hybridfree/eevblog-posts huggingface dataset:
Home reflow soldering of BGAs - Page 1
Forum section: electronics / beginners

author: jgalak
author_rank: Regular Contributor
timestamp: January 17, 2018, 06:11:50 am
content: I recently tried reflow soldering for the first time. I'd done hand soldering of SMD parts before, down to QFP-type pacakges, but this time was confronted with a QFN-20 that I didn't see any way to hand solder (especially the center ground pad), so I gave reflow soldering a try.Got a stainless stencil from OSHStencils and some paste, and made up two versions of a small board - one with a hot air station, the other with an unmodified toaster oven (just my Fluke DMM temp probe stuck through the door and a piece of thin aluminum placed under the board on top of the rack). The hot air station did ok, the toaster did great.So now I'm wondering - does this sort of home technique work on BGA chips? Or are those too finicky for this to work?

author: SlowBro
author_rank: Regular Contributor
timestamp: January 17, 2018, 06:29:45 am
content: I’m a beginner but I did read an article on Hackaday.com showing how to do it. Just google home reflow bga and there are many hits.

author: agehall
author_rank: Frequent Contributor
timestamp: January 17, 2018, 06:35:18 am
content: Showing how to do it isn't the problem - that part is simple, just apply heat (i.e. hot air) and it will reflow.The tricky parts is understanding how much heat you need to put into the board and how to distribute it evenly across the device so that all of it solders properly. In a home-gamer situation, one may not have the specific nozzles for the device in question which means a lot more reliance on experience to apply the heat.I can't say that I'm experienced with BGA chips (yet!) but I've played quite a bit with my hot air station by now and I'm starting to get a feel for how to apply the heat to ICs to get things to happen.My $0.02 would be to practise. A lot. The general idea of how to do a reflow is simple but the actual motions you need to go thru requires more than meets the eye.

author: jgalak
author_rank: Regular Contributor
timestamp: January 17, 2018, 06:39:52 am
content: I was thinking more toaster oven than hot air station. I got better results on the QFN with it (perfect connections, whereas the hot air station generated one solder bridge), and it was easier. I think the heat would be more even, too.

author: agehall
author_rank: Frequent Contributor
timestamp: January 17, 2018, 06:54:42 am
content: Whatever you have access to and works for you. I don't have a reflow oven (yet) but I'd assume it would, as you say, distribute heat more evenly. The main concern is that it is a bit harder to see what is happening but with some trial and error I'm sure you'll get the hang of it in no-time.
Home sound system - Page 1
Forum section: electronics / beginners

author: Savetheday
author_rank: Regular Contributor
timestamp: August 02, 2022, 06:33:58 pm
content: Hi EveryoneI just move to house with on the ceiling 5 speakers with different cable connections .Actially There is also separate 2 cables that connected to next room Right and Left speakers. Is it possible to make that system home theater sound system? What kind of amplifier do I need?What would you recommand?Thanks

author: Savetheday
author_rank: Regular Contributor
timestamp: August 02, 2022, 06:35:22 pm
content: AND

author: james_s
author_rank: Super Contributor
timestamp: August 02, 2022, 07:02:07 pm
content: That's exactly what those are for. Any standard A/V receiver should do the job, they're ordinary speakers, just set up your receiver the same way you would with floor speakers but hook it up to those wires instead.

author: rooppoorali
author_rank: Regular Contributor
timestamp: August 03, 2022, 08:31:22 am
content: You can see this review:https://www.whathifi.com/best-buys/home-cinema/best-home-cinema-amplifiers

author: Savetheday
author_rank: Regular Contributor
timestamp: August 03, 2022, 01:00:42 pm
content: Great I will check out the list.Thanks.I found this on amazon It's cheap and It has Bluetoothhttps://www.amazon.com/Wireless-Bluetooth-Home-Audio-Amplifier/dp/B01M9I1DO1/ref=sr_1_5?crid=32ZS1PNHJ98FI&keywords=home%2Bsound%2Bsystem%2Bonly%2Bamplifier%2Bsystem%2B5%2Bchannel&qid=1659206689&sprefix=home%2Bsound%2Bsystem%2Bonly%2Bamplifier%2Bsystem%2B5%2Bchannel%2Caps%2C157&sr=8-5&th=1

author: KellyGreené
author_rank: Newbie
timestamp: August 03, 2022, 04:20:05 pm
content: Yes, you can turn it to a home theater system. It's possible the previous residents did that. For the kind of amplifier you need, you can just do a research online to find an amplifier that'll meet all your needs as everyone's preference differs.

author: james_s
author_rank: Super Contributor
timestamp: August 03, 2022, 06:20:02 pm
content: Don't you have a home theater receiver already? Or do people not have those anymore? They were ubiquitous for many years, every thrift store usually has a few of them.

author: TomWinTejas
author_rank: Regular Contributor
timestamp: August 03, 2022, 06:20:41 pm
content: And the coax with the F->RCA adapter is for your subwoofer.

author: macboy
author_rank: Super Contributor
timestamp: August 03, 2022, 06:38:58 pm
content: Honestly I would suggest to get a 9 or 11 channel Atmos receiver, and use 4 of the ceiling speakers for front and rear height channels. Then add ether 5 or 7 speakers for front and surround channels. I have Atmos in my basement theatre with ceiling speakers and it is amazingly enveloping. I also have Atmos in my living room with reflecting(up-firing) speakers and that works ok as well. Another option is to use the back pair as surround speakers, and the front pair as front height (without using any rear height channel). You'll need to add a pair of speakers and centre speaker for the front channels. You don't really want dialog coming from the ceiling. High mounted surround channels can work well though.
Home surge & spike suppression - Page 1
Forum section: electronics / beginners

author: rthorntn
author_rank: Frequent Contributor
timestamp: March 12, 2014, 09:35:43 pm
content: Hi,I would really appreciate some advice on how to protect expensive electronics from rogue power.At the moment I just have one or two crappy power boards that supposedly have some kind of protection.How do people here protect their stuff, APC?Does anybody put protection in the fuse box to protect the whole house?What about phone, Ethernet and TV antenna protection?Lightning protection?Thanks.Richard

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: March 12, 2014, 10:29:50 pm
content: The best surge protection includes a low pass filter which has a series inductor. As well as either MOVs or Sparkgaps.Many brands around. You can get one wired into your switch board on a sub circuit, if you have space. Or one on a sub distribution board, or even one filter that covers the whole premises, but these probably need paperwork from the supply authority which is miles harder than actually wiring it.The series inductor means a small insertion loss of maybe 3% power at full load, correspondingly less at lower loads.If you go the power board way then you will have trouble getting the inductor in the filter.

author: David Hess
author_rank: Super Contributor
timestamp: March 12, 2014, 10:54:23 pm
content: An online UPS or power conditioner will work better than any surge suppressor unless it itself becomes damaged.

author: Phaedrus
author_rank: Frequent Contributor
timestamp: March 12, 2014, 10:55:50 pm
content: You can purchase or build a line conditioner. Assuming you don't need the voltage offset feature (for over or under voltage conditions) it's basically an LC filer with a couple of big ass coils and X capacitors, plus a TVS diode and MOV.

author: rthorntn
author_rank: Frequent Contributor
timestamp: March 13, 2014, 02:26:07 am
content: Thanks everyone!What about phone, ethernet and TV antenna protection, is it worthwhile, do you use it?It sounds like a power conditioner is the way to go, would you just have small ones protecting key items, what brands are best?

author: johansen
author_rank: Super Contributor
timestamp: March 13, 2014, 02:35:57 am
content: it really depends on what you want to protect against.a direct lightning strike to your 120/240v utility drop is not something many can even afford to protect against.MOVs are cheap. a handful of them installed in your fuse box will stop most "surge" events, but i have heard two cases in my life where 7200vac got dumped into someone's house because the utility worker made a mistake while replacing the pole transformer.in one of those cases the utility paid for everything they destroyed, in the other, the fire department had to be called.the short answer is buy one of those whole house arrestors that install within a few feet of the fuse box, and the reason you have to do that is because your insurance might not pay for your custom MOV box burning your house down.
Homemade Cabinet Radio Project - Page 1
Forum section: electronics / beginners

author: Vintage1873
author_rank: Newbie
timestamp: April 03, 2017, 04:08:44 am
content: Hey everyone! I'm currently throwing the idea around of making a simple radio of my own, I've repaired enough yard sale radios at this point to make me interested in making something of my own (kinda). I will be building my own cabinet, maybe 12''x12''x9'' or so. I'm a big fan of old Zenith radio's, 1930's. I want to base my project off the schematics of an older radio. Does anyone have any suggestions before I use something I'm already familiar with as a template? I'd like to get into something a bit different but definitely still an older/tube vibe. Thanks everyone and hope all is well.

author: danadak
author_rank: Super Contributor
timestamp: April 03, 2017, 12:56:59 pm
content: Here is a collection of tons of old radio/tv/audio magazines you can lookfor ideas and DIY articles, free for download.http://americanradiohistory.com/Regards, Dana.
homemade contact printer - Page 1
Forum section: electronics / beginners

author: Unknown
author_rank: Unknown
timestamp: September 08, 2012, 02:00:08 pm
content: Hi,I'm making a contact printer for print PCB traces. What fluorescent lamp should i use? I found some philips wood light 8W lamp, like these:http://www.ebay.it/itm/TUBO-LAMPADA-NEON-DI-WOOD-8W-29-CM-TL-8W-BLB-F8W-BLB-T5-/400273731874can be good?

author: madires
author_rank: Super Contributor
timestamp: September 08, 2012, 05:17:27 pm
content: Should do the job. You may also get some a little bit less expensive athttp://www.reichelt.de/Aetzgeraete-Belichter/UV-LAMPE-1/3//index.html?ACTION=3&GROUPID=3376&ARTICLE=936&SHOW=1&START=0&OFFSET=16&LANGUAGE=EN.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 08, 2012, 06:19:22 pm
content: You want the ones with the white phosphor, which look like normal tubes, not the black or clear ones.The correct ones are used for insect killers and should be easily available.

author: madires
author_rank: Super Contributor
timestamp: September 08, 2012, 07:16:26 pm
content: The blacklight lamps emit just UV-A (around 350nm), but that should work with most photosensitive lacquers (needs more time). The "real" ones also emit UV-B which speeds up the process and also works for lacquers designed for lower lambdas (around 300nm).

author: Unknown
author_rank: Unknown
timestamp: September 09, 2012, 09:47:57 am
content: ok, thanks.... i found some UVC lamps (8W for 15 euros)... should I use these instead of UVB? anyway i just need insect killers lamps, correct?

author: madires
author_rank: Super Contributor
timestamp: September 09, 2012, 07:41:57 pm
content: Yep, take the insect killers lamps.

author: Unknown
author_rank: Unknown
timestamp: September 10, 2012, 08:53:11 am
content: ok, but as I see, insect killer lamps aren't UVB they are UVA...

author: madires
author_rank: Super Contributor
timestamp: September 10, 2012, 09:30:18 am
content: As I wrote before, UV-A works with most photosensitive lacquers. If you are going for an UV-B lamp check the light spectrum. It should include UV-A and UV-B to give you a larger coverage.

author: G7PSK
author_rank: Super Contributor
timestamp: September 10, 2012, 09:41:08 am
content: If you want or need UVB you need lamps for Psoriasis treatment as they are designed to produce more UVBhttp://www.phbhealthcare.com/uvb/http://www.androv-medical.com/product/27/dermfix-1000mx-uv-b-lamp-for-psoriasis--vitiligo-or-eczema

author: Unknown
author_rank: Unknown
timestamp: September 11, 2012, 07:50:54 am
content: Quote from: madires on September 10, 2012, 09:30:18 amI see prices of UVB, it's better if i take UVA, no matter the time, the important thing is that don't ruin the photoresist... I found for 5 euros a UVA lamp, it's around 352 nm, should be "working"...
Homemade plc design(what do you guys think? - Page 1
Forum section: electronics / beginners

author: little_carlos
author_rank: Regular Contributor
timestamp: July 12, 2015, 02:34:34 pm
content: hey guys, i made a new homemade small plc design, il leave you a video so you can watch in action, in the description i leaved the circuit and pcbwhat do you guys think?https://www.youtube.com/watch?v=GHO8hFsW0z0&feature=youtu.be

author: Cliff Matthews
author_rank: Unknown
timestamp: July 16, 2015, 10:22:17 am
content: Lots of work! I didn't see any FB diodes at those relays... ¡cuidado! since no part# was given for the darlington array, I could only hope it has some built-in protection?Did you use a PICkit or a clone to program? If you're on a tight budget (apretado..) use one of these:http://www.piccircuit.com/shop/pic-programmer/55-icp02-usb-pic-programmer.htm
Homeplug noise in speakers - Page 1
Forum section: electronics / beginners

author: Benedict
author_rank: Regular Contributor
timestamp: March 10, 2015, 07:06:56 pm
content: Hi, I've bought a handmade stereo amp from my friend a while ago, and it's a decent amp. However it wasn't designed to filter out the emi coming from homeplugs (ethernet over powerline, from around 500k to 80 mhz signals). At the same time, I need a simple UPS to power my router and switch, things are next to each other and really impossible to move around. I also need to protect those devices from overvoltages. So my question is, what's better:a) get a line interactive ups? not sure how well their filters work, if at all.b) build a diy online ups with all the protection / filters?c) build/get a filter, get some cheap standby/line ups, and make a small box with overvoltage and filters in it to protect the whole thing?d) something else entirely?bonus question (lel):speakers get the 50hz hum too. nothing terrible, but still audible when nothing is playing. Any solutions to that perhaps? Installing a 49-51 Hz filter after the psu part? I'd probably need to check what's going on cause i had no ideas ripples can go past linear regulator chips. It's possible he didn't even put one inside even? Sigh

author: macboy
author_rank: Super Contributor
timestamp: March 10, 2015, 08:22:40 pm
content: If you get 50 Hz hum, this indicates poor grounding in the amp itself. You may be able to improve this, but getting it right can be tricky if you have no experience in such things (as evidenced by your friend not getting it right).

author: Benedict
author_rank: Regular Contributor
timestamp: March 10, 2015, 08:38:34 pm
content: Quote from: macboy on March 10, 2015, 08:22:40 pmWell, this will at least put me on the right track. Thx. Any ideas about the other question?

author: macboy
author_rank: Super Contributor
timestamp: March 10, 2015, 09:48:41 pm
content: Quote from: Benedict on March 10, 2015, 08:38:34 pmI would start with a snap on ferrite or two on the power cord and maybe even on the interconnects. Then i would move on to an appropriately sized filtered IEC socket. That means do not use a 15A socket if the amp will only draw 3A, since it won't filter as well as a 3A one. You could also add some capacitance across the line ... Use only X2 rated safety capacitors.

author: Benedict
author_rank: Regular Contributor
timestamp: March 10, 2015, 09:53:55 pm
content: Excellent. Thank you. Cheers. We need a beer smiley.

author: Zero999
author_rank: Super Contributor
timestamp: March 11, 2015, 09:44:17 am
content: We may be able to provide more advice if you post a schematic. Ask your friend or try reverse engineering it.Could it be a ground loop? What is connected to the inputs?Are you using properly screened cable for the input signals?Have you tried running it off a battery or bench top power supply?

author: Benedict
author_rank: Regular Contributor
timestamp: March 11, 2015, 12:57:17 pm
content: You're correct. I'll tinker around for now, but if it ends up being some silly ground loop issue, I'll get the schematic, pics, and post it here. Thx for the good will.
Homework Help - Page 1
Forum section: electronics / beginners

author: JOJOElectro29
author_rank: Contributor
timestamp: April 17, 2025, 12:59:23 pm
content: Hi I'm trying to solve a question involving finding the voltage across capacitors in a circuit under dc condition but I don't know how to solve it. I have attached my attempt. My textbook answers says that v1= 42 V & v2 = 48 V. The textbook is Fundamentals of Electric Circuits, 5th edition by Charles K. Alexander and Matthew N.O. Sadiku.

author: madires
author_rank: Super Contributor
timestamp: April 17, 2025, 01:34:22 pm
content: Under DC condition (caps charged) it's a voltage divider with three resistors and you need just to calculate the two voltages at the voltage divider. The voltages you've calculated look fine. I'd would say the textbook is wrong.

author: JOJOElectro29
author_rank: Contributor
timestamp: April 17, 2025, 01:48:22 pm
content: Alright Thanks.

author: AlexRG
author_rank: Regular Contributor
timestamp: April 17, 2025, 01:52:48 pm
content: Use Multisim to model the simplest tasks. A very useful program

author: SteveThackery
author_rank: Super Contributor
timestamp: April 17, 2025, 01:57:28 pm
content: Quote from: AlexRG on April 17, 2025, 01:52:48 pmI case you didn’t spot the smilie,don'tuse a simulator to solve the problem. Learn how to do it by hand, and thencheckyour results using Multisim.By the way, I got the same results you did using a slightly different method. You've done fine.
Honda Goldwing data bus. to lcd dash - Page 1
Forum section: electronics / beginners

author: sirromluap
author_rank: Newbie
timestamp: August 03, 2015, 04:14:08 am
content: Hello everyone, I have quite a pickle. I have a 1994 GL 1500 with a broken lcd panel. It is very common for them to fail and in the honda manual it only shows a single data line going from the radio to the display. I found out what chip is on the main controller board it is a hd44790 found a data sheet athttp://pdf1.alldatasheet.com/datasheet-pdf/view/129657/HITACHI/HD44790.htmlwhat a good lcd looks likehttp://www.shop.goldwingking.com/GL1500-133-GL1500-133.htmand what a bad lcd looks likehttp://goldwingdocs.com/forum/viewtopic.php?t=13632, I am hoping that some one might know what type of data that chip receives and if I could use an arduino of some sort to decode the data stream and display it on another type of lcd. Any input would be awesome. Thank you in advance.

author: amyk
author_rank: Super Contributor
timestamp: August 03, 2015, 11:59:16 am
content: You'll need to give us a pinout first, what type of display it is (fixed segment, graphic matrix, ...?) and whether there's a controller on the display itself too.

author: sirromluap
author_rank: Newbie
timestamp: August 03, 2015, 11:28:02 pm
content: The only pinout is the one I found in the link found in my first post. The display is a proprietary one. it has time, pressure, radio station, and a few other things that I don't know what they are.
Honeywell 500 Nixi Multimeter  - Page 1
Forum section: electronics / beginners

author: Fixy
author_rank: Newbie
timestamp: April 20, 2022, 07:09:49 pm
content: Hi AllMy first post here so also wanted to say Hello 👋Having a clear out of old test/calibration equipment and came across my old nixi tube multimeter. Its a beautiful well made instrument, almost brand new inside and you can't beat the glow of a good old fashioned tube glow.I wanted to ask what people's thoughts are on my old Nixi Tube multimeter and if it's worth holding onto? Or should I sell because I'm developing something of a hording problem.ThanksFixy

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: April 20, 2022, 10:31:02 pm
content: Anything Nixie is collected here in the US.I sold an HP Nixie counter years ago, after I fixed it. I regret the decision.

author: Cubdriver
author_rank: Unknown
timestamp: April 21, 2022, 06:31:44 am
content: A Digitest 500? Do you by any chance have a manual with schematic? I have one here in my repair queue, but have never been able to find a schematic. (And no, don't sell it!)-Pat

author: Fixy
author_rank: Newbie
timestamp: April 23, 2022, 09:16:53 am
content: Hi Pat,I do actually have a manual and some schematics, I'll track the PDFs down and post them today. Manual i found very helpful. Will keep it and get it cleaned/tested instead.

author: wizard69
author_rank: Super Contributor
timestamp: April 24, 2022, 11:18:40 am
content: If you are the collecting type Nixie tube equipment is worth preservation. I have no idea what its value is today but it is history which by itself is reason to keep it out of the dumpster.

author: CaptDon
author_rank: Super Contributor
timestamp: April 26, 2022, 01:20:53 pm
content: I was just given a Keithley 160 Nixie Digital Multimeter. It has no A.C. scales but it has some insane D.C. scales like 'NanoAmps', a 1000 Megaohm range, and a 0-1 millivolt scale. It works perfect and looks nice with a red filter in front of the Nixies. Maybe put it up for sale at the Berea Hamfest in September? I don't really need it.
Honeywell Alarm Keypad for the hard of hearing. - Page 1
Forum section: electronics / beginners

author: rlpfeifer
author_rank: Newbie
timestamp: December 06, 2014, 03:57:16 am
content: I have a client that is hard of hearing and I came up with an idea to possibly help him. I am by no means an engineer, but have some schematics and other parts that I have drawn to see if this will work. At first I had oscillation problems by connecting the DC power from the First Alert FA148CP alarm panel. I can not run additional cable so I have to share the 22/4 conductor cable at the keypads and The data Green/Yellow (Data In /Data Out) have share the same common ground so the panel can talk to the keypad. So I added a separate power supply for the keypads which still share the common ground. I built a prototype and it seems to work fairly well, but again I am not an engineer and don't know how long this circuit should work and if it is missing anything that I can't see. I had someone try to install it in a test scenario and he blew up a keypad and one of the amplifiers. The remaining amps were returned and have them set up on my work bench but can't see any troubles.Any feed back would be greatly appreciated.Thanks - Robert (USA)

author: pickle9000
author_rank: Super Contributor
timestamp: December 06, 2014, 04:47:18 am
content: A simple board of ebay will get you started. Here's one.http://www.ebay.ca/itm/PAM8403-Audio-Stereo-Amplifier-Board-Volume-Control-Class-D-Kit-Module-2-3W-/281488956400?pt=US_Amplifier_Parts_Components&hash=item418a0c9bf0

author: rlpfeifer
author_rank: Newbie
timestamp: December 06, 2014, 05:42:31 am
content: Quote from: evb149 on December 06, 2014, 05:08:38 amQuote from: evb149 on December 06, 2014, 05:08:38 am
Hong Kong Trip (Need advice) - Page 1
Forum section: electronics / beginners

author: ronniegogs
author_rank: Contributor
timestamp: June 25, 2014, 03:09:56 am
content: I am going to Hong Kong tomorrow for a week of vacation with family. Need advice on shops to visit and places to check out to buy some new gear for my small novice lab.Currently I am planning to visit these shops and other Apliu street shops.WELCG/F & 1/F, Ming Chu Building,201, Apliu Street, Sham Shui Po, Kowloon, Hong KongmasterICAddress: 7/F, New Trend Center, 704 Prince Edward Road East,San Po Kong, Kowloon, Hong KongAny other recommended shops in Hong Kong.Planning to check oscilloscopes, signal generators, DC power supply and multimeter in these shops. Will buy only if the price is so so attractive that it makes sense carrying it back with me to Singapore rather than have it shipped home directly.PS : no plans to visit Shenzhen as I will be with my family and this is only a Hong Kong Trip
Hooked audio amplifier to my scope and amp died - Page 1
Forum section: electronics / beginners

author: ghinckley68
author_rank: Contributor
timestamp: February 02, 2020, 01:50:03 am
content: I got the ground to earth part. But how does one hook an amp up to a scope?

author: oPossum
author_rank: Super Contributor
timestamp: February 02, 2020, 02:21:21 am
content: It is a bridged (BTL) amp? That would require a differential probe or using two probes and the math feature of the scope.

author: ataradov
author_rank: Super Contributor
timestamp: February 02, 2020, 02:22:42 am
content: What exactly did you hook up? It is pretty easy to kill the scope with incorrect probing. But killing the device under test is much harder. So we'll need a detailed explanation of what you did.

author: IanB
author_rank: Super Contributor
timestamp: February 02, 2020, 02:27:23 am
content: I believe a few audio amplifiers used to have a problem being operated without a load, although I think modern designs have protection against this. If you connect an unprotected amplifier to the high impedance inputs of a scope then you are effectively operating the amp with no load, and this may damage it.Also, it may be that the outputs of a mains powered audio amplifier are not meant to be connected to mains ground, and this will happen if you connect to the ground terminal of a scope.

author: supperman
author_rank: Regular Contributor
timestamp: February 02, 2020, 02:30:14 am
content: Either you got the polarity wrong.. or the amp does not use a ground (i.e. both wires swing).Basically you shorted the amp out by connecting it to the ground terminal on the Scope. As mentioned above you needed to hook the one wire to one port and the other to another scope cannel. (or use a differential probe)

author: ghinckley68
author_rank: Contributor
timestamp: February 02, 2020, 02:53:27 am
content: yeap it was running in BTL

author: ghinckley68
author_rank: Contributor
timestamp: February 02, 2020, 02:55:28 am
content: I have 50watt test load. those Al block not inductive loads

author: ghinckley68
author_rank: Contributor
timestamp: February 02, 2020, 02:57:01 am
content: So hook one probe to the negative and one to the positive? a

author: supperman
author_rank: Regular Contributor
timestamp: February 02, 2020, 05:00:30 pm
content: Quote from: ghinckley68 on February 02, 2020, 02:57:01 amyes, and you can see if there is a ground (or use the case) for the ground on both.Then go to the math function to combine them into one signal if you want to actual values.. or just know what you are looking at when you see the two waves.. since they should just be mirrored / opposite.

author: ghinckley68
author_rank: Contributor
timestamp: February 02, 2020, 05:22:12 pm
content: thanks i have a few throw aways to practice with
Hooking up a TO82 Opamp - Page 1
Forum section: electronics / beginners

author: Andrei
author_rank: Contributor
timestamp: April 13, 2015, 12:18:30 am
content: Hi,I am trying to hook up a TL082 opamp as a simple non inverting amplifier for the first time. The datasheet for the part is here:http://pdf1.alldatasheet.com/datasheet-pdf/view/173078/UTC/TL082.htmlWhat I am essentially trying to breadboard ishttp://en.wikipedia.org/wiki/File:Operational_amplifier_noninverting.svgFor the two resistors, I chose them both to be 10K for a 2x closed loop gain. The Vcc- and Vcc+ are -5V/5V respectively. The input signal is a sinusoidal waveform of 1Vpp at 1kHz. I expect a 2Vpp output, with some lag.However, when I flip the switch on on the power supply, the output of the opamp dips to -500mv and stays there with no change. If I dial up or down Vcc+ and Vcc- the output voltage decreases/increases respectivelyI checked ground to Vcc+ and it checks out at 5V and ground to Vcc- and it checks out to -5V. Vcc+ to Vcc- gives me about 600mV which seems odd?Any ideas would be appreciated, I am certain I am doing something incredibly stupid. I verified the input and the output on the scope.Thanks.

author: mushroom
author_rank: Regular Contributor
timestamp: April 13, 2015, 12:28:55 am
content: It could be oscillating...Here is an image of the output of an op amp (CA3130, single rail 0-5V supply, gain 1 buffer) without compensation capacitor :

author: Andrei
author_rank: Contributor
timestamp: April 13, 2015, 12:34:35 am
content: Hi mushroom,I pulled it up on the scope as well, the output is not oscilating, it is set at a very stable constant -400mV.

author: Andy Watson
author_rank: Super Contributor
timestamp: April 13, 2015, 01:11:37 am
content: Quote from: Andrei on April 13, 2015, 12:18:30 amMore than odd! I go as far as to say WrongEither you haven't made a common ground between your power supplies, or you have a short circuit through a diode or other silicon junction.Edit: Pictures, per chance ?

author: Andrei
author_rank: Contributor
timestamp: April 13, 2015, 02:02:47 am
content: Hey Andy,As it turns out it was a bad lead to Vcc+. Measuring the resistance across that wire lead, it's 0.3M Ohms :S, changing the lead results in expected behaviour. Quite the stupid problem ...Thanks for all the help!
hooking up breadboard oscillators to computer Line In safely without clipping? - Page 1
Forum section: electronics / beginners

author: dentaku
author_rank: Frequent Contributor
timestamp: March 15, 2013, 01:02:00 pm
content: I started messing with a 555 recently (very new to this) and I managed to get this circuit hooked up to the Line In on an old computer instead of just using an old salvaged 8ohm speaker like I did at first so I could see what it looked like with the s(M)exscope VSThttp://bram.smartelectronix.com/plugins.php?id=4and add effects to it. At first I ended up making a triangle wave (by accident) but later I dismantled it and made a regular square wave that could be pulse width modulated.There's lots of info and making oscillators and basic synths online but nobody shows how they hook them up the their computers to record the output.What's the best way to do this so that the output isn't too loud or noisy?I got it working well enough by turning down the gain on my line in all the way down to 1 but I'm assuming there's a better way?ALSO, I'm obviously working with DC here running from 4 AA batteries but audio signals look like AC to me. What should I know or what should I read so that I can understand how this works?I really would like to make a VCO with an opamp sometime like I've found in the LM324AN datasheet and hook it up to my old computer. Programming synths and making sounds is easy enough because I've been doing it for years, it's building sound making devices that's completely new to me.

author: SeanB
author_rank: Super Contributor
timestamp: March 15, 2013, 04:24:15 pm
content: Normally the line in has a maximum rating of 1V or so, and is almost always going to be AC coupled internally. You need to attenuate the voltage fed to it, using 2 resistors. A series resistor of 10kohms or so ( anything between 8 and 20k will work) and a resistor across the input of the sound card of around 2kohms ( again any value between 1 and 3k will do) to attenuate the input to something the sound card will be happy with.

author: dentaku
author_rank: Frequent Contributor
timestamp: March 15, 2013, 10:50:27 pm
content: Quote from: SeanB on March 15, 2013, 04:24:15 pmOK, a 2kohm resistor going to the tip or ring of the 3.5mm cable I'm using is easy enough. I've got a nice little 3.5mm jack I salvaged from something that plugs perfectly into a breadboard.But, what do you mean by "A series resistor of 10kohms or so"?I've been reading some more and it looks like somewhere between 0.5 and 1V is what most onboard line in jacks on generic PCs accept.
Hooking up two 24 VDC power supplies in parallel? - Page 1
Forum section: electronics / beginners

author: fncruz
author_rank: Newbie
timestamp: March 26, 2020, 01:26:18 pm
content: Hi,I have two 24 vdc power supplies that I want to power in parallel. I think all I need to do is connect the DC- from each one correct?I have a small PLC (powered by power supply 1) and some devices that need to be powered (y power supply 2). The devices have some Analog outputs that need to be connected to the PLC (as analog inputs) which is why I think I need to connect the DC- on both power supplies.Any comments would be appreciated.Thanks!

author: Zero999
author_rank: Super Contributor
timestamp: March 26, 2020, 04:23:19 pm
content: It's not recommended to connect two power supplies in parallel i.e. + to + and - to -, but that doesn't seem to be your intention. Are you talking about just connecting the - sides together? If so, then that's fine.If you're thinking about connecting both the + and - sides of each supply in parallel, then my advice is to consult the data sheet/manufacturer first. Failing that, the power supplies can be connected together with ORing diodes, which ensures no current can flow out of one of them and into the other. The downside is diodes drop a small voltage. Choose Schottky, rather than silicon diodes, for low voltage loss. An alternative to diodes is an ideal diode circuit, which uses a special IC and some MOSFETs to achieve a low voltage drop.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: March 26, 2020, 05:32:40 pm
content: Whether you can successfully connect two supplies in parallel depends on many things. If you don't understand all of them the simple answer is don't.The basic problem is that if the supplies don't output the identical voltage (think several decimal places) the higher voltage one will supply the majority (possibly all) of the load. It may even drive current into the lower voltage supply, with unknown consequences. There can also be impacts on the stability of the supplies. What will actually happen depends on the architecture of the supplies, their output impedances, stability margins, relative voltages and on how they are connected (sense leads, etc.) among other things.I would hate to guess the odds of hooking two random supplies in parallel and having it work. It might often work. But the failures can be spectacular and catastrophic.

author: schmitt trigger
author_rank: Super Contributor
timestamp: March 26, 2020, 05:53:26 pm
content: To what Catalina WOW mentions.You have to have a circuitry that balances out the voltage discrepancies, such that both supplies share current more or less equally.If your target is low cost and simplicity, I would do the following:-Choose a pair of identical brand/model supplies. If they have a voltage trim option, even better.-Trim the voltages as close as possible.-Use the two-diode approach suggested by Zero999, but use a dual schottky package, to ensure thermal tracking.-Use a ballast resistor on each output. The actual value you will have to calculate, to be at least twice the offset voltage at the maximum shared current.
Hooking up VFD to Bus Pirate - Page 1
Forum section: electronics / beginners

author: mentaldemise
author_rank: Regular Contributor
timestamp: March 31, 2015, 12:25:24 am
content: I received a M202SD08GR VFD and I'm trying to hook it up to the Bus Pirate. I have 5 wires coming into it, 2 of which are AC 6V that go through a rectifier and regulator. I'm trying to figure out how to hook the other three wires to the Bus Pirate. One of them in labeled RXD which I assume is Receive. I hooked this up toMISOMOSI on the Pirate. The other two were ground and +5 which I also hooked up the the Pirate. I've connected it in UART mode, set the Rate and parity as it says, but when I send anything to it like 0x14 to turn the cursor off, nothing happens.Any help would be great. Not even sure if what I'm trying to do is possible.

author: mentaldemise
author_rank: Regular Contributor
timestamp: March 31, 2015, 01:18:40 am
content: Okay, so I got it hooked up! I had to take +5 and GND from the display to the Bus Pirate and now I can send commands. I managed to not burn the BP out even! Now the issue is that despite following what they say to do in terms of Baud Rate and stop bits, I'm getting non-repeatable garbage on the screen. 0x14 is supposed to turn the cursor off, instead it places 2 characters. :/Would be nice if I was just doing something stupid.
hookup pins to program a PIC18F46K22 with Pickit 2? - Page 1
Forum section: electronics / beginners

author: fabien
author_rank: Newbie
timestamp: January 27, 2011, 04:24:27 pm
content: I am trying to program a PIC18F46K22 using the Pickit 2 but want to check the connection pins. I have used the PIC16F690 before but this newer chip is different. Is this correct:Pickit 2 pin 1 (MCLR) goes into PIC18F46K22 pin 1(MCLR/ VPP/RE3)Pickit 2 pin 2 (VDD) is powerPickit 2 pin 3 (GND) groundPickit 2 pin 4 (ICSPDAT) goes into PIC18F46K22 pin 4(RA2/AN2VREF-/ DACOUT)Pickit 2 pin 5 (ICSPCLK) goes into PIC18F46K22 pin 6(RA4/TOCKI)Pickit 2 pin 6 (TG1) goes into PIC18F46K22 pin 17 (RC2/AN14/CCP1//P1A)

author: oPossum
author_rank: Super Contributor
timestamp: January 27, 2011, 05:16:33 pm
content: 1 -> 1 MCLR2 -> 11, 32 Vdd3 -> 12, 31 Vss4 -> 40 RB7 PGD5 -> 39 RB6 PGC6 -> N/C

author: dimlow
author_rank: Frequent Contributor
timestamp: January 27, 2011, 05:54:58 pm
content: http://www.microchip.com/forums/tm.aspx?high=&m=552121&mpage=1#552340
Hope RF Module - HM-TRP 915 Hz, set to factory default - Page 1
Forum section: electronics / beginners

author: bshambaugh
author_rank: Newbie
timestamp: February 09, 2019, 02:04:58 am
content: I recently purchased a HM-TRP wireless transciever from Ebay. I am told that almost all modules purchased off Ebay have 3DR firmware, not the default factory firmware.https://www.ebay.com/itm/HM-TRP-Wireless-Transceiver-915Mhz-HopeRF-w-simple-UART-Program-Interface-/181750129594.How easy it is to revert back to the factory firmware? Where can I find the firmware?

author: tsman
author_rank: Frequent Contributor
timestamp: February 09, 2019, 02:50:14 am
content: AFAIK the closed source Hope RF firmware isn't available. If you want to reflash the Si1000 on the HM-TRP then you need to buy/borrow a SiLabs debug adapter. There is an open source firmware replacement on github somewhere.
Hoping someone can help please - Page 1
Forum section: electronics / beginners

author: nevets666
author_rank: Newbie
timestamp: November 18, 2017, 04:39:30 pm
content: Hi, i'm relatively new to working with electronics but have been watching the Dave's EEVBlog and Ben Heck's Youtube Channels for a few years which is what got me more in to electronics taking the next step up from just programming applications on computers.i've bought a few soldering kits and played with Raspberry Pi's and Arduino's and found i'm getting good with that so i thought i would try adapting on to other things.i've recently purchased a Blaupunkt BP-PDVD21-2 portable DVD player and i was hoping to be able to find a way to bypass the video signal for the DVD software and put in a Raspberry Pi but i'm struggling to find any information on the chips inside it.i was hoping if anyone else has worked on these or knows where to get the Datasheets for the 2 main chips which i believe control everything so that i can just bypass the video signal and replace it with the Raspberry Pi Signal.there is a Media Tek MT1389VDU QDSL which i believe controls everything (DVD/Decoding/ect) i was hoping to find a datasheet for this but i can only seem to find a datasheet for a MT1389 what is a 256 Pin Package but the one on this board is a 128 pin package.there is also another chip on the LCD Driver board which is its a EP116 1837G.And that connects to a screen with the model number B116XAN02.7I have attached pictures of the 2 Chip BelowThanks in advanced for any help that anyone can provideRegards
Hornady two Litre ultrasonic cleaner repairs Where do I start - Page 1
Forum section: electronics / beginners

author: inthedark
author_rank: Newbie
timestamp: December 08, 2020, 10:19:17 pm
content: Okay. the readers digest version of my dilemma. I bought the subject cleaner a couple of years ago along with the recommended solutions. The cleaner as been used les than eight hours. It has always been cleaned after use and properly stored away.I called Hornady to inquire where to send it for service work and the reply I received via Facebook was fast and of no use to me. Basically Hornady does not support its electronic products nor will advance the manufacturer name/address/phone for me to contact them directly. Nor is a service/trouble shooting manual available.So being that old crusty veteran former signal corps I carefully opened up the machine to see if there were any glaring faults that could be observed.There were none.Now here are the Two issues that I have, 1) the timer will not adjust from zero to the maximum time of 30 minutes. It defaults? to 5 minutes and the down button will allow you to reduce the time to 1 minute. No more/no less. The machine will run it's 1 minute in either mode of degas or clean and then shut off correctly. 2) The indicator lamp will not light to show that the heat is on.I would like some guidance as to where to test, what might I need to test(I have an electronic multimeter already) how to correctly test and lastly the most important thing of a good self study book(s) to get me on my way.Thank you for any help that you give.Chimo Ron

author: andy3055
author_rank: Super Contributor
timestamp: December 08, 2020, 10:58:02 pm
content: https://www.hornady.com/contact/

author: bob91343
author_rank: Super Contributor
timestamp: December 08, 2020, 11:39:07 pm
content: Looks like a microprocessor problem.

author: inthedark
author_rank: Newbie
timestamp: December 09, 2020, 08:19:04 pm
content: Quote from: andy3055 on December 08, 2020, 10:58:02 pmHey Andy, I have been down that road and No Joy! But, I have reengaged Hornady a second time asking for the name/contact for the company that manufactures this unit. All I can do now is wait and see. Thank you for the reply. Chimo Ron

author: inthedark
author_rank: Newbie
timestamp: December 09, 2020, 08:23:46 pm
content: Hello Bob,I have found one MP and I think that there may be two more on a second board. Would there be more than one microprocessor used in the machine?Chimo Ron
Hornet ORG1411 GPS not starting - Page 1
Forum section: electronics / beginners

author: JendrykaJ
author_rank: Newbie
timestamp: February 23, 2019, 11:08:32 am
content: I and few of my friends are designing a board for cansat. We decided to use Origin's Hornet ORG1411 as our GPS. We've assembled the board however GPS is not turning on.GPS with its power supply.Relevant part of the PCB.R27 resistor is there to work as a jumper to select between auto and manual startup of the module. Tests were conducted on both configurations. Wakeup never gets high and reset is always low. Sending startup pulses to ON_OFF in manual mode also does nothing. We also tested two separate devices, both had the same problem. Measured voltage on power rail is 1.81V with 2mV pk-pk of ripple. Thanks for your help in advance!

author: jackthomson41
author_rank: Regular Contributor
timestamp: February 23, 2019, 11:42:56 am
content: Quote from: JendrykaJ on February 23, 2019, 11:08:32 amWhy you are providing 1.8V? I have checked its breakout boards and they all are seem to be working on5V Power Supply.

author: JendrykaJ
author_rank: Newbie
timestamp: February 23, 2019, 12:02:28 pm
content: We are using only the chip with integrated antena. You've probably seen whole modules with power supply. Specification requires 1.8V:https://origingps.com/wp-content/uploads/2018/12/Nano-Hornet-ORG1411-Datasheet-Rev-4.1.pdf

author: JendrykaJ
author_rank: Newbie
timestamp: February 24, 2019, 10:28:57 am
content: I'm sorry. You were actually right.ORG1411 has two variants. One powered with 1.8V and one with 2.5-5V. I was sure that we had 1.8V version, but your answer made me look into the datasheet. Everything works now. Thank you very much!!

author: Lord of nothing
author_rank: Super Contributor
timestamp: February 24, 2019, 02:32:00 pm
content: Trust me sometimes that happened.
Hosiden HLM8302 display - Page 1
Forum section: electronics / beginners

author: WaveyDipole
author_rank: Frequent Contributor
timestamp: January 10, 2019, 12:43:28 pm
content: Does anyone have any information on this LCD display please?I couldn't find a datasheet and my internet searches so far have drawn a blank. I reviewed Dave's video on hacking a display where he was able to identify its inputs and drive it with an Arduino which provided was helpful ideas. I have identified some of the basics, for example GND and LED strip power supply pins and what looks like 12 bus pins. There are 3 other pins to identify. Once will be VCC, probably on pin1. The chip on the back is not marked except with the characters 7L2 which again draw a blank.There is no indication of what voltage it may require so I don't want to apply power to it other than perhaps testing the LEDs until I know a bit more.I believe it came out of some radio and I was hoping that I could make use of it for something.

author: WaveyDipole
author_rank: Frequent Contributor
timestamp: January 17, 2019, 04:13:44 pm
content: Well I guess it was a long shot. Giving it a bump just in case....
Hot air and Preheater jumping off point? - Page 1
Forum section: electronics / beginners

author: Szewczykm
author_rank: Regular Contributor
timestamp: January 11, 2013, 08:53:27 pm
content: I purchased a hot air station and a board pre-heater. When using my regular soldering iron, I set it at 600F and then go up or down as I might need to. Normally it stays there.I'm wondering what the same might be for the pre-heater and hot air station? Is there a general jumping off point you use?
Hot air guidance - Page 1
Forum section: electronics / beginners

author: jheatac
author_rank: Regular Contributor
timestamp: September 21, 2024, 03:18:53 pm
content: Hello.I am seeking a little guidance on soldering a 48 pin HTQFP chip back to a board. I have no experience with this. I have some experience with removal but not installation of something like this.I am using a ST-862D hot air station. For removal I had the 7mm angle tip, 750f, 30% air. It took me a minute to remove, but I didn't realize the underside was heatsinked to the board.I would assume I need to use hot air to reapply the chip.Here are my main questions. Any guidance is appreciated:1) Would my hot air settings be the same for installation?2) How do I apply solder? Do I apply solder to the pads with an iron and then hot air the chip into the solder? Do I need solder paste? (I don't currently have any). Do I hot air the chip to the board and then use an iron for the pins?3) In the failure process it blew out a trace. Pin 34 & 35 are tied together, I am just figuring on bridging the leads with solder and the jumping out to the end of the burnt pad and bridging them. Should this be acceptable? It is VCC for one channel of the audio amplifier.Thank you!