hybridfree/eevblog-posts huggingface dataset:
Reliable smaller than Cherry MX keyboard switches fdor custom keypad - Page 1
Forum section: electronics / projects

author: Jester
author_rank: Frequent Contributor
timestamp: June 27, 2024, 03:38:43 pm
content: I'm going to make a custom keypad for a piece of machinery. I was thinking of using Cherry MX low profile switches, however it seems like the minimum cap size is about 18mm x 18mm and I think the actual switch dimensions are about 14 x 14mm. I'm tight for space so looking for something smaller.I have some sort of generic numeric keypad with perfect sized buttons about 8.25 x 7.3mm (see below) these would be ideal however I have no idea what switches are used in it.All suggestions welcome. In a perfect world I would like to be able to print the caps

author: ajb
author_rank: Super Contributor
timestamp: June 27, 2024, 06:51:23 pm
content: How close together do you need the switches to be? That's what really determines the max switch dimensions. You could certainly put small 8x8mm or whatever keycaps like that on a cherry MX, for example, as long as the caps are >14mm center-to-center.At a guess from the picture, that keypad probably uses a sheet of rubber domes on top of a PCB for the switch. The underside of the dome would have a conductive pad, which comes into contact with pads on the PCB below it when the button is pressed. If you can find a keypad with the right layout of buttons, you may be able to print replacement keycaps and reuse the sheet/domes/PCB.Other than that, there are tons of switches out there, all sorts of shapes and sizes and styles, so it's hard to give a recommendation without more info. Do you care about tactile feel? Sealing? Do you need an off-the-shelf keycap (not available for many switches, so this would limit your options)?

author: tooki
author_rank: Super Contributor
timestamp: June 27, 2024, 08:15:57 pm
content: Quote from: Jester on June 27, 2024, 03:38:43 pmAs in printing legends onto the keycaps, or 3D printing the keycaps themselves?There exist tons of switch options, but as others said, you need to specify your requirements. What are your reliability requirements? What about environmental conditions? (Cherry MX are not that great in dirty environments.) Typical usage? (For example, the fairly light touch of a Cherry MX can be a liability if accidental pressing is a concern.)

author: aeberbach
author_rank: Regular Contributor
timestamp: June 27, 2024, 09:27:14 pm
content: Gateron KS-33 switches require a 14mm square plate cutout (same as regular MX) but are just over 12mm from bottom of locating pin to top of plunger, so significantly lower. Make a printed plate with 1mm between each switch and you would have a keypad around 61mm square. You could print the standard MX-stem caps for these.

author: Jester
author_rank: Frequent Contributor
timestamp: June 28, 2024, 12:49:06 am
content: Quote from: ajb on June 27, 2024, 06:51:23 pm12mm center to center would work, so just a bit smaller than the Cherry MXFairly clean environment, this will be out of the swarf path.
Reliable source for M8 Industrial Circular connector for PCB - Page 1
Forum section: electronics / projects

author: rvalente
author_rank: Frequent Contributor
timestamp: September 10, 2015, 12:59:07 pm
content: Hello Mates,Does anyone knows a reliable supply for M8 circular PCB connectors? (often used in industrial cabinets, sensors and valves).My target is something in the $1 range, the sources I've checked like TE, Molex and Fine are $4+ (Digikey price, through dists this price is certain to drop but won't be $1)I'm willing to develop our own industrial sensor junction box (just wire to wire) for the control cabinets, the main reason is cost, all guys (Murr, Phoenix, Wago, Molex and Lumberg....) are extremely costly.

author: CM800
author_rank: Frequent Contributor
timestamp: September 10, 2015, 01:25:38 pm
content: You will find in general that connectors are expensive, especially industrial ones. Many of the ones on industrial motors and so on are around £30.$4 is a fairly reasonable price.

author: rvalente
author_rank: Frequent Contributor
timestamp: September 10, 2015, 01:36:27 pm
content: Quote from: TCWilliamson on September 10, 2015, 01:25:38 pmDear TC,I agree with you, but the junction boxes may have from 4 to 16 connectors, at this price it does not payback the investment o build our own, them I'll keep being a customer for Murr, Wago, Phoenix etc...

author: tszaboo
author_rank: Super Contributor
timestamp: September 10, 2015, 02:55:44 pm
content: Quote from: rvalente on September 10, 2015, 12:59:07 pmIn any case, if you manage to find one, please let us know. M8 and M12 is quite expensive (good quality) connectors, so if there is a good source, I would like to know also.

author: thefamilyman
author_rank: Regular Contributor
timestamp: September 10, 2015, 07:36:39 pm
content: We tried making our own M12 boards for ASi but found them to be too unreliable compared to Phoenix, ifm and Pepperl+Fuchs that we normally use.You pay for quality and reliability.Reliability is perhaps the number one important factor in industrial automation. Especially when you're making equipment for other people to use 24/7. You don't want one of your products to F*out at 2am causing their plant to possibly shut down.

author: Gribo
author_rank: Frequent Contributor
timestamp: September 12, 2015, 04:47:17 pm
content: I have had good experience with Binder, however, I don't think they fit your target price. There is also Amphenol Sine which are generally cheaper variants of Amphenol.

author: rvalente
author_rank: Frequent Contributor
timestamp: September 12, 2015, 04:49:32 pm
content: Quote from: Gribo on September 12, 2015, 04:47:17 pmBinder, new brand to me, would you mind share the datasheet?How do you buy them? Through Avnet/Arrow/Future?

author: dom0
author_rank: Super Contributor
timestamp: September 12, 2015, 06:45:31 pm
content: Quote from: rvalente on September 10, 2015, 01:36:27 pmThat's probably why everyone buys standardized sensor junction boxes COTS.
Reliable source for micro HDMI Male PCB mount connectors??........ - Page 1
Forum section: electronics / projects

author: Smokey
author_rank: Super Contributor
timestamp: November 27, 2023, 07:10:39 am
content: Something like this would be perfect:Surface mount is fine too.All I can find is Alibaba sources.This is one of those problems I did not expect have, but unless I'm doing something stupid Digikey/Mouser have nothing like this.Thoughts?

author: Smokey
author_rank: Super Contributor
timestamp: November 28, 2023, 12:51:38 am
content: No male micro HDMI love? Do they have too much toxic male connector masculinity? They are "micro" connectors, so they are probably going to be compensating for that....

author: Someone
author_rank: Super Contributor
timestamp: November 28, 2023, 01:37:55 am
content: It's like trying to find PCB mount male BNC, they exist, they are made in reasonable volume, but are not stocked in regular wholesale/retail.If you need reliable volume, go ask the manufacturers. Small volume, one time buy of mystery grey market stuff.

author: Smokey
author_rank: Super Contributor
timestamp: March 03, 2024, 07:36:40 am
content: This came up again... who's going to be my new personal hero?(Ideally something with a datasheet that actually has a mechanical drawing for the pins)

author: bakulapal
author_rank: Newbie
timestamp: May 24, 2024, 07:50:57 am
content: This one looks like similar to what you are looking for:https://bossconntech.com/connector/micro-hdmi-hdmi-d-type-connector/micro-hdmi-male-connector-clamp-board-type.htmlI also found a Molex part but it's not a publicly available part.

author: wraper
author_rank: Unknown
timestamp: May 24, 2024, 08:28:22 am
content: In the past I found thatmalevideo connectors (HDMI, DP and more so micro HDMI) are either not sold by western distributors at all or barely any for ridiculous price. So if you cannot find what you need at LCSC, your only options basically are aliexpress or alibaba, ordering direct from Chinese manufacturer.

author: djawahar
author_rank: Newbie
timestamp: May 28, 2024, 03:56:50 pm
content: Hi, I'm also having the same issue. Did you find any reliable distributor for Micro HDMI connectors?

author: Smokey
author_rank: Super Contributor
timestamp: May 28, 2024, 08:29:17 pm
content: Nope. I ordered some samples from Alibaba. They showed up. That's about all I can say at this point. I haven't finished the project yet so I can't say I have a good working solution yet.
Reliable source for pouch Li-Ion battries - Page 1
Forum section: electronics / projects

author: ataradov
author_rank: Super Contributor
timestamp: August 04, 2025, 08:43:35 pm
content: Is there a reliable store for pouch Li-Ion batteries? Something similar to buydisplay.com for displays.For 18650 I had good experience with 18650batterystore.com, but I can't find anything for the flat batteries.I'm mostly interested in smaller size/capacity.

author: Peabody
author_rank: Super Contributor
timestamp: August 04, 2025, 09:45:54 pm
content: You might look at tinycircuits.com. The guy who runs it, Ken Burns, was on The Amp Hour a while back, and he talked about his 18650s, which both Mouser and Digikey also carry. But he also sells a small selection of flat cells at what appear to be reasonable prices and shipping.

author: uer166
author_rank: Super Contributor
timestamp: August 04, 2025, 10:58:03 pm
content: batteryspace is pretty alright, though not a huge selection.
Reliable triggering from the ignition on a small Honda (GX series) engine - Page 1
Forum section: electronics / projects

author: MagicSmoker
author_rank: Super Contributor
timestamp: February 21, 2019, 10:14:53 pm
content: I'm just wrapping up a bizarre contract design job, most of which I can't talk about due to an NDA, but part of the functional spec which I am able to discuss was a circuit to reliably trigger a HV switch that interrupts the output of a power supply during the entire time the spark plug is firing.There are numerous ways to skin this proverbial cat, but I opted use the signal on the wire that goes from the primary side of the ignition coil to the red on/off switch invariably found on the recoil starter housing. Since I had only a vague understanding of how magneto-based ignition systems worked, I did the sensible thing and scoped the waveforms on both the primary and secondary (capacitively-coupled) of the ignition on an actual engine (a 6.5hp "Chonda" - Chinese Honda clone - on my backup generator). It turns out the secondary signal was not at all usable for my purposes because there is a sharp negative spike of anywhere from 3kV to 10kV, followed by a prolonged (1ms or so) pedestal at the arc discharge voltage of the spark plug, which itself varies considerably over RPM, fuel/air ratio, etc. However, the primary signal looked eminently usable, except I needed to only pay attention to the negative-going part that was sandwiched in between two positive pulses, all of which occurred each revolution. While I probably could have pulled this off with a Schmitt-trigger gate and a few passives, it only cost a few more components to make a proper comparator with hysteresis so I went that route.Attached are the schematic of the actual circuit, including the HV switch portion, as well as a screenshot from LTSpice and the simulation file that generated it. The PWL approximation of the ignition signal does a credible job as the actual circuit works just as it did in the simulation, something the me of 20+ year ago would have never believed... (trust me, SPICE really sucked back then).Anyone is free to use this as they wish, so I guess that makes this open source. Enjoy!
Relying on Lipo's PCM - Page 1
Forum section: electronics / projects

author: CheekyRobot
author_rank: Contributor
timestamp: July 08, 2015, 02:52:32 pm
content: Hi, this is my first post to this forum - looks like a brilliant place to be.I've seen a handful of posts on the topic, but I guess everyone's project is different so apologies for a little repetition.I have a project that needs a 3.7v 2000mAh Lipo battery inside it to maintain power when the external supply (the main battery) is exhausted, failed or disconnected.I managed to find a great supplier for the battery and they make the EXACT size I need (sweet!).My present design uses an ADP5063 IChttp://www.farnell.com/datasheets/1741166.pdfto charge and monitor the battery from the external 9-12v supply. All good, but the IC is a QFN20-like package, which is going to be a bit of a horror to solder (perhaps I doubt my reflow skills too much?).The new supplier for the battery I found (the last one shipped my samples to me from China inside a soft toy!so I'm not too keen to use them) say that their battery has a PCM chip on it.Does anyone think that it would be good, safe etc etc to simply allow the battery to charge from a reduced and regulated feed from my external supply?Or should I not trust that? As you can tell, batteries are my blind-spotThe unit will normally only be connected to the external supply for a few hours at a time anyway but I need to cater for situations where the user instructions are ignored it's left connected.Oh, and the device itself only draws about 100-150ma, so little stress on the internal Lipo.Cheers all!
Remix of uRuler - Page 1
Forum section: electronics / projects

author: ResR
author_rank: Regular Contributor
timestamp: September 20, 2013, 05:49:28 pm
content: I made (2 hours) a little remix of the uRuler with prototyping area with triple pad islands and lithium button cell powered sideview 0603 LED lights (with resistors to protect against overcurrent) to read books at night. Two sided printed pcb used. So what do you think about it, good or bad idea?

author: SArepairman
author_rank: Frequent Contributor
timestamp: September 20, 2013, 07:12:06 pm
content: dave jones might show up at your door at 4am with a tire iron.i like it but I would never make or buy it.

author: ResR
author_rank: Regular Contributor
timestamp: September 21, 2013, 07:44:49 am
content: I have a soviet era 2-48 adjustable wrench waiting to bath in bloodIt was just a random idea, I got bored last night.

author: jancumps
author_rank: Unknown
timestamp: September 21, 2013, 07:55:34 am
content: So it's through- hole. How are you going to rulerize with it if it has solder dangling from the underside?

author: ResR
author_rank: Regular Contributor
timestamp: September 21, 2013, 08:02:07 am
content: Hmm. Good question. Needs some thinking about it.

author: EEVblog
author_rank: Unknown
timestamp: September 21, 2013, 08:34:22 am
content: Rulers that don't have have the markers going all the way to the end, are evil.

author: free_electron
author_rank: Super Contributor
timestamp: September 21, 2013, 05:14:30 pm
content: Quote from: EEVblog on September 21, 2013, 08:34:22 ami got one once that starts at 1 instead of zero. i didn't notice it until the thing i cut was 1 inch too short ...needless to say that ruler swiftly met with its demise... and the company that gve it ot me ( it was one of those promo rulers) got an earfull ...
remote bms monitoring - Page 1
Forum section: electronics / projects

author: m3vuv
author_rank: Super Contributor
timestamp: September 05, 2021, 10:56:01 am
content: Hi all,firstly im not sure if this is the right section but here goes,i have a smart bms on a homebrew 13s lithium ion battery pack,it talks with my phone over bt,i am a licensed radio ham,i wondered if its possible to hook up a spare bt modual i have to my radio on 2mtrs to enable me to monitor the bms at a 2/3 mile range while it is charging,if so whats likley involved,if its even possible,i am sure my licence conditions lets me do this,tia m3vuv,by bt i mean bluetooth.

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 05, 2021, 02:34:14 pm
content: LoRa would be a better fit for that use case, no license needed.

author: m3vuv
author_rank: Super Contributor
timestamp: September 05, 2021, 10:52:56 pm
content: and your point is what??
Remote Central Heating Project - Page 1
Forum section: electronics / projects

author: nx084f001
author_rank: Newbie
timestamp: October 11, 2015, 02:56:01 pm
content: Hi all,For a while now I've been meaning to replace the Siemens RWB30E mechanical timer unit (http://www.amazon.co.uk/Siemens-RWB30E-Programmer-Timeswitch/dp/B009A677XS) that controls my central heating with something cheap, self-made and which will allow wireless control. This is really a mini-project that I've been wanting to get round to all year and now with winter coming up I think it is a good time... To replace the RWB30E I will use a spare TI Stellaris Launchpad microcontroller unit hooked up to a NRF24L01+ which will Rx. On the Tx side I'll use another NRF24L01+ with a RPi. From there I'll create the necessary program. High-level is easy enough but actually doing it is something else and I could do with a little help to progress this along as I'm not an EE but happy to learn (I do have the AoE 3rd Edn!).The Stellaris Launchpad requires 3.3V input and [I doubt] >0.5A. The RWB30E is fitted to a specific wall-mount where it acquires power. Here's an actual picture of the mount in my home:This mount follows the spec in the data sheet for the RWB30E:http://w3.siemens.co.uk/buildingtechnologies/uk/en/building-automation/residential-controls/documentation/Documents/rwb30e_i.pdf(Since I am not a plumber/electrician I cannot say if this is a UK standard, probably is). As you can see from the RWB30E data sheet it looks like the wiring is mains AC corresponding to the boiler's input requirement (a Baxi Duo-Tech 128 HE A):http://www.baxi.co.uk/documents/duo-tec-he-a-installation-instructions.pdfThis appears to be the relay that performs the switching inside the RWB30E:Now for a few questions, please:What is the best way to power the TI Launchpad from this wall mount? I gather it would need to be a 240V AC- 3.3V DC conversion. Can you recommend a design? If possible I'd be happy to build this myself if it isn't too involved, otherwise if there are some small form factor off-the-shelf circuits I can buy I'll do that.Next I'm going to need to power a relay from the same mains input (maybe a pre-built circuit with two outputs?) and use one of the GPIO ports on the Stellaris Launchpad to hook to the collector of a transistor to action the relay (I think). Am I on the right tracks?Also, I just noticed, why is the relay pictured above only rated at 24V? Isn't that dangerous since it is connecting 240V terminals? Or is that what is needed from the RWB30E to power the relay? There's another rating on the top right hand corner - 10A 125V (still seems far off of 240V)?All suggestions welcome. Thank you.
Remote control codes for Soniq QSL326T - Page 1
Forum section: electronics / projects

author: daveatol
author_rank: Regular Contributor
timestamp: March 18, 2015, 01:30:22 pm
content: Hi all,Does anyone have a Soniq QSL326T TV remote, and would be willing to record the codes? We have one of these TVs, collected from the side of the road, which has no remote and its non-remote buttons don't work properly (TV works fine otherwise; it's just that pressing the buttons have an unpredictable, random effect).The codes can be recorded really easily, just by connecting a phototransistor across the PC microphone input. The cathode connects to the left+right signal wires with anode to GND. Audacity or a similar program can be used to record the signal (44100 or 48000 Hz, 16bit). I've done it before for a couple of different remotes, and it was kinda interesting to see the signal so clearly, and with such simple hardware.I was going to make an Android IR remote app for the TV using the codes, and you'd be most welcome to it as well, of course. None of the universal remotes I tried in the Google Play store worked with this TV and JB HiFi and Dick Smith don't have suitable remotes either, not that I want to buy one.Thanks very much for any help!Cheers,Daveatol

author: lapm
author_rank: Frequent Contributor
timestamp: March 18, 2015, 02:42:44 pm
content: Are you sure that televisions ir-receiver is working properly? Sounds like there is a reason why it was left at side of road.

author: daveatol
author_rank: Regular Contributor
timestamp: March 19, 2015, 01:09:56 am
content: Unfortunately, I have no idea if the IR receiver is working. While I could open it up and check if a signal is detected by the receiver, that wouldn't tell me if the CPU actually receives and processes the signal. I'm hoping the receiver is ok...I assumed (hoped) it was left out due to bad buttons, missing remote, and possibly the cracked bezel... this is just speculation though.
Remote control preamp - Page 1
Forum section: electronics / projects

author: timbarnes
author_rank: Newbie
timestamp: October 12, 2013, 08:10:12 pm
content: I just got my remote control preamp working - many thanks to Dave for his enthusiasm and all that I've learned from him. Also to the diyaudio community where I've been hanging out for a number of years. Construction thread is here:http://www.diyaudio.com/forums/analog-line-level/241273-remote-control-preamp-works.htmlIf anyone is interested in building something similar, I'd be happy to help.tim
Remote-Controlled PC Power button PCB question - Page 1
Forum section: electronics / projects

author: stig124
author_rank: Newbie
timestamp: December 19, 2020, 10:49:10 pm
content: Hello,I finally "made" (I'm in the middle of the making actually) a remote controlled PC power button using :- An Arduino Uno (soon be replaced with a Nano)- A Raspi 3 for network connection purposes- and a basic 5V relayIt works but it needs a PCB and enclosure to stay permanently in my setup (the relay is lying upside down actually on the bottom of my PC Case)So I made the appropriate schematic and board in EagleMy question actually is :How a PC power button work is by shorting a pin with a standby voltage (I believe it's 3.3V) with a recieving one.As I want it only to be on for around 200ms at each request I hooked the PWR+ on my Motherboard to the common pin (pin 1 of the relay) and the pin 5 (NC) of the relay to the PWR- of my Motherboard but I'm facing a dilemma here, the NO pin (pin 4 on the SCH, and on the top left hand of the relay in the PCB) of the relay will obviously be 99% of the time with the standby voltage at it's pin, which is floating actually (I know it's very dangerous in my case, but as it is temporary I take the risk).Though I can't find a way to ground it in my case, the only way I found to ground it to the GND of the Arduino but I don't know if it's a good idea as the current is produced by the motherboard, not the Arduino (And I can't ground it to the motherboard as all the gnd pin are taken)If someone could give me advices that would be awsome
Remote controlled ultrasonic dog repellent - Page 1
Forum section: electronics / projects

author: kostin
author_rank: Newbie
timestamp: May 11, 2014, 11:22:53 am
content: please delete this

author: kostin
author_rank: Newbie
timestamp: May 11, 2014, 12:09:12 pm
content: please delete this

author: GeoffS
author_rank: Unknown
timestamp: May 11, 2014, 12:25:03 pm
content: kostin,If you want to get any advice from this forum I suggest you adjust your attitude.EDIT: looks like someone has spat the dummy
Remote for home receiver acting strangely - Page 1
Forum section: electronics / projects

author: fixit7
author_rank: Regular Contributor
timestamp: June 29, 2019, 02:08:44 am
content: My remote or maybe it's the receiver(Denon 1801 AVR), butsometimes it turns on the radio and changes the volume ok,or else I have to get within 2 feet for it to work.The batteries for the remote are are at the proper voltage.The keypad and the circuit board have been cleaned.The only thing that has changed in the last month has been the addition of a dipole antenna to pull in stations for the FM radio part.But it is an unpowered antenna.Anything else I can check?Thanks,Andy

author: ogden
author_rank: Super Contributor
timestamp: June 29, 2019, 03:08:57 am
content: Electrolytic capacitor(s) in the remote may be degraded. Check or just replace. IR led is next in the list to check/replace. Less likely problem - degraded electrolytic capacitors in the receiver 5v supply of IR receiver

author: coromonadalix
author_rank: Super Contributor
timestamp: June 29, 2019, 03:27:44 am
content: Or maybe the rubber keypad keys even if they are cleaned may have lost its contact properties ...you have things like this :https://www.ebay.com/itm/262265110349

author: wraper
author_rank: Unknown
timestamp: June 29, 2019, 03:37:55 am
content: Does it stop working properly when you turn ON lights in the room?

author: fixit7
author_rank: Regular Contributor
timestamp: June 29, 2019, 04:14:33 am
content: Quote from: wraper on June 29, 2019, 03:37:55 amIt works ok when 3 CFLs are on. They are within 8 -> 12 feet of the radio.Now it is working ok.Not sure what it is called, but when the radio is turned on or off, I hear a clicking sound.Maybe some kind of relay?I am happy that the radio works ok, even if it is occasionally cattywonkus. :-)Andy

author: DDunfield
author_rank: Regular Contributor
timestamp: June 29, 2019, 10:03:02 am
content: Quote from: fixit7 on June 29, 2019, 04:14:33 amCFLs are notorious for emitting IR noise, especially when they are cold.I had the exact same problem few years back, my TV remote would usually work fine, but sometimes it's range was very short.I eventually determined that it was happening within 10 or so minutes of turning the lights on. The CFLs when cold were emitting huge amounts of IR. After they had been on for a few minutes they would settle down and everything was ok. Now that I've switched to LEDs I don't have the issue.Next time it happens, try turning the lights off.Dave

author: fixit7
author_rank: Regular Contributor
timestamp: June 29, 2019, 07:16:34 pm
content: thanks for the info.I have some led bulbs. May switch them out.They don't get hot like CFLs.Andy
Remote keyless circuit - Page 1
Forum section: electronics / projects

author: kene
author_rank: Newbie
timestamp: February 13, 2014, 12:15:53 am
content: Please does anyone have this circuit or have ideas on how to build it?

author: free_electron
author_rank: Super Contributor
timestamp: February 13, 2014, 12:39:26 am
content: infrared ? Rf ?how far ? how many buttons ?

author: kene
author_rank: Newbie
timestamp: February 13, 2014, 12:46:35 am
content: RF, 2or 3buttons
Remote power control of XY6015L - Page 1
Forum section: electronics / projects

author: IgIv
author_rank: Newbie
timestamp: July 13, 2023, 07:48:51 am
content: Hello!Has anyone dealt with this type of power supply as pictured?In this case it is XY6015L - 60V/15A. There are with the same design XY6020, 6014, 5008, DPS5015, etc. and have outputs for TTL RS232 interface (Rx and Tx) and MODBUS protocol.Well, I successfully connected to the power supply and it's no longer a problem to control it remotely. However, I have one problem that I couldn't find any information about.The staging is as follows:When one of the protections (voltage, current or power) trips on the power supply, it turns off the output, which is fine.The screen accordingly shows why it turned off the load - OVP, OCP, OPP, etc.The problem is that even after removing the cause, the screen continues to flash and keep the output off until a key is pressed on the keyboard or the power switch is "pulled".Does anyone have an idea how and if the security status can be cleared with a UI command without having to push buttons?
Remote Power Supply Switchbox - Page 1
Forum section: electronics / projects

author: jwrelectro
author_rank: Newbie
timestamp: February 02, 2016, 11:56:16 pm
content: This is a very simple project! It is a remote power supply switchbox that supports dual power supplies . This device is useful for operational amplifier circuits. I have a YouTube video where I show the unit and the unit in operation.
Remote Solar security unit with charge reg, IR detection and 433mHz comms - Page 1
Forum section: electronics / projects

author: philbx1
author_rank: Regular Contributor
timestamp: December 02, 2010, 08:49:35 am
content: Hi all,The rellos in QLD have had a hard time with break-ins and bogans with knives lately.I've made it a mission to try help in trying to come up with an 'early warning system for their property.As they already have an SMS alarm system the 'receiving' side can be covered by using a single alarm input.The property is a fair size so these 'units' would need to have long distance comms, Futulec have some nice tranceivers which should be OK, but the integration of everything is starting to look difficult.Anyway, thought I'd run the idea and thoughts by you and would like to first say that it's not so much an idea of buying something from China etc. but some open-source project that may help others.1. IR Sensor2. Driveway pressure switch.3. 5 watt Solar panel4. AGM deep-cycle battery - ie. 12v 5aH5. Low power microcontroller6. 433MHz transceiver7. LDR - for light sensingSo, I'd like to have the electronics on one board and using as little power as possible. The micro would wake up every 2 seconds and power up the IR Sensor (unless interrupted by the driveway switch). If the IR Sensor is active, do a triple-check and send of an alarm signal.Next check the LDR to see if it's night. If not, check the solar panel input, and - now this is a hard question, either set PWM for charging the battery OR use a Latching Relay (which may also use less power, of course limiting charging current by 'standard' methods).Enough for now, maybe there is a pre-built long-range solar-powered 'solution' out there which I've yet tofind but it's always a good thing to do it yourself I think.Anyway, just an idea which I'm hoping may get you all thinking of a best solution.Thanks in advance for any thoughts...

author: GeoffS
author_rank: Unknown
timestamp: December 02, 2010, 09:11:43 am
content: Quote from: hissyfet on December 02, 2010, 08:49:35 amMy only thought at this stage is that the line above may need an English translation for non Aussies

author: Jimmy
author_rank: Regular Contributor
timestamp: December 02, 2010, 10:51:29 pm
content: I have used the transmitters and recievers I would not use 433mhz because you can only have one trasmitter in the area and I had some problems with interfrance.
Remote trolling motor driver - Page 1
Forum section: electronics / projects

author: teksturi
author_rank: Regular Contributor
timestamp: April 23, 2016, 12:59:50 pm
content: Hi. I just design very basic remote boat trolling motor driver. I just hope to get opinion from design and every other aspect. It is not yet 100% complete but close enough to send board house. What I'm most thinking is mosfet latch in remote control. Would it work? Also first design with kicad. First a bit struggle with it but I'm getting better. Just have to learn all hotkeys.

author: sarepairman2
author_rank: Frequent Contributor
timestamp: April 24, 2016, 12:36:19 am
content: lmfao at the title

author: Kalvin
author_rank: Super Contributor
timestamp: April 24, 2016, 08:55:03 am
content: In schematics section "Speed Output" the MCP6001 op amp will not handle the 24V power supply too well as the maximum supply voltage is 5.5V.

author: teksturi
author_rank: Regular Contributor
timestamp: April 24, 2016, 12:21:40 pm
content: Yeah. Haven't really selected it yet. Still thank you pointing that out. I choose to use LM321.
Remoteli: The world's smallest TV remote! (?) - Page 1
Forum section: electronics / projects

author: MattHollands
author_rank: Frequent Contributor
timestamp: April 26, 2016, 04:54:13 pm
content: Hi Everyone!I haven't shown off a project in a while so thought I would post what could possibly be the world's smallest, programmable IR remote, measuring at just 39x18x5mm.https://keepdevelopingprojects.wordpress.com/category/remoteli/The construction is inspired by Dave's microcalc project. It consists of two PCBs sandwiched together with a cr1616 cell in the middle. It has 11 programmable buttons and can learn IR codes independent of protocol (within certain parameters of course, but I'm yet to find a remote it cannot copy). This is achieved by simply recording the pattern it receives and storing it in flash of the Attiny1634.It also has a cut-out in the bottom left to allow you to attach it to a keychain.Anyway, thought I would show it off as it's vaguely related to EEVBlog! Also, trap for young players (like me), ALWAYS CHECK THE ERRATA when you experience weird bugs.https://keepdevelopingprojects.wordpress.com/2015/12/16/project-remoteli-whats-wrong-with-this-pin/

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: April 28, 2016, 02:56:30 am
content: Cool, I had one of these years agoI would prepare it with the right codes and go to sports bars and turn off their TVs.Or walk into electronics stores ... etc
Remotely controlled indicator LED - Page 1
Forum section: electronics / projects

author: Spike101
author_rank: Contributor
timestamp: January 18, 2015, 10:04:52 am
content: Hi everybody.I need a suggestion for a project I'd like to realize for our house. We have a automatic garage door, and I'd like to add a remote indicator that shows, if the door is currently open or closed. Basically I would use a magnetic switch to determine if the door is in the closed position. But how can i best transfer the state signal wirelessly to one (or even better more than one) remote indicator? There are walls between the sensor and the indicator, so it should go through walls... I guess i could use Zigbee, but that seems like total overkill for this application. Is there some better, basic way to do this?thanks,Sebastian

author: SeanB
author_rank: Super Contributor
timestamp: January 18, 2015, 11:05:10 am
content: Reed switch operating a short burst of RF from a remote control transmitter. operates a short burst using a 2 button transmitter so it gives a code for open and a code for close. Receiver with 2 output channels and a simple bistable to show either open or closed. You use multiple receivers and place them well within the transmitter range.Simplest way is to have 2 switches placed on the door, and a magnet that will operate them for a brief period as the door goes past on the way to fully closed or fully open. That way you just wire in the 2 reed switches in place of the buttons. As door opens the door close button is pressed and as it reaches fully open the open button is pressed. The receiver remembers the last button pressed on the bistable so shows open.If there is a lost transmission or interference it will not however show the correct position, but it will resync on the next valid door event. Bistable can be simply 2 cross connected transistors with the outputs simply shorting the transistors and the indication LED's being in the collector leads. The receiver however will need powering all the time, preferably from an AC wall wart delivering 12V. The transmitter can use it's internal battery. You just need a 2 ( or more but some will be unused over 2 unless you want to include a door as well) button remote transmitter and a matching 2 channel receiver licensed for use in your country in an approved frequency.
remotely controlled LED scoreboards via 433MHz RF module. - Page 1
Forum section: electronics / projects

author: jasonwu
author_rank: Newbie
timestamp: April 04, 2015, 06:11:44 am
content: Hello Friends, I have been testing with transceiver module RF4432 from AppconWireless, and started with less power.First you have to configure the module as it is possible to program the output power, speed of communication between devices and between air, parity ...This is possible that RF tool is installed on the PC, and a USB adopter, which need a DRIVER that download from website.The little program is run from the rigid, because recording a small configuration file.You can see that when you connect the USB programmer creates a virtual port, in my notebook COM5Be careful, after the transceiver module, connecting with USB adaptor.all this info, can read the example of application of this detailedlyTo verify the operation, I used a CI board, welding cables, and adapting to a project that was already working, The RF4432PRO can supply the RS485 communication.SN75176 took off each plate, and following this connection. Only four pin need to connect with PIC. Other pin can be suspended.The receiver, place it in a back room of my house, the transmitter power set to level 5 (maximum 9) in my workshop, 50 meters distance, through 5 wallsAnd everything worked perfect!!This is the link of modules:http://www.appconwireless.com/PRODUCTS/showproduct.php?lang=en&id=7

author: David_AVD
author_rank: Super Contributor
timestamp: April 04, 2015, 12:09:26 pm
content: Sounds like an advertisement to me. lol

author: Simon
author_rank: Unknown
timestamp: April 04, 2015, 03:44:31 pm
content: baned
Remove 14 pin header from step file - Page 1
Forum section: electronics / projects

author: Jester
author_rank: Frequent Contributor
timestamp: September 03, 2024, 11:04:55 am
content: I have a step file for a 240x320 ILI9341 style display. As provided it has a 14 pin header that I need to remove from the step file.If someone here can do this, it would be much appreciated.

author: robson2017
author_rank: Contributor
timestamp: September 03, 2024, 11:31:52 am
content: Hello,I don't know if that's what you meant?R.

author: Jester
author_rank: Frequent Contributor
timestamp: September 03, 2024, 12:39:17 pm
content: Quote from: robson2017 on September 03, 2024, 11:31:52 amThat is perfect!Very much appreciated!Out of curiosity, what program did you use to delete the header?Have a great day.

author: robson2017
author_rank: Contributor
timestamp: September 03, 2024, 02:32:05 pm
content: I used Autodesk Inventor because that's what I have, but it could also be Solidworks, etc.Have a nice day.

author: BennoG
author_rank: Frequent Contributor
timestamp: September 03, 2024, 06:02:22 pm
content: solid edge is free for home users.It si from siemens.Benno

author: Doctorandus_P
author_rank: Super Contributor
timestamp: September 03, 2024, 06:19:04 pm
content: I did the same in FreeCAD. Just a simple:1. Extract the zip to step.2. Open in FreeCAD.3. Delete the connectors (there are three of them, each with just some pins for some reason).4. Export.5. Zip up again and post.Creating the screenshot and typing this post is more work then the actual deletion of the header.A possible thing left, is that it has the LCD, which has a red PCB on itself, and there is another green PCB with nearly the same size. I just left both of them in the file.I've been using FreeCAD for quite some years now. It's growing slowly in capability and user friendlyness, but it still has some way to go before a V1.0 release. And of course, together with it's Open Source nature, there is no way any company can ever hold my data hostage to extort (more) money or force me into the mist (cloud) with perpetual monthly subscription fees.
Remove the load of buck converter - Page 1
Forum section: electronics / projects

author: luis.ramirez
author_rank: Newbie
timestamp: May 18, 2016, 12:50:50 am
content: I have a buck converter that is delivering 6A to a load of 3ohm load.I'm measuring the output current and stop increasing the dutty cicle when the current reach 6A, at this moment the output voltage will be 18V. A few second after reaching this point the resistance will break and I will have and open circuit at the ouput.My concern is the following, the inductor's current can't change inmediatly, I guess I'll go to the capacitor increasing the output voltage, It is a risk to damage the power supply or the driver circuit because of a backward current?

author: Ammar
author_rank: Regular Contributor
timestamp: May 19, 2016, 12:43:33 am
content: This very much depends on the design of the converter. That is, whether it is designed to work in continuous mode or discontinuous mode. Generally, SMPS need to be loaded to work properly. Whether any damage occurs to it though depends on the design.

author: Fungus
author_rank: Super Contributor
timestamp: May 19, 2016, 07:53:02 am
content: As noted, it depends entirely on the design of the converter.If you're worried then you could add a clamping diode across the inductor just to be safe
removing backing from dry film - Page 1
Forum section: electronics / projects

author: coppercone2
author_rank: Super Contributor
timestamp: June 13, 2024, 03:07:00 am
content: How the hell do you remove backing from dry film? The green one.The blue one I use 2 pieces of tape and it comes apart easily (even with really old blue film). The green solder resist however resists the tape pull apart trick.I tried packaging tape and kapton tape.Is there some trick to it? Normally I have to really mangle a corner and dig in there with a pick to get a piece I can grip.Its mad annoying. Some kinda super sticky tape ? its just not strong enough.

author: Phil1977
author_rank: Frequent Contributor
timestamp: June 13, 2024, 07:57:33 am
content: Quote from: coppercone2 on June 13, 2024, 03:07:00 amI have no experience with this specific dry film, but if packaging and kapton tape are not strong enough then this double sided clear acrylic tape may help. I repeatedly experienced it being stronger than the surface it´s glueing to.

author: coppercone2
author_rank: Super Contributor
timestamp: June 14, 2024, 01:25:45 am
content: I found a semi-clean method, I spent a while with some very fine diamonds to fix one of my tweezers under magnification. It took a while but I got it strait and pointy. It seems that I can get it hooked on the gel to lift it a little.Then the trick is to get alumina tweezers, and use them to grab the clear protective layer. It seems to be the only tweezers that grips it. I made sure they close good.From this point I can get enough grip on it with a gloved hand after lifting it a little bit to pull it apart.I noticed that with this film, the tape bearly grabs it. I dunno if the dry film solder resist film has a different protector that is more slippery or something, it seems more substantial then the blue etch film's protector.With this method I only mess up maybe 1/2 a square CM of material. Just the problem is, you are supposed to do this in a dark room... I find it hard to work on it with my LED color light. I need like a red or yellow LED spot light for doing this operation. The lights I have are OK for like assembling it once you can handle it with your hands, but it sucks for working with tweezers.
Removing conformant coating gel - Page 1
Forum section: electronics / projects

author: Greg J
author_rank: Regular Contributor
timestamp: July 09, 2024, 09:46:39 am
content: PCB I'm looking at is been submerged in this "yellowish" gel , to make it waterproof. I have managed to remove most of it, mechanically, but I do wonder if there are any more efficient ways to get rid of it. The whole PCB is still in a plastic tray -and if I want to remove it entirely and see the underside of it - I will have to use other means than mechanical. I do not want to destroy it, pretty much trying to hack a device and adopt it for my own needs.It's a robotic lawnmower.

author: Phil1977
author_rank: Frequent Contributor
timestamp: July 09, 2024, 10:13:48 am
content: If it´s embedded in a tray and you do not want to destroy the tray then it gets really tricky.I think you can't avoid minimal damage like drilling a hole into the plastic tray and pressing an injection needle between the gel and the tray. Then I´d fill a syringe with ethanol or WD40 and press the liquid into that material interface. In best case it delaminates the gel from the tray and you can lift it without further damage.Of course, slight heating with a hairdryer to keep the gel as soft as possible can also help.

author: Greg J
author_rank: Regular Contributor
timestamp: August 04, 2024, 11:09:07 pm
content: seems like paint stripper did a good job.
removing crosstalk spike from a signal question - Page 1
Forum section: electronics / projects

author: john23
author_rank: Frequent Contributor
timestamp: October 26, 2024, 07:48:13 am
content: Hello ,I have build the following circuit which is a full sequencer.However the signal in Vg2 has a certain spike which caused by the M12 signal doing some kind of cross talk using some capacitor probably.Is there a way to eliminate the spike shown below?Ltspice files are attached.

author: Terry Bites
author_rank: Super Contributor
timestamp: October 26, 2024, 08:17:58 am
content: Put your schematic in a standard image format, not in your proprietary cad format and you might get a sensible response.Mind reading services are not available on the blog.

author: john23
author_rank: Frequent Contributor
timestamp: October 26, 2024, 08:27:19 am
content: Hello, I added LTspice files where you could see the whole thing.and i focused in the photo the place where i sample signal.I added photos.what is the problem?

author: Ian.M
author_rank: Super Contributor
timestamp: October 26, 2024, 09:08:41 am
content: Look at the cb junction capacitance of Q1 and the 140ns skew between Out_p and Out_n coming up.

author: john23
author_rank: Frequent Contributor
timestamp: October 26, 2024, 09:30:58 am
content: Hello Ian, Yes I know its CB capacitance which passes the spike from the nagtive -12V pulse.When I put a resistor between base and collector the pulse Vg2 gets moved exactly to the spike place(so no more spike issue).However Q1 is a mechanism where I delay P12 signal by delaying the Vbe of Q1.now that I add a resistor between base and collector ther is no more delay?Is there some solution to this problem?Thanks.
Removing ground plane under small cap trimmer - Page 1
Forum section: electronics / projects

author: jmw
author_rank: Frequent Contributor
timestamp: January 19, 2023, 08:04:03 am
content: In my progress in building a active probe, I need some very small adjustable capacitance, and went with one of these:https://www.digikey.com/en/products/detail/knowles-johanson-manufacturing/27283-3R10/9094377When I tried it out in a prototype, I found the circuit performed quite a bit out of spec, the adjustment afforded by the trimmer was measurable but barely so, and depopulating the trimmer had almost no effect on performance. The trimmer is connected as shunt to ground. With the recommended footprints, I computed the capacitance of the big circular pad to the ground plane: it was nearly 2 pF. The optimal trim value in simulation was 650 fF, so it looks like I completely swamped this trimmer with my SMD pads. When I put these parasitics back into the simulation, I was staring at nearly the same result on my instruments.So it looks like the next step should be to cut out the ground plane under these pads, but how much further beyond the pad dimensions do I need to go before the coupling is negligible? Should I remove the ground plane under all the component pads from the probe tip up to the buffer amp input or perhaps just this one?https://www.knowlescapacitors.com/getattachment/Products/Capacitors/Trimmer/Multi-Turn/Giga-Trim/Giga-Trim-Solder-Pad-Layouts.pdf
removing output DC ground from Server SMPS for series operation ? - Page 1
Forum section: electronics / projects

author: Freelander
author_rank: Regular Contributor
timestamp: December 14, 2017, 05:20:08 pm
content: I have been offered a couple of Compaq server PSU's. They are 12v output at around 500W (as they are server PSU's they only offer 12V as the main output - they are not a standard 'atx type PSU at all). The output is basically two very large tabs on the PCB offering 12V.At the moment, the DC negative is connected to case ground, which is connected to Mains Ground.I want to float the output to allow the series connection of the two units.The physical removal of the DC to Case connection is not an issue (it is a case mounting post to PCB connection only). I personally cannot see any glaring safety issues at all as the units are using absolutely top class components.I have plenty of the cheaper 'meanwell' type units - genuine and the ying tong yip types - and these are all floating outputs but I would prefer to use the far higher quality compaq units 12V units. I can understand why compaq ground referenced the DC for use as a server PSU, but when not used in that application I can see no 'obvious' reason at all against 'floating' the output.I would be interested in the thoughts of others regarding this.Your Input as always is valued.Many thanksJ.