - Page 1
Forum section: electronics / projects

author: matthuszagh
author_rank: Frequent Contributor
timestamp: September 24, 2021, 01:59:47 am
content: I'm attempting to determine how I should select an outer diameter for semi-rigid coaxial cable (this question probably applies to flexible cable as well, though I'm mostly concerned with the semi-rigid variety). Imagine both cables are identical in terms of inner conductor, dielectric and outer conductor materials, and can only differ in terms of dimensions (for example, take this pasternack 086 cablehttps://www.pasternack.com/images/ProductPDF/PECX006.pdfand this 141 cablehttps://www.pasternack.com/images/ProductPDF/PECX008.pdf).The first, and probably most important consideration is the types of connectors the cable supports. I get that.Other parameters that I think are relevant are loss, power handling, max frequency, isolation, ruggedness (how likely is the cable to get damaged due to some mechanical cause) and minimum bend radius.I believe that the larger cable would win in terms of power handling (datasheets confirm this), ruggedness, isolation and loss (also confirmed by datasheets). Ruggedness seems obvious (thicker=more rigid=less fragile). I don't have any data on isolation, but the larger cable has a slightly thicker outer conductor, so I would expect that it picks up less external noise and radiates less. Why is the loss of thicker cable lower?By contrast, the thinner cable should win in terms of minimum bend radius and max frequency. Why do thinner cables support higher frequencies?Are these trends generally (or always) true? That is, all else equal do the cable dimensions have the above effects?Any other important metrics I've missed?The takeaway from these datasheets (assuming they can be generalized) seem to be that (if your connector type supports multiple cable dimensions) you should choose the larger cable if you don't need the smaller bend radius and higher max frequency. Otherwise, go with the thicker cable. Does this seem right? Anything else?

author: David Hess
author_rank: Super Contributor
timestamp: September 24, 2021, 03:26:53 am
content: Quote from: matthuszagh on September 24, 2021, 01:59:47 amThe signal propagation inside a coaxial cable is the fundamental TEM (transverse electromagnetic) mode, but above the cutoff frequency, other modes become possible which cause undesired loss, impedance mismatch, and delay. The cable can still be used at frequencies higher than the cutoff frequency but performance is compromised.Smaller cables have higher cutoff frequencies because their dimensions are smaller.
Comparing TVS diode with same type but from different manufacturers - Page 1
Forum section: electronics / projects

author: drakejest
author_rank: Regular Contributor
timestamp: October 10, 2020, 11:50:01 pm
content: I was looking for a TVS diode for my circuit and noticed the same part number but from a different manufacturers,see components. Why does this happen? And which brand is the better one ? I have look at the datasheet and i do not see any noticeable difference. Putting aside the price, the littlefuse brand seems to have better compliance rating but is that it ?

author: Doctorandus_P
author_rank: Super Contributor
timestamp: October 11, 2020, 11:34:27 am
content: Why would part numbers be different if the parts have the same functionality?Back in the '80ies it used to be common to have "second sources" for components, which were the same components but made by different manufacturers. There may even have been some cooperation between different companies back then.Often, but not always manufacturers of parts are recognizable by a prefix or postfix at the part number or a logo on the IC.There are (or at least used to be) many manufacturers of a 74LS00 and mostly such parts are interchangeable without giving (too) much thought to them.In some applications the chips are sometimes used in a way that parts from a specific manufacturer need to be used to get reliable results.This is also an important part of the art of electronics.It is not just to make something work on your breadboard. It is also about designing products in such a way that they keep working through different batches and production tolerance combinations and with similar parts from different sources.The Chinese have turned this around a bit.They tend to use the same part number for parts that have a even remotely similar function, even when important parameters are different. Especially if it's a "well known" and "often used" part number, then profits can be made...

author: drakejest
author_rank: Regular Contributor
timestamp: October 12, 2020, 03:06:32 pm
content: who gets to name the part just whoever made it first?

author: schmitt trigger
author_rank: Super Contributor
timestamp: October 12, 2020, 03:14:38 pm
content: ExactlySignetics part numbers very often started with a 5.Even though Signetics is long gone, the 555 continues to live under dozens of different manufacturers.

author: Siwastaja
author_rank: Super Contributor
timestamp: October 12, 2020, 04:08:41 pm
content: You can choose to sell anything under name asdfgh. Unless you apply for a trademark for it, a fairly heavy process to be done if you have gazillion different part names, anyone else can also choose to sell something under name asdfgh, which may or may not be drop-in-replacement, somewhat similar, or completely different to your asdfgh.Usually, if the part name is exact match, it will be a suitable drop-in replacement inmostcases, but sometimes very small differences in seemingly less relevant parameters matter. In these cases, you need to specify manufacturer, part number, and add a note "no substitutes"; preferably with an added order code to a distributor.
comparison of metal oxide and carbon composition resistors ? - Page 1
Forum section: electronics / projects

author: coppercone2
author_rank: Super Contributor
timestamp: February 03, 2023, 09:01:51 pm
content: So I got few of the following1) PPM for MO is <400, PPM for CC is at least 1500 / degree c2) CC has low moisture resistance3) CC has high aging / year4) CC generally has greater noise behavior then other resistors5) CC will have lower inductance6) MO has higher maximum temp, which is appealing near vacuum tubes I think.I am curious about pulse overload capabilities. I did alot of replacing CC resistors that were drifted, or had burn marks on the PCB, in many old test equipment with Metal Oxide resistors, which I understood are the best choice for replacing a part that only has a 5-10% tolerance.Does anyone have good documents that show pulse overload and high stress behavior that can be compared between MO and CC resistors of similar size/value? Factoids and anecdotes welcome.

author: TimNJ
author_rank: Super Contributor
timestamp: February 03, 2023, 09:23:50 pm
content: Sorry I'm not answering your question here but have you looked at ceramic composition resistors? It's still a composition type (meaning, bulk resistive element...I think), so it will have the benefits of said type.https://www.ohmite.com/ceramic-composition-resistors/Haven't actually used them, just saw them in passing.

author: coppercone2
author_rank: Super Contributor
timestamp: February 03, 2023, 09:25:29 pm
content: oh yeah but they are never available. I tried say looking for 10 of em to replace a bunch of parts on a PCB in a power supply or whatever and it was not fruitful.That is something to keep in mind when you find some odd ball 5W CC resistor

author: coppercone2
author_rank: Super Contributor
timestamp: February 03, 2023, 09:33:52 pm
content: you know, hold that thought. I see ohmmite has a catagory for small leaded one and the PDF says its available in the E values for composition resistors.I think the last time I looked at it, I thought that the PPM might be too high. I guess you can get them, but they are priced at 20x the price of the metal oxide ones.I wonder how much better they are.

author: coppercone2
author_rank: Super Contributor
timestamp: February 03, 2023, 09:46:20 pm
content: I will get a few Ceramic resistors to run impedance analyzer tests on
compensating external error factor using main feedback mechanism in FLL - Page 1
Forum section: electronics / projects

author: john23
author_rank: Frequent Contributor
timestamp: December 30, 2024, 08:31:56 pm
content: Hello, I have built a system shown below by the attached article.Its a frequency locked loop.basicky I am using a YIG as VCO to tune it exactly to the cavity resonator.The phase and amplitude of the resonance shown below.The mixer acts as a frequency discriminator by the behavior in photo 3.So if we input a tone at some frequency and look what IF (error voltage) we get at point B as shown in photo 4 and 5 .The main problem I have is the YIG VCO.The YIG has two coils which we tune.A large coil call "tune" and a small coil called FM.The large "tune" coil is being fed near the resonance area,while the smaller FM coil is the coil I use to tune the error of the mixer IF (frequency discriminator) which compares the signal coming from the cavity resonator and the signal coming from the YIG.The second coil is FM coil:1.5uH inductance and 1Ohm resistance FM coil.sensitivity 400Khz/mAThe main problem is that I am tuning the error using the FM coil while the tune coil (which is biased by constant voltage) is not in the feedback fixing mechanism I only have the FM coil to compensate for the gap between the YIG and cavity signals.I was told to use a PI controller(between the IF output and YIG input )to compensate fro the tune drifting.Is there some strategy on how what parameters the PI controller should have to compensate for the exteral frequency drifting caused by the tune coil?Thanks.
Complementary feedback pair / Sziklai as DC filtering, solving - Page 1
Forum section: electronics / projects

author: triedgetech
author_rank: Newbie
timestamp: June 19, 2023, 11:00:03 am
content: nvm, didn't get help with thevenin process

author: wasedadoc
author_rank: Super Contributor
timestamp: June 19, 2023, 11:24:54 am
content: No, Rth is closer to 10k. When you short out the voltage source you have zero Ohms across the 15k. Then you havetwo4k7 resistors in series..

author: Marco
author_rank: Super Contributor
timestamp: June 20, 2023, 06:53:59 am
content: Quote from: triedgetech on June 19, 2023, 11:00:03 amIf that is all you want to know, don't make life hard. 5ma*180 is 900, so the PNP is always active barely.Increase R33 10x so it's definitely active, then the base current through the NPN is a bee's dick and R36/R37 don't matter much. Though R37 could be a wee bit smaller for lower noise. Currently they will drop around half a volt, which seems a lot.Your zener is wrong way round BTW. R39 is just a bias resistor for the zener, the low pass filter sees the differential resistance of the zener for AC and a voltage drop from the input for DC approximately. Save Thevenin for when it matters.

author: Marco
author_rank: Super Contributor
timestamp: June 21, 2023, 06:45:11 pm
content: Quote from: triedgetech on June 21, 2023, 03:17:47 amIgnoring R36/R37 that's not giving the NPN much headroom to work with, Schottky diode voltage is close to Vcesat. It works right now because R37/R36 are dropping so much voltage, but if you're going to rely on that you might as well make R36 larger and forget about the diode.QuoteDid you try changing R37 (the base resistor) separately from R36 (the low pass resistor)? R37 is just there for stability, but it will amplify base current noise.
Complementary half bridge driver - Page 1
Forum section: electronics / projects

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 29, 2021, 07:43:36 pm
content: If you were wondering if they make P-ch gate drivers, wonder no longer -- well maybe still a little, but this at least exists:https://www.mouser.com/datasheet/2/308/1/FAN3278_D-2311529.pdfFirst anything-P-channel driver I've even seen, I think. Dual outputs, for complementary bridge. No bootstrap, DC operation. Includes internal regulators. Only 30V max load supply. Reasonably fast, albeit somewhat weak (0.5/1A). TTL/LVCMOS input. Complementary drivers, using the totem-pole configuration like IRS2186 and friends use, but complemented obviously for each side, interesting. Quiescent current kinda high, not enough to notice in typical applications but kinda rules out battery operation.Some jank, like notice the high-side regulator on the block diagram, making a rail, labeled with its voltage...that's then shorted exactly to ground. I'm sure that's a typo, but really...Downside: completely out of stock everywhere, so uh, good luck with that. Maybe there are similar parts, or someone will come along with a big 100k order (for same, or a newer equivalent) and us little players can get some scraps, who knows...Aside, about IRS2186 and friends: they do in fact appear to be totem pole, no internal bootstrap/boost/charge pump. Vbs - V_OH is something like 1.5V at Io=0, it's a source follower pullup(!). Most others are CMOS (e.g. ye olde IR2101, or NCP5183, etc.).I've been looking through bootstrap/dual drivers today. Another trivia: haven't seen any BJT-boosted types. I'm guessing those are either not worth the effort, or are outright incompatible with the HVIC process. IIRC, they are common among low-side drivers though.Tim
Complete Project: Arduino & TLC5940 LED Driver + Blender Render - Page 1
Forum section: electronics / projects

author: noSun
author_rank: Contributor
timestamp: December 26, 2015, 06:58:13 pm
content: This is my latest project. The most involvedproject I've done so far. Everything was completely modeled in Blender.The video features Blender animation, 3D printing, board fabrication, project assembly & final demonstration.

author: MattHollands
author_rank: Frequent Contributor
timestamp: December 27, 2015, 01:02:59 pm
content: Very pretty! If only I had a 3D printer

author: prasimix
author_rank: Unknown
timestamp: December 27, 2015, 03:01:07 pm
content: Awesome usage ofBlenderand 3D printing. I'm wondering how big is an effort for experienced Blender user to make such model and after that make a preparation for 3D printing. Many people wish to have in the neighborhood someone like you (me first).

author: BFX
author_rank: Frequent Contributor
timestamp: December 27, 2015, 05:09:32 pm
content: Big effort for simple construction but nice

author: noSun
author_rank: Contributor
timestamp: December 27, 2015, 09:12:34 pm
content: Thanks all.I've done other project where I modeled them too... I am beginning to accumulate a descent component library (resistors, caps and such).thanks for watching.
completed project: Analog-ish themed digital RGB LED wall clock. OVERKILL ! - Page 1
Forum section: electronics / projects

author: Asim
author_rank: Regular Contributor
timestamp: March 25, 2017, 11:01:30 am
content: Hello people of earth!.I recently completed my wall clock and I thought of sharing the project here.while surfing youtube, I came across this video which inspired me to build my own.1. Mechanical design & constructionthe design consists of:a. front face of plywood cut by laser cutterb. Back face of plywood which is sandwiched between the front face the electronicsc. acrylic diffuser ( will be inserted in the front face) to distribute the LED light evenly.2. Electronicsa. 182 addressable RGB LED known as WS2812b or neo pixel in the maker community where used to display time, day, & date. ( this is the overkill )60 LEDs to represent the arrow for the minutes + 12 LEDs for the hours + 110 LEDs as the matrix display for the date & dayb. control boardall the PCBs in one pictureassembly completed.Picture of the front facePicture of the back faceThe clock in action.9:52 , 24/03 <<< 24th of March9:52, Friday AMnote: I decided to remove the seconds because it was too muchwhat is left to do is a bit of artsy coding to play with RGB leds.Hoping you find it interesting.Regards,Asim

author: BrianHG
author_rank: Super Contributor
timestamp: March 25, 2017, 11:48:07 pm
content: That green thing pointing down to the left between 0:15 to 0:30Just modifying that inner circle arrow shape, or, change the animation's combination should cover up the problem.

author: Asim
author_rank: Regular Contributor
timestamp: March 26, 2017, 04:01:44 am
content: Exactly what I thought 😂
Completed: rfm12trx - Page 1
Forum section: electronics / projects

author: kiu
author_rank: Newbie
timestamp: August 19, 2012, 10:01:08 pm
content: Hi,i finished my latest project called rfm12trx. It is a simple RFM12 433 Mhz transceiver, which can be used to control and monitor all kinds of tinker projects. Just plug it to an USB port, fire up a terminal and start transmitting data. Hope you like it and build some great project based on this technology...Check it out:http://www.schoar.de/tinkering/rfm12trx/All files (eagle, mechanics, src, bom, ...) are published and available under creative commons.kiu
Complex frequency of an exponentially damped sinusoidal function - Page 1
Forum section: electronics / projects

author: T. Mandresy Billy
author_rank: Newbie
timestamp: December 02, 2018, 05:37:25 pm
content: In my textbook,Engineering Circuit Analysis 8.Ed by William H. Hayt (Chapter 14, Section 14.1 page 536)I stumbled across a section explaining the complex frequency. The goal is to cover the concept of complex frequency when it comes to exponentially damped sinusoidal functions.https://my.pcloud.com/publink/show?code=XZPPlg7ZngPpIC2dhafb9scO3EVjpHvok5pyHOW DID THIS HAPPEN?How did eσt become ejσt out of the blue?And why did ej(ωt) become ej(jωt) ? Any help would be much appreciated.

author: Wimberleytech
author_rank: Super Contributor
timestamp: December 02, 2018, 06:02:55 pm
content: It comes from Eulers relationship

author: T. Mandresy Billy
author_rank: Newbie
timestamp: December 02, 2018, 06:11:07 pm
content: Thanks for stopping by. I know this Euler's relationship. The real mystery is below. Look at it and you will find, from the mathematical expressions that:exp(σt) become exp(jσt). How did this happen?why did exp(jωt) become exp(jjωt)?AN ADDITIONAL j SUDDENTLY APPEARS.

author: Wimberleytech
author_rank: Super Contributor
timestamp: December 02, 2018, 06:15:38 pm
content: Sorry...when the image came on my screen i did not see the last line.It is just algebra to get to the last step. First get all terms in the form of e^x and then recombine.There is a typo in the book. That accounts for the extra j. It should not be there.

author: T. Mandresy Billy
author_rank: Newbie
timestamp: December 02, 2018, 06:34:33 pm
content: Glad to be reassured it was just a typo. I will email the editor about this then.

author: SiliconWizard
author_rank: Super Contributor
timestamp: December 02, 2018, 06:46:40 pm
content: Yes it's incorrect. They introduce the notion of complex frequency:s = σ + jωprobably as a preliminary to get you to the Laplace transform.

author: Wimberleytech
author_rank: Super Contributor
timestamp: December 02, 2018, 07:46:12 pm
content: Quote from: T. Mandresy Billy on December 02, 2018, 06:34:33 pmLOL...I am an author of an EE textbook. I hate it when someone informs me of an error...but they creep in, no matter how hard you try.
Compliance for projects in Australia - Page 1
Forum section: electronics / projects

author: Votality
author_rank: Contributor
timestamp: May 10, 2015, 03:15:49 pm
content: Hi,A number of years ago now (10+) a friend of mine who used to work in tv repair in Australia, but also made custom electronics projects got out of the industry due to diminishing returns of consumer electronics repairs and the costs of getting compliance for custom electronics projects.Just wondering what regulations and compliance requirements there are for "one off" or small designs selling hundreds of units. I thought I remember him saying that he at-least needed a restricted electrical license (for anything 240v related) and needed each design to be verified (making it uneconomical). Do the regulations apply to audrino type projects with plugin module type designs?

author: moffy
author_rank: Super Contributor
timestamp: May 11, 2015, 01:29:51 am
content: Yeah it is pretty rigorous. Don't know all the details but it is pretty hard to do anything without EMI lab qualification. But projects, like those in Silicon Chip, Jaycar seem exempt. Also it is a complaints based system, I doubt much of what is imported from China would actually qualify. Even the new Waratah trains if you drive by a train line seem to heavily interfere with AM broadcasts, but they still run. It's probably their 3 phase inverter drives, harmonics right in the AM band.

author: kjs
author_rank: Regular Contributor
timestamp: May 11, 2015, 02:34:07 am
content: I only know the Australian market from exporting to it. After the US it's one of the easiest to get things there. Opposite to the US it doesn't have these crazy law-suits with completely unpredictable outcome. We refuse to ship anything to the US but sell quite a bit in AUS.The worst one to sell to is the EU as everything is regulated and customs watches it extremely well........

author: sean0118
author_rank: Frequent Contributor
timestamp: May 11, 2015, 05:59:39 am
content: I was thinking about this recently, do the regulations change if the device is sold in kit form? If the end users house burns down you could blame it on poor assembly...

author: kjs
author_rank: Regular Contributor
timestamp: May 11, 2015, 06:12:21 am
content: That's the work-around for the EU but the kit must clearly state that it is only approved for assembly by or under the supervision of a person educated in electronics........ Then the user is responsible for meeting regulatory requirements.