hybridfree/eevblog-posts huggingface dataset:
Voltage Source (IEPE) sensor interface to MCU - Page 1
Forum section: electronics / projects

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: July 19, 2016, 02:26:14 pm
content: Hi,I just wanted to know how to power and interface these kinds of sensors to my MCU ADC, for example AC102-1A sensor,https://www.ctconline.com/fileup/3DNEWPDF/AC102series_datasheet_3D.pdfhow should I power the sensor and read it's dataany suggestions are welcome.

author: ajb
author_rank: Super Contributor
timestamp: July 19, 2016, 07:12:35 pm
content: From their website:https://www.ctconline.com/FileUp/PrdDS2011/5_TI_PwrRequirements_DS.pdfQuoteQuoteSo provide it with a 2mA current, and you'll get a ~12V+/-5V signal out of it. You can either offset the output or AC couple it to get it into a range that your MCU's ADC can handle. You'll need to attenuate it as well, which can be a simple voltage divider.

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: July 20, 2016, 05:19:48 am
content: Thanks for your help,there is another question, can I replace the CR220 with a LM317 in constant current mode?

author: ajb
author_rank: Super Contributor
timestamp: July 20, 2016, 11:34:51 am
content: Maybe, the LM317 isn't specified for output<10mA. It might not behave very well at currents below that. There are several other constant current source topologies you could use.

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: July 20, 2016, 12:10:29 pm
content: Thanks, Do you recommend any cheap one?

author: ConKbot
author_rank: Super Contributor
timestamp: July 21, 2016, 02:19:39 am
content: The current source needs to faster than your gauges signal by a significant amount so its current output remains high impedance, otherwise it it can start to distort your signal. With the resonance of those gauges at 23khz, you can assume signal up to that (though don't try and measure something near resonance, best case it will read way higher than actual, worst case it breaks the gauge)An lm317 starts to run out of steam in the 10-100khz range (output impedance rises for a voltage output, drops for a current output) But a zener/pnp current source, or jfet or depletion mode mosfet current source will have plenty of bandwidth for this.

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: July 23, 2016, 05:07:15 am
content: Thanks
Voltage source switching with FETs - Page 1
Forum section: electronics / projects

author: 3cdb
author_rank: Newbie
timestamp: February 23, 2023, 11:51:36 pm
content: Hi all!I figured I'd ask on this forum about possible fixes/recommendations/ideas for what I'm trying to do.I've been trying to make a small circuit which switches its output either from a regulated +5Vdc source, or from a +4.2Vdc source (from an 18650 cell).The idea is that when the 5V is connected, the output is 5V but when the 5V is disconnected, the output is 4.2V instead.I have come up with a circuit so far, but after building and testing, it does not seem to workI have attached the circuit I have come up with so far.Anyone have any ideas of what I can do?

author: Kim Christensen
author_rank: Super Contributor
timestamp: February 24, 2023, 12:52:52 am
content: Maybehave a look at this pageto see exactly how complex you need to go. (I think a version of example 2 will work for you)

author: Peabody
author_rank: Super Contributor
timestamp: February 24, 2023, 04:21:51 am
content: This circuit should work. If both supplies are connected, the one with the higher voltage will be selected.

author: inse
author_rank: Super Contributor
timestamp: February 24, 2023, 07:49:35 am
content: Two Schottky diodes would not do the job?

author: Peabody
author_rank: Super Contributor
timestamp: February 24, 2023, 03:24:44 pm
content: Yes, two diodes would certainly work, but then you have a 0.3V voltage drop in the battery line which reduces the effective battery life. The mosfet replaces the diode in that line, and the drop is very low when it's turned on.
Voltage supply Isolation  - Page 1
Forum section: electronics / projects

author: gauravmp
author_rank: Regular Contributor
timestamp: June 13, 2016, 05:35:06 pm
content: Hi,I'm working on a board : DC2425A(http://www.linear.com/solutions/7266) and it requires to be powered by +9V and -9V. I'm made a simple 2 resistor voltage divider by having the middle point between resistors going to GND and the other ends going to +9 and -9. However, when I wire the circuit, I got different values of voltages. So I figure I need to isolate my supplies. Could someone tell me how I could isolate the supply?Thanks

author: madires
author_rank: Super Contributor
timestamp: June 13, 2016, 05:55:14 pm
content: A voltage divider is a bad power supply because the voltages will change with the load. What is your power source?

author: gauravmp
author_rank: Regular Contributor
timestamp: June 13, 2016, 06:12:40 pm
content: I'm using a laboratory power source. How would you recommend I have my supply?

author: madires
author_rank: Super Contributor
timestamp: June 13, 2016, 06:16:52 pm
content: Does your lab PSU got two outputs? Or do you got two lab PSUs?

author: gauravmp
author_rank: Regular Contributor
timestamp: June 13, 2016, 06:20:25 pm
content: Yes, I have two supplies and I did try supplying using both but as soon as I connect it, the voltage on the display changes.

author: madires
author_rank: Super Contributor
timestamp: June 13, 2016, 06:26:12 pm
content: Are both lab PSUs isolated (the outputs)? How did you connect them to the board?

author: gauravmp
author_rank: Regular Contributor
timestamp: June 13, 2016, 06:30:37 pm
content: I figured it out! It turned out the current was limiting.
Voltage/Current rating of Relay for Inductive load - Page 1
Forum section: electronics / projects

author: Gowda1
author_rank: Contributor
timestamp: December 20, 2020, 12:26:59 pm
content: Hey,I selected a relay for my application by seeing the maximum and current rating of Relays but I am confused if the relays works fine with the given rating for all kind of loads.In my circuit the relay is being used in the primary side of the resonant converter which is working under 40A rms and 400VAC(Load is primary side of transformer,inductive)The relay which I selected has rating of max 50A and 480VAC. I could not really understand the contacts rating for different loads. Im really confused it I can use this relay for my application. Please let me know if u have any leads to this. I attach the relay datasheet for your reference.Thanks in advance

author: S. Petrukhin
author_rank: Super Contributor
timestamp: December 21, 2020, 09:31:39 am
content: With an inductive load, it is still necessary to take into account the opening possibility. When the inductive load is switched off, an arc may appear and the contacts may burn out. This is very sensitive at the specified current. Usually, magnetic starters (contactors) are used for such capacities.

author: rvalente
author_rank: Frequent Contributor
timestamp: December 21, 2020, 02:51:48 pm
content: Check for AC1 and AC3 current ratings

author: Vovk_Z
author_rank: Super Contributor
timestamp: December 22, 2020, 02:33:59 am
content: For inductive load we have to increase a rated current of a relay. The more inductive load is - the large margin we need. That is why 50A reated relay most likely is too weak. So you possibly need a relay with about 100A rated current or so.(You can get a key to a proportion from that datasheet).

author: bdunham7
author_rank: Super Contributor
timestamp: December 22, 2020, 02:49:52 am
content: Quote from: Gowda1 on December 20, 2020, 12:26:59 pmPlease read the data sheet more carefully. It is not rated for 50A and 480VAC, at least not both at the same time. The 50A rating is for purely resistive loads at 277VAC, and then for only 10,000 operations. There is no 'transformer' rating, but the closest one is the ballast rating for 20A/277VAC and only 6000 operations. I think the relay is completely inadequate for the load you listed.This might work:https://www.mouser.com/ProductDetail/Omron-Electronics/G7EB-1AP1-DC24/?qs=sGAEpiMZZMtGt%252Bn33CgIP91%252BgkwxD%2FD42ZXqu8psTb8%3D
Voltcraft DPS-4005PFC repair/conversion log - Page 1
Forum section: electronics / projects

author: cat87
author_rank: Regular Contributor
timestamp: August 11, 2015, 06:18:31 pm
content: Hello fellow EEV Bloggers,I would like to share with you my most recent project and that is an attempt to bring back to life a Voltcraft switchmode power supply.More detailed information and pictures can be seen on my blog page:http://electronicsplayground.blogspot.ro/2015/07/project-1.htmlThis thing will do 0-40 Volts and 0-5 Amps...when it has all its parts that is. This PSU unfortunately is missing some, most important of which are the two micro-controllers that take care of the LCD, the keys, the rotary knob and the ADC.So, I decided to give this piece of german engineering a second change and get it working to full order. The Arduino is a nice solution to this, but the number of pins on my Leonardo is nowhere near the necessary to completely get this PSU working. But, for start, it'll have to do.I plan a buying a Mega and having my way with that, after I get some things actually working.So far, I've managed to get the knob working, the ADC, which is an AD7541, and the LCD, which was a real pain, but that's because I don't have the patience to read long datasheets. By the way, the LCD controller in this thing is an PCF8576 and some initial code for this can be found on my blog page.The next step would be to wire in the Arduino Mega and see how all the bits and pieces fit together. Funny thing about this PSU is that the ADC drives both the voltage and the current limiting, so I thing this might actually be a matter of timing to get my voltage and current limit values just right. In the attached schematic, there are two caps, C29 and C30, that hold the ADC output values for these. This is going to be interesting.Anyway, I'll try to keep this post updated with my progress and hopefully, will soon have a working PSU.

author: cat87
author_rank: Regular Contributor
timestamp: August 11, 2015, 06:22:42 pm
content: And these are the pics that were supposed to be attached to my first post. Oops
Voltech TF2000 remote control tool - Page 1
Forum section: electronics / projects

author: carb_enjoyer
author_rank: Newbie
timestamp: October 28, 2023, 11:20:21 am
content: Hi everyone!I just want to share my git repositoryhttps://github.com/LM13700/TF2000-remote-toolswith a very simple script in python, which allows reading data remotely from the TF2000 Frequency Response Analyzer. Hope somebody will find it useful.

author: abdulwaiz
author_rank: Newbie
timestamp: March 26, 2024, 10:21:00 am
content: Hi!Thank you for sharing the code for Tf2000 but i am unable to run your code.Which IDE do you have used to Run this Code.i am using usb to serial port convertor.Kind RegardsAbdul Waiz

author: carb_enjoyer
author_rank: Newbie
timestamp: June 17, 2024, 04:21:51 pm
content: Hi,sorry for the late reply. I've just updated the readme file with some instructions on how to prepare a setup.I'm not using an IDE but Python's virtual environment, for code editing VS Code, but it's simply a personal preference.In my setup, I also use a USB-to-serial converter. Are you sure you are using a properly connected cable? The readme file in the repo describes which pins need to be connected.Please let me know if you still have any questions!Mateusz
Voltgae regulators and Capcitor size  - Page 1
Forum section: electronics / projects

author: bunrector
author_rank: Newbie
timestamp: June 17, 2015, 11:27:34 pm
content: Why do most voltage regulator data sheets call out 805 or 1206 size capacitors? I don't usually do power, but I am laying out a DDR3 termination regulator. 3.3V in and 1.5 & 0.75 V out.If I can find a capacitor that has a high enough voltage rating and low enough ESR in a smaller package, would that suffice, or is there some other reason that larger case sizes are called out? Heat?P.S. These are ceramic caps.Thanks.

author: moffy
author_rank: Super Contributor
timestamp: June 17, 2015, 11:41:08 pm
content: Heat and therefore life expectancy. Larger package more surface area to dissipate heat.

author: tautech
author_rank: Super Contributor
timestamp: June 17, 2015, 11:45:50 pm
content: Also AFSIK polarised caps in higher values won't be avaiable in small SMD packages.

author: Fungus
author_rank: Super Contributor
timestamp: June 18, 2015, 09:45:49 am
content: This seems relevant:https://www.eevblog.com/forum/blog/eevblog-742-why-electrolytic-capacitors-are-connected-in-parallel/
voltmeter circuit using BL0937 - Page 1
Forum section: electronics / projects

author: samirahmed
author_rank: Newbie
timestamp: March 03, 2024, 10:27:59 pm
content: hi, I am designing circuit to measure ac voltage only of any source I am using BL0937 and add random load (capacitor 470nf) to Just complete circuit.the output of pin CF1 is 1.8V but after I add transistor to turn on optocoupler or without transistor when I direct connect CF1 pin to optocoupler the voltage of CF1 pin drop to 0.2v so nothing work can you help me.the output must be pulsed to measure the voltage using input capture.

author: Kleinstein
author_rank: Super Contributor
timestamp: March 04, 2024, 09:09:20 am
content: The capacitor at the supply is rather small with 20 nF. There is a slight chance the supply could collaps under the load from the optocoupler. The current to the optocoupler is quite high - usually one could get away with well less current (more like 5-10 mA) and thus more like 220 or 330 ohm instead of 88 ohm.Is the supply voltage correct ?The polarity of the pulses could also be an issue. A relatively slow optocoupler that is highly overdriven may take more than 40 µs to turn off and may thus hide such a pulse.

author: Terry Bites
author_rank: Super Contributor
timestamp: March 04, 2024, 02:32:54 pm
content: How much Zener current is that? 1.7A*3.3 is 5W, that'll melt your poor diode.I doubt the application circuit for the BL0937 would meet any regulatory standard.Don't skimp on mains supply circuits, your life and your home deserve a few bucks more effort.Make a better protected supply that's less likely to catch fire. Check out this page from TDK, great advice.www.tdk-electronics.tdk.com/en/373562/tech-library/articles/applications-cases/applications-cases/everything-for-capacitive-power-supplies-from-a-single-source/1380514If you need to change pulse polarity do it on the LV side.
Voltmeter not liner - Page 1
Forum section: electronics / projects

author: House91320
author_rank: Regular Contributor
timestamp: May 30, 2011, 07:57:35 pm
content: i have this curcethttp://www.eleccircuit.com/icl7107-icl7106-digital-voltmeter/and the voltage is fine at one end but way out on the other. for exampel an imput of 1 volt is corect on the meter but an imput of 19 is off by 10.

author: bilko
author_rank: Frequent Contributor
timestamp: May 30, 2011, 08:33:30 pm
content: I assume that you are using the 1M ohm input resistorFrom the details posted on the website ...The voltmeter can also be configured to measure different voltage ranges and display higher voltage resolution. Replacing 1M with 100K resistor will allow to measure 0 – 19.99V voltages with 0.01V (10mV) accuracy.

author: House91320
author_rank: Regular Contributor
timestamp: May 30, 2011, 08:48:31 pm
content: i should have mentioned i am using the 100k

author: bilko
author_rank: Frequent Contributor
timestamp: May 30, 2011, 09:04:33 pm
content: What do you get when you measure between pin 36 and ground ?

author: House91320
author_rank: Regular Contributor
timestamp: May 30, 2011, 10:01:27 pm
content: 2 its suppose to be one isnt it

author: bilko
author_rank: Frequent Contributor
timestamp: May 30, 2011, 10:38:28 pm
content: Yes according to the docs

author: House91320
author_rank: Regular Contributor
timestamp: May 30, 2011, 11:22:02 pm
content: i am looking at the docs and it says a differences of 1v between 35 and 36

author: qno
author_rank: Frequent Contributor
timestamp: June 01, 2011, 07:58:52 am
content: Note that the 7107 has a differential input.Both inputs need to be between 1.5 and VCC-1V.In short you can not use this chip when the powersupply and the measurement ground are the same.Use a floating power supply.

author: bilko
author_rank: Frequent Contributor
timestamp: June 01, 2011, 03:31:12 pm
content: Quote from: qno on June 01, 2011, 07:58:52 amIt is OK to use this chip in single ended mode, tie pin 30 (in Lo) to ground. Check Intersil application notes Fig 12.
Voltmeter trouble - Page 1
Forum section: electronics / projects

author: House91320
author_rank: Regular Contributor
timestamp: June 10, 2011, 12:24:54 am
content: I just built a voltmeter and its doing something that doesn't make any sense. i am using the refrance from the data sheethttp://www.intersil.com/data/fn/fn3082.pdfand i am using a 7660 to generate the -5. the problem i am having is the device is building up a voltage and according to the datasheet it shouldn't and any voltage i put in maxes it out.

author: House91320
author_rank: Regular Contributor
timestamp: June 10, 2011, 12:53:29 am
content: I have figured out the problem its setup for 200mv is there any way to add a resister to allow it to measure 20v

author: House91320
author_rank: Regular Contributor
timestamp: June 10, 2011, 02:16:29 am
content: i added a divider an it fixed it
Voltmeter troubles - Page 1
Forum section: electronics / projects

author: PotatoBox
author_rank: Regular Contributor
timestamp: September 02, 2017, 10:22:13 pm
content: So I have an old panel mount analog voltmeter and I planned on using it for my bench power supply project, but for some reason it doesn't read correctly.I try to measure a 9v battery, that works fine, as well as other batteries... but when I try to measure a 5v wall wart, for example, the voltmeter's needle just goes off the charts.Am I doing something wrong?

author: Zero999
author_rank: Super Contributor
timestamp: September 02, 2017, 10:25:14 pm
content: Have you measured the wall wart with a different meter?Is the wall wart regulated? Most modern 5V units are but some cheap unregulated PSUs are still around. It if isn't regulated, then the output voltage, with no load, will be much higher than the rating.

author: PotatoBox
author_rank: Regular Contributor
timestamp: September 02, 2017, 10:29:26 pm
content: Quote from: Hero999 on September 02, 2017, 10:25:14 pmI'm pretty certain it is regulated. It is an old cell phone charger. And yes, I measured it with my multi meter and I am certain it is 5v.
Volts per amp for a Honeywell CSLA2EL? I'm stupid or it's a mystery - Page 1
Forum section: electronics / projects

author: FCguy
author_rank: Newbie
timestamp: January 15, 2018, 04:13:02 am
content: So call me a newb if this ends up being easy but we have a little problem in our student shop. We have a Honeywell CSLA2EL mounted to a breakout PCB. A 10uF cap from the supply rail to ground is the only thing on the board other than the connector header.https://www.digikey.com/product-detail/en/honeywell-sensing-and-productivity-solutions/CSLA2EL/480-4826-ND/3072998For the live of me and my fellow student we cannot find any datasheet to define the volt per amp metric. A quick check of similar devices has at least a graph of the amps vs output pin voltage. What are we missing here?Many Thanks!

author: Phoenix
author_rank: Frequent Contributor
timestamp: January 15, 2018, 04:26:35 am
content: The datasheet (second document link on Digikey) lists the sensitivity of that model at 4.3 mV*N when supplied at 8V. I expect that meas 4.3 mV per turn per amp.

author: tautech
author_rank: Super Contributor
timestamp: January 15, 2018, 04:39:04 am
content: Welcome to the forum.Looking at the datasheet I see what you mean, but there are some #'s that indicate sensitivity however amps are not mentioned.https://sensing.honeywell.com/index.php?ci_id=49794Sensitivity seems related to supply voltage and for an active CT that makes sense.So grab a PSU and set a current limit and pass a lead through the CT and check that you have the same CT output as listed for the model you have.....it's stated on the Digikey product page and datasheet as 4.3mV/N. N= # turns.So for a single conductor passing through the CT, one would expect 4.3mV/Amp@8V supply for the CSLA2 series.An additional wrap of the conductor will double sensitivity. (N=2)Check it out to confirm, an easy exercise.

author: FCguy
author_rank: Newbie
timestamp: January 15, 2018, 04:57:19 am
content: We quickly tested the unit with a 9 volt battery (falling through the high 8.x SOC) supply voltage and 5 turns (N=5) of wire through the device with the following resultsOutput VoltsCurrent through part?V?V/(I*N)4.3300.00NANA4.3161.000.0140.00284.2952.520.0350.00277...
Volume Meter Beginner Project - Page 1
Forum section: electronics / projects

author: Tom10000
author_rank: Contributor
timestamp: March 21, 2018, 09:30:02 am
content: Hello,I recently finished my volume meter project and I decided to post a couple of photos of it here the project uses the Lm3915 and it displays a volume of an audio signalI have included the links to the photos hopefully this works

author: Richard Crowley
author_rank: Super Contributor
timestamp: March 21, 2018, 09:35:17 am
content: It seems the photos didn't make it into your posted message.....

author: Tom10000
author_rank: Contributor
timestamp: March 21, 2018, 09:47:40 am
content: I have now attached links to the photo hopefully that works

author: ovnr
author_rank: Frequent Contributor
timestamp: March 21, 2018, 11:06:14 am
content: No, it doesn't. Upload the images here, or use an actual image host like imgur.

author: Tom10000
author_rank: Contributor
timestamp: March 21, 2018, 07:49:31 pm
content: I couldn't upload them so I just uploaded them to imgur
Volumetric Visualizer display Feedback wanted - Page 1
Forum section: electronics / projects

author: Quwat
author_rank: Newbie
timestamp: October 20, 2013, 06:25:41 am
content: Hello EveryoneI have completed my music visualization prototype and I would like to see what you think.I made a video that shows and explains my design,is the full versionis the summarized version.After seeing my design I would be grateful for you to answerthese questions.Note the feedback itself is for schoolwork, so your participation is important.Thanks
Volunteers Wanted for the Maxun One Solar Bike Project – Join Us! - Page 1
Forum section: electronics / projects

author: MaxunPeet
author_rank: Newbie
timestamp: June 24, 2024, 10:59:14 am
content: Hello everyone, I'm Peter.We are looking for enthusiastic hobbyists with experience in 3D CAD design, Arduino C++ programming, or electronics to join our volunteer project, the Maxun One Solar Bike Project.Albert van Dalen is the inventor of the Maxun One and I am helping to bring attention to his Maxun One Solar Bike Project.This project offers a unique opportunity to contribute to a new sport focused on solar-powered cycling without ever needing to charge the battery. Just like a sailboat, but with PV panels! It is important to emphasize that this project has no commercial purposes and is entirely based on voluntary efforts.For more information about the project, see here:https://avdweb.nl/popular/solarbike/maxun-solar-bikeWe are based in Maastricht, and it would be convenient if you live within a 200 km radius. However, it is certainly not a problem if you live on the other side of the world.If you are serious about contributing, we would love to have you on our team!Join us and let's innovate together.Sign up here:https://maxunone.budgettair.nl/Application-Form-EN/Best regards, Peter
Volvo MOST to audio out. - Page 1
Forum section: electronics / projects

author: Oneminde
author_rank: Regular Contributor
timestamp: August 20, 2016, 10:08:13 pm
content: My dilemma is this: I am planing to upgrade the sound system in a Volvo. Volvo has used the MOST (Media Oriented Systems Transport) since 2008. My goal is simply to either locate a schematic or get help in designing a MOST -> TosLink or analog out so that the audio signal can be sent to a DSP.I am aware of the Russian Trioma MOST -> TosLink 2.0 but uncertain about the quality.Basically; How is the MOST-25 signal converted to sPDF/TosLink ?Oneminde

author: amyk
author_rank: Super Contributor
timestamp: August 21, 2016, 01:23:49 am
content: And the winner for most un-searcheable bus name goes to... MOST.The file MOSTSpecification_3V0E2.pdf might be what you're looking for. Microchip seems to have products for it.

author: Oneminde
author_rank: Regular Contributor
timestamp: August 21, 2016, 12:09:03 pm
content: LOL, I did find some documents last night that I will look through.- FunctionBlock_AudioAmplifier_2V4-3- MOST_Book_2- MOST_FIBEX_Cookbook_1V0- MOST_FunctionBlock_AudioDiskPlayer- MOST_MSC_Cookbook- MOSTSpecificationVia the MOST corporation webpage. And yes I also stumbled upon the Microchip chip's.
Voyetra Digital Orchestrator Pro / Plus discoveries - Page 1
Forum section: electronics / projects

author: CaptDon
author_rank: Super Contributor
timestamp: September 24, 2024, 01:02:07 pm
content: I posted this in projects since it is one of my musical projects. I have run DOP on my 16 bit W98 machine for probably 25 years and it really is a nice program. Cost around $149.00 way back when but indeed worth it. I did a fresh install on my 32 bit WinXP machine and used it for several years as a playback work station. I recently found that it will save the peculiar .ORC files and load them perfectly but if you try to save a .mid MIDI or .rmi RIFF MIDI you get a strange 'square root' error message and no matter what compatibility mode you choose in the XP properties the problem remains. All of your work disappears and the program closes. You can compose and so forth, but only save as .ORC and sadly most other DAW programs can't deal with .ORC files. It is a must to have a W98 machine available so you can convert old .ORC files to .MID or .RMI Ham radio dinosaurs like me are the most notorious cheap skates on the planet and yes I know there are newer programs out there but this one works so good and I own the license!! One of the reasons I kept a 'hot rodded' W98 machine around with a hot swap bay. My hot swap inserts includes a ZIP100 and a ZIP250 IDE drive and industrial folks around town have asked me to copy their ZIP drive data to other media like jump drives. As ALF says "No Problem". Cheers mates!! Hope this information may help some of our MIDI pals!! (I'll convert your .ORC files to .MID in exchange for some Brennivin or Icelandic lamb, both a bit hard to find here in the states)
VQFN Pad Size vs Pin Size - Page 1
Forum section: electronics / projects

author: meshtron
author_rank: Regular Contributor
timestamp: February 19, 2025, 06:29:47 pm
content: Trying to get some new boards made with matte black solder mask and aluminum core and the fab shop is telling me the soldermask spacing on my VQFN IC (ATTiny88) is too close together to allow specifically matte black solder mask between the pins. I've already altered my footprint to shrink the pad size from the maximum pin width to nominal, but I think to get clear of the requirement, I would need to shrink my pads even more (to be somewhere between minimum and nominal part size).I do all my own assembly and reflow, but am still relatively new to this. My assumption is that shrinking the pad size below nominal could lead to not enough room to form solder fillets, but I don't know how much that even matters for VQFN parts like mine. The datasheet provides chip dimensions but unfortunately no pad/soldermask dimension or guidance.Here's the relevant datasheet/package to look at.Appreciate any input. The fallback is to just go to green soldermask which is okay for these prototypes but my next order will be production parts and matte black (or at least black) is pretty important for our product.

author: meshtron
author_rank: Regular Contributor
timestamp: February 19, 2025, 06:59:57 pm
content: I think Reddit got my head on straight here. Even on an aluminum board, there's a layer of dilectric between the copper and the aluminum. That layer is not subject to size restrictions/tolerances because it's integral (vs soldermask which is painted on).So, I just need to get PCBWay to make this the same way we always have with no soldermask between the pins and we'll be fine.
VR 55V  - Page 1
Forum section: electronics / projects

author: GigaJoe
author_rank: Frequent Contributor
timestamp: July 13, 2018, 03:36:21 am
content: Hello,So I'm in process of building amplifier .... First brick would be a voltage regulator .... here one below , with trigger current protection ( when you crank it, amp will just turn off, a nice annoying feature)opamp : MC34071, Photocoupler PC817 (channels are independent and protection turn off a second ch over opto , psu dual, with equal VR, so VP then common ground)board 1 channel:trigger reaction on overload:Questions:Is the reaction time for triggering overload are sufficient (to avoid damage) ?Is the way to improve the reaction time ?any suggestion in overall ?
VR goggles display driver board - Page 1
Forum section: electronics / projects

author: Psi
author_rank: Super Contributor
timestamp: December 23, 2012, 04:52:14 am
content: I've got two pairs of these HeadPlay VR goggles however they're missing the driver box which provides the video inputs.Since they're pretty much useless without it i thought i'd open one up and check what, if any, electronics they have inside.Who knows, maybe i can hack up a composite input myself.There's two chips in the goggles, a MSP430 micro running at 8mhz and a DS90CF386 LVDS Receiver.I'm thinking the micro either does OSD overlay or backlight pwm or both.The LVDS receiver looks to take the differential channels coming in on the cable and convert them to RGB vsync + hsync.The thing that's weird is how it runs the actual LCD panel.There should be a driver somewhere since LCDs don't run from RGB vsync/hsync directly.Seems unlikely the 8mhz msp430 has enough power to drive the raw lcd lines at 30fps directly.Any ideas how it might work?EDIT: looking at the datasheet i noticed something i missed before. The RGB out of that chip isnt analog, it's 8bit digital per color. So maybe the MSP430 would have enough power to handle V/H addressing while the digital color data comes in from the LVDS Receiver directly.I've connected power up, all the regs/ICs get power and the 8mhz oscillator runs but there's nothing on the lcd.Probably doesn't run until it gets a video signal.DS90CF386 datasheethttp://www.ti.com/lit/ds/symlink/ds90cf386.pdfMSP430F1222http://www.ti.com/lit/ds/symlink/msp430f1222.pdf
VRE3050 die image - Page 1
Forum section: electronics / projects

author: plesa
author_rank: Frequent Contributor
timestamp: October 20, 2015, 05:55:04 am
content: It is not same porn like LTZ1000, VRE3050 is hybrid chip made by Apex or in past Thaler Corporation, Cirrus Logic. Reference is quite noisy and expensive 80-100 USD in this specification.http://media.digikey.com/pdf/data%20sheets/cirrus%20logic%20pdfs/vre3050.pdfDont turn it on, take it apart

author: daqq
author_rank: Super Contributor
timestamp: October 20, 2015, 06:24:01 am
content: Thanks for the image!If you're into this stuff, take a look at:http://zeptobars.ru/

author: crispy_tofu
author_rank: Super Contributor
timestamp: October 20, 2015, 08:11:25 am
content: That's amazing and very interesting, thanks!

author: TiN
author_rank: Super Contributor
timestamp: October 20, 2015, 10:26:26 am
content: Neat, show us more SEM pornThat M in circle somehow hints me to Motorola.... perhaps design originator?

author: Andreas
author_rank: Super Contributor
timestamp: October 20, 2015, 06:57:44 pm
content: Quote from: gazelle on October 20, 2015, 10:50:14 amAfaik the Keithley 2000 runs on a LM399.Only the 2002 uses a LTZ1000.Have you measured the 0.1..10 Hz noise on the VRE3050?According to datasheet it is typical 3uVpp (which is a average value for a buried zener reference).Ok the 2 samples that I measured showed 8-11uVpp. (which is more or less that of a cheap bandgap).with best regardsAndreas

author: BarsMonster
author_rank: Contributor
timestamp: October 21, 2015, 04:29:41 am
content: Quote from: plesa on October 20, 2015, 05:55:04 amIf you send it to me, I can make optical photos of this :-) Looks very interesting, just recently I've decapped LT1021 ;-)PS.And this is actually request to everybody: If you for example have static-zapped some expensive/high-end analog chips, they still will make great photos if you send them in (mikhail@zeptobars.ru) :-)

author: TiN
author_rank: Super Contributor
timestamp: October 21, 2015, 04:53:42 am
content: How about modern digital chips?gazelleLater Keithley 2100 are using LM399 again.Keithley 2000,2001 using selected LM399Keithley 2002 using LTZ1000A

author: BarsMonster
author_rank: Contributor
timestamp: October 21, 2015, 05:21:40 am
content: Quote from: TiN on October 21, 2015, 04:53:42 amModern digital stuff (<90nm) often beyond human comprehension, and beyond limits of optical microscopy. I do digital stuff too, but it is rarely that exciting.
Vref Advice needed (ADR3425 and the like) - Page 1
Forum section: electronics / projects

author: JPortici
author_rank: Super Contributor
timestamp: September 10, 2016, 01:15:43 pm
content: Hi folks,for my new weekends project i want to design a small, portable, low-ish cost calibrator. At this moment i am trying to find out which voltage reference to use for the precision ADC/DAC (and multimeters vref of course)one of the Vrefs i am considering is the ADR3425ARJZ-R7, not the best but the low frequency noise should be low enough to be less than a 16 bit LSBDatasheet:http://www.mouser.com/ds/2/609/ADR3412_ADR3420_ADR3425_ADR3430_ADR3433_ADR3440_AD-878965.pdfAs you can see, the feedback path is not explicitely connected to the output pin and i wanted to use this at my advantage. The Load regulation is not that good BUT if i buffered the voltage reference output and took the feedback after the buffer opamp i should achieve a Vref independent on the current load and at the same time eliminate the offset introduces by the opamp so i could focus on a low noise, not necessarily low offset one.The initial accuracy and the line regulation isn't that good either but, again i could use the two at my advantage: i could power the reference from a DAC and vary its supply voltage, hence adjusting the output to the required precision.is all of that something that makes sense? (Let's forget about the temperature for one second, assume it to be fairly constant)

author: TiN
author_rank: Super Contributor
timestamp: September 10, 2016, 05:46:09 pm
content: How portable is portable for you? Battery powered i'd expect? If few hours/day of battery life good enough for you, i'd go for good old heated LM399. Once you have it warmed up, aged and measured by calibrated 6.5d DVM, you will have good enough reference for any 5.5 digit needs.Check on Ian's box for good reference of such project:http://youtu.be/-bkINyHdLG4

author: JPortici
author_rank: Super Contributor
timestamp: September 11, 2016, 09:33:54 am
content: Portable is a self contained instrument (voltage sources, counter, awg, dc and waveform inputs, screen) about the size of the one in the video. i want to see how precise i can get
VREF regulator for DDR memory - Page 1
Forum section: electronics / projects

author: technix
author_rank: Super Contributor
timestamp: October 25, 2018, 04:50:26 pm
content: How do I generate a stable and strong VREF for a point to point DDR3 bus, from an Allwinner A13 to a Chinese-made DDR3 chip?The A13 reference schematics used two separate resistor dividers for that, but since I am using a fairly new DRAM brand their current draw can overwhelm those 1k resistor dividers, and being limited to 0603 or bigger SMD parts and can not use either blind vias or microvias means I don't get a lot of real estate among all the vias and bypass capacitors. What I have in mind now is a single VREF regulator placed somewhere in the middle of the bus, probably on the back side, to generate a strong enough VREF for both the DRAM chip and A13 to share: the reference voltage is generated by dividing VDDMEM using two 10k resistors, and an op amp like LMV321 is used to push the current. Questions:1) Is this overkill?2) Do I need a push-pull helper stage at the output of the op amp? (BAT54S + MMBT8050 + MMBT8550 - I am using transistors supporting up to 1.5A here.)

author: Benta
author_rank: Super Contributor
timestamp: October 25, 2018, 05:13:11 pm
content: There are plenty of DDR VREF ICs out there, even combined with termination. TI would be a good candidate.

author: technix
author_rank: Super Contributor
timestamp: October 26, 2018, 02:31:39 am
content: Quote from: Benta on October 25, 2018, 05:13:11 pmBeing a point-to-point connection (a 16-bit controller with up to 512MB space matched to a 16-bit 512MB chip) I think using a VREF/VTT regulator would be overkill and expensive. LMV321 and MMBT8050/MMBT8550 are all dime a dozen cheap parts.

author: technix
author_rank: Super Contributor
timestamp: October 26, 2018, 07:11:09 am
content: Quote from: blueskull on October 26, 2018, 02:53:07 amI couldn't find shunt regulators but LMV321 is cheap enough.Quote from: blueskull on October 26, 2018, 02:53:07 amI am not using VTT at all.Quote from: blueskull on October 26, 2018, 02:53:07 amI asked them for samples. They will need to know what kind of controller you are using (usually the main chip's make and model) and what general market sector you are targeting.
VS Code for Microchip PIC development - Page 1
Forum section: electronics / projects

author: ricko_uk
author_rank: Super Contributor
timestamp: October 28, 2021, 07:41:09 pm
content: Hi,has anybody used VS Code (NOT Visual Studio) for writing code for PIC controllers?If so:1) is it easy to setup?2) Do you then compile using MPLAB?3) Does it work ok with the source files being open in both MPLAB and VSCode at the same time?Thank you

author: MadScientist
author_rank: Frequent Contributor
timestamp: October 29, 2021, 06:59:25 am
content: Xc8 can be configured to run from the command line , I created a version that platformio uses and I use platformio in VSCodeBut to be honest I now use MPLABX, it’s just easier to setup

author: JPortici
author_rank: Super Contributor
timestamp: October 29, 2021, 08:10:20 am
content: Quote from: MadScientist on October 29, 2021, 06:59:25 amand you have the debugger.

author: ricko_uk
author_rank: Super Contributor
timestamp: October 29, 2021, 09:36:48 pm
content: Thank you both!How easy is it to setup if you have never used VS Code before?Does it have debugging capabilities for in-circuit debuggers like J-Link and/or ICD4?Thank you again!
vs1053 recording audio - Page 1
Forum section: electronics / projects

author: patriotaSJ
author_rank: Newbie
timestamp: August 10, 2015, 07:07:06 pm
content: hi, my name is ramiro i'm from argentinai'm trying to recorder with vs5310i add my arduino shceme editi follow thehttps://learn.adafruit.com/adafruit-vs1053-mp3-aac-ogg-midi-wav-play-and-record-codec-tutorial/ogg-recorderbut i did not have luckythis my video problemi hope you can help methanks for your time
vt100 portable terminal - Page 1
Forum section: electronics / projects

author: legacy
author_rank: Super Contributor
timestamp: September 11, 2018, 05:07:45 pm
content: I am designing a project likethisbut portable

author: ogden
author_rank: Super Contributor
timestamp: September 11, 2018, 06:22:37 pm
content: Quote from: legacy on September 11, 2018, 05:07:45 pmWhy? - Just use virtually any Android phone/tablet with BT serial adapter and VT100 emulator application likeBlueterm.

author: legacy
author_rank: Super Contributor
timestamp: September 12, 2018, 11:37:12 am
content: Quote from: ogden on September 11, 2018, 06:22:37 pmbecause Android is pure shit for mebecause I hate tablet and smart-phonesbecause tables and smart-phones do not have a physical keyboardbecause when tables and smart-phones have a keyboard it's usually shittybecause I want to create my own engine

author: ogden
author_rank: Super Contributor
timestamp: September 12, 2018, 12:20:56 pm
content: Quote from: legacy on September 12, 2018, 11:37:12 amLOLAre you purist? For you only good operation system most likely is OpenVMS, right?Btw tablets and android phones do indeed have physical (tactile) keyboards. They are calledBluetoothmechanical keyboards.Just one example of at least dozen:https://www.logitechg.com/en-us/products/gaming-keyboards/g613-wireless-mechanical-gaming-keyboard.html
VU Meter Kit - Page 1
Forum section: electronics / projects

author: tony3d
author_rank: Frequent Contributor
timestamp: May 16, 2014, 01:08:12 am
content: Hi all, does anyone know of a decent VU Meter kit or schamatic? Just like to add some bling to my little Topping Tripath amp.

author: oPossum
author_rank: Super Contributor
timestamp: May 16, 2014, 07:35:31 am
content: The LM3914/15/16 are the classic level/VU meter chips. Many kits use those. Quad compartors like the LM339 are also used in some kits and reduce the cost a bit.Using a small micro would also be an option - many are less expensive than the LM391x series chips.

author: tony3d
author_rank: Frequent Contributor
timestamp: May 17, 2014, 11:13:30 am
content: Thanks everyone for the info. I'll check into it.
VU meter noise - Page 1
Forum section: electronics / projects

author: harps
author_rank: Regular Contributor
timestamp: April 03, 2018, 05:44:26 am
content: helloi have an ADC working and I am hoping to add a VU meter to aid with levels going to it's analogue inputI wonder before fitting a VU should I add a diode or a circuit of some type to the power line to prevent any noise coming from the VU?i will add a diode to the signal input, and I will physically shield the VU with either sheet metal or metal tape. But I wonder can noise travel back through the power line too? Are any noise prevention components needed?I include a picture to aid the question. (attached)perhaps i should use a 9v regulator for the VU's also?thank you.

author: Richard Crowley
author_rank: Super Contributor
timestamp: April 03, 2018, 07:26:43 am
content: Not really enough information to reply to. The devil is in the details not in evidence.What is the nature of the power supply circuit between the power transformer and the LED VU display circuit? It could be quite robust and immune from any noise, or it could be flimsy and flaky and passing noise easily.What kind of bypassing and filtering does the LED VU circuit have internally? It could be a nice quiet neighbor, or a noisy undesirable.How good is the 5V regulator circuit? Shouldn't it be essentially filtering out any noise coming around from the LED VU circuit?Does the lack of an arrow suggest that the "Analog Audio Device" is powered independently?Frankly the most problematic part of the diagram you show is that "audio diode" (whatever that means?)Connecting a REAL diode to the prime audio path is NEVER a good idea.Again, since this is only a detail-free block diagram, we don't really know enough to make a useful comment.
VVD - Page 1
Forum section: electronics / projects

author: richcj10
author_rank: Unknown
timestamp: January 27, 2015, 05:19:51 am
content: I am working on a variable voltage drive for pumps and fans/ It takes about 28 - 21v on the input and can on demand take the output from 8-24v @ 8-10A on the output. The 24v output will of coarse not be meet when the input ( battery) is dead. I made something before but it was at 3A. Any IC ideas would be great. I need something that is low part count.Thanks

author: ajb
author_rank: Super Contributor
timestamp: January 27, 2015, 06:22:40 am
content: So you supply varies from 21-28V, and you need an adjustable output from 8-24V, but the output voltage never needs to exceed the input voltage--did I understand that correctly?If it's to drive a motor of some sort and you don't need to boost the voltage, can you just use PWM? That's a heck of a lot easier than trying to provide a regulated voltage at 8-10A.If you need a regulated voltage, I think the only low part count solution would be an off the shelf DC-DC module, but I don't expect that modules with such a wide adjustment range at that power level are common (or cheap).

author: qwaarjet
author_rank: Regular Contributor
timestamp: January 27, 2015, 07:33:09 am
content: I've used the ltc3789 in a similar operating range to what you are describing. Though I was using as part of a solar panel mppt/ li ion charger so it wasn't as striped down as it could be.http://www.linear.com/product/LTC3789

author: richcj10
author_rank: Unknown
timestamp: January 27, 2015, 05:01:18 pm
content: Quote from: ajb on January 27, 2015, 06:22:40 amThe reason it needs to be "regulated" (we could have ripple on the line) is that we are controlling the voltage to water pumps that are brushless. The control circuitry is built into the pump. If we control it with PWM, it my not regulate so well making the pressure in the cooling line not constant. This will cause our readings to be off (known and measured) and heat transfer not constant to a given voltage. The pump is not as much of a problem as the fans. The fans run on 12v and have an average current of 2.8A. I want to have head room on top of that. Also we may be controlling more than on fan on each output.
VW Analogue Clock Repair - Mechanical but driven by SCL5419AE - Page 1
Forum section: electronics / projects

author: jcrubin
author_rank: Frequent Contributor
timestamp: October 06, 2017, 12:16:14 pm
content: Below is the Troubleshooting and repair project i've just completed for a common clock found in 1970's VW and Porsche automobiles using this hard to find IC SCL5419AE as a driver with a suitable replacement found.Enjoy,1 of 22 of 2
w2aew's Circuit Fun: Control an RC Servo with an adjustable DC voltage  - Page 1
Forum section: electronics / projects

author: Maxlor
author_rank: Frequent Contributor
timestamp: December 11, 2014, 11:02:42 pm
content: Thanks forAlan, I enjoyed it. Plus, you explained it in such a way I can understand it. Coming from the digital domain, figuring out this analog stuff takes some effort for me.A friend of mine is into robots and thus uses servos a lot, maybe this'll help make things easier for him. Controlling servos using a micro controller's hardware PWM controller can be inprecise because all the action happens between 4% and 8% duty cycle usually with only so many steps available in that range, so using a DAC of some sort with this idea is a nice alternative.What happened to your hands though? Looks like you got into a fight with someone wearing spikes...

author: nkw
author_rank: Contributor
timestamp: December 11, 2014, 11:38:59 pm
content: I think all the videos I've seen by w2aew are great. As a software guy diving into hardware, between EEVblog and w2aew I've been binge watching Youtube. For every bit as entertaining as I've found the EEVblog, the w2aew videos are super clear, concise and informative.At first I was really jealous of the incredible equipment w2aew has in his videos. It makes the equipment in my budding ham shack/lab look like a set of tinker-toys. Actually I am still jealous, but I stumbled across a webpage which discussed his occupation and employer -- I don't feel so bad now.

author: w2aew
author_rank: Super Contributor
timestamp: December 12, 2014, 01:06:55 am
content: Quote from: Maxlor on December 11, 2014, 11:02:42 pmGlad you liked it! With regards to the condition of the back of my hands... ...blame on cleaning out the gutters on the house without gloves on. But, it's pretty typical. If it wasn't the gutters, then it's from working on the cars, or the yard, or....

author: w2aew
author_rank: Super Contributor
timestamp: December 12, 2014, 01:12:08 am
content: Quote from: nkw on December 11, 2014, 11:38:59 pmYes, being a Field Applications Engineer for Tektronix has its benefits. I'm very fortunate to have found my dream job, and have a very understanding wife!