hybridfree/eevblog-posts huggingface dataset:
GPS reception for embedded devices - tips and tricks? - Page 1
Forum section: electronics / projects

author: Corporate666
author_rank: Unknown
timestamp: July 02, 2013, 04:41:25 am
content: I'm working on a design that will require a GPS module. The housing for the device will be aluminum and the front surface will have a circuit board with LED's on it behind a piece of acrylic.I don't know much about GPS reception, but I know devices like the iPhone can be made of metal with some plastic/glass surfaces and still have good reception - so I think it can be done.My plan at the moment is to either place a surface mount GPS antenna on the circuit board behind the acrylic screen, or perhaps to place an all-in-one GPS module beneath the display board and specify an opening on the top PCB such that the GPS antenna will not be covered by any circuit board above it.If I mount the antenna on the LED board, I need to consider connecting it to the GPS module below (not sure of the specifics of connecting GPS antennas).Anyone have any advice?My main concerns are:-Will having a GPS antenna mounted in a 1.5" diameter aluminum cylinder with an acrylic/perspex cover on one end provide suitable GPS reception (unit will be for outdoor use with plastic surface pointed relatively skyward).-I know very little about antennas. What spec(s) do I want to focus on for best performance?-What issues do I need to consider when connecting the antenna to the GPS module (I'm thinking things like... trace length, isolation from other traces, isolation from the housing, capacitance, etc? I have no idea what is important. Or is it just an easy straight connection?)-Anything else I need to consider or that I'm overlooking?I've ordered this module for testing and getting some code working:http://learn.adafruit.com/adafruit-ultimate-gpsbut still very much open on the module for the final design.Thanks!
GPS RTK robot mower - Page 1
Forum section: electronics / projects

author: Miles Teg
author_rank: Regular Contributor
timestamp: September 17, 2022, 09:23:12 am
content: Hello Forum,I’m opening a subject here to follow my new personal project.Name: Yet another GPS robot mower.Don’t know if there is already equivalent project here. I made a little research on the forum and found nothing associated.Little story: Since 2013 I was making EE design on audio, UI prototype for microwave oven, kitchen robot.End 2019, last electronic project on a nice domotic gateway with LCD screen (google home like)/2020 I switch 100% to environmental project management for my big retail company. Carbon footprint, Life Cycle Assessment, ecodesign. I was excited and involved in this.End 2021, burn out, depression.Nearly one year later and 9 months off I’m maybe 80% back. I leave this company and I’m willing to get back to EE.I still have free time maybe until this end 2022. And to test myself and gest used again to electronic design, thinking, EDA, programming…Got already a functioning Robot mower (Worx) at home. Doing it’s job, but I’m a little bit frustrated by its logic and how it could remain stuck sometimes (too often…)I’ve discovered the openmower project through this video:Found that great, will help to adjust easily the lawn perimeter without moving wires, and let the robot get access by itself to the 3 other small areas around my house (200+80+30m²).So good project to get brain at work again and could have nice finality at home.Here is the old robot mower I found for 140€, a biffy ~40kg, 3 blades, 24V lead batteries robot. RL2000T-72 likeAside my not so small Honda mowerBefore cleaningWould be great to share with you my progress and questions.I’m confident on the HW, but still have lot of questions on the SW choice. Go on Ardumower or Openmower “frameworks”? Or adapt mine with help of a SW engineer friend?Hope this project will create some interest here. I got back in few minutes presenting first block diagrams, component search…

author: Miles Teg
author_rank: Regular Contributor
timestamp: September 17, 2022, 09:46:31 am
content: Here is my actual block diagram, with listed inputs, actuators present on the mowerDriving motors should be ok with the use of 3 DRV8432, on 2 separated boards.On GPS side, before maybe integrating the GPS module directly on main board I will use the ArdusimpleF9R moduleOn Xbee connector I need to find an ESP32 like thing to provide correction GPS RTK from internet to the GPS module. Wifi module should be use also to provide orders and data to main CPU/MCUNeed to experiment battery, BMS and design power supplies around a 7S3P 24V 10Ah LiIon battery.DC/DC covnerter for battery charge would be a on shelf module.-> Need to find a good brand for this Pack + BMSAnd finally get study onOpenMowerandArdumowerto know best SW solution to start designing the CPU or MCU solution. Maybe get our own adapter Ardumower on a ST32F4. Will need to adapt or design the base control SW.
GPS time-beacon (clock that sends time over xbee) - Page 1
Forum section: electronics / projects

author: linux-works
author_rank: Super Contributor
timestamp: August 14, 2015, 09:28:06 pm
content: part of my IoT series of experiments and hacks.it gets time from a ublox neo-7m series gps module, keeps time in the DS3231 rtc module, displays to a 1" oled display (white, behind orange filter) and broadcasts time in checksummed-ascii datagrams over xbee.any other client who is tuned to that xbee PAN can get the updates and set their local clock from this.a client that boots up can also do a GET over xbee and not have to wait for the next broadcast interval.
GPS trolling motor conversion kit - Page 1
Forum section: electronics / projects

author: 1sciguy
author_rank: Contributor
timestamp: August 09, 2021, 04:14:16 pm
content: Been looking at boat trolling motors lately for my small skiff. Apparently the latest thing on the market is a GPS "anchor" or "spot lock" where the motor steers itself and changes thrust to lock itself in position. They cost upwards of $2000-$3500, yet old manual trolling motors can be purchased for under $100. There is definitely a market for a young engineer to make an upgrade kit for DIY people. Not sure of the patent implications, but this is essentially drone technology. I would imagine a GPS chip, microcontroller, and PWM speed controller can be under $100. Rotation of the unit is the hardest part when you want it to be saltwater corrosion resistant. Anyway, thought I would throw the idea out there if anyone wants to explore it. I would do it myself if I weren't so busy with other projects.
GPS Week Epoch Approaching. 6/4/2019 - Page 1
Forum section: electronics / projects

author: CJay
author_rank: Super Contributor
timestamp: February 13, 2019, 08:35:09 am
content: Article linked below, but basically we're about to run out of weeks for GPS because the protocol only allows for a 10 bit number to describe the GPS week so if your GPS receiver has a dodgy week handling procedure then you may be in trouble...I'm pretty sure the Timenuts will be well aware of this but for those of us here who aren't as 'timenutty' and rely on GPS receivers for various things, be aware and keep an eye out for odd behaviourhttps://www.theregister.co.uk/2019/02/12/current_gps_epoch_ends/

author: LapTop006
author_rank: Unknown
timestamp: February 13, 2019, 01:41:08 pm
content: Note that this is the third rollover, so we've been through this before.Most hardware designed by companies around for the last one have a mitigation that assumes any week number that is less than the firmware build date likely means a rollover has happened, so it tends to only be very old recievers that break, and then slowly as they age out.

author: CJay
author_rank: Super Contributor
timestamp: February 13, 2019, 03:55:29 pm
content: Absolutely, a lot of modern receivers will handle it gracefully and there will be no problem for them, I hope mine will too but I will be watching (or logging at least) to find out.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: February 13, 2019, 04:06:17 pm
content: Relatedhttps://www.gps.gov/cgsic/meetings/2017/powers.pdfI might have to dust off my Motorola VP Oncore receivers for the ROFLs... not sure what they do at week roll.
GPS/Bluetooth dual band antenna - Page 1
Forum section: electronics / projects

author: Sebastian
author_rank: Regular Contributor
timestamp: September 06, 2014, 12:03:29 am
content: I want to use this antenna for a project:http://at.mouser.com/ProductDetail/TDK/ANT016008LCD1575MA1/?qs=sGAEpiMZZMuBTKBKvsBmlJJhlM%252b9V0JU3pet0NuRnw8%3dMy question is probably pretty stupid. I am just lacking practical experience with RF designs, I am sure there is a standard solution for my problem, I just can't think of a good one right now.The recommended layout has a single 50 Ohm connection but I have to connect the antenna to two devices, the Bluetooth chip and the GPS modul (or an external LNA). (Both with a band-pass filter for there frequency band in front of them)My first guess would be to build a power splitter but then I obviously loose half the power of my signals.Is there a better solution for my problem? I also thought of using transformers with 50 Ohm impedance on the chip side and 100 Ohm on the antenna side and connecting the 100 Ohm sides in parallel (or 25 Ohm and in series), but I couldn't find transformers like that.EDIT: Well, just after I posted this, I found something promising: Is a diplexer the magic part I need?
gpsdo antenna - Page 1
Forum section: electronics / projects

author: Vgkid
author_rank: Super Contributor
timestamp: June 10, 2014, 06:01:53 pm
content: I recently aquired a gpsdo, i cannot mount an antenna outside, but i can put it in a window. Would it be possible to buy a regular 5v gps antenna and use that, as opposed to a regular antenna.

author: jpb
author_rank: Super Contributor
timestamp: June 10, 2014, 06:13:51 pm
content: One thing to watch out for is the antenna voltage. Modern gps use 3.3V and so modern active antennas are geared for this. Older gps modules used 5V and older antennas are geared for this. I have a modern gps module that produces 3.3V and I bought a GPS antenna off e-bay which turned out to require 5V and it is not happy with 3.3V. I then bought a second timing antenna that is happy with any voltage between 3V and 10V.Other than that I've just used a 3.3V puck antenna in a window and it worked ok - not as good as my outside antenna, but ok.You'll just need to try it and see, the main issue is it will find it harder to keep track especially older units that are less sensitive than modern gps ones.

author: Vgkid
author_rank: Super Contributor
timestamp: June 10, 2014, 10:29:33 pm
content: This is the antena I was looking at:http://www.ebay.com/itm/Antenna-magnet-GPS-Active-TNC-male-plug-90-1575-42MHz-3-5V-RG174-3M-cable-/261348083058?pt=US_Radio_Comm_Coaxial_Cables_Connectors&hash=item3cd98f4572or going with the trimble alternative

author: edpalmer42
author_rank: Super Contributor
timestamp: June 10, 2014, 11:35:26 pm
content: Quote from: Vgkid on June 10, 2014, 10:29:33 pmI don't see anything that says what the gain of that antenna is. It might be good - might be bad.Ed

author: Vgkid
author_rank: Super Contributor
timestamp: June 11, 2014, 12:41:29 am
content: I bought a generic one, now to wait.
GPSDO Frequency Standard 10 MHz DIY - Page 1
Forum section: electronics / projects

author: 0xFFF0
author_rank: Regular Contributor
timestamp: August 21, 2021, 06:51:00 pm
content: GPSDO Frequency Standard 10 MHz DIY. A small project of the last 2 years.Measuring principle: FLLMCU: SAMD21OCXO: Morion MV89AGNSS: Ublox Neo-7M GPSBest measurement result: 6.2E-12 over 4:30h (window closed)Typical measurement result: 5E-11 over 0:16hConnections: 2x 10 MHz sine (+10 dBm into 50 ohms), 3x 10 MHz TTL , 1x 1 PPS TTL, USB-BLogging on SD card and via USBPower consumption: 12 watt (warmup: 30 watt)Metal housing (weight: 2.6kg)

author: MIS42N
author_rank: Frequent Contributor
timestamp: September 05, 2021, 11:27:34 pm
content: What OCXO? Circuit?

author: bob91343
author_rank: Super Contributor
timestamp: September 06, 2021, 03:12:26 am
content: I'd love to have something like that.
GPSDO - multiple satellite systems - Page 1
Forum section: electronics / projects

author: mojoe
author_rank: Frequent Contributor
timestamp: February 17, 2024, 11:04:08 pm
content: For GPSDO use, I know that it is recommended to use just one GNSS system, like GPS. I've also read that you want SBAS/QZSS off. I wonder, has anyone actually done a comparison of the various combinations, and the effect on timing? I'm thinking that since GPS and Galileo both use the same L1/E1 frequency, that the use of those two may not be as problematic as using GLONASS.What effect would leaving SBAS/QZSS on after a survey-in and setting a static position have on timing?If anyone could point to a study where these various combinations have actually been tested, that would be very useful.

author: Solder_Junkie
author_rank: Frequent Contributor
timestamp: February 18, 2024, 10:20:30 am
content: In comparison with my rubidium, using a TinyPFA and TimeLab, I could see no difference in short term stability with my GPSDO, between using GPS, Galileo, or GPS+Galileo. I have left it set on GPS only.If you cannot mount an outdoor antenna with a clear view, using a "hockey puck" magnet mount vehicle antenna on a window ledge with a disc of steel underneath it, will likely work OK. If you are not seeing a good number of GPS satellites, consider adding Galileo as well, but not the Russian or Chinese systems as they are not as accurately controlled as the USA or European ones. My GNSS module is a Ublox M8T with a roof mounted "mushroom" antenna from Leo Bodnar.Having read various manufacturer publications on the subject, the recommendation is just as you found; use a single satellite service (GPS), do not use position correction input (there is no point as you are not navigating), use an outdoor antenna with a good view of the sky, "survey in" the location of the receiver over a period of around 24 hours or more, and use a timing GNSS receiver in preference to a navigation one.For what it's worth, my own measurements between an M8T (timing) and a 6M (basic GPS only navigation) is that with the M8T you can improve the short term stability to about 50% less jitter, it sounds a lot, but we are splitting hairs and spending around 10 times as much for the basic GNSS module. I can obtain around +/-2 parts in 10^11 with an M8T and around +/-4 or 5 parts in 10^11 with a $10 eBay board with an Ublox 6m (or likely fitted with a Chinese fake version at that price). I also have a Leo Bodnar GPSDO and that is only +/-3 or 4 parts in 10^10. All these measurements are short term "per pixel" frequency difference measurements against a rubidium over a 30 minute period using an outdoor antenna. I am only interested in the short term accuracy for holding amateur UHF radio equipment on frequency, or for use with my counter and signal generator.Using a high quality oven is perhaps more important than GPS modules/settings. I use Toyocom (NEC/Epson) TCO6703N ovens which have an SC cut crystal, I bought them several years ago on the surplus market.Hope that helps a little.SJ
GPSDO PLL tuning - Page 1
Forum section: electronics / projects

author: Clemgill
author_rank: Contributor
timestamp: May 26, 2024, 06:12:46 pm
content: Hi,I am working on a GPSDO based on Lars Walenius' design,and looking for information on how to optimize the PLL parameters (PI loop)Such as the : Gain, Time Constant and Damping.I am (reasonably) familiar with the PLL theory (R.E. Best, F.M. Gardner and other references).Lars provides some hints on how to tweak and optimize the constants in his design,but it does not cover the whole story, and I have difficulties to connect theory with practice.I would appreciate sharing experience gained on similar systems.Thanks for pointing me to such helpful references if you know any.
GPSDO project in Silicon Chip magazine (Oct 2018) - Page 1
Forum section: electronics / projects

author: intabits
author_rank: Frequent Contributor
timestamp: October 20, 2018, 02:02:01 pm
content: There've been a few threads recently about GPS disciplined oscillators, and I expected that someone might have mentioned a GPSDO project starting in the current issue of Silicon Chip magazine, but I can't find any references to it, so I'm making one here.I won't try to describe it's features, as that is better done by the first two pages of the part 1 article, which can be seen here:-http://www.siliconchip.com.au/Issue/2018/October(clink on the article link #5 at the left)

author: Gyro
author_rank: Super Contributor
timestamp: October 21, 2018, 10:47:06 am
content: Unfortunately, when you look at the 'shopping list' down at the bottom of the left hand pane ('Micromite backpack' etc), it starts to look expensive.The biggest issue I see is the non-availabilty of source code - programmed device or Hex file only, that limits understanding and no ability to modify.

author: jpb
author_rank: Super Contributor
timestamp: October 21, 2018, 12:56:05 pm
content: Quote from: Gyro on October 21, 2018, 10:47:06 amOne difficulty with publishing a design in a magazine is that you need to use new, available components which means you're restricted to using a TCXO and then building an oven for it to keep costs down.The advantage of a DIY approach (such as Lars) is that you're free to use OCXOs from ebay which are much cheaper than their new counterparts.The presence of cheap GPSDO units on ebay means that the main purpose of building one is educational, to tailor the design and have fun. I agree with you that a key part of building one published in a magazine is to be also able to experiment so access to source code is important.

author: floobydust
author_rank: Super Contributor
timestamp: October 21, 2018, 05:24:43 pm
content: Are we sure the (app) source code is closed?The S/W link is confusing:Firmware (HEX) files and BASIC/C source code for the GPS-Synched Frequency Reference [0410718A.hex]Firmware (with pre-loaded BASIC code) and BASIC source code for the GPS-Synched Frequency Reference.Includes Micromite firmware v5.04.Inside the download package you will also find the MPLAB X project and C source code for the required CFUNCTIONs.Micromiteinterpreter firmware forMMBASICis pre-compiled. Maybe C was used for the algo and then linked in to MMBasic?

author: Gyro
author_rank: Super Contributor
timestamp: October 21, 2018, 06:12:11 pm
content: Ah, that's better then!

author: intabits
author_rank: Frequent Contributor
timestamp: October 22, 2018, 04:07:48 am
content: Quote from: Gyro on October 21, 2018, 10:47:06 amI plan on using my own controller, so I only need the analog/oscillator sections in the top part of the block diagram.I've ordered the parts for those, came to around AU$68 (for TWO sets).
GPSDO with XOR phase comparator - control loop filter design - Page 1
Forum section: electronics / projects

author: iMo
author_rank: Super Contributor
timestamp: February 10, 2021, 09:03:17 pm
content: This is anexcel tablewith my attempt to calculate the R and C values for the low-pass filter used in the XOR based phase comparator loop.I compiled the calculation from various information fragments. In case you are going to discipline your OCXO with so called Miller's design you may found it useful for the estimation of your filter values. You have to know a few parameters of your setup, however.
GPT 4Qn Hell! - Page 1
Forum section: electronics / projects

author: Terry Bites
author_rank: Super Contributor
timestamp: January 08, 2023, 02:30:09 pm
content: We must create an account for GPT on the blog.I prompted:"suggest a good opamp for use in audio amplifiers"Botty replies:"There are many good opamps that can be used in audio amplifiers. Some popular ones include the LM4562, the OPA2134, and the LME49720.The LM4562 is a high-performance, high-fidelity audio opamp that is widely used in professional audio equipment. It has very low noise and distortion, and can drive difficult loads with ease.The OPA2134 is another popular choice for audio applications. It has low noise and distortion, and can deliver high output currents.The LME49720 is a high-fidelity audio opamp that is known for its low noise and distortion. It is often used in high-end audio equipment.Ultimately, the best opamp for your application will depend on your specific requirements and circuit design".
GR8874 PWM controller ic - need help - Page 1
Forum section: electronics / projects

author: Chriss
author_rank: Frequent Contributor
timestamp: October 31, 2017, 10:36:17 am
content: Hi!I have to repair a power supply where is a GR8874 pwm controller ic which controls the G of a fet.That is nice and cool.The schematic is very similar (almost the same) like on this link on page 9.http://www.grenergy-ic.com/d/datasheet110314/eng/GR8874-Datasheet-V1.2-20101022.pdfThis is the GR8874 datasheet.The PSU is not powering.I checked the rectifier diodes, FET, capacitors, zener on the primary side.Nothing is bad.Also searched for some short on the secondary side and there I also didn't find anything bad.What I suspicious is the pwm ic on the primary side.When I measure for short on the GR8874 between pin 4 and pin 2 I have a short, the ic is out of circuit until measuring.Actually I have a resistance aroun 22 Ohm between the pins.I assume it is in short and that is the reason why the psu didn't work.Can somebody approve my thinking?Thanks.Best regards.

author: danadak
author_rank: Super Contributor
timestamp: October 31, 2017, 02:18:21 pm
content: Based on part block diagram that sure looks like a part failureas that pin has a comparator on it looking at pin voltage, and 22ohms will not provide any significant signal for comparison.That being said measure the pin with + of ohmmeter on pin 2,ground of meter on pin 4. If you did opposite that would turnon parasitic substrate diode and you could see a low impedance.Regards, Dana.

author: Chriss
author_rank: Frequent Contributor
timestamp: October 31, 2017, 07:20:32 pm
content: Makes no difference how I put my pins of my ohm meter.The reading is almost the same, around 22 Ohm.I will try to get a new ic.I'm almost sure does the ic if bad.Thanks for commenting.My best regards.
Grabbing power from a garage door wall controller - Page 1
Forum section: electronics / projects

author: larrybud
author_rank: Contributor
timestamp: December 08, 2024, 03:05:14 pm
content: I have a Chamberlain Whisper Quiet + garage door, about 10 years old, and I'm making and ESPHome controller to monitor and control the door. This particular door opener is a 2-wire connection, and it has two way communication between the motor and the door controller. The wall controller has a backlit LCD screen, and monitors the battery backup level for the garage door motor, has the time, temp, and will control the door open/close, the interior light, and you can lock the controls of the door, so it's not just a simple on/off or "doorbell" type controller. There's 18V going to the controller.I put my scope on the two wires and you can see the communication happening with some pulses between the wall controller and motor. I wasn't able to decode this communication to control the door, and instead just decided to solder a couple of wires to the PCB where the open/close switch is, and I can easily mimic the manual switch with a relay that's connect to the ESP Home.Now comes time for powering my ESPHome. I made a couple of attempts to try to tie into the 18V to the wall controller by using a buck converter, but the converter interferes with the signals that come across the line, and I'm no longer able to open and close the door, because the signals are smoothed out over the wire. I took the input cap off the buck converter to see if that would help any, but still no result.Could there a *simple* way to tie into this without affecting the signals? I certainly can run a separate 5v supply to my ESPHome device, it's not a really big deal, but this is as much of a learning exercise as it is a useful project.

author: edavid
author_rank: Super Contributor
timestamp: December 08, 2024, 04:15:39 pm
content: The best way would be to tap power from inside the wall unit, since it will already have the necessary filter to avoid disrupting the communications.I doubt you will be able to tap enough power for WiFi though. Maybe Bluetooth.

author: larrybud
author_rank: Contributor
timestamp: December 08, 2024, 05:37:00 pm
content: That's a good idea, thanks!
Grafting a Hakko 907 onto a Micron Soldering Station - Page 1
Forum section: electronics / projects

author: ludzinc
author_rank: Unknown
timestamp: January 09, 2015, 03:13:50 am
content: My adventures in making a 907 thermistor sensing handle work with a thermocouple based soldering station.http://ludzinc.blogspot.com.au/2015/01/soldering-station-conversion.html
Graphene semiconductor - Page 1
Forum section: electronics / projects

author: moffy
author_rank: Super Contributor
timestamp: January 31, 2024, 03:22:01 am
content: The following research at Georgia Tech sounds interesting:https://research.gatech.edu/feature/researchers-create-first-functional-semiconductor-made-grapheneThey claim to have grown graphene on a SiC substrate and doped it to make a semiconductor with 10x the electron mobility of Si. They also made and tested a planar MOSFET, if scalable it would be very interesting.
Graphic display driver ic - Page 1
Forum section: electronics / projects

author: House91320
author_rank: Regular Contributor
timestamp: July 14, 2011, 07:24:38 pm
content: Dose any one know o a parallel to serial display driver for a display like thishttp://www.newhavendisplay.com/index.php?main_page=product_info&cPath=3_114&products_id=4161or should i just use a micro.

author: ElektroQuark
author_rank: Unknown
timestamp: July 14, 2011, 08:27:12 pm
content: Use a micro. There are plenty of examples on the Net.

author: nyo
author_rank: Contributor
timestamp: July 14, 2011, 08:32:12 pm
content: Check out the datasheet for it, like many lcd displays, you can wire it parallel or serial

author: House91320
author_rank: Regular Contributor
timestamp: July 15, 2011, 01:52:52 am
content: I went with an msp430.
Graphic Equalizer for a tube amplifier - Page 1
Forum section: electronics / projects

author: luiHS
author_rank: Frequent Contributor
timestamp: February 02, 2024, 01:06:43 am
content: Hi.For experienced audiophiles. Can adding a solid state graphic equalizer to a HIFI tube amplifier cause it to lose its typical tube sound?. This question is also applicable to using a solid state phono preamplifier.I have been looking at some tube equalizer schemes, it would be more complex than a solid state one, but if this way the tube sound is preserved I would opt for that option.Another option that I was considering is to use a DSP, but I suppose that the problem would be the same as a solid state equalizer in terms of how it can affect the sound of the tubes.

author: themadhippy
author_rank: Super Contributor
timestamp: February 02, 2024, 01:16:50 am
content: QuoteIf you mean a tube power amp then no, as your eq or pre is before the tubes get involved

author: moffy
author_rank: Super Contributor
timestamp: February 02, 2024, 03:17:29 am
content: Quote from: luiHS on February 02, 2024, 01:06:43 amTubes introduce a characteristic distortion the 'tube sound' so passing that sound before or after through a neutral non distorting preamp, equalizer, DSP, amplifier etc. will not alter the 'tube sound' which is introduced by the tubes.
graphic equalizer with gyrator issue TL072 - Page 1
Forum section: electronics / projects

author: dave_j_fan
author_rank: Regular Contributor
timestamp: August 22, 2020, 02:56:58 pm
content: this is an equalizer with gyrator elements.i have tried to realize it with Tl072opamp.i made just for 60hzhow to connect it on 15 0 -15vso far i have not been able to get clear audio via this.also pot for 60hz filter dont show any change when i vary.

author: ledtester
author_rank: Super Contributor
timestamp: August 22, 2020, 03:31:51 pm
content: Here's an article describing the circuit:http://www.geofex.com/Article_Folders/EQs/paramet.htmNote that in the other schematics Vb is defined by a voltage divider between +9 and GND:So for adaptation for 15-0-15 I would use 15 for "+9", -15 for "GND" and 0 for "Vb".

author: dave_j_fan
author_rank: Regular Contributor
timestamp: August 22, 2020, 06:05:49 pm
content: ok .thank u for very accurate reply.i will try the same
Graphics library for a menu based display interface - Page 1
Forum section: electronics / projects

author: trevwhite
author_rank: Frequent Contributor
timestamp: May 17, 2017, 04:13:01 pm
content: I have a project coming up and I am looking to see what is out there. The system itself has basic menu options required for configuration.I believe at present I will use STM32 but am open to other suggestions.So far I have found the following two. Has anyone got any experience using them and can offer any advice ? I would really like to implement a nice colour user interface but I am not sure how much resource this would take up. Any comments on this would be great.The library does not have to be free but I dont think I can spend £1000s on it.https://my.st.com/content/my_st_com/en/products/embedded-software/mcus-embedded-software/stm32-embedded-software/stm32-standard-peripheral-libraries-expansions/stemwin.license%3d1495035751424.htmlhttps://ugfx.io/overviewThanksTrev
Graphics overlay vendors? - Page 1
Forum section: electronics / projects

author: testingguy
author_rank: Newbie
timestamp: July 29, 2013, 05:30:47 pm
content: I'm using inkjet-produced graphics overlays for prototypes and they work great but now I need to find a source who make them in small runs (~25 per order).The bare aluminum panel is 70 x 134mm and the panel has 3 tact switches poking thru and a single LCD cutout. So the overlay would need to be molded over the tact switches but nothing tricky. I'm assuming polyester or polycarbonate overlay material, or similar.Any recommendations for firms that have competitive small run prices? (Google spits up a ton of companies that do these things...)Thanks,Chris B.

author: Mike Warren
author_rank: Unknown
timestamp: July 30, 2013, 12:49:30 am
content: I have no idea, but am very interested in the topic. I just got a quote for some small Lexan labels and 500 costs less than twice the price of 100.

author: testingguy
author_rank: Newbie
timestamp: July 30, 2013, 01:30:03 am
content: I sent out a bunch of RFQs today so I'll share what I find from US vendors. I'm still amazed at how many companies do this. I did notice that several of the US companies were showing direct association with a facility in China where they probably get the actual work done dirt cheap.Chris B.

author: mamalala
author_rank: Unknown
timestamp: July 30, 2013, 05:59:53 pm
content: Do you need monochrome or multi-colour?If monochrome is OK for you, check out Alucorex:http://www.bungard.de/index.php?option=com_content&view=article&id=26%3Aalucorex&catid=3%3Abungard-produkte&Itemid=77&lang=englishThat way you can make your own nice front panels quite easily. Dunno about a supplier local to you, however. If in doubt contact Bungard directly, they are usually quite friendly and helpful.Greetings,ChrisEdit: You may also want to check for a small screen-printing rig, like those used for printing t-shirts. Basically it is just a frame with a screen fixed to it under tension. You apply an emulsion to the screen and let it dry, then you expose and develop it. Afterwards you can use that to apply ink paste with a squeegee to whatever flat object you have under it. You may end up spending 100 bucks or so for a basic kit, but aafter that the running costs are only the photo-emulsion, the chemical to remove the emulsion layer from a used screen, the ink and the photo (litograhpic) film used to do the exposure.

author: testingguy
author_rank: Newbie
timestamp: July 30, 2013, 10:13:47 pm
content: Mamalala, thanks much for the suggestions. I'm looking for a full color process but I did take a look at the Bungard site. Looks like a good supplier. As far as setting up to do that in-house I'm looking to outsource the labor for front panel metal and overlays. If volumes ever get to the point that margins matter I'll certainly consider it.I expect to start getting quotes from US vendors starting tomorrow.Chris B.
GraphicsCards Holes:  Plated, or what?? - Page 1
Forum section: electronics / projects

author: frogblender
author_rank: Regular Contributor
timestamp: February 08, 2023, 06:50:15 pm
content: Shown below is a the heatsink support clip from an RTX3090. I am interested in the screwholes: Couple of questions:1. Are these holes plated?2. Do the holes have a toplayer copper pad?3. What is the purpose of the silver dots (I assume these are vias... and they opened the stencil so each received a blob of solder? why?)Any help appreciated.

author: thm_w
author_rank: Super Contributor
timestamp: February 08, 2023, 11:42:14 pm
content: Quality of the photo is too poor to really say, but its probably plated, top copper.Here is a better photo from xdevs:https://xdevs.com/doc/xDevs.com/ocg_1080/pexmon.jpgexplanation on vias:https://electronics.stackexchange.com/questions/240092/why-do-some-pcbs-put-vias-around-mechanical-through-holeshttps://www.eevblog.com/forum/beginners/
Graphs won't be plotted to the end of simulation time in Simulink - Page 1
Forum section: electronics / projects

author: cadena
author_rank: Contributor
timestamp: April 17, 2020, 01:05:51 am
content: Hi everyone,I am having the issue that I am trying to run an FOC algorithm in Simulink (see image attached) but the graphs are plotted until 0.5 when the simulation is set to 10 seconds (see image attached). Does anyone know what could be happening ? Thanks in advance.The file can be found in the following MatlabExchange link:https://es.mathworks.com/matlabcentral/fileexchange/39605-vector-control-of-permanent-magnet-synchronous-motor-pmsm
GrasPiB - GPIB interface for Raspberry Pi - Page 1
Forum section: electronics / projects

author: nitromethane
author_rank: Contributor
timestamp: December 30, 2021, 05:47:22 pm
content: HiSo long story short, after I ended up buying a couple of old bench multi-meters from ebay, I soon wanted to connect them with some sort of a computer to do logging and maybe some math on measurements they provide.Being that both instruments are from about mid 80s they come with GPIB ports, and none of my PCs (not even my 486DX2 build) have a port like that. I needed some sort of an interface device that would preferably work with a modern operating system.While I could just buy a USB adapter and be done, I instead decided to design a Raspberry Pi and linux-gpib compatible interface board with a couple of extra features such as power regulator, fan and RS232 port.So I present to you my first open source hardware project GrasPiBSource files and documentation is available on Github:https://github.com/an-ven/graspibI hope, this is of interest and/or use to someone, comments are welcome.

author: coromonadalix
author_rank: Super Contributor
timestamp: December 31, 2021, 12:13:12 am
content: ImpressedQ: can the rs232 port act as a console port or you can interface some serial devices too, like the gpib port ?

author: nitromethane
author_rank: Contributor
timestamp: December 31, 2021, 10:10:06 am
content: RS232 port can both be configured as console port for the OS and can be used to to talk to other devices.
gravity induction - Page 1
Forum section: electronics / projects

author: thomaspfenning
author_rank: Newbie
timestamp: February 16, 2022, 09:46:46 pm
content: This may be one for Dave Jones. I bought a water filter from amazon. It has a water quality sensor built in ( they claim) , You push the button and a blue led comes on, and supposedly when the filter needs changing the red light comes on. Mine started blinking blue. This appears to be a fault the company claims and needs to have the gravity induction sensor replaced. I got curious. The only other reference to a GIS (gravity induction sensor) is with a coffee cup heater which just turns on a heater due to the weight of the coffee mug (gravity). So, I took the unit apart. I found a 8 pin microcontroller and a 2 pin smd device acting as a voltage divider with the battery feeding an input of the MCU. Plus the 2 led's. The smd device is odd, it has gold plated ends with a grey plastic center, unlike any device I have seen so far. The only other clue as to what this is doing is the printing on the small pcb saying "three month". So is this just a timer device to make you buy a new filter every three months. Then why use the strange sensor device. And how would the device know when the filter was used. My thought is that maybe the device is a tilt sensor and it counts usage by the number times it gets tilted. I will test the device for that action.If anybody knows what this is or why nowhere on the net is there any explanation, especially by the company which can by found by searching for gravity induction.

author: TimFox
author_rank: Super Contributor
timestamp: February 16, 2022, 10:56:45 pm
content: Back in grad school, we used legitimate water filters to produce de-ionized water for laboratory purposes. The simple indicator for cartridge replacement measured water conductivity by putting noble electrodes in the water, which would short out a neon bulb when the conductivity was too high.
Gravity-wave detector - Radio Electronics April 1986 - Page 1
Forum section: electronics / projects

author: floobydust
author_rank: Super Contributor
timestamp: January 01, 2017, 01:13:32 am
content: Anyone remember thisRadio Electronics April (1986) Fool'scircuit?I was a total sucker and breadboarded it to find out for myselfIt has a really weird oscillating (ringing) output that seems to be the op-amp's noise low-pass filtered... but also with "amplitude-modulated astrophysical events"! Who can resist listening to that?It's great for investigating microphonic capacitors. I put the output into an audio amp and surprised to lightly tap capacitors and hear it loudly, along with the gravity waves

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 01, 2017, 01:26:06 am
content: As it turns out, all those proposals (and weekend projects) that popped up over the years, were about 10^9 times too insensitive to actually see cool stuff out there. But we've solved that, finally.Tim

author: Richard Crowley
author_rank: Super Contributor
timestamp: January 01, 2017, 01:33:30 am
content: I have a friend who works at LIGO Hanford. I am hoping she can arrange a tour sometime.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 01, 2017, 02:13:56 am
content: I would love to see the stabilization systems documented!Tim

author: Seekonk
author_rank: Super Contributor
timestamp: January 01, 2017, 05:30:29 am
content: I remember the Black Noise Generator, A loop of wire on a BNC mounted in a black bean soup can.

author: Twoflower
author_rank: Frequent Contributor
timestamp: January 01, 2017, 02:52:43 pm
content: Quote from: T3sl4co1l on January 01, 2017, 02:13:56 amBad luck: the Omega Tau Podcast has half of the issues done in English. But this one is German. So if you understand German this is a very good Podcast covering the Small German Detector GEO600:Relativität und Gravitationswellen. Which does a lot of research which later will deployed to the other systems.The suspension systems for Ligo and GEO600 are described here:http://www.physics.gla.ac.uk/igr/index.php?L1=research&L2=suspensionsAdditionally the mirrors are adjusted using magnetic and electrostatic fields. The latter is in development and currently only used in the GEO600. If my memory serves me right.
Grayhill Touch Encoder - Page 1
Forum section: electronics / projects

author: awallin
author_rank: Frequent Contributor
timestamp: February 20, 2018, 09:11:34 am
content: Digikey just sent me info (spam) about a new grayhill touch encoder:https://www.digikey.fi/en/videos/g/grayhill/grayhill-touch-encoderpretty cool for DIY instrument control/UI$180 in single quantities and ~8 weeks delivery...

author: frozenfrogz
author_rank: Frequent Contributor
timestamp: February 20, 2018, 12:33:15 pm
content: Call me old-school, but I love having dedicated knobs for everything. Particularly on specialized equipment - the kind the video advertises for - I would not want to bother with multi-purpose click-swish-drag interface crap. It slows down operation and introduces more opportunity for errors. Old studio equipment or plane cockpits can not be wrong
grease wire to wire shrink tube splice? - Page 1
Forum section: electronics / projects

author: coppercone2
author_rank: Super Contributor
timestamp: November 25, 2018, 02:34:29 am
content: If you make a wire splice by fusing two wires inline, do you put dielectric grease on the joint before heat shrinking it?It's something new I saw and I wonder if one should bother. Does the heat shrink still work properly?

author: floobydust
author_rank: Super Contributor
timestamp: November 25, 2018, 02:58:23 am
content: I think it's more of a psychological pacifier, seen it done for extra protection against oxidation. It doesn't always work, if the silicone grease can get washed out.Some heatshrink needs around 260°C which I think melts the grease and it dribbles out. It's just messy.I prefer to use thick-walled heatshrink which has hot glue inside. That seals up against water too.It all depends on what you are sealing against- temperature, pressure, abrasion etc.

author: coppercone2
author_rank: Super Contributor
timestamp: November 25, 2018, 03:25:43 am
content: yea the idea I think is for moisture resistance but do you get any significant ingress into a solder joint through a heat shrink and does the grease react with the sleeve material since its not really ideal? I thought it might cause it to decay by diffusion or something.With crimp to crimp or butt splice crimp I understand because the tension varies with temperature cycles and it walks mechanically so you can imagine oxide creep in, since it will expand and show a bit of exposed skin, oxidize, then it won't be able to contract as well and then it might abrade and re oxidize and so on but I don't think the process is similar for solder joints.How long does the grease last? Can't it act like a sponge to absorb hydrocarbons which make the plastic vulnerable?I know some hot glues can absorb moisture and it begs the question, are the electronics grade hot glues/premade glue filled heat shrinks totally different or just better the normal hot glue?To this point I have been using regular heatshrink twice over for that kind of joint. For commercial joints I used the solder thats built into heat shrink you attach with a hot air gun for speed (no glue in this).Can the grease or phase change glue (or is it just viscosity change) actually make a connection worse over a LONG time scale?Electronics grade silicones are different I think because they chemically cure to a tighter molecular structure (I think?)Say you are using teflon wire.
Great Gnuplot script for waveform display - Page 1
Forum section: electronics / projects

author: eTobey
author_rank: Super Contributor
timestamp: December 23, 2024, 10:42:00 am
content: Hi,i made a script for Gnuplot, that has two key features:- plot files in the folder- create x/y grid tics depending on zoom"Hauptmessung.plt" loads "Messungensetup.gp" from the parent folder. Files to plot have to be in the folder with "Hauptmessung.plt".To have the x/y tics set, click left mouse.The filenames had to be renamed, because they would not upload otherwise.It does not work with spaces in filenames!(Developed with Siglent csv waveform files)Enjoy this present!Merry Christmas!
Great idea or crap: battery pack with USB actually connected to something - Page 1
Forum section: electronics / projects

author: technix
author_rank: Super Contributor
timestamp: June 14, 2015, 07:49:47 pm
content: From time to time I am forced to charge my battery packs from a externally powered USB hub. This made me wonder if I can make some use out of the USB signal lines while drawing lots and lots of juice from the power rail. Then this occurred to me: can I put a USB-enabled microcontroller into it, report the battery health, and maybe implement the USB Power Delivery protocols to allow safe supply of up to 10 (using traditional USB sockets) or maybe even 100W (using USB Type-C) of power.The idea is to start with the TP4056 Li-ion charger chip (1A charging current maximum, but that is still larger than the 500mA standard USB current limit, so negotiation is still required), a digipot, and a USB-enabled microcontroller like ATmega32U4.When power is applied to the device, the micro keep the battery from charging until it either finds out that it is connected to a wall charger, or it have negotiated with the power source over some protocol (supported: USB Power Delivery for hosts compatible of using this USB 3.0 over USB 2.0, out-of-band using USB Type-C connection, or the protocol used by Apple iPad to coax Macs into pushing extra juice through the USB port), or decided to settle down at 500mA. Then the charging current is adjusted to less than the negotiated current level.If the micro found out that it is connected to a computer, it can present itself as either a HID or a serial port to allow computer software to monitor and control charging of the battery pack, and if the battery pack is in fact plugged to a USB Type-C port that allows a peripheral to power the host like the one on the new MacBook, to switch the battery pack into back-powering mode.

author: Wisnaeme
author_rank: Unknown
timestamp: August 15, 2015, 02:10:17 pm
content: Not tried this, but could you detect the computer by simply watching the USB data lines for some voltage/clock etc?Program the 4056 to be at say 500mA if a clock/data can be detected otherwise let it go at full 1A.To force data you could throw a simple USB chip on the power data lines. A CH340 or something cheap.Maybe just detecting the USB pulldowns on a computer would be enough to work?Just thinking aloud at the moment. All untested.
Great summary of design considerations for resistors - Page 1
Forum section: electronics / projects

author: robrenz
author_rank: Super Contributor
timestamp: August 13, 2012, 05:06:43 pm
content: Very nice compilation of things you should know about resistors by analog devices.http://www.analog.com/static/imported-files/rarely_asked_questions/moreInfo_raq_resistors.html

author: saturation
author_rank: Super Contributor
timestamp: August 17, 2012, 04:55:57 pm
content: Nice. It complements what's on wikipedia. A good specs handbook is the US DoD book, free:http://www.everyspec.com/MIL-HDBK/MIL-HDBK-0099-0199/MIL-HDBK-199A_21650/Also, find other articles by the author, James Bryant; they are typically succinct and entertaining. That he was educated by Jesuit priests showhttp://www.highbeam.com/doc/1G1-172345090.htmlhttp://www.amazon.com/gp/pdp/profile/A3RK9GXAUB1HD7

author: robrenz
author_rank: Super Contributor
timestamp: August 20, 2012, 02:26:47 am
content: Thanks saturation, I found a lot of articles by him that are now in my reading list.

author: EEMarc
author_rank: Regular Contributor
timestamp: August 20, 2012, 04:30:56 am
content: Very good information on resistors. I already knew most of it, but there were a couple that I haven't heard of. One thing I didn't see was Positive Temperature Coefficients vs Negative Temperature Coefficients, or PTC vs NTC. It turns out, you can use both for a sensor to carefully to compensate for temperature changes over a fairly large temperature range.Also as sensors, resistors, and other components age, they tend to change. This is why a good manual or automatic calibration is important to have.