hybridfree/eevblog-posts huggingface dataset:
Altium previous and next document shortcut not working - Page 1
Forum section: electronics / projects

author: ricko_uk
author_rank: Super Contributor
timestamp: June 01, 2022, 05:20:21 pm
content: (reposted in Altium forum and deleted this one)Hi,according to Altium's documentation to "Step forward to the next document in the sequence of documents that have been made active in the main design window" the shortcut is Alt+Right Arrow and for the previous one is Alt+Left Arrow. See here:https://www.altium.com/documentation/altium-designer/shortcut-keysBut they don't seem to work AND I cannot find where I can set it up as shortcut. Any idea?Just to be clear I am not looking for the "Cycle forward to the next open tabbed document" which is Ctrl+Tab and that does work. That often switches to a library or other files I currently have open. I just want to quickly move back and forth between two or three documents I am curently working on (i.e. between a couple of SCH sheets and a PCB sheet during placement.Also:- how do you setup a custom function for two extra mouse buttons you often have on various mice?- how do you change the wheel direction?Any suggestion?Thank you

author: thm_w
author_rank: Super Contributor
timestamp: June 01, 2022, 10:13:23 pm
content: Move your thread to the correct forumhttps://www.eevblog.com/forum/altium/

author: ricko_uk
author_rank: Super Contributor
timestamp: June 02, 2022, 12:49:28 am
content: I don't think I can move it to another forum - cannot see any options to do so.I now reposted it there.@Admin, can you please delete this one.Thank you
[SOLVED] Altium - Shielded cable - Page 1
Forum section: electronics / projects

author: moffy
author_rank: Super Contributor
timestamp: June 23, 2025, 04:00:22 am
content: I am running an older version of Altium v10, does anyone know of a symbol or method for schematics to display a shield? At present I am just using the elipse drawing tool, not the best. Suggestions appreciated.

author: ftg
author_rank: Frequent Contributor
timestamp: June 23, 2025, 02:17:09 pm
content: When I was drawing wiring harnesses in Altium 17 I also used the elipse drawing tool for cable shields.If that was your question.I have not come across anything much better since then.

author: moffy
author_rank: Super Contributor
timestamp: June 23, 2025, 10:41:21 pm
content: Well, the elipse looks like the solution, thanks for your response.

author: thm_w
author_rank: Super Contributor
timestamp: June 23, 2025, 11:22:50 pm
content: https://www.eevblog.com/forum/altium/

author: moffy
author_rank: Super Contributor
timestamp: June 23, 2025, 11:48:02 pm
content: Quote from: thm_w on June 23, 2025, 11:22:50 pmDidn't know it existed, thanks for the direction.
Altium simulation not working correctly?  - Page 1
Forum section: electronics / projects

author: ricko_uk
author_rank: Super Contributor
timestamp: April 25, 2021, 12:07:06 am
content: Hi,(NOTE: I uploaded this in the Altium designer section too and tried to delete it but couldn't)I use the latest Altium (updated a couple of days ago) and I was trying to simulate a circuit and not getting the results I expected.So I simplified it over and over again until I got to a very basic resistors and capacitors circuit. And it still does not seem to work.For example in the attached circuit, changing the resistor values of R1 and R2 (even by very large amounts) does not change the voltage Vin...The sim setup gives "green" on all setup checks...Attached is the full schematic/sim.Am I doing something wrong?Thank you

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 25, 2021, 01:42:13 am
content: R1 is 0.001 ohms. Use "Meg".SPICE is case-insensitive, so they had to hack it like this. Else use floating point (1e6).Tim

author: ricko_uk
author_rank: Super Contributor
timestamp: April 25, 2021, 06:52:08 pm
content: Thank you Tim!
Altium Solder mask expansion rule. - Page 1
Forum section: electronics / projects

author: titium
author_rank: Newbie
timestamp: September 19, 2014, 04:59:09 am
content: In the video linked below dave makes reference to setting the solder mask expansion rule to 1.5mil however after speaking to the manufacturer PCBzone in NZ, they have told me he lowest I should go for is 8mil.I guess what im asking is, are there any manufacturers that do small quantity boards (at a decent price) that can go down to 1.5mil. Or should i just not bother with the solder mask between the pads.With the 8mil rule I have no solder mask (or very little) between IC pins particularly the ones with smaller pitch (0.5mm-0.65mm)

author: ludzinc
author_rank: Unknown
timestamp: September 19, 2014, 05:10:54 am
content: Quote from: titium on September 19, 2014, 04:59:09 amSmallest Solder mask 'sliver' should be 8mil. If you have a 1.5 mil expansion, that equates to pad edges being no closer than 11mil.

author: titium
author_rank: Newbie
timestamp: September 19, 2014, 05:16:42 am
content: here is the reply i got from pcbzone when i asked if i should reduce the solder mask expansion"If you were to reduce the grow on the mask openings i think we would run into alignment issues, so i would leave it as is. It should still solder fine."They then went on to say that the solder mask expansion should be >8mil preferably 10mil

author: Precipice
author_rank: Frequent Contributor
timestamp: September 19, 2014, 08:53:14 am
content: Quote from: titium on September 19, 2014, 04:59:09 amThis...There shouldn't be any copper between pads, so what are you hoping the solder mask will do? At fine pitches, you just need to get things right, and surface tension will make it all work.There always comes a point where it's not worth it. Granted, 8mil expansion and 8mil sliver is quite old-school, and it's easy enough to find a fab that can beat it if you want to pay, but short answer, don't sweat it.

author: marshallh
author_rank: Unknown
timestamp: September 19, 2014, 04:19:14 pm
content: Depends on the fab's processes. I use 3mil expansion and haven't had a problem. Then again most of my boards use pretty fine pitch small parts.Modern LPI soldermask lets you get away with really small necks like this.
Altium - solder mask sliver - Page 1
Forum section: electronics / projects

author: tree
author_rank: Regular Contributor
timestamp: July 14, 2014, 04:44:52 pm
content: Hello folks,I would appreciate your help solving the following Altium problem. I want to be able to ignore the solder mask sliver violation for same net objects. For instance, I want the design rule checker to ignore the minimum solder mask sliver rule for a via and pad of the same net since they are already shorted and I don't care if the solder mask between them isn't present. However, I want the solder mask sliver rule to be violated when the objects are part of different nets. It would be nice if I could create a rule for this, but I'm having difficulties coming up with a custom query to do this. The other possibility would be to ignore specific violations, but I don't think Altium can do that.Thanks.

author: Rufus
author_rank: Super Contributor
timestamp: July 14, 2014, 06:50:41 pm
content: We have a specific Altium forum where this should have been posted. Maybe a mod can move it.Solder mask slivers are not a problem of lack of isolation. Thin slivers can not be manufactured so the board house will either remove them or reject your data.

author: tree
author_rank: Regular Contributor
timestamp: July 14, 2014, 06:54:24 pm
content: Quote from: Rufus on July 14, 2014, 06:50:41 pmI understand, but how do I get the software to recognize the slivers which are too thin only between different net objects and mark them, and only them, as violations.

author: Precipice
author_rank: Frequent Contributor
timestamp: July 15, 2014, 08:27:38 am
content: Is this not more easily spotted by setting up a pad-pad (different net) clearance rule? (as long as you're not doing weird things with soldermask pullback on a per-pad basis).
Altium SVN version control stuck in "refreshing" state  - Page 1
Forum section: electronics / projects

author: ricko_uk
author_rank: Super Contributor
timestamp: March 30, 2022, 01:01:21 pm
content: Hi,in all of a sudden Altium SVN version control started showing refreshing (the grey circle in the attached screenshot) and remaining stuck in that mode so I cannot do any commits. I can use 100% of Altium but cannot add or do any commits.What is weird is that it shows the same for all projects open in the project group including some projects/files that I have not open in weeks (they are just still part of the same project group when I open Altium). It also does that regardless of the project group I open.I tried everything including restarting Altium and the PC. After restarting it seems to work for a bit but either after a while or after the first commit it goes back to the status mentioned above.Any suggestions to fix?Thank you

author: tszaboo
author_rank: Super Contributor
timestamp: March 30, 2022, 01:19:01 pm
content: What I found for SVN, the fix is usually not on the client, but on the server side.Most of the commit and update related problem was Linux file access rights related. Which is not about the SVN user, but the "user that runs the SVN server", they had to add 777 or smt like that to the folders.

author: thm_w
author_rank: Super Contributor
timestamp: March 30, 2022, 08:55:09 pm
content: You should post altium questions here:https://www.eevblog.com/forum/altium/ask a mod to move it.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 31, 2022, 12:20:57 am
content: On Windows it'll be TortoiseSVN or something like that, which, I forget if that's the be-all-end-all or if it uses a related thing as a backend? But yeah, that'd be the "server" end.Try clean / repair or whatever it's called? Also, what's the Storage Manager panel say, if anything?Tim

author: ricko_uk
author_rank: Super Contributor
timestamp: March 31, 2022, 05:12:35 pm
content: Thank you all.I could not find a repair option but after doing a Windows update it started working again.
Altium to PDF compilation stuck - Page 1
Forum section: electronics / projects

author: afitzg
author_rank: Newbie
timestamp: July 27, 2020, 09:19:11 am
content: Hi, sorry if this is the wrong board...I've got a 5-sheet schematic in Altium Designer 20, and was trying to get PDFs from it, and it's stuck in this loop:Compiling [Sheet 1].SchDoc...Compiling [Sheet 2].SchDoc...Compiling [Sheet 3].SchDoc...I left this going overnight, and it's still going the morning after. This happens when I use MS print to pdf, or the Altium PDF wizard. Anyone else had this before?
alum electrolytic capacitor potting or other ways to mechanically secure cap - Page 1
Forum section: electronics / projects

author: b177
author_rank: Contributor
timestamp: April 27, 2025, 06:05:52 pm
content: My question today is how to mechanically secure a large electrolytic cap being added to an existing device. The cap legs are bent 90d and installed into the pcb. The cap is floating above the smd components due to space constraint.The pcb is already being potted, ~3 mm above the surface. I know it is not recommended to encapsulate aluminum electrolytic caps. Potential problems include covering/sealing the vent (on the top), causing excess pressure to the case (fully encapsulated), and risk of the potting compound migrating through the polymer seal at the bottom. The last risk is what I am concerned about here. Is the problem specific to the epoxy migrating through the holes for the leads? through the polymer material itself, or through the outer edge where the seal mates with the can body?thanks

author: incf
author_rank: Frequent Contributor
timestamp: April 27, 2025, 06:16:04 pm
content: Soft RTV goop under it after potting might work so long as (1) they are chemically compatible and (2) there is good adhesion (there might be no adhesion between the two, which would be bad).You might want to have the capacitor totally outside of the potting.
Alumilite Mini Casting kit Tutorial/First impression - Page 1
Forum section: electronics / projects

author: cenobyteq
author_rank: Newbie
timestamp: August 01, 2011, 05:20:14 pm
content: Hello everyone, I'm excited to have stumbled on this site. I love the video blogs and the website in general. I'm sharing my experiences with this plastic casting kit. I welcome any feedback or other similar product recommendations.HTML:http://www.armjunkie.com/?page_id=541PDF:http://www.armjunkie.com/wp-content/uploads/2010/07/Alumilite-Mini-Casting-Kit_Arm_Junkie_v1_2.pdf
Aluminium robot arm for powder coating - Page 1
Forum section: electronics / projects

author: machinebyte
author_rank: Newbie
timestamp: March 10, 2022, 04:10:11 pm
content: So finally I've done as an proof of concept some robotic arm based on few atmegas 328 and RPi 3b+. Atmegas are to control hybrid-servos especially encoder's positioning whereas RPi is for GUI, I/O and is used as a main unit to communicate with atmegas and other stuff. My last update of this project was to program a turntable where some details are hung to be powder coated. I developed some script which enables to create some robotic arm's path with additional I/O interface. You can see it there:.Regards,Martin
aluminum nitride PCB substrate - Page 1
Forum section: electronics / projects

author: CopperCone
author_rank: Super Contributor
timestamp: December 04, 2017, 12:10:55 am
content: Can this stuff be drilled with carbide drills?Can it take the impact of a copperset via kit?I want to make my own RF PCBS.

author: darrell
author_rank: Regular Contributor
timestamp: December 04, 2017, 12:57:06 am
content: AlN is a hard brittle ceramic and is drilled with diamond or lasers. It's used for it's extremely high thermal conductivity. The usual metal on these ceramic substrates isn't solderable (the gold dissolves leaving a titanium adhesion film). If you are asking these questions, you probably want something more like Rogers RO4350B which can be drilled like FR4 and is copper clad. Even Isola FR408 is decent to 10 GHz or so. OSHPark uses that on their 4 layer service.

author: CopperCone
author_rank: Super Contributor
timestamp: December 04, 2017, 10:14:36 pm
content: I wanted to go up to 20GHz
Aluminum PCB USB-C Connector - Page 1
Forum section: electronics / projects

author: bjkayani
author_rank: Newbie
timestamp: March 08, 2022, 05:15:39 pm
content: Hello AllNew forum member here. I am designing an Aluminum PCB for this LED project. It needs to have a USB-C Connector on it. From your experience, is it better to have an SMD connector or through hole connector on Aluminum. Through holes on my AluminumPCB wont be plated through.I am just trying to think through which route will be more mechanically sound and what would be the cost difference between the two.Thanks for your insight.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 09, 2022, 02:56:32 pm
content: Aluminum PCBs usually do not support through holes for electrical connections other than ground, so I assume the "through hole" connector only uses through holes for ground. I would go for that if the pins are long enough to bend over on the bottom of the PCB and then glue in place for added strength. Also add a pair of holes on the board with the connector in the middle to allow adding a bracket (attached using screws from the bottom) to reinforce the connector.
Am I correct in assuming this boost regulator has reverse voltage protection? - Page 1
Forum section: electronics / projects

author: Starlord
author_rank: Frequent Contributor
timestamp: January 20, 2018, 07:02:20 pm
content: http://www.ti.com/lit/ds/symlink/tps61253.pdfThe datasheet for this regulator mentions "reverse current protection" in regards to the shutdown mode, but it does not mention reverse voltage protection in general.For example on page 16 it states:QuoteAnd on page 17 it says:QuoteHowever if you look at the block diagram on page 15, there is a PFET between VOUT and SW, and no direct connection between VIN and VOUT aside from the inductor between VIN and SW. And the PFET is oriented such that the body diode, which is not pictured for whatever reason, should have the negative side pointed towards VOUT. So in theory, if I have 5V on VOUT from a USB port, it should not be able to flow back into my battery even if the battery is too dead for the regulator to output 5V, right?

author: Wimberleytech
author_rank: Super Contributor
timestamp: January 20, 2018, 09:36:21 pm
content: Quote from: Starlord on January 20, 2018, 07:02:20 pmShutdown operation depends on driving the gate of the PFET high during shutdown, to turn it off. My guess is that the supply sourcing the control of that gate comes from Vin. Therefore, if Vin were a dead battery, you may well have current flowing into the chip from Vout.I dont see enough detail in the datasheet to be absolutely confident in the analysis above

author: Starlord
author_rank: Frequent Contributor
timestamp: January 20, 2018, 10:44:17 pm
content: What about this one?http://www.ti.com/lit/ds/symlink/tps61235p.pdfThe interesting thing about this one is that while in the first one the PFET is backwards, as one would use it in a reverse-polarity protection circuit, in this one it is forwards, but the body diode(s) are shown, and they're weird. Instead of one diode pointing towards the source, there are two facing each other, which would seem to indicate that no current can flow in either direction through the body diode.But even so, I still can't tell if the PFET on VOUT will conduct to VIN under any circumstances.
AM modulation with Agilent DSO-X-2000 - Page 1
Forum section: electronics / projects

author: tiofilo75
author_rank: Contributor
timestamp: October 18, 2013, 06:40:20 am
content: I've been playing with the build in wave generator on the oscilloscope and learning about AM modulation. I learned how to use the FFT math function as well which was neat since I could see the message and carrier frequencies instead of just drawing them out in class. The carrier frequency is set at 5 Mhz while the message frequency is set at 10khz. I set the center frequency on the FFT to 5Mhz with a span of 50 KHz. These oscilloscopes are freaking awesome.
AM Modulator - Page 1
Forum section: electronics / projects

author: Chryseus
author_rank: Regular Contributor
timestamp: July 26, 2013, 11:40:57 pm
content: Hey guys, this afternoon I put together a little AM modulator for aligning and testing vintage AM radios, after playing around for a couple of hours I got something that works reasonably well, so I would appreciate any suggestions to improve this.Schematichttp://u.cubeupload.com/Chryseus/xtw4kN.pngForgot to mention supply is 15V to gnd.Output, I actually improved this a fair bit by adding 1k in series with the 2.2uI do have a few specific questions:What would you consider the best option for the carrier oscillator, 100kHz to 10MHz sine?The loss in my isolation transformer is very high, what other methods could I use, optical ?Would I be better off using a higher gain BJT than a JFET, assuming my sources are low impedance ?

author: w2aew
author_rank: Super Contributor
timestamp: July 27, 2013, 01:54:23 am
content: Repectfully, what you have created is not amplitude modulation. It appears to be simply a summation of the audio and carrier signal. With AM, the carrier magnitude is varied with the audio. With your circuit, the carrier is simply shifted up and down with the audio, at roughly the same magnitude.Take at look at the AM waveform on this wiki page, and compare it to your scope waveform to see the difference.https://en.wikipedia.org/wiki/Amplitude_modulationThe choice of the carrier oscillator depends on what test frequency you want to use for your radio work. If you want to inject the signal into the IF of the receiver you're working on, such as 455kHz. Or, you might want to inject at the RF input, so the test frequency should fall within the receiver's frequency range.

author: Chryseus
author_rank: Regular Contributor
timestamp: July 27, 2013, 11:40:08 am
content: Ahh yes I see what you mean, guess I have more experimenting to do

author: djsb
author_rank: Super Contributor
timestamp: July 27, 2013, 01:19:31 pm
content: I built an AM modulator circuit for class use in my last job (technician at a UK university) using an MC1496 IC.http://www.tsc.uc3m.es/docencia/LEC/manuales/mc1496rev4f.pdfI just used the application circuit in the data sheet and made sure that the power supply to the circuit was properly decoupled (otherwise the regulator oscillates badly).Works fine.David.
Am n00b - Installing line level input on amp - PLZ HLP - Page 1
Forum section: electronics / projects

author: Ryeno
author_rank: Newbie
timestamp: October 18, 2018, 02:24:55 am
content: I have a Vandersteen 2W powdered subwoofer.The amp only have high-level inputs.I want to install a mono low line level RCA input.The amp looks like thisThe 3 main components on the PCB are1. RC4136Nhttp://www.ti.com/lit/ds/symlink/rc4136.pdf2. PC1298Vhttps://4donline.ihs.com/images/VipMasterIC/IC/NECE/NECED020/NECED020-1298V-1.pdf3. Motorola MDA-2502 Bridge RectifierIt looks like a simple circuit but I'm a total n00b so I don't know where to start.Please help.

author: t1d
author_rank: Super Contributor
timestamp: October 18, 2018, 04:43:30 am
content: I don't know the answer, but the capacitors appear to beverydamaged. If so, they will need to be replaced.
AM RF rejection - how to help needed  - Page 1
Forum section: electronics / projects

author: AllTheGearNoIdea
author_rank: Unknown
timestamp: April 05, 2020, 12:27:08 pm
content: Although my main interest is collecting and repairing test equipment I do on occasions dabble in radio repair. I would like to do some before and after testing and see how a particular radio compares to the manufacturer’s specifications. If you cannot measure it how do you know you have made an improvement etc.I’m today playing with a fairly typical domestic receiver of the 60s and 70s and need some practical advice on how to test the AM rejection against manufacturer’s specifications sheet.The radio specifications quotes” 40db {Signal to noise ratio greater than 50db}My IF is 470khz.Having tuned in the radio to the signal generator do I then increase the frequency off generator by 2 x IF and make measurement with the modulation on and off to get the signal to noise ratio.Where do I make the measurement I am guessing it could be at the output of either the IF stage or speaker dummy load. I should keep the signal level very low to avoid activating the ALC ?Is the 40db part of the specifications telling me the amplitude of the image Frequency should be 40db down on the level at the frequency the radio is tuned too.I have never done this before so just need some help with the basic setup and getting the procedure correct. I do have basic test gear including RF test sets.Thanks regards Chris

author: iMo
author_rank: Super Contributor
timestamp: April 05, 2020, 02:16:17 pm
content: FYIhttps://archive.org/details/PracticalRadioFrequencyTestAndMeasurement/page/n197/mode/2up
AM Transmitter PCB Layout - Page 1
Forum section: electronics / projects

author: Spankyty
author_rank: Newbie
timestamp: March 02, 2025, 08:43:10 pm
content: I converted my AM Transmitter schematic to a PCB. I added 2 gnd vias for each trace via. I have an 8mm grid of gnd vias across the PCB. Could someone with pcb and rf noise experience please let me know if there's any flaws here? Sure there is many. lol. I am unsure about how to shield the trace for the output connector if I even have to and if I even need that big of a trace for 50 ohms impedance.. The 2 previous PCB's failed with tons of noise. My power traces are .5mm and everything else is .254mm. The vias are .7mm diameter and .3mm drill. 2 gnd planes on each side of pcb.Here is my project:https://easyeda.com/editor#project_id=fe8387c0ea33430ebabebbc2fc093288Here is my github:https://github.com/Spankyty/AM-TransmitterHere is a 3d version:Thank you.

author: shabaz
author_rank: Frequent Contributor
timestamp: March 02, 2025, 09:34:44 pm
content: Hi,Nice project. I'd like to build it someday too perhaps.The PCB layout is quite spread out, and it could be good to move the mic amp portion closer to the input and potentiometers, and move the reference clock and divider further away, since it's at 10 kHz which is right in the middle of the audio spectrum. Personally I would not have this clock generation in the center of the board. Your audio input travels the entire distance along the lower length of the PCB, it should all be far closer together. Also, optionally, you could remove the potentiometers and replace with trimmer resistors and make all that a lot more compact if desired.A couple of the net names are a little confusing, it may be better to change "RF-INPUT" to be "CARRIER" or "TX-FREQ" or similar, and change "TUNE" to be "MODULATED-RF" or similar. Also, the text "OUTPUT TUNING" is really "ANTENNA TUNING" (otherwise some will think it tunes the frequency..). The text "RF SWITCHES" should be "FREQUENCY SELECT".Also, on the PCB top layer, you could have a larger gap between the copper fill and the traces. It's only serving the purpose of balancing copper on both sides, since you've already got a proper ground plane on the underside.You might also want to add some silkscreen with descriptions for what some of the connectors and switches are for (you've got some text on the board, but it seems incomplete).

author: aeg
author_rank: Regular Contributor
timestamp: March 04, 2025, 06:08:23 am
content: Unless you pinpoint the cause of the poor performance, it could return with the new boards.

author: daisizhou
author_rank: Super Contributor
timestamp: March 04, 2025, 08:07:55 am
content: Quote from: Spankyty on March 02, 2025, 08:43:10 pmIn my opinion, it might be better to choose a 4-layer PCB layout.

author: aeg
author_rank: Regular Contributor
timestamp: March 05, 2025, 09:24:06 am
content: Quote from: daisizhou on March 04, 2025, 08:07:55 amA lot of radio transmitter kits worked fine with single layer PCBs - not even 2-layer.
Amazon Echo - is the mic disabled via analog circuit? - Page 1
Forum section: electronics / projects

author: ivc
author_rank: Newbie
timestamp: October 26, 2016, 06:52:15 pm
content: In this video aboutJeff Bezos being interviewed by Walter Isaacsonat around the 6 min mark, Bezos claims the mute button on the Amazon Echo is physically connected to the mic amplification circuit, making it impossible to enable again via software.Would be interesting if someone with an Echo could do some inspection and find out if this is true.

author: NiHaoMike
author_rank: Super Contributor
timestamp: October 27, 2016, 03:25:15 pm
content: There do seem to be a few SMD components right under the mute button, I'll have to try working out what they do.https://www.eevblog.com/forum/reviews/teardown-amazon-echo-dot-2/

author: Berni
author_rank: Super Contributor
timestamp: October 28, 2016, 05:24:26 am
content: Fun story about mute buttons:Cisco voip phones have the handset switch connected to the microphone amplifiers mute pin. This is so that when the headset is hung up "on hook" on the phone there is no possibility to listen to the microphone. But what a bunch of hackers found out that there is also a GPIO pin connected to that switch so that the software knows when you picked up the phone.What they did was use some injected code to switch that GPIO pin in to output mode, this then pulled down the switches signal, making the microphone amplifier turn on and they could stream your top secret conversation out to the internet without the handset being picked up.
Ambient light range for dimming TFT display - Page 1
Forum section: electronics / projects

author: ricko_uk
author_rank: Super Contributor
timestamp: May 27, 2022, 05:50:46 am
content: Hi,what are the min and max lux values for ambient light useful to determine the backlight brightness of a TFT display?i.e. the min lux value for a low-light room where you can set the backlight to a minimum and a lux level at which you would start setting the brightness to the maximum?Thank you

author: ajb
author_rank: Super Contributor
timestamp: May 27, 2022, 03:44:19 pm
content: Well, the minimum ambient lux value could be zero, if the display is the only light source in the room, to 130,000 lux if it's used in direct sunlight. Narrowing the range down at all depends a lot on the application. Something like a radio that might be used in a bedroom at night would need a very deep-dimming backlight, but an industrial control panel used in a brightly lit factory won't need nearly as much range. Plus the optimal backlight level will depend on other factors than just the incident flux, like the direction that flux is coming from, whether the front of the display is glossy or matte, and what's in the visual field around the display.

author: ricko_uk
author_rank: Super Contributor
timestamp: May 30, 2022, 11:08:00 pm
content: Thank you ajb
Ambient light sensor response time - Page 1
Forum section: electronics / projects

author: espena
author_rank: Contributor
timestamp: May 16, 2024, 01:49:05 pm
content: I am thinking of adding a VEML7700 ambient light sensor to a NTP/GPS timed LED clock that I'm working on in order to auto-adjust the display brightness.By placing the light sensor beneath the front glass among the LEDs (which is pretty much my only option), it will be disturbed the brightness of the display. So I will have to turn the display off to do a proper ambient light readout (or simply sync the VEML readouts with the PWM drivers).I was thinking of blanking the display for a very few milliseconds, reading the ambient light and then turn the display back on. Since I want the adjustment sequence to be unnoticeable for the human eye, I'm granted only a few milliseconds. Probably at or below 10 ms.Is VEML7700 sufficiently responsive for this to work? How much time will the sensor need to settle? Normally, I would say that 10 ms is an ocean of time -- perhaps not quite so in this case...I tried to find some clues on whether my approach will work from the datasheethttps://www.vishay.com/doc?84286, but to no avail. It might be possible to deduce something from the i2c timing characteristics.Is there anyone here having experience with ambient light sensors and response time? Either for the VEML7700 specifically or in general?

author: PlainName
author_rank: Super Contributor
timestamp: May 16, 2024, 01:56:48 pm
content: The datasheet gives a refresh time, based on the integration time and power saving mode. It lists 600ms as not quite best value (doesn't give data for 50ms integration time). Bottom of page 9.

author: Algoma
author_rank: Frequent Contributor
timestamp: May 16, 2024, 01:57:03 pm
content: The display brightness is a known value, it can be calibrated out. Perhaps take frequent readings with the display on, adjusting for the known brightness. Then Blank it to take cailibration readings every minute when the time changes. A display flicker with a digit change will be less noticable. Or only blank the (minute) digit nearest the sensor, the one that is changing the most often.

author: eutectique
author_rank: Frequent Contributor
timestamp: May 16, 2024, 02:10:36 pm
content: VEML7700 has programmable integration time from 25ms to 800ms (register 0, bits ALS_IT). Nowhere near 1ms. Here is theapplication note.

author: espena
author_rank: Contributor
timestamp: May 16, 2024, 03:18:57 pm
content: Oh, it was there all the time, in my face (I swear, I did read the doc, but not thoroughly enough, obviously). Thanks! Far too long integration time. I guess I will have to try calibrate out the display's illumination instead, as suggested by Algoma.
Ambitious project; 2S-4S battery charger with SEPIC/BUCK-BOOST input/output. - Page 1
Forum section: electronics / projects

author: Oxmstr
author_rank: Contributor
timestamp: October 12, 2021, 06:44:07 pm
content: I'm thinking about first power project for work. We modify portable fridges for medical purposes to have a battery backup (so not mutch space). We currently use self made 2170 3S3P battery packs (120WH) with off the shelf components ("300W" XL4016 CC/CV step down converter for battery charging and "150W" XL6009 step up to maintain 13.2V output from batteries).Currently used solution is not the best because of the quick self discharge rate (from 100% to 0 in about a week of not using) and that the integrated power supply is constructed that it has a fan blowing on it when it's working, but when it's only charging the fan is turned off so it doesn't get any airflow and gets quite hot. Also people don't understand how CC/CV charging works, so when a battery display shows 100% and they disconnect the power they wonder why it shows less than 100%, so I'd like to maybe also implement a coulomb meter / gas gauge.Can be MCU controlled (I have intermidiete arduino "skills")My prelimenary idea is:– 2 SEPIC / buck-boost converters (if outside the cost, at least 1 for charging and step up for discharging), one for charging and second for discharging– BMS with balancing (2S – 4S)– thermal probe for PSU that can detect if it gets hot so it lowers the current for charging– intput ORing / reverse diode protections, everything has AC in and DC in (12V and sometimes 24V input from car), so an ideal diode / oring circuit / diode to prevent charging the car battery from the internal batterycool to have:– gas gauge / coulomb meter (not sure how to do display, cheap oleds have problem with burn in, probably better to use 5 LEDs for 0,20,40,60,80,100 SOC)– low battery sound alarmRequirements:BOM to be less than 20€/25$ (too ambitous?).Physical (not final):less than 2cm in height, slim (3cm); can be long (10cm), noise is not an issue so can have active cooling. Could even be two separate boards like BMS with charging + discharging board.2-4S balancing BMS,"low" self discharge (?less than 10mAh?)80W, 8A, 9V-30V charging100W, 10A, 9-24V output (fixed 13V if too expensive)
AMC1301 voltage sensing - Page 1
Forum section: electronics / projects

author: m.jayid
author_rank: Newbie
timestamp: April 18, 2021, 06:33:53 pm
content: Hi everybody .I would like to use the AMC1301 as a voltage sensor .to sense the input of a DC source =400V.according to its datasheet the voltage drop between VINP and VINN should be maximum 250mV.I choose R1=R2=1Mohm.What would be the values of R3 and R3'.Thank you .
AMC1350: Bandwidth and unused output questions - Page 1
Forum section: electronics / projects

author: 3Deye
author_rank: Contributor
timestamp: February 04, 2024, 02:49:00 pm
content: Hi,I'm looking for an isolation amplifier for a 2Vpp 250KHz signal which appears to be challenging to find. The closest I could find is the AMC1350 and I have the following questions:1) The frequency of interest in my application is 250KHz and the BW of the AMC1350 is 275KHz up to 300KHz, will this be sufficient? I understand that AMC1350 introduces 0.4 attenuation which is not a problem to me. If not, are they any other more suited options?2) Only a single-ended output from the opamp is needed, how to terminate the unused output?Thanks!
Ameba RTL8722DM/CSM is now supporting TensorFlow Lite "Magic Wand" example - Page 1
Forum section: electronics / projects

author: dakamaster
author_rank: Newbie
timestamp: June 30, 2021, 01:52:41 pm
content: Introduction to Google TensorFlowTensorFlow (TF) is an end-to-end open-source platform for machine learning.It has a comprehensive, flexible ecosystem of tools, libraries, and community resources that lets researchers push the state-of-the-art in ML,and developers easily build and deploy ML-powered applications.TensorFlow Lite for MicrocontrollersWhile TensorFlow Lite (TFL) for Microcontrollers is designed to run machine learning models on microcontrollers and other devices with only afew kilobytes of memory. The core runtime just fits in 16 KB on an Arm Cortex M3 and can run many basic models. It doesn't requireoperating system support, any standard C or C++ libraries, or dynamic memory allocation.Ameba and TFL for MicrocontrollersAmeba is an easy-to-program platform for developing all kinds of IoT applications. AmebaD is equipped with various peripheral interfaces, includingWiFi, GPIO INT, I2C, UART, SPI, PWM, ADC. Through these interfaces, AmebaD can connect with electronic components such as LED, switches,manometer, hygrometer, PM2.5 dust sensors, …etc.Magic Wand Example Running on Ameba RTL8722DMMaterials• Ameba D [RTL8722 CSM/DM] x 1• Adafruit LSM9DS1 accelerometer• LED x 2Example ProcedureConnect the accelerometer and LEDs to the RTL8722 board following the diagram.Download the Ameba customized version of TensorFlow Lite for Microcontrollers library athttps://github.com/ambiot/ambd_arduino/tree/master/Arduino_zip_libraries.Follow the instructions athttps://www.arduino.cc/en/guide/librariesto install it.Ensure that the patch files found athttps://github.com/ambiot/ambd_arduino/tree/master/Ameba_misc/are also installed.In the Arduino IDE library manager, install the Arduino_LSM9DS1 library. This example has been tested with version 1.1.0 of the LSM9DS1 library.Open the example,“Files” -> “Examples” -> “TensorFlowLite_Ameba” -> “magic_wand”.Upload the code and press the reset button on Ameba once the upload is finished.Holding the accelerometer steady, with the positive x-axis pointing to the right and the positive z-axis pointing upwards, move it following the shapesas shown, moving it in a smooth motion over 1 to 2 seconds, avoiding any sharp movements.If the movement is recognized by the Tensorflow Lite model, you should see the same shape output to the Arduino serial monitor. Different LEDs willlight up corresponding to different recognized gestures.Note that the wing shape is easy to achieve, while the slope and ring shapes tend to be harder to get right.Reference and Q&AMore information on TensorFlow Lite for Microcontrollers can be found at:https://www.tensorflow.org/lite/microcontrollersFor more examples, please visit our official website: bit.ly/ambiot1Please join our FB Forum to further discuss with us:https://bit.ly/ambiotfbOr join our forum to bring up any questions:https://bit.ly/ambiotforum
AMLA150 Loop Antenna help identify  - Page 1
Forum section: electronics / projects

author: daniel444
author_rank: Regular Contributor
timestamp: October 01, 2024, 05:37:53 am
content: i bought this AMLA150 Active Magnetic Loop Antenna kiti need help to identify the ic chip it uses as they have sanded the label offi want to buy a replacement chipthe bottom of the chip has 592 written on itit might use the same chip as the MLA-30 antennathanksDaniel

author: Bryn
author_rank: Regular Contributor
timestamp: October 01, 2024, 08:00:29 am
content: Most likely to be an Si5351A.

author: ftg
author_rank: Frequent Contributor
timestamp: October 01, 2024, 10:26:39 am
content: Quote from: daniel444 on October 01, 2024, 05:37:53 amThat sure sounds like NE592.The pinout also seems to match.Here's a datasheethttps://www.onsemi.com/pdf/datasheet/ne592-d.pdfQuote from: Bryn on October 01, 2024, 08:00:29 amWhat on earth would a synthesizer do in a receiving antenna amplifier board?

author: daniel444
author_rank: Regular Contributor
timestamp: October 01, 2024, 12:21:38 pm
content: thanks mate, im not sure why they sanded the label off the chip , but it has annoyed me

author: moffy
author_rank: Super Contributor
timestamp: October 01, 2024, 01:22:07 pm
content: An equivalent to the NE592 is the National Semi LM733 if available.

author: mikerj
author_rank: Super Contributor
timestamp: October 01, 2024, 02:09:56 pm
content: Pretty much all of these cheap loop antenna kits use the NE592 or equivalent.

author: Bryn
author_rank: Regular Contributor
timestamp: October 01, 2024, 03:31:49 pm
content: Quote from: ftg on October 01, 2024, 10:26:39 amSorry... my research has failed me
Ammeter µA-mA - Design choices and questions - Page 1
Forum section: electronics / projects

author: CookieEater
author_rank: Contributor
timestamp: June 13, 2023, 07:17:15 pm
content: Hello,First off, I know of µCurrent and other solutions. I would like to have an ammeter integrated into my programming/debugging interface device. One device that does it all.I mostly work on battery powered devices which either consume moderate amounts of current (<100mA), or are altogether ultra low power devices running on coincell batteries. Based on the two modes of operation I have quite odd prerequisites:3.3V and 5V mode, powered over USB, 3.3V using a buck converterBandwidth >1kHz (would love to have more)<500µA: µA accuracy>500µA: 1-2% accuracy<=100mA maximum consumption (would love to have more)I want to either output these measurements over serial and do some work on them there, or put them into consumption ranges using the mcu and present these and the respective operating times on a display, calculating the overall consumption and estimating battery lifetime.I see three different design possibilities for this:A) Using two shunt resistors in parallel. One in the lower ohms range, one that is considerably higher. The former I would connect/disconnect automagically, a classic autorange feature if you will.B) Cascading differential amplifiers and taking measurements along the different stages, comparing measurements and picking the stage with the currently most accurate measurement/that is not out of range.C) A shunt resistor in the lower ohms range, and a transimpedance amplifier for the lower current range.Different questions arise:1)For A), how to properly engage/disengage the lower resistance shunt resistor? Use mosfets? Use analog comparators to switch them, or use an MCU? In all those respects, what are the issues arising from this? I suspect delays both in terms of reacting to a high voltage drop event and also some time will probably pass until the mosfets become fully closed/opened.2)For B) and C), how to deal with adc inputs from the amplifiers that are way outside the maximum ratings for the adc/mcu during high power consumption phases? Are a zener diode and a series resistor for the adc input enough?3)In terms of picking the right components, what are things I have to look out for? How little a voltage can I expect to measure accurately, and when do I have to consider specific effects/noise/etc.? For example, I can pick a X bit ADC and say I can get VRef/2^X precision on paper (and more with oversampling), but will I get issues with noise in the µV range?Reading up on this is something that I have found to be very difficult for me, as I have not seen a way to incrementally get to a solution, rather it seems that I would need to account for and know a lot of things at once or in larger portions, which has been a quite overwhelming experience so far.Likewise, I do keep coming back to the idea of being able to measure currents with my programming/debugging device, and how neat it would be.Thank you for your time and suggestions
Ammeter adjustment / shunt  - Page 1
Forum section: electronics / projects

author: s57aw
author_rank: Newbie
timestamp: February 12, 2014, 04:12:07 pm
content: Hello,I would like to mesure reverse voltage difference from linear potenciometer with 40uA Ammeter. I get 10.70v DC from the pot and that needs to be full scale on ammeter and 9.5 v should be 0 on ammeter. So I want a 40uA meter movement to indicate zero when there is 9.5v and full scale when there is 10.7v.Source voltage to the pot is 12.05vI need to add shunt resistor and probably some resistors / trimmer in series to get just a right value.I am not a professional and I would be happy to get some help on this valuesRegards,Robert

author: Paul Price
author_rank: Super Contributor
timestamp: February 12, 2014, 06:11:30 pm
content: You might start with this..Or the other circuit shown to get Reverse Voltage Difference(RVD).

author: s57aw
author_rank: Newbie
timestamp: February 12, 2014, 10:30:15 pm
content: Thanks a lot ... it helpedRobertQuote from: Paul Price on February 12, 2014, 06:11:30 pm
Amount of solder/solder paste... - Page 1
Forum section: electronics / projects

author: alank2
author_rank: Super Contributor
timestamp: March 20, 2015, 03:23:17 pm
content: Hi Everyone,So I've got one of those 7351 viewers and it has the least, nominal, and most settings for pad sizes. I've baked a few boards with success, and I used stencils with a .005 thickness from oshstencils.One of my early failures was using a pad size that was too small and it didn't have enough paste to wick up into the part when reflowing.My question is this - I often see pcb's on eBay where the thinnest of solder is present, you can make out all the legs of parts and they look more plated with solder than coated with solder if that makes sense.My thought is a more is better so long as you don't get bridges, but I wanted to hear what the wisdom here at eevblog is on this. More, less, what is the ideal?

author: GreyWoolfe
author_rank: Unknown
timestamp: March 20, 2015, 09:00:41 pm
content: I weigh in on the less is more. No real experience with SMD but I was taught to use just enough solder to cover the pad and wick up onto the component leg. The larger the pad and component leg, the more solder is needed but it shouldn't form a mound. Again, just enough to cover the pad and wick up onto the component leg. More may be considered wasteful. To me, you are forming an electrical connection not an unbreakable mechanical connection and that electrical connection doesn't need the solder piled on. IIRC, in an old Dave video, he sides on the less is more side also. It will be interesting to see what others have to say.

author: nanofrog
author_rank: Super Contributor
timestamp: March 21, 2015, 10:20:52 am
content: Even if you don't create any bridges, you don't want to "pile it on". You want to create a fillet anywhere the component lead makes makes contact with the pad.NASA Training Program: Student Workbook for Hand Solderingwould be worth your time (.pdf), as wouldNASA's Workmanship Pictorial Reference(this one covers more than just soldering).If you like videos, Pace put up some really good ones on YouTube (don't let their age fool you, they're really good).Basic Soldering Lessons 1 - 9Rework & Repair Lessons 1 - 8
Amp limiting controller.  - Page 1
Forum section: electronics / projects

author: Hornnumb2
author_rank: Regular Contributor
timestamp: September 01, 2020, 08:56:44 pm
content: I have a frozen drink machine and for some reason it froze up the other night and stripped the plastic gear that operates the mixing paddle. Is there something that I could buy to put in line with the paddle motor that when it got to a certain amp draw that it would shut the power down to that motor? Thanks Michael

author: Etesla
author_rank: Regular Contributor
timestamp: September 01, 2020, 09:16:19 pm
content: look into PTC resettable fuses. Its a one component solution that just goes in line with the motor. They aren't the most ideal solution, and they don't have really accurate trip points, but if you think that there is a big difference between the working current of the motor and the 'stalled' current in the motor, these might be something to look into.
AMP MCP vs Metri/Weather Pack terminals - same crimper & seals? - Page 1
Forum section: electronics / projects

author: r-mm
author_rank: Contributor
timestamp: March 28, 2021, 08:13:55 pm
content: Hi all I'm looking at a power distribution box which uses AMP MCP terminals. These sure look similar to Metri/Weather packs. Does anyone know if the same crimper and even wire seals can be used? I ask because I have those in hand but am not finding a crimp tool for the MCP besides the pricey factory tool.Box -https://www.waytekwire.com/item/45634/?utm_source=cat233Terminals -https://www.waytekwire.com/item/30098/TE-Connectivity-1-968855-1-Tin-Plated/

author: tooki
author_rank: Super Contributor
timestamp: April 01, 2021, 03:16:41 pm
content: Download the drawings of both and see if all the dimensions are the same??
Amp reference - Page 1
Forum section: electronics / projects

author: yalect
author_rank: Regular Contributor
timestamp: March 13, 2020, 07:44:55 pm
content: I would like to ask you about IC EUP9863 (audio amp) Datasheet.Thanks

author: Zero999
author_rank: Super Contributor
timestamp: March 15, 2020, 10:27:19 pm
content: The AD9863?https://www.analog.com/media/en/technical-documentation/data-sheets/AD9863.pdf