hybridfree/eevblog-posts huggingface dataset:
Reverse engineering/reprogramming a cheap novelty audio device - Page 1
Forum section: electronics / general

author: Halcyon
author_rank: Unknown
timestamp: April 22, 2024, 10:10:25 am
content: See attached.I was given one of these novelty "buttons" where each press has a different sound effect/phrase, seems like chosen at random. These are just mass produced single-sided boards with various different themes, so I'd imagine there would be a way to reprogram the chip with different audio.I've buzzed out the pins, which seem to be:Unknown ICPin 1 - Battery positivePin 2 - SpeakerPin 3 - D1 (Unpopulated)Pin 4 - SwitchPin 5 - SpeakerPin 6 - Battery negativePin 7 - N/C (?)Pin 8 - D2 (Unpopulated)D1Pin 1 - To IC Pin 3Pin 2 - To Battery positiveD2Pin 1 - To IC Pin 8Pin 2 - To Battery positiveAny ideas where I can start? I do have an EPROM reader/writer, but not sure if the above pinout resembles anything standard?

author: tom66
author_rank: Super Contributor
timestamp: April 22, 2024, 10:13:26 am
content: I had always assumed these were based on OTP/eFuse ROMs and are not reprogrammable. When we were looking at Nuvoton chips for audio the sales rep mentioned they have low cost audio options which omit the flash and are either mask ROM (for very high volume) or OTP (for mid-high volume).Example:https://www.nuvoton.com/products/smart-home-audio/audio-speech-controllers/powerspeech-series/n588hp340-otp/

author: Halcyon
author_rank: Unknown
timestamp: April 22, 2024, 10:17:35 am
content: Quote from: tom66 on April 22, 2024, 10:13:26 amAhh bugger!

author: tszaboo
author_rank: Super Contributor
timestamp: April 22, 2024, 10:26:02 am
content: Quote from: Halcyon on April 22, 2024, 10:17:35 amI've even saw Jingle bells IC, which had 3 pins:PowerGNDJingle bells

author: Halcyon
author_rank: Unknown
timestamp: April 22, 2024, 10:28:36 am
content: Well there goes that idea. Maybe I can rip the guts out of this one and replace it with a programmable module.

author: Gyro
author_rank: Super Contributor
timestamp: April 22, 2024, 01:03:40 pm
content: Replace the speaker with an LED (and maybe a series resistor) and you have a randomly flickering light. It's surprising how many random LEDs (tea lights) play pretty little oriental tunes when you shine them into a phototransistor. [Edit: a lot of the more modern ones produce some nasty white noise sounds].
The Spark Plug Story - Page 1
Forum section: electronics / general

author: BrianHG
author_rank: Super Contributor
timestamp: April 20, 2024, 05:48:54 pm
content: Enjoy:

author: mawyatt
author_rank: Super Contributor
timestamp: April 20, 2024, 06:25:21 pm
content: Interesting, a lot more complex than one might thinkBest

author: langwadt
author_rank: Super Contributor
timestamp: April 21, 2024, 07:05:08 pm
content: 3:00 as soon as the spark strikes the air ionizes and voltage drops drastically

author: coppercone2
author_rank: Super Contributor
timestamp: April 21, 2024, 07:20:06 pm
content: the spark plug gauge and the spark plug cleaner. i wonder how well those high end plated ones clean lol
Code Poetry - Page 1
Forum section: electronics / general

author: Omega Glory
author_rank: Regular Contributor
timestamp: April 18, 2024, 03:22:49 am
content: Anybody here every try writing code poetry? Here's an attempt in Python. This will run (assuming "ant.py" exists), but doesn't do anything. The best code poems actually have some kind of neat side effect.

author: EPAIII
author_rank: Super Contributor
timestamp: April 18, 2024, 05:52:41 am
content: Some people haveENTIRELY TOO MUCHtime on their hands.(It doesn't rhyme, but it has a sort of meter.)

author: SiliconWizard
author_rank: Super Contributor
timestamp: April 18, 2024, 06:50:09 am
content: https://en.wikipedia.org/wiki/Shakespeare_Programming_Language

author: Omega Glory
author_rank: Regular Contributor
timestamp: April 18, 2024, 01:57:52 pm
content: @EPAIIIYeah, it doesn't rhyme, but I was trying to limit myself to keywords as much as possible, which makes it hard. TheCode:open("you","r")was fun because the "r" actually does something here (tries to open the file "you" in read mode). And the fact that it comes between the aCode:try:andCode:finally:means if the file doesn't exist, the exception will be caught. Though to be fair, the underscore will evaluate to False which may prevent the open from running due to "short circuit" evaluation of the logical and. Ah, and the first if statement will evaluate to False anyway.@SiliconWizardShakespeare is great, hahaha. Have you seen Chef?https://esolangs.org/wiki/Chef(nice example),https://www.dangermouse.net/esoteric/chef.html(syntax)

author: SiliconWizard
author_rank: Super Contributor
timestamp: April 18, 2024, 08:06:20 pm
content: Quote from: Omega Glory on April 18, 2024, 01:57:52 pmYes, I had seen Chef. In the same vein, there is also Rockstar:https://codewithrockstar.com/

author: paulca
author_rank: Super Contributor
timestamp: April 21, 2024, 07:14:10 pm
content: while( you.love(me.love(you)) ) {}
Fast prototyping hack:  10 layers PCB in 2 hours, no chemicals, IT8705F, ALC201A - Page 1
Forum section: electronics / general

author: RoGeorge
author_rank: Super Contributor
timestamp: April 20, 2024, 05:58:55 pm
content: In case you wonder "but why?", I am learning how to write a Linux kernel driver, and that is how a hardware guy is doing software.So far exercised with writing a driver for an RGB LED, then for reading a button, outputting PWM to a buzzer, and reading a 16-bits ADC (an SPI kernel driver forADS1118). During this time I've kept adding wires with various peripherals, until the Raspberry Pi header became full of wires, and the workbench full of ziplock plastic bags:Even so, those peripherals were too simple to exercise more advanced aspects of a kernel driver. So, I've searched my chips inventory for whatever else I might have in stock and worthy for a kernel driver, and preferably something more useful than just a blinking LED.The candidates were an RTC chip (my RPi doesn't have an onboard clock with battery, it needs internet to get the datetime), a UART chip, or a 10-bit 40MSPS ADC. Though, in terms of ADC choices, the low speed 16-bit ADC would be more useful as a high resolution data logger for the lab.An LPT (parallel printer port) would have been a useful addition, too, because I have an old FPGA board with an LPT programmer, and no LPT port in the current PC. I went through my EE scrap boxes looking for a LPT chip, and realized no motherboard has them since the times of the ISA cardsMore recent motherboards are using a super IO chip, with a low pin count bus, and with all the HW controllers for low speed peripherals in it: LPT, 2xUART, IR, smart card reader, 48 gpio, 8-bit ADC w 8ch, 3xPWM fan, floppy disk controller, flash writer, etc. That is what i.e. the IT8705 is doing.That chip would make a very useful Raspberry Pi hat, and offer plenty of hardware devices to practice further with the kernel drivers writing.Bonus, near the IT8705F (the LPC IO chip), there is an I2S sound codec ALC201 (Raspberry Py only has one line out Jack, no input, and even the line out is not from a proper codec, the line out sound is played through 2 PWM pins). So, yet another opportunity to exercise writing a sound driver.That is, if the two chips are still functional after the motherboard hack.
Neural-net technology: How AI Learned to Talk (IE: ChatGPT) - Page 1
Forum section: electronics / general

author: BrianHG
author_rank: Super Contributor
timestamp: March 09, 2024, 04:35:37 am
content: This is the latest in the history of how we developed neural-net technology.Let me know if you want me to post the rest of the series...

author: BrianHG
author_rank: Super Contributor
timestamp: April 21, 2024, 01:21:15 am
content: 3-Blue1Brown's series:Part 5Part 6
Boston Dynamics new Atlas Robot. - Page 1
Forum section: electronics / general

author: BrianHG
author_rank: Super Contributor
timestamp: April 17, 2024, 07:20:12 pm
content: Winner, or Looser?

author: globoy
author_rank: Frequent Contributor
timestamp: April 17, 2024, 09:18:08 pm
content: It's supposed to be pretty strong too (according to an IEEE article).On one hand it looks pretty amazing. It may not look quite as polished as some of the other humanoid robots but BD has history actually deploying robots with Spot and they have a powerhouse manufacturing partner as owner who can give them both a market and invaluable testing ground.On the other hand, when I consider the rush to get AIs controlling these things, it's kinda the stuff of nightmares the way it just starts coming at the camera while getting itself aimed forward...

author: BrianHG
author_rank: Super Contributor
timestamp: April 17, 2024, 10:12:38 pm
content: It's the speed at which it was able to effortlessly get up which is the impressive part.It doesn't even look like it was even doing it as fast as possible.As for it's looks, it looks like it was designed to operate in harsh environments.

author: ClarenceMorse
author_rank: Newbie
timestamp: April 18, 2024, 06:36:01 am
content: No doubt. It looks good so far. Carry on!

author: jonovid
author_rank: Super Contributor
timestamp: April 18, 2024, 02:56:06 pm
content: I say bring on the Robotic Olympicswould like to see two of them wrestling.alsowould like to see a 4 legged robot greyhound canter then gallop up to 40 mphleaving Spot the dog in the dust.as a fan of robot wars & battlebotswheels are so passe IMO

author: SiliconWizard
author_rank: Super Contributor
timestamp: April 18, 2024, 08:04:17 pm
content: This is impressive robotics but probably extremely expensive - I'm wondering who's the primary target market? (I mean, beside the military?)

author: AVGresponding
author_rank: Super Contributor
timestamp: April 19, 2024, 05:13:08 am
content: Maintenance in extreme hazard environments, and if the price comes down due to mass production, that would open the door for a multitude of uses

author: BrianHG
author_rank: Super Contributor
timestamp: April 19, 2024, 09:35:33 am
content: Looking at it, I would have to bet that the torso must be something like 75%-85% battery if they want to get some serious hours of work per charge...

author: mawyatt
author_rank: Super Contributor
timestamp: April 19, 2024, 12:39:03 pm
content: Reminds of the DARPA Wait, What Conference in St Louis way back, where Boston Dynamics had a demo of all their robots. While watching, the Robot Dog came around and sat right in front and scanned me, very spooky!!BTW think this Robot is done with electro-mechanical methods, the earlier Atlas utilized hydraulics.Best,

author: bitwelder
author_rank: Super Contributor
timestamp: April 19, 2024, 12:51:07 pm
content: Quote from: BrianHG on April 19, 2024, 09:35:33 amOn that account, I wonder what happens if it falls in the water...

author: AVGresponding
author_rank: Super Contributor
timestamp: April 19, 2024, 01:22:12 pm
content: Quote from: bitwelder on April 19, 2024, 12:51:07 pm
Controlling 24v Contactor w/ 12v...? - Page 1
Forum section: electronics / general

author: bigjoncoop
author_rank: Regular Contributor
timestamp: April 18, 2024, 07:30:14 pm
content: I've got a TE LEV200A5NAA High Voltage DC Contractor, that's rated at 900v / 500a with a 24v coil. (Datasheet Attached)I'm using it to remotely contol the output of a large 12v lithium battery bank. (the battery bank already has the necessary management system, I'm just using this to wirelessly control the output)I've tested the coil using 12v and it seems to close the contacts just fine... Now I know that the magnetic field that closes the contacts will be weaker by using a lower coil voltage.Now I know that I could easily just use a small step up / boost converter (which I have tons of 😜), but that would just add another point of failure which I'm really trying to avoid in this situation.I'm assuming that the only inherent risk is that the contacts may open inadvertently due to the lower voltage. Correct? I don't see how the lower coil voltage, could make them get stuck closed...I'm basically asking a question that I already know the answer to, but I'd rather double check then have a catastrophic issue!***Oh, as I mentioned the contactor is rated at 900v @ 500a and I'm only using it with 12v and a maximum of 100a continuous for no more then 30-45 minutes at a clip.***

author: AVGresponding
author_rank: Super Contributor
timestamp: April 19, 2024, 01:09:34 pm
content: Given it lists the dropout voltage as 1-5VDC for the 24V coil I suspect you'll be fine

author: bdunham7
author_rank: Super Contributor
timestamp: April 19, 2024, 01:24:38 pm
content: Once the contactor is activated, it won't let go until the voltage drops a lot. The only risk I see is that even though it is operating at 12V or 12.6V now, it may not always operate at that voltage since it is far below the spec. Also, it may not operate when the battery bank is not fully charged and you have less than 12V. You could characterize it by trying to actuate it with a power supply at various voltages to see where the minimum is.

author: tom66
author_rank: Super Contributor
timestamp: April 19, 2024, 01:25:48 pm
content: Quote from: AVGresponding on April 19, 2024, 01:09:34 pmAgreed. The biggest risk is that the coil doesn't activate in the first place. Once it is activated, it will be fine.Over time, you might find that wear causes the required activation voltage to increase but I would expect most of the time you will get away with it.
Robomow PC Toolkit - Page 1
Forum section: electronics / general

author: trikzjumper
author_rank: Newbie
timestamp: April 17, 2024, 05:49:54 pm
content: HelloI have been looking for the following software: Robomow PC ToolkitSince it is only provided to offiicial dealers at Robomow it is hard to find the software anywhere.Anyone has the program and is willing to upload the software so i would be able to configure my RS model directly.Thanks
PCIe Gen5 over external cables ?? - Page 1
Forum section: electronics / general

author: frogblender
author_rank: Regular Contributor
timestamp: April 16, 2024, 03:17:34 pm
content: I'm designing a system that requires two systems to be connected by an external PCIe Gen5 cable, with eight lanes (x8).Anyone have any ideas on what to use?"MCIO" aka "Mini Cool Edge" aka "SFF-TA-1016" can handle Gen5, but is for internal cabling only.

author: thm_w
author_rank: Super Contributor
timestamp: April 17, 2024, 09:29:33 pm
content: https://www.serialcables.com/product-category/gen5-mcio-cables/Look on the left side they have a few types.I assume internal only because its unshielded and not that robust?

author: amyk
author_rank: Super Contributor
timestamp: April 18, 2024, 12:01:46 am
content: How long?Have you considered Thunderbolt? It's basically external PCIe.
Rocker switch needs spring? - Page 1
Forum section: electronics / general

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: April 14, 2024, 06:07:26 pm
content: I took a DPDT rocker switch apart because it failed. There was no continuity on one circuit and the rocker was stuck in the off position.It's a ON-ON type.So I took it apart and was surprised to see there's no spring. I thought there needs to be compression somewhere to make the contacts toggle.I was able to get continuity back but when I re-assembled it the rocker only worked a few times and got stuck again. Forcing it made the rocker pop out from its holder.Attached picture.1 is the body, 2 are the contacts that go into 1, 3 is the toggle, 4 is the cover.I would have expected a tiny spring somewhere on #3 to keep the black plastic .. thing... anvil... whatever securely pressing down?It's very annoying because this particular switch model is used on all kinds of Commodore drives and is expensive to get an exact replacement.My previous switch problems were all solved with precision disassembly but now I can't remember if there was a spring in them.What do you think? Should there be a spring?

author: CatalinaWOW
author_rank: Super Contributor
timestamp: April 14, 2024, 06:59:16 pm
content: The toggle handle appears to surround a plunger connected to the black plastic anvil. My guess is that any spring is probably inside the cavity of the handle. And since it didn't pop open on you probably has little or no compression left.Hard to really say without pawing over and twisting and turning the parts with my own hands.

author: amyk
author_rank: Super Contributor
timestamp: April 15, 2024, 12:15:53 am
content: They may not need a separate spring if the natural elasticity of the materials is enough for an over-center effect.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: April 15, 2024, 03:04:56 pm
content: Yeah I checked, sometimes the metal shaft is hollow and there's a teeny-tiny bouncy spring that likes to eff off under the floor boards, not in this case, it's solid.I had also considered the fact that the metal body part probably has some give but that means it all depends very much on the exact mating position and retention.All in all, I've spent more energy typing than just ordering new switches.I'll just order a bunch and get over it...
Strange Battery Charger Behavior... Any Ideas?  - Page 1
Forum section: electronics / general

author: bigjoncoop
author_rank: Regular Contributor
timestamp: April 20, 2024, 03:56:39 pm
content: Hey just want to say thank you guys ahead of time for all of your help over the years!!!This time I got a strange scenario going on using two digital smart Chargers in parallel charging 1 battery.(PHOTO ATTACHED)So I have two of these Chargers and I'm powering both of them through one repurposed server power supply, and they're both connected to the same battery.I set each one to 14.6v, but when I start one of them the other one also shows about the same charging current on the output... WTF??? So to clarify, when I start charger "A", the display on Charger "B" is also showing roughly the same charging current on the output but is still off(it's powered up but but not started)....Oh in case it's relevant, I'm not using the Chargers in their "charging mode" but using the adjustable CC/CV power supply feature that's built in.*** I haven't tried to start charger "B". As soon as I started charger "A", I realized what was happening and didn't want to risk burning them up ***Is this a common occurrence or is something strange going on?I've used (carefully & monitored) different types of battery chargers in parallel before (not these), and have never had this happen though.Would installing a diode in forward bias on each one, stop this from happening or does it even matter? Is it safe to just start both Chargers?

author: IanB
author_rank: Super Contributor
timestamp: April 20, 2024, 04:18:57 pm
content: If it does not say in the instructions that you can use one battery charger in parallel with another charger on the same battery, then you are not supposed to do this.

author: floobydust
author_rank: Super Contributor
timestamp: April 20, 2024, 05:52:36 pm
content: Many battery chargers switch the output on/off using a low-side N-ch mosfet.Because you are using the two chargers in parallel (same power source) the one with output ON is providing a (-) return for the other that has output OFF.I think you're just bypassing that OFF charger's (low-side) output switch, so it starts providing current.Does that make sense? If you reversed roles, other charger ON and this one OFF, same drama.

author: PlainName
author_rank: Super Contributor
timestamp: April 22, 2024, 04:37:55 pm
content: QuoteSure. Learn to use the forum's image tools, and then something other than just one quarter of some huge photo will fill my browser window and I'll be able to see what you're asking.
Is there a proper name for this particular cover/plug/pin/bung? - Page 1
Forum section: electronics / general

author: Halcyon
author_rank: Unknown
timestamp: April 11, 2024, 01:35:34 am
content: A bit of an odd one... I'm after a flexible/compliant rubber or silicone "plug" with a flat head that I can just push-fit into small holes in both timber and metal, to essentially cover and disguise the hole. Similar to the little end-pins you get with some ESD tubes to keep IC's from falling out the ends. I don't know if there is a proper name for these or if anyone can suggest a product they've used in the past.The holes are approximately 3.5 to 4.0mm in diameter.

author: 44kgk1lkf6u
author_rank: Regular Contributor
timestamp: April 11, 2024, 03:12:42 am
content: Searching for ribbed plug yielded some results.

author: notsob
author_rank: Frequent Contributor
timestamp: April 11, 2024, 03:18:12 am
content: Try google for "blind hole plug"

author: abeyer
author_rank: Frequent Contributor
timestamp: April 11, 2024, 03:30:12 am
content: Quote from: 44kgk1lkf6u on April 11, 2024, 03:12:42 amyeah... for certain types of holes that need plugging.

author: shabaz
author_rank: Frequent Contributor
timestamp: April 11, 2024, 04:14:06 am
content: I believe the technical term (as Beavis & Butthead would also describe it) is, as you say, a bung.There are silicone bungs (photo below), or, if you don't want that level of softness, perhaps plastic blind rivets (or variants such as the ones in the photo below) might suit your needs. Those plastic rivets are really handy for all sorts of purposes, e.g. keep two sheets joined together, but they could also just be used as a plug.This site has a lot of the plastic options.For full flushness, there are rubber tapered plugs (photo of those below too).

author: SeanB
author_rank: Super Contributor
timestamp: April 11, 2024, 07:54:15 am
content: Easiest is a tube of acrylic or silicone sealer, and wipe over the hole to leave a blob in the hole, and wipe after with a damp cloth. Fast, cheap, and works well.

author: Halcyon
author_rank: Unknown
timestamp: April 11, 2024, 10:38:25 am
content: Quote from: SeanB on April 11, 2024, 07:54:15 amIn this instance I want it to be removable.I ended up finding something (which I hope works) listed under "Snap in locking hole plugs, rubber panel seal cover flush type panel round for kitchen rubber bulkheads waterproof sealing plugs" (read in Big Clive's voice).

author: EPAIII
author_rank: Super Contributor
timestamp: April 12, 2024, 06:24:47 am
content: Rubber corks?

author: armandine2
author_rank: Frequent Contributor
timestamp: April 12, 2024, 07:00:26 am
content: grommet gets used herehttps://www.reevite.co.uk/grommets/blind

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 12, 2024, 08:10:19 am
content: Brings to mind such as these,https://www.mcmaster.com/products/hole-covers/protective-plugs~/of course YMMV, you'll probably want to find your local equivalent as McMaster is fairly US-specific IIRC, but as a list of examples, that's fine.Tim
The interest of this assembly before the power supply - Page 1
Forum section: electronics / general

author: Bill
author_rank: Contributor
timestamp: April 11, 2024, 04:24:28 pm
content: Hello everyone,I have just noticed that there is an assembly installed before each power supply unit, I would like to know why ? what is the point of this assembly ? and why the one framed in red has a breaker and the other does not, what is the difference between them ?Thank you so much !!

author: AVGresponding
author_rank: Super Contributor
timestamp: April 12, 2024, 05:34:47 am
content: The purpose of the "no fuse breaker", and "NF", are to isolate the unit from the supply so that it can be safely worked on.
Engineering Comedy - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: April 06, 2024, 10:57:33 am
content: I'm only two minutes into this and I have to post it!Don McMillan used to be a chip designer at VLSI, and a stand up engineering comedian.

author: lowimpedance
author_rank: Super Contributor
timestamp: April 06, 2024, 11:19:15 am
content: I had never given much thought to the fact that all my shorts and pants were cargo!...Until now.Thanks for posting, had a good laugh.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: April 06, 2024, 11:41:54 am
content: Quote from: lowimpedance on April 06, 2024, 11:19:15 amUS version of Matt Parker

author: mendip_discovery
author_rank: Super Contributor
timestamp: April 06, 2024, 01:19:37 pm
content: Also watch some of Dave Gorman's early work, he does enjoy data and graphing.He once tried to find all the other Dave Gorman that are alive.

author: mawyatt
author_rank: Super Contributor
timestamp: April 06, 2024, 05:14:53 pm
content: @ Dave,BrillantBest,

author: schmitt trigger
author_rank: Super Contributor
timestamp: April 06, 2024, 09:23:04 pm
content: The reason that the Marriage Logic’s truth table output became Don is Wrong when Don and Laura are wrong, is an XAND function.

author: rsjsouza
author_rank: Super Contributor
timestamp: April 06, 2024, 10:22:42 pm
content: Don McMillan is very good. He's been around for some time.

author: armandine2
author_rank: Frequent Contributor
timestamp: April 09, 2024, 09:18:43 pm
content: ... not the above specifically, but it didn't work for me, and it is working less and lessso .. shhhh ... I must be a 1 in a million
Re HN: The Electrical Items Collection - Page 1
Forum section: electronics / general

author: MuhScopeBroke
author_rank: Contributor
timestamp: April 12, 2024, 01:54:14 pm
content: Thought this forum would find this interesting.Original Post:https://news.ycombinator.com/item?id=39998446Link From Post:https://samuele963.github.io/electrics/index.html
What Happened to the ship from Planet of the Apes 1968? - Page 1
Forum section: electronics / general

author: Homer J Simpson
author_rank: Super Contributor
timestamp: April 07, 2024, 03:40:50 pm
content: Interesting video on the design and history of the ship from the movie.This channel looks at what has happened to the props from the old science fiction movies.https://www.youtube.com/@MoviesMusicMonsters/videos
Does this connection make any sense? - Page 1
Forum section: electronics / general

author: chupocro
author_rank: Contributor
timestamp: April 04, 2024, 08:24:39 pm
content: I am looking at the connection examples of sometoggle switch from AEwhich has two indicator LEDs and can't see any sense in connecting theNOcontact to thecathode of the green LEDas in the connection diagram in the picture I marked with the red arrow.Can anyone spot any reason why would one want to make such a connection which connects battery plus with the green LED's cathode?

author: AVGresponding
author_rank: Super Contributor
timestamp: April 05, 2024, 05:38:47 am
content: Who says it's connected to the cathode? It's more likely it's connected to the anode, and the cathode is common with that of the red LED, and that the diagram merely shows the connections for OFF=GREEN ie the device being controlled by the switch is "safe".Or it could just be wrong, it does happen.

author: tooki
author_rank: Super Contributor
timestamp: April 05, 2024, 11:38:22 am
content: Quote from: AVGresponding on April 05, 2024, 05:38:47 amUmmm… the datasheet shown? On the bicolor LED model, the drawing clearly shows the “LED:+” pin, then “LED:G” and “LED:R” pins instead of the “LED:-” pin shown on the single-LED model. Since LED+ is the anode, and there’s only one, it has to be the common, meaning the cathodes are separate.

author: tooki
author_rank: Super Contributor
timestamp: April 05, 2024, 11:49:18 am
content: Quote from: chupocro on April 04, 2024, 08:24:39 pmIt doesn’t make any sense at all. There’s no way for current to flow.

author: AVGresponding
author_rank: Super Contributor
timestamp: April 05, 2024, 12:58:01 pm
content: Quote from: tooki on April 05, 2024, 11:38:22 amYeah, I agree, it's implied. Note to self: no posting before fully waking up in the morning!Depending on the PIV of those LEDs, it might well light the red one with enough voltage...In fact, at 220VAC, it'll be lighting them both. For a short time...

author: chupocro
author_rank: Contributor
timestamp: April 06, 2024, 01:52:20 am
content: Quote from: tooki onYesterdayat 01:49:18 pmThere are different images with the same mistake - seems as sellers are replicating the same schemetics. Here isanother onewith added legend describing how it was supposed to work.There are listings where LEDs would work as expected but the load is connected in series with the LEDs. I can't find those at the moment but I'll post the link if I find them again.
Engineering Consulting Rates in Australia? - Page 1
Forum section: electronics / general

author: SeoulBigChris
author_rank: Regular Contributor
timestamp: April 07, 2024, 09:05:22 pm
content: As the title says, what’s a ballpark range for electronic engineering consulting fees in the region? Let’s assume an engineer with 40 years experience that is very broad, spanning everything from systems engineering, hardware design, firmware coding, small scale manufacturing, and remote field testing. Say, typically hourly (or daily) rates vary from xxx to zzz dollars. Please note which currency, please, given that the dollars are different.I have no idea how to quote a potential gig down under.
Aim-54 Phoenix Missile And F-111 Aardvark Development Program - Page 1
Forum section: electronics / general

author: Homer J Simpson
author_rank: Super Contributor
timestamp: April 03, 2024, 02:19:45 am
content: Some cool footage from the phoenix missile program.

author: coppercone2
author_rank: Super Contributor
timestamp: April 03, 2024, 05:12:16 am
content: I wonder if we will go back to this style once it has a powerful defense laser so it does not need the stealth. I hate how the modern ones look (bubble gum style). instead of stealth you would just put more heavy lasers and bigger engines

author: SiliconWizard
author_rank: Super Contributor
timestamp: April 03, 2024, 05:25:28 am
content: Doesn't look very environmentally-friendly if you ask me.

author: coppercone2
author_rank: Super Contributor
timestamp: April 03, 2024, 06:57:23 am
content: just kick that drum of the tet over the fence into that pond when your done rinsing those parts we need em real clean

author: eutectique
author_rank: Frequent Contributor
timestamp: April 03, 2024, 10:58:50 am
content: Quote from: SiliconWizard on April 03, 2024, 05:25:28 amDo Good Things™[ Specified attachment is not available ]

author: SiliconWizard
author_rank: Super Contributor
timestamp: April 03, 2024, 09:39:23 pm
content: Nice!

author: coppercone2
author_rank: Super Contributor
timestamp: April 03, 2024, 10:34:25 pm
content: it keeps the environment friendly
Old incandescent panel lamps - Page 1
Forum section: electronics / general

author: cosmicray
author_rank: Frequent Contributor
timestamp: March 30, 2024, 04:22:51 pm
content: Over across the river, is a (rather atypical) DIY building materials store. There was one room in the back, that has been in disarray for at least 10 years (that I'm aware of). Few days ago I was over there looking for something, and noticed the lights were on in this room, and the door was open. So I peeks in, and saw a number of racks of Midwest parts bins, one of which contained these panel lamps. My guess is they date back 10-20 years (possibly more). The number 47 lamps I've not seen locally since Radio Shack closed operations. The others I am less familiar with. Are any of these HTF ?

author: EPAIII
author_rank: Super Contributor
timestamp: April 03, 2024, 11:42:43 am
content: An internet search for "HTF" only returns "Happy Tree Friends" for the first two and a half pages. Then one reference to "The Housing Trust Fund (HTF)". Then on the fifth page I saw "Hi-Tech Fasteners".Then on page 8 I got "Hard To Find" as a term used on E-bay.I bet you would get more responses if you just said that instead of the abbreviation.As far as how hard to find they are,https://www.amazon.com/s?k=light+bulb+%2347&ref=nb_sb_nossYou can take it from there for the other sizes. I suspect all of them can be found with a quick internet search.Quote from: cosmicray on March 30, 2024, 04:22:51 pm
VHDL CODE QUESTION - Page 1
Forum section: electronics / general

author: Austin
author_rank: Newbie
timestamp: April 03, 2024, 02:12:38 am
content: Hi ! I'm new to the forum.If I'm doing something wrong,please tell me.I'm trying to make a 32bit counter in a FPGA.What I want to do is measure pulse with.I wrote the code below and came up with a question.When the rst is 1 FPGA circuitry will try to do TMP<=cnt; and cnt <=X"00000000"; at the same time.At least that's what I thought.Whill this code run stably and reliably ?library IEEE;use IEEE.STD_LOGIC_1164.ALL;use IEEE.STD_LOGIC_ARITH.ALL;use IEEE.STD_LOGIC_UNSIGNED.ALL;entity Top isPort ( clk : in STD_LOGIC;rst : in STD_LOGIC;count : out STD_LOGIC_VECTOR(31 downto 0);hold : out STD_LOGIC_VECTOR(31 downto 0));end Top;architecture Behavioral of Top issignal cnt : STD_LOGIC_VECTOR(31 downto 0) := (others => '0');signal TMP : STD_LOGIC_VECTOR(31 downto 0) := (others => '0');beginprocess(clk, rst)beginif rst = '1' thenTMP<=cnt;cnt <=X"00000000";elsif rising_edge(clk) thencnt <= cnt + 1;end if;end process;count <= cnt;hold <= TMP;end Behavioral;

author: Daixiwen
author_rank: Frequent Contributor
timestamp: April 03, 2024, 10:46:20 am
content: This may work in a simulator at first, but on the next clock edge after you put rst to 1 the simulator will execute the process again, go into the if rst = '1' branch, and copy the value of cnt (now 0) into TMP.In the actual implementation in an FPGA, TMP and cnt will be asynchronously connected together and TMP will continuously read cnt as long as rst = '1' so you will end up with TMP being 0 anyway.The asynchronous branch with the if rst = '1' should only contain initial values for your signals, that should be applied during a reset. All the rest of the logic should be in the clock part of the process. I would suggest to have a separate 'load' signal to load the counter value, independently to the reset signal.Code:entity Top isPort ( clk : in STD_LOGIC;rst : in STD_LOGIC;load : in STD_LOGIC;count : out STD_LOGIC_VECTOR(31 downto 0);hold : out STD_LOGIC_VECTOR(31 downto 0));end Top;architecture Behavioral of Top issignal cnt : STD_LOGIC_VECTOR(31 downto 0) := (others => '0');signal TMP : STD_LOGIC_VECTOR(31 downto 0) := (others => '0');beginprocess(clk, rst)beginif rst = '1' thenTMP<=X"00000000";cnt <=X"00000000";elsif rising_edge(clk) thenif load = '1' thenTMP <= cnt;cnt <= X"00000000";elsecnt <= cnt + 1;end if;end if;end process;count <= cnt;hold <= TMP;end Behavioral;A few other suggestions:avoid using STD_LOGIC_ARITH and STD_LOGIC_UNSIGNED. Those are non standard packages, and will cause confusion if you ever need to mix unsigned and signed vector. Use NUMERIC_STD instead and the dedicated signed and unsigned types instead of std_logic_vector to make counters.if your 'load' pulse signal is external to the FPGA and not synchronized with the clock, you will need to register it a couple of times to avoid metastability problems. If you google "metastability filter" you should find some good articles on why this is necessary and how to implement them.EDIT: sorry I only noticed after I replied that the OP double posted his question
Another AliExpress Wonder??? - Page 1
Forum section: electronics / general

author: watchmaker
author_rank: Unknown
timestamp: April 09, 2024, 11:11:16 am
content: I just HAD to try this.https://www.aliexpress.us/item/3256806171665566.htmlThere are a lot of nice ICs in it, a high quality zif and a nice display. Not all is lost if it is worhtless.Tried it to ID Ics and it works.Not sure about the test functions though.The issue is that who knows what it reports? In grad school, while working on my Ph.D. I was assigned as the research methodology consultant to a cardiologist creating a risk factor score for heart attacks based on the Framingham study (simple multivariate regression). He was using a friend for coding the reports. I had to tell him that the report program was nothing but a "print" command and a pseudo-random number generator.Since then, I have been very skeptical of test processes I do not understand unless they are created by known trusted sources. Very sad that today there are so many vanity pubs in science and the art of assessing the professional reputation of an author is lost. The rise of pseudo science. And far too many journal retractions. Oops, rant.I just ordered the parts needed to assemble my RetroChip from DigiKey (PITA, but only about $130) and I will compare the test results.

author: thm_w
author_rank: Super Contributor
timestamp: April 09, 2024, 09:11:38 pm
content: Tape or lift one of the pins and run the test, see what happens.Obviously its not going to catch every single failure mode, but if one of the inputs is shorted, or one of the outputs is short, it should detect that.

author: watchmaker
author_rank: Unknown
timestamp: April 10, 2024, 01:29:53 am
content: Yes, it reports fault. There seems to be an issue with the Li battery and its charging ckt. Even when the charge LED is green, it works correctly randomly. May be a bad example, or just not ready for prime time. Interstingly, it is easy to return. Sent me a label to ship it to a return center in Deleware.The Diode test away off. 7.8V for a 3 V LED.
EMF fluctuations in a negative reactance ring - Page 1
Forum section: electronics / general

author: Sredni
author_rank: Frequent Contributor
timestamp: March 31, 2024, 09:55:41 pm
content: I promise I am not trying to revive a dead horse (read on and it will be clear why it is not so) but I am posting in this part of the forum for good measure.Back in the good old days of the Kirchhoff vs Faraday rap battle, someone suggested I tried to analyze a Lewin ring (two resistors in a loop that encircles a region of variable magnetic field) that employed capacitors instead of resistors. Well, about a year ago I did just that and also made a video that showed results in accordance to what was predicted (and yes, the Kirchhoff party would interpreted in their own way, while the Faraday party would insist it's the other way around, so let's accept that andnotgo down that road again). Here's my old video:https://youtu.be/qTzqIYrc_HsYeah, despite my charismatic scenic presence, the perfectly timed script, along with my utter mastering of the English language and uncanny fluent British pronunciation, audio and video quality is close to zero. So I thought I might remake the video and possibly switch from mains frequency to the variable frequency of the function generator to show that, within the limits of the frequency response of the toroidal core, the theory (that keeps Ohm's law - in its generalized form - alive in all parts of the ring, but does away with KVL) held.And indeed, everythingseemedto work nice, but today when I was preparing to record the video, I've noticed that when I raise the frequency above a few tens kHz (but still under 100 kHz), I get appreciable, seemingly random, fluctuations in the electromagnetic force.I therefore put the remake on the back burner, and I am now going to make a dedicated video to document these flukes (I am not sure I know how to do a live on YouTube to get instant feedback, maybe I'm not even allowed) and I will try to put it online in a few minutes to get direct feedback.I am wondering if there is some theoretical reason for the EMF fluctuations I am seeing and if you have suggestions on how to perform the measurements in order to identify the problem.BRB with the new video.

author: Sredni
author_rank: Frequent Contributor
timestamp: April 01, 2024, 02:02:35 pm
content: Herehttps://youtu.be/Y2C9NxfXqLM?si=2QQxX9mES_31YIHr
Disassembly a M68HC11 binary - Page 1
Forum section: electronics / general

author: charlycop
author_rank: Newbie
timestamp: March 31, 2024, 10:50:41 am
content: Hi Guys,I'm trying to find a tool to disassemble the M68HC11 complied binary I have. It comes from a motorcycle Aprilia ECU eprom.I tried Ghidra, but it seems not to handle this 8-bit processor. I tried C.A.T.S, but it crashes, and DSH11 doesn't even start.Any idea?Thanks for your help.

author: DavidAlfa
author_rank: Super Contributor
timestamp: March 31, 2024, 10:54:38 am
content: Check this, modded Ghidra with HC11 support:https://www.eevblog.com/forum/microcontrollers/help-who-can-reverse-compile-27c1001-firmware-internally-i-encountered-difficu/msg5051164/#msg5051164

author: Benta
author_rank: Super Contributor
timestamp: March 31, 2024, 12:01:33 pm
content: Here's assembler and disassembler:https://www.techedge.com.au/utils/

author: DiTBho
author_rank: Super Contributor
timestamp: March 31, 2024, 03:07:02 pm
content: Quote from: Benta on March 31, 2024, 12:01:33 pmlinks to binary are gone - 404

author: Benta
author_rank: Super Contributor
timestamp: March 31, 2024, 04:52:18 pm
content: Didn't check that. Here it is:

author: charlycop
author_rank: Newbie
timestamp: April 01, 2024, 07:05:42 am
content: Quote from: Benta on March 31, 2024, 04:52:18 pmAs I said in my question, I have it and it doesn't run (see attached). But thanks a lot, and you are right, I need just to make it work. Do you think with a virtual box of winXP or Win7, it will run ?

author: Zoli
author_rank: Frequent Contributor
timestamp: April 01, 2024, 07:19:41 am
content: Quote from: charlycop on April 01, 2024, 07:05:42 amIt's a 16 bit app(DOS, AFAIK); you can run thru virtual machines, emulators, orWinevdm.

author: charlycop
author_rank: Newbie
timestamp: April 01, 2024, 08:16:15 am
content: Quote from: Zoli on April 01, 2024, 07:19:41 amYes, ok I tried on WinXP, it's working thanks a lot.
tweeter - Page 1
Forum section: electronics / general

author: pete g
author_rank: Regular Contributor
timestamp: March 30, 2024, 08:40:39 pm
content: hi all,i need clarification on tweeters. i see piezo tweeters listed as having 8 ohm impedance, do they have a voice coil? i thought they were made with crystals. what is the 8 ohms in reference to? is it non-piezo tweeters that have 8 0hms resistance?

author: David_AVD
author_rank: Super Contributor
timestamp: March 30, 2024, 08:44:04 pm
content: Remember that (DC) resistance and (AC) impedance are not the same thing.

author: coppercone2
author_rank: Super Contributor
timestamp: March 30, 2024, 10:25:25 pm
content: use LCR meter

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 30, 2024, 10:38:58 pm
content: A piezo tweeter can be basically modeled with a capacitor in series with a resistor. The piezo element is essentially capacitive. The series resistor models the losses.The impedance of any speaker can only be given as a graph vs. frequency (and even multiple curves, vs. power, but let's keep it simple).Piezo tweeters typically have a pretty high impedance below their cut-off frequency. The range for which the impedance is more or less constant (it isn't) depends on the specific tweeter, but it's usually something between a few kHz to a few tens of kHz.They absolutely do not have a voice coil, that's one of their plusses for high frequency response. Basically, it's a piezo element that moves a cone of some sort.Something to read:https://pispeakers.com/PIE_Speaker_Application_Note.pdf
Does the Individual Components of E Waste have value as Second Hand Components - Page 1
Forum section: electronics / general

author: jonovid
author_rank: Super Contributor
timestamp: March 29, 2024, 02:10:15 am
content: we know most electronic waste has Precious metals requiring crushing and granulation for its extraction.but is the individual components in e-waste worth salvaging?I give for example any used solder on psb's.or un-crushed ferrite cores hold any value worth recovering for reuse in the electronics second hand market?

author: CatalinaWOW
author_rank: Super Contributor
timestamp: March 29, 2024, 03:23:35 am
content: Depends on your living situation. For most in the developed world there is very little that is worth the effort to salvage. There are a few exceptions, mostly driven by collector or fad markets. And even in the developed world many people don't have unlimited hobby budgets so salvaged components as an avoided cost can make sense. But there is no way to make a decent living selling them.On the other hand, in undeveloped countries where there few environmental or safety restrictions and labor is cheap there are fairly substantial salvage operations. Buying from these operations is risky for those with first world standards because they have neither the equipment or the profit margin to do much to evaluate those salvaged components, but can provide access to otherwise unavailable parts.

author: tooki
author_rank: Super Contributor
timestamp: March 29, 2024, 04:25:01 pm
content: Quote from: jonovid on March 29, 2024, 02:10:15 amRecycled solder is already being used in big-name commercially produced electronics.As for components: most of the time the residual value of the component is far less than the cost to extract it safely, never mind test and repackage it.

author: nctnico
author_rank: Super Contributor
timestamp: March 29, 2024, 04:50:17 pm
content: Desoldered components are being sold. A couple of years ago I received a batch of desoldered chips. I ended up sending them back as the advert claimed the chips to be new.

author: tunk
author_rank: Super Contributor
timestamp: March 29, 2024, 04:54:18 pm
content: Maybe higher value components like transformers from linear PSUs,10-turn potentiometers, high wattage resistors, etc.

author: madires
author_rank: Super Contributor
timestamp: March 29, 2024, 05:07:01 pm
content: It depends:- source of obsolete parts for repair of old devices- cheap/free parts for playing around and experimenting- hobbyist budget (transformers, ferrite/ironpowder cores, heatsinks and so on are expensive)- environmental reasons (reusing is better than recycling)
US Road Trip + Eclipse - Ideas wanted for electronics tour - Page 1
Forum section: electronics / general

author: tom66
author_rank: Super Contributor
timestamp: March 28, 2024, 06:32:38 pm
content: As some will know, there is a total solar eclipse crossing the US on April 8th, 2024. This will be the last chance to see a total solar eclipse in the continential USA for about 20 years.I will be doing a road trip from Los Angeles towards a friend in Arkansas to see the eclipse among other things; then onwards to Houston flying home two weeks later, all in a Tesla Model Y (maybe I'm crazy, we'll see how much I go crazy at superchargers...) I'm hoping it's not going to be cloudy on the day!The trip is something I've wanted to do for some time, I don't often fly long haul (last was over 6 years ago) and I'm looking to catch as many sights as possible.I'll be stopping in Vegas for one night, seeing the Grand Canyon (south side) and driving through the Rockies, stopping in Denver for one night, and then New Orleans and Houston after the eclipse with about two days in each. Our return journey will involve a long layover in NYC too.Is there anything I should see electronics- or engineering-wise in these areas? I'm definitely seeing the NASA museum in Houston, and likely will see the hackspace in Denver.

author: tooki
author_rank: Super Contributor
timestamp: March 28, 2024, 07:36:31 pm
content: If you're into vintage computers, the System Source Computer Museum in Hunt Valley, Maryland (about a half hour north of Baltimore City) is outstanding. Aside from being a colossal collection, a lot of the systems are operational and can be used by visitors! Tours are free and worth it.https://museum.syssrc.com/If you do go, the blue and white Power Mac G3 on display used to be mine.(When I was packing to move from Maryland to Switzerland, I had to let go of my old Mac collection, and the owner of System Source saw my craigslist ad and took it all!)
What is shunting resistance? - Page 1
Forum section: electronics / general

author: ballsystemlord
author_rank: Frequent Contributor
timestamp: March 31, 2024, 04:40:52 am
content: I tried to search, but I only got shunt resistor results, which is not what I'm looking for.I was reading this:https://download.tek.com/document/Obtaining_More_Accurate_WP.pdfI'm not understanding at all what the top half of the 2nd page is trying to convey. If I measure between points 1 and 8, there's only one resistor there, so I should get an accurate result, right?Thanks!

author: soldar
author_rank: Super Contributor
timestamp: March 31, 2024, 08:23:12 am
content: The current is also going through all the other resistors. Look carefully.

author: ballsystemlord
author_rank: Frequent Contributor
timestamp: March 31, 2024, 04:04:01 pm
content: Ah, yes. So that's what they mean. Thanks!