hybridfree/eevblog-posts huggingface dataset:
Anyone knows what theses chips might be? - Page 1
Forum section: electronics / beginners

author: ali6x944
author_rank: Frequent Contributor
timestamp: August 26, 2024, 07:28:31 am
content: found some chips with strange part numbers, tried googling them but didn't score any hits...for easy reference here are the part numbers/markings from top left to bottom right:B57 696U3170411C(m)(C) 1984[made by intel]-------------------B57732H 9307[made by Harris Semiconductor]-------------------B57851826350THnn9230 B[made by Philips]-------------------F314ARB57497[made by TI]-------------------L575A94A318[made by ST]-------------------F314BRB57545[made by TI]i think they are using some special part number for automotive or other specialized applications, i tried scanning the windowed chip as a rom chip in a TLS866CS and i got a reading so its probably a UV rom but i am not sure which size...

author: Gyro
author_rank: Super Contributor
timestamp: August 26, 2024, 08:48:54 am
content: All of the Bxxxx numbers are in-house part numbers for the automotive(?) company rather than actual part numbers. The other numbers are date and maybe batch code. Yes the first part is a UVEPROM, you may be able to narrow down which one on your TLS866CS, and knowing that it is an Intel one (but even if you know the size, you probably won't be able to identify the programming voltage (Vpp).If I had to guess, I would say that the Harris chip might be an analogue switch and the Philips part, and ADC or DAC, but that really is just a guess. The 8 pin ones could be anything - opamps, switching regulators or whatever.Having the parts still fitted to the PCB might have given more clues.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 26, 2024, 09:58:11 am
content: Would also add op-amp/comparator, discrete logic, etc. to the list. I have a few comparable Harris and Philips chips (with identifiable numbers) and I'm guessing you've seen others so they're very much standard packaging styles for the companies.A microscope on the EPROM could solve that one pretty quickly, but otherwise, yeah the pinout will very likely be industry standard, but exact timing and Vpp are a question mark. Timing could be characterized, and I suppose Vpp ramped up until it "sticks", but that's starting to be a lot of effort just to identify something.Tim

author: squadchannel
author_rank: Frequent Contributor
timestamp: August 26, 2024, 10:39:13 am
content: EPROM has 28 pins, so it would be between 64K-256K.can read the chip ID on the EPROM with the TL866.8 pins, can guess the role of the pin from the circuit. Unless it is something special, I think it is an op-amp or comparator.14 and 16 pins, I wonder. Logic IC?If you just showed me IC pics, well, I wouldn't understand.

author: jmelson
author_rank: Super Contributor
timestamp: August 26, 2024, 03:20:02 pm
content: Quote from: Gyro on August 26, 2024, 08:48:54 amA quick ohmmeter check might verify that nothing terrible will happen if you put the EPROM in a programmer and try to read it out. There is a chance there is a copyright notice in the code written into the program there. That would tell who this all was for.Jon
Anyone recognise the company logo on this chip I am trying to identify? [Solved. - Page 1
Forum section: electronics / beginners

author: Buk
author_rank: Contributor
timestamp: December 29, 2021, 01:13:07 pm
content: Solved: Found the logo on avery long list of logosand thenthe chip on the manufacturer's website.This is my best attempt at getting a picture of it:And drawing showing basic dimesions:The chip is part of a 7S BMS, and is possibly similar to something likethis.I really need to find a spec sheet for this exact device, but searches for the text on the chip: "10CB" & "N60G" have found nothing even vaguely right.I've also attempted to match the logo on the chip to a manufacterer without success.Can anyone suggest a new avenue of research?Thanks, Buk
Anyone seen a source for this connector? - Page 1
Forum section: electronics / beginners

author: rthorntn
author_rank: Frequent Contributor
timestamp: October 13, 2023, 06:38:26 am
content: Hi,Sorry for the bad photo, connector has 2 large pin sockets for power and 4 pins for who knows what, I want to make a custom power cable for a friend so it only needs the 2 larger sockets, reverse image search returned zero, so I'm a bit stuck, its from a Shimano fishing reel. Its a pretty standard sized DIN with a captive nut, the actual meat of the connector is ~13mm.Please help me identify this, no worries if it completely proprietary, if so, perhaps there's a suitable DIN that has those two power pins in the same location so that I can just remove the other pins?Thanks.Richard

author: Swake
author_rank: Frequent Contributor
timestamp: October 13, 2023, 12:47:56 pm
content: That is an aviation style connector or bulkhead connector. With 2 types of pins in the same connector this is most probably something exotic.

author: Swake
author_rank: Frequent Contributor
timestamp: October 13, 2023, 12:58:39 pm
content: They seem to be available somehow:https://www.ebay.com/itm/353959390508

author: Terry Bites
author_rank: Super Contributor
timestamp: October 14, 2023, 10:02:55 am
content: Take a dive into the Hirose catalog.Hi-ro-se.

author: tooki
author_rank: Super Contributor
timestamp: October 14, 2023, 10:16:32 am
content: Quote from: Terry Bites on October 14, 2023, 10:02:55 amDo you have a particular series in mind? I skimmed over the Hirose website yesterday, having had the same hunch as you, and came up dry.

author: Terry Bites
author_rank: Super Contributor
timestamp: October 14, 2023, 12:23:55 pm
content: I seached for 2+4 circular and found this. Close but no cigar I think.I've seen those leads on ALI for 8 bucks.https://www.aliexpress.us/item/3256805822711847.html?spm=a2g0o.productlist.main.7.56deAG7jAG7j0Z&algo_pvid=e23e66f1-31cf-4101-b412-2f1664fe8709&algo_exp_id=e23e66f1-31cf-4101-b412-2f1664fe8709-3&pdp_npi=4%40dis%21USD%2121.52%218.06%21%21%2121.52%21%21%4021038edc16972861416123226e744a%2112000035300505204%21sea%21US%210%21AB&curPageLogUid=Mg0KSTPPovx2
Anyone use CircuitMaker2000 ?  - Page 1
Forum section: electronics / beginners

author: lordvader88
author_rank: Frequent Contributor
timestamp: March 16, 2017, 01:01:36 pm
content: Its a freeware circuit simulator, its pretty easy to use. However its old and not very good it seems and anything to do with oscillating circuits. Maybe it just the simple ones I've tried to make, but they're all just examples from teaching electronics sites.Probably a bunch of other things it doesn't simulate well either. Somewhere I have an older copy of Multisim, time to dig it up and try it.

author: danadak
author_rank: Super Contributor
timestamp: March 16, 2017, 11:02:35 pm
content: I use it and other quite often. It seems simplest, sort of, but libraries out of date.I think you can import models, I swear I did it long ago, but not recently.Regards, Dana.

author: JRosario
author_rank: Contributor
timestamp: March 16, 2017, 11:19:05 pm
content: Quote from: danadak on March 16, 2017, 11:02:35 pmWhat is the other if you don't mind me asking?

author: danadak
author_rank: Super Contributor
timestamp: March 17, 2017, 11:53:23 am
content: LT Spice, Microcap, Tina TI.Regards, Dana.

author: lordvader88
author_rank: Frequent Contributor
timestamp: March 17, 2017, 02:29:09 pm
content: Nothing I've tried making oscillates. Once and a while this this while grape a few cycles of base current.
Anyone used breadboards with these pads ? - Page 1
Forum section: electronics / beginners

author: Back2Volts
author_rank: Unknown
timestamp: September 14, 2016, 01:20:18 am
content: They looked like would be better than plain rings. I was looking for square pads, and run into these.http://www.robotshop.com/en/100x75mm-protoboard-double-sided.htmlhttp://www.robotshop.com/en/flower-22-double-sided-protoboard.htmlI would like square pads at a reasonable cost, but, not sure why, they are hard to find. May be these are better.
Anyone used Helix Semiconductor products? - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: October 08, 2020, 06:40:50 am
content: HiHas anyone used these products:https://www.digikey.com/en/product-highlight/h/helix-semiconductors/efficient-ac-dc-and-dc-dc-power-solutions?Any experience ? Are they reliable?
Anyone used SLA5032? Does it work properly with Sigrok? - Page 1
Forum section: electronics / beginners

author: volvo
author_rank: Newbie
timestamp: January 04, 2023, 07:29:44 pm
content: HelloAnyone owns or have used SLA5032?https://sigrok.org/wiki/Sysclk_SLA5032Is it a decent option?I got curious how these saleae clone works, my question is just for education purpose. I mean, is there any change inside the hardware itself to emulate any specific proprietary communication? Or all they do to fool Saleae software is advertise their USB with ID of a Saleae device?Thanks
Anyone with a Vibe CBR12 car powered subwoofer. - Page 1
Forum section: electronics / beginners

author: qoole
author_rank: Contributor
timestamp: March 13, 2013, 05:58:27 pm
content: Hiya,I have recently been asked to repair a Vibe CBR 12 powered sub. Having traced the board out and found the problematic area (the SMPS PWM IC) I noticed something else.If anyone has one of these and is willing to pop the back cover off and take a photo of the main board for me I'd much appreciate it.On the board in front of me I have a slot marked 'R81' with a resistor silkscreen footprint but the actual component is a Ceramic 100nF cap.What I want to know is it a wrong component or a silkscreen mistake?Thanks,AlexEDIT: I have attached a photo of the cap in question. Please also notice the audio wankery (to use one of Dave's phrase) of 'Vibe' branded Electrolytics!

author: Jonny
author_rank: Regular Contributor
timestamp: March 31, 2013, 07:38:39 am
content: Would be curious to know but probably irrelevant. Trace the circuit and look at datasheet for IChttp://www.fairchildsemi.com/ds/KA/KA3525A.pdfand decide if it should be a cap or resistor. Either way, it used to work so is probably ok (i.e. slikscreen error)I've seen a few failed car amps and is usually FETs and associated drive transistors and resistors that get smoked along with them, doesn't usually take out the drive IC but I guess anything's possible if it went bang loud enough.

author: SeanB
author_rank: Super Contributor
timestamp: March 31, 2013, 11:58:24 am
content: Probably was a resistor to trim voltage a little in production, but was replaced by a capacitor ( who cares if the voltage it makes now is 5% different) as it had an oscillation problem and this was an easy way to reduce loop gain and calm it. Most likely you have a lot of crispy FETs and drivers, along with some burnt resistors, along with the failing "Vibe" OHL junk caps that caused the carnage by going high ESR. Replace them all, and the caps as well, and put a 6A diode across the input as a crowbar diode as well, it might have been reverse connected. Power up with a H1 lamp in series with the power ( or a 20A power supply) with both filaments in parallel, so that you do not fry anything too fast if there is another fault.Edit: Check that optoisolator D9 as well, I do not trust them at all. It looks like C14 has popped the bottom seal in any case, from the stain on the PCB.
Anyone with diptrace experience  - Page 1
Forum section: electronics / beginners

author: sairfan1
author_rank: Frequent Contributor
timestamp: February 28, 2025, 05:02:13 pm
content: I'm posting this question here because offical diptrace forum hardly answer to any question.i found it really hard, while drawing schematic when we connect a component pin to some network, or sometime when we Add new network. there are too many steps involved like right click on component pin > select connect to network > on network window > select network from dropdown (or on network window click add new network) > give name to new network > click okI tried to find (Add new network) action in short cut menu but its not available there.I wanted to know if there is some simpler approach for this. please refere to attache image.

author: BillyO
author_rank: Super Contributor
timestamp: February 28, 2025, 11:47:15 pm
content: I've been using diptrace for years. I usually draw in the nets unless there is a bus involved. To me anyway, it makes it far easier to follow the design rather than dissociated chips with net names at their pins.
Anything amazingly wrong with this card edge connector idea? - Page 1
Forum section: electronics / beginners

author: Mechanical Menace
author_rank: Super Contributor
timestamp: August 15, 2015, 06:38:34 pm
content: I'm thinking of just sandwiching one PCB with edge connector strips on both sides between two PCBs with edge connector strips on one side with a plastic frame around them.This is just for a toy project and not expected to last an amazing amount of insertion-removal cycles.

author: TheElectricChicken
author_rank: Frequent Contributor
timestamp: August 15, 2015, 06:45:55 pm
content: without the flexible parts then a piece of dirt will hold rigid connections apart. Thermal warping of the board may do the same thing.If you are looking for a cheap fix, maybe something like those rubber strips that are conductive on the edge of a LCD would slip into the sandwich. I would not expect they can carry much current though.

author: Andy Watson
author_rank: Super Contributor
timestamp: August 15, 2015, 06:46:21 pm
content: What happens if the PCBs and/or ABS is warped (as we look in to the page) ? I think you will have difficulty maintaining a reliable connection simultaneously across all the contacts.

author: Mechanical Menace
author_rank: Super Contributor
timestamp: August 17, 2015, 04:14:55 pm
content: Quote from: TheElectricChicken on August 15, 2015, 06:45:55 pmTrue, but it's for a prototype of a toy so doesn't need to last long. Would probably only have the "cartridge changed" 10-20 times in total too.QuoteIt's not the money. It's just that's something I can do now instead of digging through a list and waiting for delivery.Quote from: Andy Watson on August 15, 2015, 06:46:21 pmGrub screws in the ABS lol. but good point.Thanks.

author: Galaxyrise
author_rank: Frequent Contributor
timestamp: August 17, 2015, 04:41:31 pm
content: If you can't solder the pcbs together, then maybe use some conductive glue? (along with screws) I'd still worry that the glue wouldn't last even the short use you have in mind, but I'd think it has a better chance than relying on ABS to clamp it tight.
Anything which will turn off a device if there is faulty earthing? - Page 1
Forum section: electronics / beginners

author: novicefedora
author_rank: Contributor
timestamp: July 30, 2020, 04:24:55 am
content: Anything which will turn off a device if there is faulty earthing?Is there such a device?And what are alternatives to earthing?I think earthing the Faraday shield will be risky because anyone cut the earthing wire. Is there any alternative to earthing which I can attach to the faraday shield which will keep absorbing and keep moving the electronics. Maybe an LED and Capacitor setup?

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: July 30, 2020, 05:08:18 am
content: plenty of info herehttps://en.wikipedia.org/wiki/Earthing_system

author: novicefedora
author_rank: Contributor
timestamp: July 30, 2020, 05:15:16 am
content: Quote from: HackedFridgeMagnet on July 30, 2020, 05:08:18 amThere is no information on the link about a device which will turn off if there is faulty earthing. And there are no alternatives to earthing.

author: aneevuser
author_rank: Frequent Contributor
timestamp: July 30, 2020, 01:42:32 pm
content: Quote from: novicefedora on July 30, 2020, 04:24:55 amI'm not quite sure what you want, but try looking for what may be variously called an ELCB (earth leakage circuit breaker), RCCB (residual current circuit breaker) or RCD (residual current device), or similar.
AoE 2 edition emitter follower biasing question - Page 1
Forum section: electronics / beginners

author: todorp
author_rank: Regular Contributor
timestamp: December 31, 2019, 12:40:55 pm
content: Hi all, I was reading AoE 2e chapter on BJT transistors. When discussing the emitter follower configuration the authors state the following (p.71 - Follower with split supplies):"Because signals often are near ground it is convenient to use symetrical positive and negative supplies. This simplifies biasing and eliminates coupling capacitors.Warning: You must always provide a dc path for base bias current, even if it goes only to ground."Could somene please clarify the warning for me: why is this necessary?Thanks,Todor

author: Paul Rose
author_rank: Regular Contributor
timestamp: January 01, 2020, 03:16:52 am
content: In the attached schematic, C1 is a DC blocker, and R3 to ground establishes the DC voltage (zero in this case) that the AC voltage is centered around. This allows you to figure out the emitter voltage.If you don't have R3, what is the "center" voltage of your input waveform?

author: Paul Rose
author_rank: Regular Contributor
timestamp: January 01, 2020, 05:14:11 am
content: It might help to think of what would happen if you turned the amplitude of your AC source down to zero. It would be like removing the AC source and blocking capacitor. Then (unless you have R3) the base would be connected to nothing. No base current, so no emitter current. The output voltage would be the negative rail (due to the emitter resistor).You want to establish a stable DC system. Base current can flow from ground (0v) through R3, through the B-E junction to the negative rail (-15v).BTW: The R3 value I picked was too big given the emitter resistor. Use the design rules from the book to pick a better value.

author: todorp
author_rank: Regular Contributor
timestamp: January 02, 2020, 10:56:51 am
content: Ok, I get it. Thanks a lot for the clear explanation.Tod
AoE diode limiter - Page 1
Forum section: electronics / beginners

author: Blaffetuur
author_rank: Regular Contributor
timestamp: April 06, 2015, 12:15:17 pm
content: As many other people, I am reading The Art of Electronics.On page 37 I come across this:Why are those two diodes facing the same way ?

author: Blaffetuur
author_rank: Regular Contributor
timestamp: April 06, 2015, 12:17:44 pm
content: Is this correct ?

author: PA0PBZ
author_rank: Super Contributor
timestamp: April 06, 2015, 12:26:12 pm
content: Quote from: Blaffetuur on April 06, 2015, 12:17:44 pmNo, it's wrong. Expect to find some more errors...

author: ConKbot
author_rank: Super Contributor
timestamp: April 06, 2015, 12:32:23 pm
content: Nope not correct, obviously the voltage can swing negative there, without being clamped. They would be facing opposite ways (anti-parallel) to be implemented as a bipolar clamp. This is done a lot of times for protection of RF receivers, as their signal is usually pretty low. Even a nice hot signal coming in of 0dbm is ~320 mV Vp, and as long as the diode capacitance isnt too high, it doesnt cause too much in the way of problems.

author: SeanB
author_rank: Super Contributor
timestamp: April 06, 2015, 01:02:19 pm
content: Post the error in an email to the publisher. As they get them they will add it to the errata section on the website of the book. Quick, or you will lose out, they might pay for these.No book is entirely error free, even though it was initially proof read, went back to the author for a final proof, had galley copies sent out for final edit then finally went to bed with all the errors they found corrected.

author: daddylonglegs
author_rank: Contributor
timestamp: April 10, 2015, 09:13:53 am
content: From:http://artofelectronics.net/errata/page 37, Fig 1.78: the diodes should point in opposite directions, found by John LarkinThe website also has contact information for reporting other errors.

author: Blaffetuur
author_rank: Regular Contributor
timestamp: April 10, 2015, 09:28:05 am
content: Quote from: daddylonglegs on April 10, 2015, 09:13:53 amI sent an email, this is the reply:Thanks Blaffetuur, you are correct. But two others have already pointed out that error; the first one is listed on the errata page at our website. Keep looking, maybe you'll find a new one!Win
AoE solution to bjt exercise  - Page 1
Forum section: electronics / beginners

author: leblanc
author_rank: Regular Contributor
timestamp: August 02, 2015, 04:26:00 am
content: I'm trying to solve a problem from AoE 2nd edition. I don't have access to solutions. If someone has a link to a solution manual, that would also be awesome.The question is pretty open-ended. It just asks to describe how the circuit works (with regards to input bias current cancellation).This is my explanation, can anyone confirm or add to it?- This is a differential amplifier, with high gain (R1/2re, where re is determined by collector current with the relationship Ic*VT, where VT is ~25.3mV at ambient temperature).- Q3 and Q4 form a current mirror, keeping their collector (and emitter) currents the same.- The curent source makes the CMRR very high (since current sources have near-infinite output impedance).- the current source pulls an equal amount through Q1 (and Q2) and the corresponding transistors on the other side- Since collector current of Q1 and Q2 are approximately the same, and they're beta matched, they will also have the same base current.- But since Q3 provides all of Q2's base current, Q4 will need to provide that same current to Q1's base. So all the DC biasing for the differential amplifier comes from the "VE + 2V supply"- input impedance is high (Q4's collector looks like a current source with negligeable admittance, Q1's input impedance is 2re*(beta+1))- VE+2V rail is used because we want it to be as low as possible. If we used Vcc, Q2's emitter would sit at two diode drops under Vcc, which would severely limit our output swing.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 02, 2015, 04:29:21 pm
content: You've pretty much got itTim

author: leblanc
author_rank: Regular Contributor
timestamp: August 03, 2015, 02:01:42 am
content: Thanks Tim!

author: LvW
author_rank: Frequent Contributor
timestamp: August 03, 2015, 08:18:51 am
content: Quote from: leblanc on August 03, 2015, 02:01:42 amWait a minute......are you really satisfied?It is the purpose of the shown circuit to provide DC BIAS CANCELLATION.Where did you describe this function?(Just a small correction: re=VT/Ic)

author: leblanc
author_rank: Regular Contributor
timestamp: August 03, 2015, 12:17:39 pm
content: LvW, I explained the DC bias cancellation when I saidQuote from: leblanc on August 02, 2015, 04:26:00 amQuote from: LvW on August 03, 2015, 08:18:51 amOops! I've been doing re = Ic*(25Ohm/mA) instead of re = (25Ohm*mA)/Ic for weeks now, I probably would have kept on doing it for quite a while if you hadn't pointed that out. Thanks

author: LvW
author_rank: Frequent Contributor
timestamp: August 03, 2015, 01:41:32 pm
content: Quote from: leblanc on August 03, 2015, 12:17:39 pmIf you know how it works (purpose of the current mirror) - OK.In this case, you can forget my doubts (because you did use the wording "how the circuit works"
AP5100 buck weird behaviour - Page 1
Forum section: electronics / beginners

author: Al3X05
author_rank: Newbie
timestamp: August 18, 2024, 09:19:06 am
content: Hello all,First time postI need your expertise..I have made a buck converter using the AP5100WG-7 exactly as per the datasheet for 3v3https://www.diodes.com/assets/Datasheets/AP5100.pdf(page 2).The only changes to the design are the diode B230A-13-F in place of B230A and SM3521-3R3MT for the inductor.The input voltage is 12V. There is very little load in the order of 10mA. The output always measures 0.8V, EN measures 4.5V >1.2V for ON, BST measures 5.6V and finally FB measures 0.8V.I am not sure if there is something I am missing, can I use this as a light load buck to power a micro?

author: squadchannel
author_rank: Frequent Contributor
timestamp: August 18, 2024, 09:39:37 am
content: Why use switching at a light load of 10 mA?As you can see from the efficiency graph in the datasheet, switching are very inefficient at light loads. And they tend to be unstable.If it is only 10mA, use an LDO. Is there any reason why you can't use it?But I think there are other causes for the no output. As far as I can see, there is no problem, Board design, etc. could be considered.

author: Al3X05
author_rank: Newbie
timestamp: August 18, 2024, 10:02:49 am
content: I guess I could use an LDO, have in the past, but I think because of the difference in voltage it had to work pretty hard and was getting warm. So wanted to go a more efficient route and make the overall supply smaller as well.But it should still do the correct output voltage though, regardless of load (besides when current limited)?On that note, I have also removed all the load from the board and the output voltage is still unaffected.I have tried to keep the active loop small, there is a ground plane for return.

author: Chalcogenide
author_rank: Regular Contributor
timestamp: August 18, 2024, 11:54:53 am
content: If FB measures 0.8 V that means that the IC is working and regulating fine, but you have a shorted R203 or C203, or a very wrong value for R203 (maybe 49.9 ohms instead of 49.9k).

author: Al3X05
author_rank: Newbie
timestamp: August 18, 2024, 03:40:05 pm
content: Thanks! Will check it out! perhaps put a pot on it to make sure

author: Al3X05
author_rank: Newbie
timestamp: August 18, 2024, 04:12:43 pm
content: And you were quite right! R203 is indeed the wrong value
AP60-150 IC8 firmware - Page 1
Forum section: electronics / beginners

author: richardkb
author_rank: Newbie
timestamp: September 04, 2023, 03:59:16 pm
content: Hi AllI have searched the net and the forum for the said file.Does anyone have or know where to get said file.RegardsRich

author: liaifat85
author_rank: Regular Contributor
timestamp: September 05, 2023, 03:49:24 pm
content: I think you can contact the manufacturer. It is made by Farnell.
APC 1500 UPS sometime makes noise, is it something serious? - Page 1
Forum section: electronics / beginners

author: sairfan1
author_rank: Frequent Contributor
timestamp: December 21, 2022, 04:39:29 pm
content: My APC 1500 UPS sometime makes noise for a while, I want to know does it need some service, some part needs to replace OR its not safe to leave it running? I uploaded video at Youtube for referencehttps://youtu.be/KgtG6Dz1KVM

author: argentas
author_rank: Newbie
timestamp: December 22, 2022, 09:28:57 pm
content: Difficult to tell from the video, but could it be a noisy fan? I replaced the fan in my APC UPS recently because the bearings were on their way out and it was causing an intermittent vibration.But in relation to your original question - how often is 'sometimes'? and for how long is 'a while'?Does it make this noise when running from mains power, or only during a powercut whilst running from battery?These UPS tend to perform a self-test periodically - I think mine is configured to do this once per week, and it lasts around a minute. During that time it will be running from battery power, the fan will be running, and there will be noise from the inverter.

author: DrGeoff
author_rank: Frequent Contributor
timestamp: December 22, 2022, 09:31:19 pm
content: Are you sure that isn't the self-test?Most UPS self-test the battery loading at least once a week by switching to inverter supply for about 10 seconds and measuring the battery discharge rate. This is how they report failing batteries.

author: sairfan1
author_rank: Frequent Contributor
timestamp: January 23, 2023, 06:54:45 pm
content: Sorry I missed the conversation. its not a fan noise its something like sometime we get from transformers.
APC 8000KVA Battery modification - Page 1
Forum section: electronics / beginners

author: TheGenesis
author_rank: Contributor
timestamp: November 14, 2014, 12:28:47 am
content: Hi,i've just bought a SURT8000XLI UPS on ebay.The Unit internally takes 4 Strings of 96V (8x 12V 5Ah) AGM Batteries.On the back there 2 Anderson 150A Connectors for the first aditional battery Pack (4 Strings each).I'd like to reduce the number of batteries from 32 to 16 using 17Ah batts instead of 5Ah's.But I can't find any information, that clarifies if the batteries are connected by 2 x 192V (2 in series, both paralelled) or by 1 x 384 (all in series).The Unit starts only, if all 4 Strings are connected ... but this could be a failsave feature.Does anyone know the DC Voltage wich the UPS is using?Or is there a safety way to connect only 2 String to both inputs?Thanks in advanceTom

author: Riotpack
author_rank: Regular Contributor
timestamp: November 14, 2014, 02:43:18 am
content: http://www.powerfirm.com.au/uploads/55521/ufiles/APC_Tech_Spec_PDFs/UPS%20&%20Accessories/SURTXLI_Tech_Specs.pdfPage 17 - It looks like +/- 192V so they are all wired in series with a 0V centre taphttp://www.apcmedia.com/salestools/aste-6z8lsp/aste-6z8lsp_r3_en.pdfPage 6 - Explains connecting external packs and the requirement of 2x192v packs

author: TheGenesis
author_rank: Contributor
timestamp: November 14, 2014, 04:16:16 pm
content: Wow! Thanks!I've read the Tech-Specs so many times and never notice this Info.Is it possible to build some DC-to-DC Converters and use them in series to build the 384v supply voltage?I think of 8 x 12v-to-48v (66A-to-16A) ... while ignoring the charger ... is such a boost conversion possible and/or practical?
APC AP9617 Card not acquire IP address - Page 1
Forum section: electronics / beginners

author: Hammer8
author_rank: Newbie
timestamp: August 06, 2022, 02:21:44 am
content: Hi, I am trying to connect to my UPS using the web interface on a AP9617. The card has a solid green light on the right and a blinking yellow light on the left which, I think, means the card has acquired an IP address from my dhcp server.However, when I scan my network to find out what is the IP address, it does not show up. I have set my dhcp server to use option 43 to enable cookies with the string 01:04:31:41:50:43. I have also tried resetting the card by pushing the small hole with a pin for 20 seconds and also tried setting a static IP address using my dhcp server based on the MAC address of the card, but nothing seems to work. I cannot ping the card using the static IP address I set.Any ideas on what I can try next?Thank you!

author: JustMeHere
author_rank: Frequent Contributor
timestamp: August 06, 2022, 02:26:54 am
content: Wireshark. Look for the DHCP request broadcast. Also look for the ARP requests.

author: agehall
author_rank: Frequent Contributor
timestamp: August 07, 2022, 05:49:57 am
content: Use the arp command on your computer to assign an IP to the MAC-address of the APC NIC. Then connect to that IP and see what the card is actually doing. Or does the card have a serial interface? If so, connect to that and check the settings.
APC UPS Transformer humming - Page 1
Forum section: electronics / beginners

author: J.harris
author_rank: Newbie
timestamp: October 19, 2013, 05:00:04 am
content: I have a 1500VAC APC UPS that is about 6 years old. I acquired this unit because it makes an annoying loud humming sound as it warms up and the owner no longer wanted it. I determined the sound is coming from the transformer and silences with pressure being applied to it. The transformer originally didn't have bolts installed holding the plates? (not sure of the correct terminology) together, so I installed some and the noise is down considerably.The noise is very tolerable now, but cutting out the hum altogether would be wonderful. Does anyone have any advice on how to make this any better?

author: SeanB
author_rank: Super Contributor
timestamp: October 19, 2013, 05:30:54 am
content: A steel angle to apply force to the laminations held by the bolts will help more, with a thin sheet of bakelite between the angle and the laminates as well to reduce eddy currents as well. If you do not insulate the plate it will make a shorted turn and damage the transformer. Insulate the bolts from the angle though with fibre washers and a sleeve in the hole. A thin sheet of silicone rubber on the mounting plates to provide sound isolation will help as well, as it will provise extra sound damping.

author: geraldjhg
author_rank: Regular Contributor
timestamp: October 20, 2013, 12:00:21 am
content: and put it far awayor pot it in tar

author: Psi
author_rank: Super Contributor
timestamp: October 20, 2013, 12:07:01 am
content: A while back i had a UPS that started making a rather loud and strange humming sound when running on battery.It turned out to be 1 of the mosfets failing, the switching waveform wasn't right and that was causing the sound in the transformer.If the hum your hearing doesn't sound like general 50hz hum then it could be something similar.The hum i got really didn't sound good, so it was pretty obvious something wasn't right.The UPS still worked though, but i suspect it wouldnt have handled full load.It was under warranty so i didn't bother trying to fix it, just sent it back.
APPA 98IV multimeter and accessories from other manufacturers - Page 1
Forum section: electronics / beginners

author: Kirill V.
author_rank: Regular Contributor
timestamp: August 12, 2021, 11:08:09 am
content: Hi all,My multimeter is APPA 98IV and I want to buy some high-quality accessories but from other manufacturers.For example, I want to buy test leads. When I look at the leads specifications, I see the same thing:"4mm safety system".https://www.sks-kontakt.de/en/test-measurement/products/product?nr=9341741https://www.schuetzinger.de/files/msfk_a341_1.pdfIt seems that this guarantees complete interchangeability between accessories and DMM regardless of the brand or manufacturer, right?It's one thing when I look at pictures and drawings, and quite another thing is to find out the opinion of those who have already bought and used accessories not offered by the manufacturer of the multimeterThanks!

author: tooki
author_rank: Super Contributor
timestamp: August 12, 2021, 01:23:33 pm
content: There can be minor differences in the diameters of the shrouds, so it’s notguaranteedin the strict sense, but it’s highly unlikely you’ll run into trouble.The only places I’ve ever encountered safety bananas that don’t fit are a) on a super cheapie $5 multimeter whose gap for the shroud only went half as deep as the jack itself; and b) not on the meter side, but on accessories: I have a set of Fluke leads with interchangeable probes, clips, etc, and I have the same thing from Keysight. One set of accessories doesn’t like the other’s leads, it’s just a bit too snug.So if you already have safety banana accessories, then you’d wanna try a few plugs before making a big purchase. But if you’re only referring to the meter side, I wouldn’t worry whatsoever.I’ve heard that some early safety banana jacks on meters don’t fit all the modern safety plugs, but we are talking decades ago. Modern gear should be no trouble at all. (My oldest meter is a Keithley 197 that’s from the late 80s IIRC, and all my safety plugs fit into it perfectly, as it already used what I would call “modern” safety sockets.)

author: Kirill V.
author_rank: Regular Contributor
timestamp: August 12, 2021, 02:49:48 pm
content: Yeah, after all, there are no guarantees, I suspected this.Quote from: tooki on August 12, 2021, 01:23:33 pmI am a little upset, because I want to buy separately the leads and separately such accessories that you are talking about, and from different manufacturers. Because this way I can assemble a very inexpensive set for my needs. One company offers very expensive leads, but quite affordable probes, for example, and another company-on the contrary.I noticed that German manufacturers such as Hirschmann or Schuetzinger provide detailed drawings of all accessories with dimensions. I think, having this information, it is possible to determine quite accurately whether their accessories are combined with each other, right?
Apple Airport SMPS Cap Replacement - Page 1
Forum section: electronics / beginners

author: SgtRock
author_rank: Unknown
timestamp: September 24, 2011, 03:36:08 am
content: Greetings EEVBees:--My Apple router SMPS went TU today. I soldered its jack plug onto a linear wall wart I had in the junk box, so I am back in operation, beauty. The ASMPS has a 400V 56uF Cap. which has gone open (16 megohms), and is bulging, top and bottom. I have two questions. (1 When the cap went open, is it likely to have taken any other components with it. (2 Can I replace it with a junk box 400V 47uF Cap., which measures 42uF. If I have to order a Cap. for it, I will just throw it in a peanut butter jar and wait till I am placing a Digikey order for something I really need.“I do believe that it's the first time in history that fire has ever melted steel." Rosie O'DonnellBest RegardsClear Ether

author: amspire
author_rank: Super Contributor
timestamp: September 24, 2011, 03:48:17 am
content: There is a high likelyhood that Apple have chosen a low ESR (effective series resistance) capacitor, so replacing it with an unknown junk box capacitor is probably not the best idea.The ESR generates heat in the capacitor as it conducts the switching currents and mains ripple current. The higher the ESR, the more heat. The more heat the quicker the capacitor deteriorates, causing the ESR to go higher. An accelerating loop. So if you want a reliable fix, get the lowest ESR capacitor you can find.There is a good chance nothing else is damaged. Just check that the input rectifiers are not shorted or open circuit.Check the capacitor temperature - 85C or 105C is usually printed on the case. If Apple used a 105 deg C cap, make sure you replace it with a 105C cap.Richard.
Apple Bluetooth - Page 1
Forum section: electronics / beginners

author: hamdi.tn
author_rank: Frequent Contributor
timestamp: February 21, 2018, 10:12:42 am
content: Hi everyone,Quick question about Apple bluetooth co-processor that need to be integrated in any commercial hardware compatible with apple.i looked around and am kind of lost, does this co-processor concern BLE communication only Bluetooth 2.0 too.if my hardware will use only Bluetooth 2.0 profiles to communicate do i need this co-processor ?Thanks.

author: Wilksey
author_rank: Super Contributor
timestamp: February 21, 2018, 11:46:09 am
content: I believe that it only applies to BT Classic, and that WiFi and BTLE are not required to have this security processor.I have only done stuff for Android, but looking into iOS - just in case we needed to break into the Apple domain (thankfully not) - it seems LE is OK without the secondary processor.The only thing I didn't conclude on, if it makes a difference to you, is their MAC hopping in discovery, i.e. the MAC address changes whilst in discovery mode to stop tracking, I am not 100% sure what peripherals this applies to, but is present on the newer iOSes.

author: hamdi.tn
author_rank: Frequent Contributor
timestamp: February 22, 2018, 11:47:02 am
content: Thanks Wilksey,According to Homekit Accessory protocol documentation we have to add this coprocessor as well for BLE.Manufacturer for classic BT (Microchip or ST) indicate that it's required as well that's for sure.So apparently any hardware using Bluetooth to communicate with Apple stuff will require a co-processor.Hamdi

author: kripton2035
author_rank: Super Contributor
timestamp: February 22, 2018, 01:07:25 pm
content: seems that cypress bluetooth boards are ok with apple devices

author: Jeroen3
author_rank: Super Contributor
timestamp: February 22, 2018, 01:13:18 pm
content: https://developer.apple.com/support/homekit-accessory-protocol/If I understand this correctly, the it's solely anAuthenticationCoprocessor , which means it only does cryptographics for authenitication that your product isMFI.

author: Wilksey
author_rank: Super Contributor
timestamp: February 22, 2018, 01:41:39 pm
content: Are you sure you need the co-pro for LE?Everything I have seen states that BT Classic requires the MFI chip, but any LE profile does not.I have an NRF52 dev kit that works with Apple iPhones, and that doesn't have any extra chips.You can look here, not sure if it'll tell you anything useful:https://mfi.apple.com/MFiWeb/getFAQ.action#4-2It does state that a few BT classic protocols do not require the MFI auth processor, but most do, like the RFCOMM (BT Serial), but LE does not.I've only ever used that one chip with Apple, not owning anything Apple I can't really test, I believe Lairds bt600 LE modules also work with Apple OOTB.

author: hamdi.tn
author_rank: Frequent Contributor
timestamp: February 22, 2018, 04:10:05 pm
content: You can use BLE without adding the coprocessor, it work. but only in non-commercial application.https://developer.apple.com/support/homekit-accessory-protocol/
Application Notes Collection - Page 1
Forum section: electronics / beginners

author: hammy
author_rank: Unknown
timestamp: May 15, 2013, 01:44:15 pm
content: Hi!Is somewhere out there the possibility to download the Application Notes in a bundle? The TI or NS website is not very handy/comfortable.When all these PDF's are on my mac, I can easily search through the content with Spotlight. But to get all together and to keep them up to date is nearly impossible this way.Any hints?Hammy
Application using this Development kit - Page 1
Forum section: electronics / beginners

author: Freshman
author_rank: Regular Contributor
timestamp: December 05, 2024, 02:25:40 pm
content: I was handed over this SAME54 Xplained Pro development kit (https://www.microchip.com/en-us/development-tool/atsame54-xpro) to come up with some end application by my college senior.Since, this development kit is not like an Arduino or RPi kit, I was not able to find any application that would make use of it.I did search online but couldn't find. Can someone point to some links that would make use of this kit for an application or point out some idea that I can try?I apologize if this question is not be asked in this forum. Since, I couldn't find anything online, Please let me know or let me know the forum where this question would be more sensible.

author: Benta
author_rank: Super Contributor
timestamp: December 05, 2024, 10:11:27 pm
content: I have a feeling you've misunderstood your assignment...
Applications for 18.5v 4400mAh Lithium Ion Battery Packs? - Page 1
Forum section: electronics / beginners

author: Jeebiss
author_rank: Newbie
timestamp: March 28, 2014, 11:08:22 pm
content: Hey guys,I have been watching the blog for a really long time and finally made my way to the forums!I have an interesting offer on the table to acquire about 1000 or so 18.5v 4400 mAh Lithium Ion battery packs. My question to you guys is whether or not they are worth buying. My goal would be to resell them, but ideally in a way to benefit different maker and tinkerer communities (i.e. cheeeap). I just don't know if there would be any interest in these slightly obscure batteries. My first thought is RC applications.Just want to clarify, I am not trying to pitch the sale of batteries to you guys, I am just wondering if they are something that could be useful to people. I know 18.5v is rather non-standard, but there are step-down converters and regulators that could make clean 15v or even 12v outputs from them.

author: Psi
author_rank: Super Contributor
timestamp: March 28, 2014, 11:11:22 pm
content: They sound like they're from cordless drills. 18.5V would be common voltage for thatThe real question is are they any good. There are lots of shit batteries out there.It also depends on their physical size, they're more useful if they're flat rather than round cells.

author: Jeebiss
author_rank: Newbie
timestamp: March 30, 2014, 07:31:27 pm
content: Quote from: Psi on March 28, 2014, 11:11:22 pmI inquired, and apparently they were used in voting equipment of some sort. From the pictures I was given, they look very similar to this one on ebay.http://www.ebay.com/itm/18V-18-5V-21V-4400mAh-18650-Rechargeable-Lithium-ion-Battery-Pack-Power-Sources-/221157436987?pt=US_Rechargeable_Batteries&hash=item337e02ae3b

author: SeanB
author_rank: Super Contributor
timestamp: March 30, 2014, 07:42:26 pm
content: They will not be good for high currents, but you might be able to finally realise Dave's portable PSU using them, though you will not have the USB recharge capability at any rate other than extra slow. You could also use them for an external laptop battery extender, adding the charge circuitry to charge from the existing 19V brick. That would be a very useful device.
Applying Dc offset to an LFO - Page 1
Forum section: electronics / beginners

author: iampoor
author_rank: Frequent Contributor
timestamp: March 01, 2016, 05:03:24 am
content: HiI am currently working on a design with some Vactrols controlled by an LFO. The LFO I am using is PIC based and outputs a wave from .25hz to 12hz. The wave output is 1v peak-to-peak. I need to apply a 6.5v DC bias voltage to the LFO output to drive the Vactrols. The design is powered from a single +9v supply. I am thinking of using a DC coupled Noninverting opamp buffer biased at + 6.5v and DC coupling the output straight to the Vactrols.Is this a reasonable way to solve the problem, or are there other simple topologies that would work?? Or does anyone have any other suggestiuons or potential "traps"? I am a young player.
Applying heat shrink to LMR-400 cable - Page 1
Forum section: electronics / beginners

author: matthuszagh
author_rank: Frequent Contributor
timestamp: January 18, 2025, 02:27:25 am
content: How careful do I need to be applying heat shrink to LMR-400 cable? LMR-400 uses a foam PE and is not as heat-insensitive as PTFE.The official installation instructions for my connector (EZ-400-NMH-X:https://timesmicrowave.com/wp-content/uploads/2022/08/ez-400-nmh-x-installation-instructions.pdf) require heat-shrinking the boot and don't say anything about limiting temperature or time, so it must have some ability to withstand hotter temperatures. But I have heard people caution against soldering connectors to LMR cables.I'm also applying a heat shrink label to the cable for identification.Any thoughts here? Should I reduce my hot air gun temp? Should I be careful how long I expose hot air to the heat shrink?I wasn't particularly careful with the first cable, and now I'm wondering if I should have been. I will measure this on a VNA once I get the necessary adapters before proceeding with the other cables, so that should give me a pretty good idea of performance.

author: Vovk_Z
author_rank: Super Contributor
timestamp: January 18, 2025, 01:26:05 pm
content: I don't see a problem until you are going to fry a heat shrink. Just don't use 400 C deg.For example PTFE RG402 cable can be easily soldered typically without any problem. I have soldered RG402 to quite large flange N-type connectors at 320-330 C on T12-C6 tip. It took about 20-25 seconds to heat up this connector and make solder flow. The result was quite fine (I have measured it after).

author: matthuszagh
author_rank: Frequent Contributor
timestamp: January 18, 2025, 02:06:26 pm
content: It’s not PTFE I’m worried about though. The dielectric of LMR-400 is foam PE.

author: jpanhalt
author_rank: Super Contributor
timestamp: January 18, 2025, 03:08:21 pm
content: It has a maximum usable temperature of 185°F (85°C). The little time needed for regular polyolefin heat shrink is only a little above it and is probably OK; however, low-shrinkage heat versions that shrinks at 80°C are available:https://buyheatshrink.com/low-shrink-heat-shrink-tubing-2-1?srsltid=AfmBOooYjLiV9R5qRoUGHLgCEB4lIMqc2fM4eNGYPtnb3bi4ZIZPz1pG