hybridfree/eevblog-posts huggingface dataset:
Model Rocket Flight Recorder - Page 1
Forum section: electronics / projects

author: Ionforbes
author_rank: Contributor
timestamp: July 12, 2021, 12:35:31 pm
content: Hello Everyone,Just finished this model rocket flight recorder, thought some of you might be interested.MCU is an ATmega1608. I chose it as it's modern, 8-bit (I'm a bit daunted to try 32-bit MCUs yet!), has exactly the right number of pins and I already have an Atmel programmer. It just measures the barometer output for height and integrates the accelerometer output at 4 kHz to work out speed.The barometer is a KP234, normally used in engine intake manifolds. From 0 to 1500m, the output goes from 4V down to 3V (scaled by a voltage divider referenced to a 3V zener). To make use of a greater ADC range with the internal 2.56V reference, I used an ISL28534 instrumentation amplifier to amplify the difference between the 3V zener reference and the KP234 output by 2. In retrospect it's a massively overkill chip for the job but the datasheet looked nice.The ADXL3266 accelerometer is just connected straight to the uC's ADC input, as I'll be using just about the entire +16g range and maybe even -16g range (I imagine aerodynamic deceleration just after motor burnout is quite high). I'm only using one axis though, as I'm assuming vertical acceleraion will completely dominate and should alone give good speed estimates.Besides that, there's a pair of FETs for deploying parachutes and beacon lights though I doubt I'll use these as I don't trust them. A TCR1050m display shows the max height/speed afterwards.The fat capacitors are there to keep the uC powered for a bit in case of power interruptions from vibration or whatever.Feel free to tear my design apart; I want to make it better next timeIon

author: vad
author_rank: Frequent Contributor
timestamp: July 12, 2021, 01:39:31 pm
content: Why pins PD5, PD6 and PD7 are connected in parallel to Parachute net?

author: Ionforbes
author_rank: Contributor
timestamp: July 12, 2021, 04:12:22 pm
content: Quote from: vad on July 12, 2021, 01:39:31 pmRedundancy, in case one pin fails the parachute will still deploy. Not sure if it'd do anything really.

author: Zero999
author_rank: Super Contributor
timestamp: July 13, 2021, 08:12:53 am
content: Quote from: Ionforbes on July 12, 2021, 04:12:22 pmConnecting pins in parallel like that is more of a liability, than improving reliability. What if one pin goes high and another low? You could use ORing diodes to prevent this, but I'm not sure it gains you much.Real safety critical/high reliability systems use two different microcontrollers, running different software, to monitor one another, in case one fails, or behaves irratically. If the rocket isn't huge, then you don't have to worry about safety too much.

author: richard.cs
author_rank: Super Contributor
timestamp: July 13, 2021, 11:03:28 am
content: Perhaps if you really want redundancy on the parachute trigger you could scrap the parallel pin thing and instead replicate Q1, but driven from another source than the microcontroller - say a hardware timer triggered at launch by a comparator on the accelerometer or by a spring-loaded switch.
Modeling Complementary Current Output in LTSpice - Page 1
Forum section: electronics / projects

author: Evan.Cornell
author_rank: Regular Contributor
timestamp: January 18, 2020, 08:11:23 pm
content: Hello, I am looking at AD9102 for use in project. It has complementary current output pins (datasheet says differential, but it is complementary). IOUTFS is about 4mA.From the datasheet:The DAC output current equations are as follows:IOUTP = IOUTFS × DAC INPUT CODE/2^14IOUTN = IOUTFS × ((2^14 − 1) − DAC INPUT CODE)/2^14where DAC INPUT CODE = 0 to 2^14 − 1.My question is this: how can I accurately model in LTSpice this complementary current output, so I can verify the signal conditioning I am putting on the DAC output?

author: magic
author_rank: Super Contributor
timestamp: January 18, 2020, 08:35:01 pm
content: Not sure if you need two ideal current sources (F2, search "cur") configured to produce complementary sinewawes/steps/whatever or something more sophisticated?(It's also possible to generate the complement from a reference source).

author: Evan.Cornell
author_rank: Regular Contributor
timestamp: January 18, 2020, 08:39:11 pm
content: So how would I configure the sources if AD9102 is set to generate a sine wave, that means IOUTP is only pushing current for the positive half of the output wave and IOUTN is only pushing current for negative half of the output?

author: SiliconWizard
author_rank: Super Contributor
timestamp: January 18, 2020, 08:51:36 pm
content: Don't forget to model the output impedance if you want to model things "accurately". The DS states something like 200Mohm.

author: mikerj
author_rank: Super Contributor
timestamp: January 18, 2020, 09:17:37 pm
content: Quote from: Evan.Cornell on January 18, 2020, 08:39:11 pmThat isn't quite how the outputs work. In the positive half of the waveform IOUTP will be higher than IOUTN (and vice versa), but both outputs will be sourcing current until you reach a waveform peak/trough when one output will be at zero.You can use the behavioural current sources in LTSpice to emulate this behaviour, something like the attached circuit. This is far from a simulation as everything is ideal.
Modeling LED  - Page 1
Forum section: electronics / projects

author: Patrick66
author_rank: Regular Contributor
timestamp: April 03, 2024, 01:26:17 am
content: Hello everyone, is this the correct way to model the LED of 20W using two 10W LED based on the figure below with the datasheet of the LED? Thank you in advance for the help.

author: Zero999
author_rank: Super Contributor
timestamp: April 03, 2024, 07:28:17 am
content: Why create a new thread?https://www.eevblog.com/forum/projects/modeling-led-in-ltspice/

author: Halcyon
author_rank: Unknown
timestamp: April 03, 2024, 09:35:18 am
content: Duplicate thread.
modeling the  effect of pullup resistor to current drive a load - Page 1
Forum section: electronics / projects

author: john23
author_rank: Frequent Contributor
timestamp: August 24, 2024, 04:35:57 pm
content: Hello, pullup resistor Is a mean to increase pullup current of an IC to drive a load.Is there some simple device with a load wherei could see if the pullup resistot does the job or not?Thanks.

author: PGPG
author_rank: Frequent Contributor
timestamp: August 24, 2024, 11:42:44 pm
content: Trying to understand what you are asking...You distinguish between IC pullup current and pullup current added by pullup resistor and you are interested only in current added by this resistor.So you not ask about internal pullup as it is included in IC pullup current.From that it looks that you are asking for device to check if that external pullup resistor is not broken. To check resistor you can use ohmmeter but I don't know if the ohmmeter meets your requirement of being a simple device.
need more BP CURVES - Page 1
Forum section: electronics / projects

author: MacIntoshCZ
author_rank: Regular Contributor
timestamp: December 27, 2023, 08:40:40 pm
content: Trying to model core for losses but need BP curve atleast for two different frequencies. But in datasheet is only one for 100Khz ->https://www.tdk-electronics.tdk.com/download/528886/f7953b4caf14b9c4a15e34b60fb09812/pdf-n97.pdfIs there any place where this curves can be found (without asking distributor)?Thanks
modern dieselelectric subs - Page 1
Forum section: electronics / projects

author: m3vuv
author_rank: Super Contributor
timestamp: April 16, 2021, 01:58:05 pm
content: just wondered if they now use lead acid cells now or lithium ion?

author: penfold
author_rank: Frequent Contributor
timestamp: April 16, 2021, 03:10:59 pm
content: It's an interesting question. For military applications, I believe the answer may be considered a secret since it has implications on the performance and range of a sub. There are definitely manufacturers of li-ion submarine batteries and with fewer exemptions from RoHS etc for military applications, increases in performance and safety of li-ion, there are fewer reasons to go lead-acid. I believe the Japanese have announced the use of li-ion in some subs.The submarine "industry" closer to home is however very, very conservative and the programme life can be upward of 80 years which puts constraints on the availability of supply, dependency on other nations that produce sufficient quantities of lithium and a need to stockpile spares, all of which make lead-acid more favourable. I would imagine that there is a certain amount of flexibility designed into the system for both diesel-electric and nuclear subs such that some of the risks can be mitigated and an alternative battery technology be changed in during the 10- or 20-year refits.Hope that's something to go on, but I don't think it's an exclusive yes or no answer across the board.

author: ledtester
author_rank: Super Contributor
timestamp: April 16, 2021, 05:03:31 pm
content: Maybe lithium-ion:https://www.theguardian.com/world/2019/jul/23/russia-submersible-fire-faulty-battery-may-be-cause-reportsQuoteAnother article (2018) about the Japanese using Li-ion for one of their subs:https://www.lithium-battery-factory.com/submarine-lithium-batteries/One issue mentioned is dissipating the extra heat given off by Li-ion batteries.

author: bsdphk
author_rank: Regular Contributor
timestamp: April 16, 2021, 05:28:19 pm
content: Funny story...Some Country™ tried refurbish their submarine's lead-acid's with LiON, without doing the math, and not only was it no longer a submarine, it nearly capsized in the dock.Since then refurbishing to LiON has in at least one case been done by keeping the bottom-most layer of batteries as lead-acid, but it will depend entirely on the design if that is possible.New designs all seem to be LiON, and for a good reason: Less hydrogen.
Modern general purpose audio JFETs - Page 1
Forum section: electronics / projects

author: John B
author_rank: Frequent Contributor
timestamp: March 14, 2019, 02:39:36 am
content: I'm starting to run low on my old bags of TO-92 JFETs that I used for general audio. Stuff like PN4416, 2N5457, along with other numbers PN4393 and 2N5486 that I ran out of long ago.I think they are all obsolete now. I was looking around on LCSC.com to see what they have. As an aside note, JFETs are listed as MOSFETs, making the search harder.Am I right in thinking that the modern equivalents in SMD packages are:PN4416 -> MMBF44162N5457 -> MMBF5457I also had a look on Digikey Aus to see what they have. None of those regular ones are listed, but at least they have a catalogued list of JFETs.But now seems like a good time to see what others are using for general purpose audio JFETs. Sometimes I use them for their linear qualities, sometimes just as switches.

author: jlmoon
author_rank: Unknown
timestamp: March 14, 2019, 05:26:50 am
content: 2n7000 / 2n7001 are cheap and work well for low power stuff. Make great switches too!

author: jwm_
author_rank: Frequent Contributor
timestamp: March 14, 2019, 06:08:04 am
content: Quote from: jlmoon on March 14, 2019, 05:26:50 amThose are MOSFETs, not JFETs.

author: Calvin
author_rank: Regular Contributor
timestamp: March 14, 2019, 06:22:31 am
content: Hi,the 4391 to 4393 should still be active from ONSemi.Then there are the lownoise Toshiba-clones LSKxxx form Linear Systems.A newer lownoise device could be the 2SK3547.regardsCalvin

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 14, 2019, 03:57:46 pm
content: Quote from: John B on March 14, 2019, 02:39:36 amWell, compare datasheets. The 2N5457 and MMBF5457 share the same datasheet (obviously with different power dissipation figures). Eg:https://www.onsemi.com/PowerSolutions/product.do?id=MMBF5457PN4416 and MMBF4416 seem to have slightly different characteristics from what I found but again datasheets will help.I've personally used the MMBF4393 with no noticeable difference compared to 2N4393, same with SST201 instead of J201.

author: John B
author_rank: Frequent Contributor
timestamp: January 31, 2021, 07:47:06 pm
content: Press F to pay respects to the 4416 JFET.

author: profdc9
author_rank: Frequent Contributor
timestamp: February 01, 2021, 05:16:35 pm
content: There appears to be Central Semiconductor parts. I have used the 2n5486 in RF projects, but it appears to have low noise figure at low frequency (1.5 dB or so):https://www.mouser.com/Search/Refine?Keyword=2n5486Also makes a 2N5457 replacementhttps://www.mouser.com/ProductDetail/Central-Semiconductor/2N5457-BK-PBFREE/?qs=OlC7AqGiEDlzXz7ZBahsRQ%3D%3DKind of expensive but still available.

author: Zero999
author_rank: Super Contributor
timestamp: February 01, 2021, 08:12:51 pm
content: The 2SK2394 looks decent for low noise applications.https://docs.rs-online.com/8558/0900766b8127c95a.pdf
Modern replacement for obsolete IC - Page 1
Forum section: electronics / projects

author: CanOfSardines
author_rank: Newbie
timestamp: October 07, 2023, 05:47:27 am
content: I'm working on a video mod for an old Atari system. The circuit I'm copying calls for an obsolete Fairchild partFMS6400 Dual Channel Video Drivers with Integrated Filters and Composite Video Summer. I've only been able to find it from sketchy sellers in China. However, based on the data sheet and my mediocre understanding of electrical engineering, it seems to be essentially a video OP amp. Assuming this is the case, would current production Video OP amp similar toMAX457work as a replacement?Any opinion or suggestion is welcome. Feel free to call me mad as well.

author: moffy
author_rank: Super Contributor
timestamp: October 07, 2023, 06:04:47 am
content: It looks like the FM6400 does quite a bit more than just amplify, it also does a DC restoration of the video signal:https://www.analog.com/media/en/technical-documentation/application-notes/an-1603.pdfas well as providing a composite output. Do you need the composite output? It also works as a low pass filter.

author: coromonadalix
author_rank: Super Contributor
timestamp: October 08, 2023, 01:38:00 am
content: its a family of 6401 ... 6410b 6413 6414

author: RES
author_rank: Regular Contributor
timestamp: October 08, 2023, 06:08:57 pm
content: https://www.digikey.nl/en/products/base-product/on-semiconductor/488/FMS6400/37444

author: wraper
author_rank: Unknown
timestamp: October 08, 2023, 06:12:13 pm
content: Quote from: RES on October 08, 2023, 06:08:57 pmAnd it shows obsolete and zero in stock. You could get some from Aliexpress though. If it's just for one-off and not production, that's a viable option to get them.

author: thermistor-guy
author_rank: Frequent Contributor
timestamp: October 09, 2023, 05:45:24 am
content: It seems to be available:https://octopart.com/search?q=FMS6400&currency=USD&specs=0Rochester lists it:https://www.rocelec.com/part/FSCFMS6400CSAvnet lists it, noting that its stock comes from Rochester:https://www.avnet.com/shop/us/products/onsemi/fms6400cs-3074457345628497958The problem is the MOQ. For low qty, Chinese sources may be your only bet. Good luck.

author: Terry Bites
author_rank: Super Contributor
timestamp: October 10, 2023, 05:20:16 pm
content: have look through this comprehensive selectionhttps://www.ti.com/amplifier-circuit/special-function/video/products.html
Modern SBC based interface/display for old spectrum analysers like Tektronix 492 - Page 1
Forum section: electronics / projects

author: Fflint
author_rank: Frequent Contributor
timestamp: October 25, 2024, 01:58:53 pm
content: I could swear I remember seeing some projects (yes, plural) using a raspberry pi or an ESP32 with minimal extra hardware to sample data from horizontal/vertical outputs of these old, but still very capable spectrum analysers like Tektronix 492 and display it on a nice hdmi screen/share over the network.Recently the digital storage board in my Tek 492 had a fault and it was painfully obvious how usefult of a feature it is when I couldn't use it for a while. I use it all the time. With a tracking generator it turns it into a "poor man's almost-VNA". You can do stuff like measure VSWR of a 5.8GHz antenna by doing an initial sweep with a dummy load, saving it to memory A, then doing the actual sweep with the antenna and displaying A-B. This is just one example of how it greatly extends the basic functionality (without it you would need to have a truly linear setup).The digital side of my Tek 492 is very minimalistic. Basically it has just two memories. It can do peak hold and subtraction. That's about it. I imagine how much more it could do if it had a raspberry pi sampling the data. It would be great to just hook up to the original memory bus and use the original calibrated ADC, but it is going to be much simpler to just process analog data available on back ports.Does anyone know about any site of such project? Google is failing me, but as I said, I'm pretty sure I rememebr seeing something like this.Someone, might ask, why do this when you have NanoVNA. You'll never be able to sample phase information with a SA. True, but what it lacks by not being a real VNA it makes up by the linearity and the frequency range. With external mixers I have I can use it up to 70-some GHz. Try to do that with a NanoVNA...

author: coromonadalix
author_rank: Super Contributor
timestamp: October 25, 2024, 02:11:56 pm
content: if you search Tektronix 492 or 492p hacks and mods, you get some answers, some eeprom hex files dumps etc ... some could be dudor some search here too give some results ...groups.io toogood luck

author: mr ed
author_rank: Regular Contributor
timestamp: October 26, 2024, 02:51:21 am
content: Python script? I have one that just grabs the screen, drives a browser, writes a jpg and csv. You need pyvisa etc and a chinese usb-gpib cable. Comment out what u don't need. It runs binary mode so the screen transfer is under a second.
modern voltage sensing ic equivelent - Page 1
Forum section: electronics / projects

author: m3vuv
author_rank: Super Contributor
timestamp: January 27, 2022, 07:27:20 pm
content: Hi all,i am after a modern equivelent to an mc3423 over voltage sensing ic,the price for the originals here in the uk is about £15 a pop! or 5 from china for about £7,is there a modern inexpensive equivelent?,cheers.

author: tlhsglm
author_rank: Contributor
timestamp: January 27, 2022, 09:52:11 pm
content: Did you checked ic's below Related Electronics Part Number topic?https://www.alldatasheet.com/datasheet-pdf/pdf/12081/ONSEMI/MC3423.html
modify cheap ebay battery tab welder for dual pulse - Page 1
Forum section: electronics / projects

author: m3vuv
author_rank: Super Contributor
timestamp: July 12, 2021, 08:35:15 pm
content: Hi all,i have a 5 mosfet battery tab welder its the mk 1 version with the white buttons,the fets went sc and set on fire on the first weld,i modded it like shown by luca in youtube vids,now to the point in hand,i built a tab welder with a microwave transfo,i used control board from ebay to fire a ssr to turn on the transfo,the controller can set pulse lenth of both pulses and the pause between them,my battery tab welder works fine however,i want to drive the fets from my dual pulse controller,could i replace the output from the original battery tab welder with the one from my dual pule controller,the welder i have is like the maple leaf welder but has 5 fets and a mosfet driver ic driven from the mcu,any ideas?,cheers in advance. its like the one in this with the white buttons,sort of rev1

author: m3vuv
author_rank: Super Contributor
timestamp: October 18, 2021, 02:20:50 pm
content: no ideas anyone?,it works fine as it is after mods but i think a dual pulse could be better,if only just to play.

author: coromonadalix
author_rank: Super Contributor
timestamp: October 18, 2021, 02:25:24 pm
content: normally you need the source code to do such a mod, we have this welder here, and it does a great job for battery tabs, no need for an dual pulse ??Try to find the maker for them ... send them an email ??

author: m3vuv
author_rank: Super Contributor
timestamp: October 18, 2021, 05:02:28 pm
content: it was more to do with hooking the output up from the dual pulse modual that currently drives a ssr with a mot transformer welder to the car battery welder,ie inject the output from the dual pulse timer into the car battery powered spot welder,is that clear?
Modified USB cable for kinect 2 on PC? - Page 1
Forum section: electronics / projects

author: KedasProbe
author_rank: Frequent Contributor
timestamp: August 30, 2014, 11:03:52 am
content: Kinect 2: is a HD 3D video camera for the gaming console Xbox onehttp://www.ign.com/wikis/xbox-one/Xbox_One_KinectM$ made it incompatible with the PC so they can sell the same device again but now for your PC.Obviously if you already have one people don't want to pay 200$ for a second one.Hence people want to see what needs to be hacked to make it work on the PC.I like to know what needs to be done to make it work on a PC, so any info....This is a video of people claiming that a modified USB3.0 cable made it work.Although they don't say what the modifications are, (probably because they want to be the first to sell those cables)Basic Teardown:https://www.ifixit.com/Teardown/Xbox+One+Kinect+Teardown/19725

author: amyk
author_rank: Super Contributor
timestamp: August 30, 2014, 01:17:07 pm
content: Does this help?http://openkinect.org/wiki/Kinect_2It sounds like all MS did was put a proprietary connector on the end of the cable.

author: KedasProbe
author_rank: Frequent Contributor
timestamp: August 30, 2014, 01:30:19 pm
content: Yes, it seems only an extra 12V need to be provided, everything else is just connections.That explains the power supply in the video above.Then there is probably also some tweaking with drivers since they say they got the audio working first and now also the video.Now we would need an idea about the required current.
Modify an LNA? - Page 1
Forum section: electronics / projects

author: mojoe
author_rank: Frequent Contributor
timestamp: February 14, 2024, 08:16:32 am
content: I want to provide some additional amplification to a GPS antenna, to make up for the loss through a passive splitter. I'm currently using a 2-way splitter, which has a 3 dB loss at each port (yes, I'm DC blocking on the 2nd port). I want to buy the 3-way version that has 4.8 dB loss. The signal levels I'm getting now through the 2-way splitter are sufficient, but on the low end. Another few dB loss will only worsen the situation. The antenna is indoors, and there is no possibility of mounting it outside. It is mounted on a section of PVC pipe, to get it up to the ceiling in the upstairs room.I could buy a purpose made GPS amplifier, but they are too pricey for me. I have a Nooelec LNA that is rated 20 MHz to 4 GHz. The LNA is powered by the bias tee voltage from an SDR, however, it doesn't pass DC through to the antenna. For SDR use, this is what you want. I need to pass the DC on, to power the HP 58532A GPS antenna that I am using.Attached is the datasheet for the LNA. In addition, I have clipped the simplified block diagram, so you don't have to download the PDF. There are quite a few more components on the board, including protection diodes on both input and output. My question is, if I adda wirean inductor to jumper the DC to the antenna side, on the left of the capacitor, so DC doesn't get to the amp from that direction, will this work without frying anything? Is this a good idea?I know that this LNA is very wideband, but the GPS antenna isn't going to pass any unneeded frequencies, and the feedline is double shielded coax.Edit: Unless someone can point me to an inexpensive, amplified, 3 or 4 port GPS splitter that has moderate gain.

author: tszaboo
author_rank: Super Contributor
timestamp: February 14, 2024, 03:58:06 pm
content: You can place a part called "bias T" between the LNA and the antenna, and power it from there. What you plan to do is building in this bias T into the LNA's box, before and after the LNA, that would work as well if made correctly.

author: David Hess
author_rank: Super Contributor
timestamp: February 15, 2024, 01:36:25 am
content: I am surprised that the HP 58532A GPS antenna does not have enough gain by itself.

author: mojoe
author_rank: Frequent Contributor
timestamp: February 15, 2024, 03:03:53 am
content: With the antenna indoors, the highest I'm seeing with the 2-way splitter is 42 dBc. The 3-way will knock another 2 dB off of that. Most sats are in the 30's or lower.

author: jbb
author_rank: Super Contributor
timestamp: February 15, 2024, 08:22:52 am
content: Possible stupid idea: why not stick another GPS antenna up next to your existing one?

author: mojoe
author_rank: Frequent Contributor
timestamp: February 15, 2024, 10:02:13 pm
content: To compare things, I want to use the same antenna and feedline. Besides, the HP antenna is much better than any other GPS antenna that I have.
Modify an "on-line" UPS to act more or less as a hybrid inverter - Page 1
Forum section: electronics / projects

author: szix96
author_rank: Newbie
timestamp: September 20, 2022, 03:30:56 pm
content: Hello all,I am trying to use one of these Chinese "on-line" UPS (FSP champ 3k or Huawei UPS2000-A-3KTTS or other Chinese "on-line" UPS based on 72V Battery)Link:https://drive.google.com/drive/folders/1gHkGKRHs5HiKuCMkqvcKODbWy5uzNb38?usp=sharingMy goal would be to attach a new DC source e.g. a solar MPPT.My first tought was to connect the MPPT to the battery, but sadly this is a cheap "on-line" UPS and it has no constant link to the battery during normal operation just when the Mains rectification fails guess better power efficiency and cheaper parts.So my next goal would be to step-up the MPPT voltage from 30-80VDC to 370VDC to the same voltage as the rectified H-Bridge DC rail has.Sadly I cannot find a better way to connect a new DC source in a way that it is works like a hybrid inverter, in which the Solar only helps out the incoming Mains power when solar is available and do not feed back to the Mains.And question would be that is there a known circuit/boost converter which could accomplish this goal with a price tag which is not over shoot a new hybrid inverter?If there is none but you would help me with designing one I am happy to pay for it.I found some 40-70W solutions on trusty Aliexpress with 370,0,-370 rails, but nothing else.Any help is really appreciated.Many thanks in advance.P.S.MOD's:if this is opened to a wrong category please move it to a correct one.

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 20, 2022, 10:20:49 pm
content: Quote from: szix96 on September 20, 2022, 03:30:56 pmThe rectifier will not allow current to back up to the mains unless it's synchronous, extremely unlikely at mains voltages. Just set the MPPT output voltage limit to just above the PFC setpoint and it will give preference to the MPPT for powering the load. Managing battery charging would require another mod.What you really want is a "zero export inverter", which feeds power back to your breaker box but limit it so that it doesn't go out to the grid, only to your on site loads.

author: szix96
author_rank: Newbie
timestamp: September 21, 2022, 09:48:10 am
content: Hi NiHaoMike,Thank you for your reply, my goal would be not to feed back to mains but to feed in to the Rectified DC side of the Mains to share the load side between the rectified Mains and the MPPT.In this way when the MPPT can supply power then the load would be lower on the Mains side, and when it cannot there would be no switching between MPPT and Mains source of power just shared.The load side will be not connected back to mains and the load is only connected to the load side of this diagram:Thinking something like this:https://drive.google.com/file/d/1aNJX0-PIluXEZGo016KgMvfA8mgZDXjT/view?usp=sharing

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 21, 2022, 01:45:41 pm
content: Quote from: szix96 on September 21, 2022, 09:48:10 amThat should work.
Modify Weller WXD2 using vacuum pump instead of compressed air to achieve vaccum - Page 1
Forum section: electronics / projects

author: 4cx10000
author_rank: Regular Contributor
timestamp: August 04, 2025, 04:07:18 pm
content: I am about to modify my Weller WXD2 to work with a vacuum pump instead of using compressed air (35L/min / 58-87 psi) (which is connected to an inlet at the rear of the WXD2) to achieve vacuum. I bought a small vacuum pump which is quite powerful and does not make that much noise. I tried it by simply connect it to the hose that goes to the desoldering iron WXDP120 and it works extremely good. I have used the WXD with compressed air for a long time and it sure works fine, but I am tired of the noise from the compressor so that is why I am heading for a vacuum pump.Inside the WXD2 there is a valve that control the vacuum flow and is activated by a little button on the WXDO120. What I want to accomplish is to modify the vacuum unit, which I have not seen physically yet, in order to connect vacuum to the rear inlet instead of compressed air and thus, as I hope and believe, I will be able to use a 1-10 second delay for the vacuum. As I understand a delay of just a few seconds will somehow buffer the vacuum and when the valve releases it will create a very powerful and instant action that will effectively suck the joint clean from solder – I hope!Before I even open my WXD2 to see how it looks like inside, my question is if someone has some wise words along the way too what I hope will end up in success?
Modifying $3 DMM (Generic 838) for extremely fast DC/Ohm response. - Page 1
Forum section: electronics / projects

author: DavidAlfa
author_rank: Super Contributor
timestamp: February 18, 2024, 06:43:17 pm
content: My brother's car died, the control unit in the steering wheel was taken over by some angry gremlins, it's turning random stuff on, like wipers, lights, not recognizing the key and making incomplete beeps, like it was rebooting or something.As I don't have any portable scope to watch the voltages, and a DMM is too slow to catch spikes/drops, I thought on modifying a cheap AliExpress DMM I threw in the boot some time ago for emergencies.Basically:- Reduce the input RC integrator.It's made of 1M + 100nF, swap to 1nF so it allows much faster response.- Increase the RC oscillator frequency to have more readings.It's 100K + ?pF, running at 48KHz. Replaced with 22K resistor, increased to about 120KHz, giving a lot more readings per second.Now it can detect square signals up to 25Hz.LCD update rate is about 10Hz.Not that I can see a value changing so fast, it's about seeing something is wrong there.If the voltage is steady you'll get a fast changing decimal.Also this provides extremely fast "beep" response, unlike before where it took 1/2 sec.Downsides: AC voltage is useless as the integrator no longer filters properly. Not a problem in a car.
Modifying a 1KHz Low Distortion Audio Range Oscillator - Page 1
Forum section: electronics / projects

author: enut11
author_rank: Super Contributor
timestamp: January 29, 2022, 09:52:59 am
content: This audio signal generator design is sold on eBay as a 1KHz Low Distortion Audio Range Oscillator. Preferred power supply is +/-15v although it will work down to +/-9v or less. At 15vDC it outputs up to 7vRMS. A 2K pot on the output is all that is required for variable amplitude.It can be purchased as a kit or fully assembled. Performance is excellent with distortion <<0.01% and if fed from a regulated supply provides a very stable amplitude.

author: enut11
author_rank: Super Contributor
timestamp: January 29, 2022, 10:02:39 am
content: My application needs a variable frequency up to about 20KHz so I was playing around with changing the values of R6/R7 (ganged 10K pot) and C1/C2.Frequencies lower than 1KHz were easy to achieve but the high frequency limit seems to be about 6KHz after which the signal becomes unstable in both frequency and amplitude.I suspect this may have something to do with the amplitude control circuitry around TL071 but I do not understand how this part of the circuit works.Any suggestions on how to proceed?

author: Renate
author_rank: Super Contributor
timestamp: January 29, 2022, 02:27:38 pm
content: I think you have to decrease C3/C4 proportionally to increase speed of response and retain stability.

author: enut11
author_rank: Super Contributor
timestamp: January 29, 2022, 08:17:23 pm
content: thanks @Renate. Changing C4 to 0.047uF and C1/C2 to 0.0047uF allowed me to push the frequency up to 12KHz before instability. Lower frequencies were not affected by this mod.

author: Vovk_Z
author_rank: Super Contributor
timestamp: January 29, 2022, 11:50:59 pm
content: R1, R2, R3 values influence stability too. So you may play with them.
Modifying an ESP32-Cam to capture 8bit parallel - Page 1
Forum section: electronics / projects

author: pieroc91
author_rank: Contributor
timestamp: March 30, 2023, 02:51:51 pm
content: Hi everyone.Well what the title says, i'm trying to capture data from an 8bit parallel ADC and the ESP32-cam seem to be a perfect starting point.The included OV2640 camera is a 10 bit parallel device wired for 8 bit plus Pixel clock, exactly what i need to capture.It includes an 4MB PSRAM for buffer, I only need to capture 2MB.It has an SD Card to store the capture data.First of all I wanted to know if anyone has already tried and can confirm that is actually doable. And what I mostly need is some help with the code, I'm mostly used to gate level coding and high level coding makes me feel quite lost.Any help is greatly appreciated.
Modifying control signal from 0-10V to 25%-75% of supply  - Page 1
Forum section: electronics / projects

author: somlioy
author_rank: Regular Contributor
timestamp: January 03, 2019, 11:03:17 am
content: I have a component that has a nominal supply of 24V from two batteries.The component also has a signal input which is voltage controlled. The voltage range of the signal is dependent on the supply voltage,ie. ranging from 25% to 75% of the supply voltage. Outuside this range the component goes into an error state.How could I controll this component from either 0-10V or 4-20mA (1-5V over 250ohm) ?
Modifying current loop circuit - Page 1
Forum section: electronics / projects

author: sw_guy
author_rank: Regular Contributor
timestamp: January 15, 2024, 08:45:45 pm
content: Hi,Maybe someone could help me to modify the circuit the way that "Smart sensor" part is always on. I think U5 is maintaining stable current only when Rload is connected. And it did not even do that since MAX4493 blew right away I connected power. Not sure why it was chosen to the circuit the first place - for me it looks like it can't handle the worst case voltage scenario. But the primary objective is to keep smart sensor running one way or another.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: January 15, 2024, 09:28:32 pm
content: When I saw those maxim chips I immediately lost any interest.

author: sw_guy
author_rank: Regular Contributor
timestamp: January 16, 2024, 03:07:14 am
content: I am not a fan of Maxim myself either. What I am thinking of is to connect grounds together (switch point) and create a constant current circuit replacing the U5 circuit. However, the accuracy is then as good as the constant current circuit is... and that can be probably mitigated by using the reference voltage that would give a constant reference voltage for the constant current circuit. Maybe there is a better option...sw guy

author: sw_guy
author_rank: Regular Contributor
timestamp: January 24, 2024, 09:14:00 pm
content: I solved the original requirement separating the smart sensor part (which is STM MCU in practice) totally separated from the circuit. Connection between MCU and DAC is done using SPI isolator. I just have another issue: the DAC I am using (together with the SPI isolator) consumes too much current. I don't think I can use the MAC4493 part for DAC. I could use it to SPI isolator, but still the total consumption is 5.4 mA.I am iterating options to make it work. Any ideas?The best idea I've have had so far is to make constant current circuit and make alternative return path.sw guyThe current version of the circuit is this:

author: sw_guy
author_rank: Regular Contributor
timestamp: January 25, 2024, 06:31:20 am
content: Hmm... maybe just adding a resistor to provide second return path is enough :-)

author: sw_guy
author_rank: Regular Contributor
timestamp: January 25, 2024, 02:44:16 pm
content: I though the idea of adding alternative return path using constant current circuit would work, but it does not. Well, it works, it reduces the current a bit from the main circuit, but still the minimum current flowing thru the measurement load is 5.4mA and it is naturally 1,5mA too much..
Modifying Makita ADP05 for General DC Source Use - Page 1
Forum section: electronics / projects

author: VK5RC
author_rank: Unknown
timestamp: December 26, 2015, 07:20:42 am
content: I have quite a few of Makita's 18V LiIon LXT tools and have accumulated quite a few of the batteries and was looking for a good lithium battery for Ham field use. I saw Mikeselectricstuff's youtube where he started a truck having recharged its battery using one of these batteries.The hard part is making a nice fixture to attach to the battery with reasonable contacts, and my local hardware store had ADP05 (the USB charger) for AUD 30, while not cheap, in headache saving and durability, it ends up being reasonable value for money.The ADP05 comes apart easily with two screws, the circuit card is soldered in by two flying leads only. Attach a cable, a bit of heat shrink, a zip tie cable restraint, a FUSE then my standard DC connector, the Anderson Powerpole.And as Dave would say "Bob's your Uncle"!

author: nukie
author_rank: Frequent Contributor
timestamp: February 06, 2016, 11:28:49 am
content: Quite a bit of electronics for a 18V to 5v 2A x2 buck circuit, looks like its got seperate components for individual circuit. Nicely done, good buy for the price.
Modifying the frequency of a ZVS oscillator - Page 1
Forum section: electronics / projects

author: maqce
author_rank: Newbie
timestamp: December 08, 2021, 05:11:07 pm
content: Hi everyone,I recently buit a ZVS oscillator (Mazzilli's) for an ozone generator. The output frequency is above 20kHz and I'd like to lower it around 10kHz. How can I modify this circuit (schematic below) ?Thanks,Max

author: Weston
author_rank: Regular Contributor
timestamp: December 08, 2021, 06:53:00 pm
content: The resonant frequency is determined by the parallel resonant tank circuit formed by the 0.68u capacitor and the magnetizing inductance of the transformer, as measured from the two ends of the primary winding.You can lower the frequency by increasing the capacitance or by adding more turns. At some point you might need to worry about the transformer saturating at a lower frequency, so it might be better to add more turns? That would also decrease the output voltage though.

author: moffy
author_rank: Super Contributor
timestamp: December 10, 2021, 01:50:28 am
content: A lower frequency also tends to mean higher circulating currents, through the transformer/capacitor and switches.

author: bob91343
author_rank: Super Contributor
timestamp: December 10, 2021, 06:30:55 am
content: Also maybe increase inductance of the choke from the power source.This circuit probably saturates the core on peaks, which tends to reduce feedback and make the oscillation decay. I think. Then it restarts in the opposite side.
Modular Car Radio with a Raspberry Pi + Touchscreen - Page 1
Forum section: electronics / projects

author: Symax
author_rank: Contributor
timestamp: December 26, 2018, 05:36:22 am
content: I'm pretty sure there are other Raspberry Pi car radio projects out there, but I want to make sure at least the radio has the basic features of AM/FM radio and potentially a CD/DVD player as well as a (real time) clock.Other potential features:Backup cameraGPS with turn by turn directions (and potentially automatically set the clock time with timezone boundaries)Auto dim and auto volume levelsBluetooth pairing with many devicesUSB port for flash storage and readingOption to play DVD movies from flash drive or DVD playerPossibly a 5 CD/DVD changer (if one can be found)Option via a Cell phone module for cellular data and/or voicePossibly read OBD-II diagnosticsSome voice controlsScrew terminals supporting a multitude of car radio jack types.I do realize that the majority of the space for a standard car radio could easily be taken up by that of a slit based CD/DVD player For the containment size, so far I'm looking to standardize on the equivalent case size provided in the Ford Windstar since the Official 7" Pi touch screen is about that same size (unless a better touch screen is found). At the moment I'm looking for feedback as to what components to include, and would prefer easily obtainable/standardized parts. I do realize that creating a custom PCB for all of this is more than likely necessary. I am aware that there are many other Single Board Computers are available besides the Raspberry Pi. I personally am fond of the ASUS Tinkerboards myself. The idea here is to balance cost, availability, and functionality all within one package. At the moment, I'm leaning towards using the Raspberry Pi 3B+ as the base for this project. I may be swayed to use a Pi Zero, but I do want enough computing power to handle all of the features. I realize this project will require hardware development along with software development (I'm a fan of Ubuntu OS myself).An example component I am looking for feedback on is the AM/FM chip:https://www.silabs.com/products/audio-and-radio/multi-band-radios/si4822-26-27-40-44-radio-receiversBased on the chart and datasheets on that page, I am considering one of the Si4826, Si4827, or Si4844 chips and am looking for feedback as to which one would be best in this application as I'm unable to discern any of the differences between them.As for the modularity of this radio, I consider GPS, Cellular, Camera, Microphone, and possibly a few other non-standard devices to be optional.As for tools that I have available to make this happen; I do have a soldering iron and a 3D Printer. I do have a Toaster oven that I've attempted to convert into a reflow oven, but I have not used this since I built it.As for the CD/DVD module, I want a slit based player and not a tray based player. If you can help me find a source of this type, that would be great!If you want to provide links to other similar projects, I'm willing to examine them.
Modular plugs and stranded/solid wire - Page 1
Forum section: electronics / projects

author: iXod
author_rank: Frequent Contributor
timestamp: March 23, 2020, 02:17:17 am
content: Years ago I would specify Ethernet 8P modular plugs for use with either solid or stranded conductors.I look on Mouser now and using the parameter search, there's no filter for solid/stranded wire.Have things changes such that present offerings can be used universally? Or...?Thanks.

author: Monkeh
author_rank: Super Contributor
timestamp: March 23, 2020, 02:19:16 am
content: There are some universal types (three prongs on the contact), but otherwise, still the usual split. Most don't know of it, doesn't surprise me Mouser don't have a filter for it.

author: iXod
author_rank: Frequent Contributor
timestamp: March 23, 2020, 02:37:44 am
content: The few times I mentioned the fact (unique plugs for each wire type) I got blank stares.One of those secret facts that probably causes lots of intermittent problems in the industry...

author: Monkeh
author_rank: Super Contributor
timestamp: March 23, 2020, 03:04:25 am
content: On a semi-related note, I've just discovered that these are a thing:https://www.rdm.com/R-M-Products/Twisted-Pair-Cabling/FM45-Connectors-and-accessories/FM45-Cat.-5e-Connector-IP20-straight/Plug-FM45-Cat.5e-shielded-or-unshielded-AWG-23-to-26-IP20-568A-B-plastic-housing-R-M

author: ejeffrey
author_rank: Super Contributor
timestamp: March 23, 2020, 02:47:26 pm
content: There are some universal plugs, but stranded wire is by far the standard. Anything you get that doesn't specify you should assume is for stranded.Field termination of plugs is also much less common than jacks. Normally you use solid wire for your horizontal run with jacks on both sides and premade stranded cables to connect to the switch and end device.
modular portable prototyping - Page 1
Forum section: electronics / projects

author: mpp2508
author_rank: Contributor
timestamp: August 05, 2025, 06:11:24 am
content: I am developing a method for prototyping electronics that is resistant to transportation. I lack feedback from potential stakeholders in the development of this project. The first two links are for a rough understanding of what is being discussed. Most likely, you will have to use a translator. But the main idea is clear from the pictures.https://habr.com/ru/articles/808847/https://habr.com/ru/articles/873896/I would be glad to receive your comments and questions, either with ideas for modules or with tips on where else we can organize discussions.https://mpp2508.github.io/The site on GitHub pages is for reference once it is organized. It is currently being filled. There is practically nothing there.I will try to explain briefly why this is necessary. The main idea is to assemble prototypes of electronics in a short time for debugging software or individual hardware solutions. Moreover, this prototype is monolithic, not a tangle of wires on the table. Which is critical if you are developing control electronics for some machine that is located in another place, where you often have to carry the prototype for joint debugging. Or there is a need to carry it from place to place. Even if it is constantly on the table, it is much more pleasant to work with a monolithic prototype than with something that is difficult to move from place to place, fearing to break the design.In addition, if you have several projects that you periodically return to work on, such prototypes are quickly turned off and put on the shelf, and their place is taken by another similar one.There is another application for this prototyping approach. If there is a need for equipment that can be assembled by yourself, but it will be in demand once or several times. That is, buying or making it in the usual way is not particularly profitable, because after use it will turn into a dust collector. And if there are modules, you can assemble, use and disassemble.Something like that.Keep in mind that the text is written with the help of a translator, so there may be some oddities.example of a half-scaler project for a 2k display, for exposing photoresist. module with two ssd2828.possible option for storing modulesblack pill stm32f401STLink v2.1logic analyzer on cy7c68013a

author: coppercone2
author_rank: Super Contributor
timestamp: August 05, 2025, 06:32:38 am
content: I think the box should be conductive plastic with a ground point if your serious (as most electronics card storage boxes are)prepare to pay $100 for a slick plastic box