hybridfree/eevblog-posts huggingface dataset:
USB-C Power bank Loopback Keep TS80 on - Page 1
Forum section: electronics / general

author: JosiahCochran
author_rank: Newbie
timestamp: May 21, 2020, 03:25:37 am
content: Hello,I recently purchased a TS80 USB-C soldering Iron and a USB-C battery pack so make it portable. I have noticed that if I let the Iron go into standby mode the battery immediately shuts off and sometimes even shuts off while I'm soldering. I'm assuming that at low current draw the battery assumes your device is fully charged and decides to cut current. I have read of some people plugging in a LED as a dummy load to fix this issue. my power bank has two charge ports so I was wondering if anyone more familiar with what the input and output circuitry typically looks like for one of these battery packs could tell me if there is any risk in plugging the USB-C output to the mini USB-C input for charging the pack to create a dummy load that is just circulating the power (of course with losses, but I'd like to know risks before I look at efficiency, basically I'd rather use the charging cable, which I'd normally have on me, than carry around a dummy load).Josiah

author: JosiahCochran
author_rank: Newbie
timestamp: May 25, 2020, 12:47:49 am
content: Ok, I tried it and it gave a low battery error so no that wont work (basically connected the charge and discharge rails so not a good idea). opened up the battery pack which was a pain because the battery was glued to the opposite side of the board and I broke a contact on the battery. Battery still worked when I touched the contacts together, tried soldering and it didn't work, contact must be made of aluminum. I also can no longer get the pack to light up by touching the contacts so I think trying to solder it ruined it. Anyway, all that was on the board was this componenthttp://www.southchip.com/Private/Files/6369707360764726641960589520.pdf, a debadged micro, and some fets and passives. I was originally thinking in opening it I could find a way to keep it from shutting off by moding the board, but I don't want to reverse engineer this circuit and it looks like this chip is only made to power one usb output, meaning there is only one current sense and so as long as I can dummy load the second port the chip should stay on I believe. Bought some cheap usb led's on amazon. I'll try it with the LED, the open one up to take out the LED and just put a reisotor. If it works I'll put amazon links so anyone else getting a TS80 knows at least one easy solution to the poweroff issue.Josiah
Tactile Power Button  - Page 1
Forum section: electronics / general

author: trungosu
author_rank: Contributor
timestamp: May 20, 2020, 09:55:53 pm
content: Hi,We are using this Push-button power switchhttps://www.adafruit.com/product/1400I know it's not the best for the power button but we put it on our PCB already.The problem now is with the membrane switch we use to connect to this instead of the push buttonhttps://encrypted-tbn1.gstatic.com/shopping?q=tbn:ANd9GcRNmPsr2f_CTOflObuuBWFaPOk_xCZz3ri6sBzrwkrR_dq-3GCK4zaDY2uoYRVe18YzglCyqU9yOeAml1lt1R6Mmc41GRbR6vFDWNBRAcsmzflc_UrgutxkYw&usqp=CAELook like it's really sensitive. Sometimes when I was moving the PCB, the board got power. Or maybe power off when it's on.I know we could change to a better button but is there any quick fix for this problem. We even removed the membrane switch and we still had the same problem but happened less.Is there only because of the membrane switch or anything could trigger the power button?
€ for a Homemade Solar Cell Installation? - Page 1
Forum section: electronics / general

author: Lord of nothing
author_rank: Super Contributor
timestamp: May 19, 2020, 06:14:31 pm
content: HiWe have a Garage (Red) next to our Neighbour (Green) and Cyan is our Roof.[ Attachment Invalid Or Does Not Exist ]Orange mean "good" Sunligt and Red mean "much more" Sunlight.My idea is to put Solar Cells on the Garage in some degree angle.I am quite optimistic because its marked Orange. One small downer the Light could only come from South and West because East is the Wall from our Neighbour. I read here some Solar Cell cost ~150€ who sound reasonable.What does a Inverter cost? Sorry for that stupid question is possible to use at the same time both Source Mains + Solar? School was so long ago...Thanks
buck feedback - should trigger what change? - Page 1
Forum section: electronics / general

author: mikeinfodoc
author_rank: Regular Contributor
timestamp: May 17, 2020, 12:12:05 pm
content: if I have a feedback network on a buck circuit (such as a voltage feedback)...Should/would it generally want to trigger a change in :Frequency? ...or...Duty Cycle?In other words, would it be better to adjust duty cycle? or frequency? (of pwm) in order to adjust output voltage?

author: David Hess
author_rank: Super Contributor
timestamp: May 18, 2020, 02:19:32 pm
content: Either can be used. Common switching regulators vary their duty cycle to control the output but constant off-time switching regulators like the old 78S40 instead effectively alter their frequency. Both methods of operation have their virtues.
Would BY500 diode work in buck? - Page 1
Forum section: electronics / general

author: mikeinfodoc
author_rank: Regular Contributor
timestamp: May 16, 2020, 11:47:40 pm
content: Would the by500 diode work in a 5 volt 3amp 100khz'ish buck circuit?I am especially curious if it would operate fast enough?

author: wraper
author_rank: Unknown
timestamp: May 16, 2020, 11:57:11 pm
content: It will work. But converter will have poor efficiency due to large forward voltage.

author: Circlotron
author_rank: Super Contributor
timestamp: May 17, 2020, 12:34:27 am
content: Forward voltage drop at 3A is about 1V. Much better to use a Schottky diode. Find one that has just enough reverse voltage rating, lower reverse voltage rating generally means lower forward voltage drop.
EV charge cable: Avoid the tripping hazard - Page 1
Forum section: electronics / general

author: f4eru
author_rank: Super Contributor
timestamp: May 10, 2020, 04:32:03 pm
content: Hello everybody,I put online my fist kickstarter with this EV charge cable management thingiehttps://www.kickstarter.com/projects/criehl/chargehangerBe quick, the 20 first to order get the lower price of 50 Euros!

author: NiHaoMike
author_rank: Super Contributor
timestamp: May 13, 2020, 10:35:25 pm
content: Over $50 for a bent metal rod seems a bit excessive.

author: f4eru
author_rank: Super Contributor
timestamp: May 14, 2020, 12:03:21 pm
content: Yes, it's a bit expensive, but it's more than just a rod, it's 3 pieces of stainless steel in small series, and also the shipment is expensive due to the size.There's a "light" version now, made of Aluminium.

author: nctnico
author_rank: Super Contributor
timestamp: May 14, 2020, 04:03:16 pm
content: Looks OK but I'd modify the design so it can survive someone pulling the cable down. Probably mount the end on a spring instead of a fixed bracket. I wouldn't worry about price though; you'd probably pay $50 in a shop for something similar (unless from Ali-express). Is the design patented c.q. trade-marked yet?

author: NiHaoMike
author_rank: Super Contributor
timestamp: May 14, 2020, 10:15:26 pm
content: At $50, most users would expect a mechanism to pull the cord up when not in use. Easiest way to do that while keeping the same basic design would be to rotate the wall mount so that the rod swivels down. Then add an adjustable spring mechanism to counter the weight and an adjustable stop to limit how high it goes.

author: SolarMan
author_rank: Contributor
timestamp: May 15, 2020, 01:30:56 pm
content: I wasn't so impressed by the picture... But then I saw the videoVery clever! I wish you well with the project
Home AC outlets show surge protector fault - SOLVED - Page 1
Forum section: electronics / general

author: NY2KW
author_rank: Regular Contributor
timestamp: May 12, 2020, 06:55:07 pm
content: I live in an area with frequent lightning activities. At least once year either through a ground surge or nearby EMP i lose some electronic device in the house, eg cable box, remote lighting controller, TV, etc. I have Trip-Lite isotel surge protectors since and they have worked well. I rarely use my fax and found it wasn't getting a dial tone. The fax phone line is dedicated for fax and comes from cable provider, same as internet and TV and is grounded at home entry and I run the phone line to the trip-Lite and back to fax machine, I noticed the Trip-Lite fault led was on. I disconnected phone line, bypassed the surge protector and fax was fine However fault on surge still showing. I used 2 outlet wiring testers and the outlet is wired correctly. The Trip-Litr shows no fault on any other outlets in my home. The are 4 outlets on the problem line for one circuit breaker and all test normal with outlet tester but all show a surge fault on the Trip-Lite. I disconnected everything connected to these 4 outlet outlets and still see a surge fault light from all of these four outlets. Flipping circuit breaker did not help. The wiring is only 5 years old, we gutted and rewired the entire house by licensed electricians and it was inspected. I am 99% sure that there was no fault light before and this is something pretty new. With covid-19 and my age and risk factors I am reluctant to have anyone come into the house right now but I am concerned about a potential fire hazard. Any advice other than to shut off the circuit breaker for now?thanks in advancejerry

author: Ice-Tea
author_rank: Super Contributor
timestamp: May 12, 2020, 07:29:48 pm
content: According to the manual:QuoteBoth a phase reversal or gnd fault are fairly easiliy checked. Check resistance between a known-good gnd point and the one of the suspected outlet. Check voltage between corresponding phase-pins of good and bad outlets.And if you have any doubt on whether you can do that safely, if you're not confident: don't do anything, call an electrician.

author: NY2KW
author_rank: Regular Contributor
timestamp: May 12, 2020, 11:11:39 pm
content: thanks the Outlet tester middle green led bled through to the right led making it seem both were lit. Testing ground to a good ground revealed NO GROUND. I turned off the circuit breaker for now. I have worked with DC HV in radios but don't know my way around a circuit breaker panel but I assume the ground wire is daisy chained in series from the panel to the first outlet and then in series to each on the line. Since all 4 are missing ground, it's either the first one or down at the panel. I powered the breaker off and can check the first outlet as I recall the direction the wiring was taken from this room to the breaker panel. Maybe Ill get lucky.thanks
Short-Circuit Protection of Relay, i2t Rating - Page 1
Forum section: electronics / general

author: Alti
author_rank: Frequent Contributor
timestamp: May 10, 2020, 08:36:45 pm
content: Whenever I want to use a thyristor or triac, the short-circuit protection is one of the parameters considered and i2t for fusing is given in every triac datasheet. Including survivability charts for Itsm. I know how to deal with that. Also contactors have the peak short-circuit current specified (in kA).What about an electromagnetic relay?I have an application where there might be a short circuit in a mains powered circuit that includes a relay in a loop. I imagine a scenario where the relay is already closed, bad luck happens and some other componet fails. This causes the current to increase in microseconds to some peak value. I am using a 80A2s fuse, this guarantees limited peak current (lets say 500A peak) and limited i2t (lets say 200A2s) but I just wonder if this is adequate for a closed 16A relay.. I do not intend to interrupt the short circuit with a relay but with a fuse, once the component that failed is fixed and fuse replaced, I expect this relay to continue operation, with some predictable lifetime reduction.Any hints?Relay example:Schrack 41083wwwLinkto datasheet.
Flat 16mm offline AC-DC flyback 60W - Page 1
Forum section: electronics / general

author: Oleander
author_rank: Contributor
timestamp: May 11, 2020, 01:02:32 pm
content: Hello,I am about to design an off-line universal line AC-DC 60W flyback. The additional requirement is the height of the PCB < 16mm.The most problematic will be the main power transformer.I think about planar transformer or a core like a EFD30/15/9.Of course full primary to secondary isolation of 4kV is a must.Has anyone designed a successfull product like that ?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 11, 2020, 04:27:25 pm
content: Yes, someone has:https://www.digikey.com/product-detail/en/cosel-usa-inc/TUNS100F12/1776-1810-ND/704493321mm seems to be the lowest among assembly level components:https://www.digikey.com/product-detail/en/xp-power/VCT60US12/1470-2293-ND/4488672Yes, planar is a strategy that can be employed here. Among DC-DC isolator modules, 100W at 12 or 24V in a 1/4 or 1/8-brick size (and under specified height) is fairly common, and they often use planar elements.I think you will find that the major components (transformer and inductors) are not the limitation, but the filter capacitors and EMI filter will be the most challenging.Tim

author: Oleander
author_rank: Contributor
timestamp: May 11, 2020, 06:25:04 pm
content: I found an interesting flyback transformer : 760871333 from Wurth Elektronik. Seems to fit my goals.Filtering elements like 100nF caps and common mode toroidal inductor can be placed horizonally.Also, the bulk 150...220uF/400V cap can be made of smaller ones placed horizonally.Thanks for the remarks guys, I'll show you the design when it progresses.
Assitance on buck converter circuit. - Page 1
Forum section: electronics / general

author: mrpea
author_rank: Newbie
timestamp: April 27, 2020, 02:02:00 am
content: Hi there,I have used this circuit before but i have been told that it can be a bit noisy so can anyone assist me on the layout of my buck circuit and if there is any obvious changes i need to do before sending to the the PCB manufactures? I had spoken to an engineer recently and moved D14 closer to pin 2 on U17.here is the circuit diagramhttps://drive.google.com/open?id=1cssyZvg4D_lcM9n7d3kUdysevW86LTLWAll PCB Layershttps://drive.google.com/open?id=1KLnmObj2ylv6aF7WWZa5BWL3nb--1D-TTopPCB Layershttps://drive.google.com/open?id=14830g-REbtq5H1LVDhLs9Vebf9oWLeMEBottom PCB Layershttps://drive.google.com/open?id=1a0IBWqlrDboUfCkAFSWWAQe1iIVT7sjMthe buck converter is from E14https://au.element14.com/texas-instruments/lm2576sx-5-0-nopb/dc-dc-conv-buck-52khz-to-263-5/dp/3008145Thanks.

author: ahbushnell
author_rank: Frequent Contributor
timestamp: April 27, 2020, 04:56:55 pm
content: Quote from: mrpea on April 27, 2020, 02:02:00 amWhat are the trace widths on the 3 amp conductors? For 1 OZ copper and 20 C temperature rise looks like a 60 mil (1.5mm) trace width should work. That would be an outer conductor.

author: mrpea
author_rank: Newbie
timestamp: April 28, 2020, 02:15:28 am
content: Its a 50mil trace, and its going on a 2oz PCB.however I don't anticipate 3A being used on this line,, it will most likely never see over 1.2A but i have to have headroom in there for switching of my several relays.and its a 2 layer PCB.

author: ahbushnell
author_rank: Frequent Contributor
timestamp: April 28, 2020, 12:34:45 pm
content: Quote from: mrpea on April 28, 2020, 02:15:28 amSounds good. 50 mils with 2 oz copper gives 4.3 A with 20C rise. Sounds like you are in good shape. I use an ap by Saturn PCB design for this.

author: thinkfat
author_rank: Unknown
timestamp: April 28, 2020, 12:47:16 pm
content: No EMI reduction on the input?

author: mrpea
author_rank: Newbie
timestamp: April 29, 2020, 12:03:37 am
content: Quote from: thinkfat on April 28, 2020, 12:47:16 pmThanks ill throw in a filter on the input..
Cheap PWM board - what controller chip - Page 1
Forum section: electronics / general

author: jb79
author_rank: Contributor
timestamp: April 13, 2020, 11:02:16 am
content: Hi,I've got a cheap PWM board from Aliexpress with a 0-5V input (potentiometer or analog voltage) here that I want to use for a project. The problem is that the Chinese ripped off the label of the chip, so that it's impossible to find out what's inside the easy way.The 4 pins used for the main function are as follows: +5V: 1, Ground: 8 , Vin: 5 and Gate: 4.It seems pin 2, 3, 6 and 7 are not needed for the main functionality but might cover usefull other functions (softstart,...). They have no connections except to the unpopulated pinheader.Does anybody have an idea, what chip it is or could it be?

author: madires
author_rank: Super Contributor
timestamp: April 13, 2020, 12:05:02 pm
content: Most likely an inexpensive MCU which costs only a few cents. And the pin header is for programming the MCU.

author: jb79
author_rank: Contributor
timestamp: April 13, 2020, 03:24:10 pm
content: Hi again,the common used MCUs are out of question:Attiny: +5V and ground don't matchPIC: pin 4 is the high voltage programming pin, and input only too. That won't work because it's used for driving the gates on tis board.So that means no special functions ;-)

author: Siwastaja
author_rank: Super Contributor
timestamp: April 19, 2020, 03:39:36 pm
content: The world is full of commonly used MCUs besides PIC and AVR. Multiple Chinese brands costing a few cents each exist.
APC UPS modding - good idea? - Page 1
Forum section: electronics / general

author: src1989
author_rank: Contributor
timestamp: March 24, 2020, 11:46:20 pm
content: as i'm stuck in the house for the next while, i've thought i should have some backup power for my workbench. workbench is situated in my loft, so plenty ventilation and it's possible to build an enclosure in case of battery leakage...my needs would be a macbook charger (possibly a laptop charger as well), soldering iron, glue gun, LCD computer monitor, 2.1 audio amp, bench PSU and LED lighting, so maybe 3-400W total. In my mind i'd be using it from cold-start and not have it hooked up all the time.I haven't bought anything yet, but I was thinking of buying one of those APC UPSs off ebay, modding it to include either a 12v output where i can plug in an automotive USB charger (i know the 8Bit Guy did this) or a native USB regulator and increasing the battery capacity.i'm looking for reccommendations for batteries to replace or add into the UPS. the stock batteries (from my understanding) provide minutes of power, i'm looking for a few hours minimum.

author: cpuerror
author_rank: Regular Contributor
timestamp: April 18, 2020, 02:02:41 am
content: It's generally not a great idea. The APC UPSes have too small heat sinks because they are only meant to run for the short period the battery would last, they aren't meant for continuous heavy load. You may also overheat the integrated battery charger with bigger batteries. You can add a fan to blow over the heatsinks and transformer to try to mitigate this.There are power packs that use lithium batteries and will do what you want safely but they aren't cheap.
Spinx cables - Page 1
Forum section: electronics / general

author: Wimbledon013
author_rank: Newbie
timestamp: April 02, 2020, 01:15:52 pm
content: Hey,I found the next thing on the internet, Special cable that align the electrons in a power cable.By doing so it saves energy and makes that batteries can hold more power, charge faster and have a longer life span.https://spindeco.fi/https://www.spinxcables.com/What do you think? Is this possible and does it really works?I know that in the audio cable's playing a big role in the sound.

author: maukka
author_rank: Unknown
timestamp: April 02, 2020, 01:34:32 pm
content: Quote from: Wimbledon013 on April 02, 2020, 01:15:52 pmIt doesn't work, naturally. I actually tested some LED lights and audio amplifiers using those power cables and there's no difference in any metric (distortion, power, efficiency, power consumption, you name it).Sure, you can hear a difference, but that doesn't take a revolutionary technology...

author: Lord of nothing
author_rank: Super Contributor
timestamp: April 03, 2020, 04:29:50 pm
content: QuoteWhen I see or better Hear some People with crappy Earphones in there Ear play Music so loud that People from the other side of the Bus, Tram,... could her that I would say even the crappiest cable would fit there need at Home.

author: ahbushnell
author_rank: Frequent Contributor
timestamp: April 07, 2020, 11:39:52 pm
content: Quote from: Wimbledon013 on April 02, 2020, 01:15:52 pmI need to put my boots on for this one.

author: Gyro
author_rank: Super Contributor
timestamp: April 08, 2020, 07:30:33 pm
content: Quote from: Wimbledon013 on April 02, 2020, 01:15:52 pmWelcome to the forum.There is a specific 'Dodgy Technology' sub-forum specifically for posting about products of this type.You can either move it yourself or use the Report to Moderator link and ask them to move it for you.
dimensions and materials for LIPO battery caddy? - Page 1
Forum section: electronics / general

author: coppercone2
author_rank: Super Contributor
timestamp: April 19, 2020, 06:40:53 pm
content: What would a good lipo battery caddy look like, that allows for expansion and has minimum flammability?The idea being to make a battery bank inside of something like a VHS cassette shelf, so each battery is I guess glued with tape to one side of the 'shelf' and is given expansion room as it ages.What should the dimensions be? What dielectric materials are good? Glued ceramic blocks and plates?The enclosure would still be metal with this thing floating in the middle by some air gap.

author: Technomaniac
author_rank: Contributor
timestamp: April 22, 2020, 10:48:28 pm
content: I replaced three 12v SLA batteries in my battery bike with a bunch of LiPo cells that I bought on the bay. The "cells" are about three times the length of a D cell and slightly larger in diameter. There was plenty of spare room in the plastic battery cassette that fits the bike, so I used rubber strips to hold them firmly in place. The strips are glued to the box, and there should be no problems with expansion. The "cells" put out something like 3.3 volts, and have a nice metal thread screw on each end. I had to make up lots of link wires with lugs on the ends and because I don't trust crimping, everything was soldered, and because soldering the lugs swells and misshapes the plastic sleeves they come with (automotive lugs from Utilux) I removed the sleeves. This meant that there was a risk of shortcircuiting between lug and the outer cases of the cells which had heatshrunk sleeves. Jiggling along the edge of the bitumen which where I live is full of patches and irregularities, may have worn through the batteries sleeves, so I used a hole saw of the appropriate diameter to make Laminex washers to go between the lug and the end of the cells. I bought a charger which is purportedly designed for LiPo. This was a cheapie, because the expensive ones were above my budget by heaps. I have been using these cells for at least a year. I was led to believe that the Po versions of the batteries don't explode. The original sealed lead acid batteries were not giving me good service because I would run them down too low - if you're at the supermarket you need to get home! I believed that LiPo batteries were more tolerant of abuse in that regard. So far they haven't blown up or caught fire. The capacity of the cells is 10AH. The Lead acids were 12AH. But the choices when buying the LiPo were non-existent. Particularly the Po variant.
"Vario Tech" Power Generator - Relabel (Chineese) product? - Page 1
Forum section: electronics / general

author: Lord of nothing
author_rank: Super Contributor
timestamp: April 03, 2020, 04:01:57 pm
content: HiHere in Austria original "Vario Tech" Power Generator will put on a Auction soon.Well it seem the are coming from the "Vario Tech" them self who it seem get Bankrupted.Are the re labled Chinese one? Or any other Brand to get some kind of Sparparts?https://www.aurena.at/auktion/2716/Stromerzeuger_0Vario_0Tech?pagetype=s&page=1&pagesize=96&sorting=none&rel=30I could not find anything who is working right now.The "way back machine" dont show me anything promessing.I would say its better to stay away from there products?Thanks
260V 1A power supply. Stacked LED drivers? - Page 1
Forum section: electronics / general

author: judge
author_rank: Contributor
timestamp: March 27, 2020, 02:02:28 pm
content: I need a 260V/1A power supply for a project I would like to do. Voltage requirement isn’t exact. I was think of stacking 5 or 6 of thesehttps://www.trcelectronics.com/View/Mean-Well/LPV-60-48.shtmland would be interested in opinions (other than that could kill me. Yes I know). The datasheet has some statements that give me concerns. For example, they say the maximum number on a single 16A circuitbreaker should be 3. They say the inrush current is 60A. They also claim an 86% efficiency but quote 1.2A (AC) in at 115V giving 1.25A (DC) out at 48V. That seems more like around 50% efficiency.Also interested in other options. This would be in the US.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 28, 2020, 02:30:42 am
content: If isolation is not needed, take a PFC circuit and tweak down the output voltage.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 28, 2020, 04:58:44 am
content: If you want to redesign for 240V input, change to a buck PFC.

author: judge
author_rank: Contributor
timestamp: March 30, 2020, 03:51:44 am
content: I’ve never heard of these circuits, so I’ve googled them and I’m left wondering if you had a specific circuit in mind, since of themselves, they don’t seem to produce voltages that are any different from any other AC/DC converter.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 30, 2020, 12:41:17 pm
content: For testing purposes, an isolation transformer is always a good idea. For the hobbyist on a budget, an inverter powered from a surplus server PSU is a cheap way to make one.

author: judge
author_rank: Contributor
timestamp: March 30, 2020, 03:54:06 pm
content: Thanks guys, I’ll certainly stick with the stacked PSUs, but I am now intrigued about what I am missing as regards the comment re. PFC circuits. Any pointers would be interesting.
campstove-2 generates electricity from wood ? - Page 1
Forum section: electronics / general

author: benyB
author_rank: Newbie
timestamp: March 25, 2020, 03:47:49 am
content: https://www.bioliteenergy.com/products/campstove-2does anyone know how this product is generating electricity from heat ?If it works well i'd like to DIY my own version!Or is it BS?the fire / lithium battery feels a bit dangerous?

author: TerminalJack505
author_rank: Super Contributor
timestamp: March 25, 2020, 04:02:33 am
content: A couple of years ago I ran into someone on the hiking trails that had a stove similar to this. I don't know if it was this specific brand or model.I not sure what technology it uses to generate power. He said that itdidwork but it didn't do a very good job of generating power and that it would take "forever" to charge a phone. I don't know if the technology has improved any since then or not.

author: oPossum
author_rank: Super Contributor
timestamp: March 25, 2020, 04:10:34 am
content: It can be done with a TEC (Peltier).https://en.wikipedia.org/wiki/Thermoelectric_coolingHere is a video showing a DIY system with an explanation of how it all works.

author: ahbushnell
author_rank: Frequent Contributor
timestamp: March 25, 2020, 03:14:08 pm
content: Quote from: benyB on March 25, 2020, 03:47:49 amThermoelectric generator.https://en.wikipedia.org/wiki/Thermoelectric_materials

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 25, 2020, 10:32:41 pm
content: It doesn't work very well.Maybe a stirling engine driving a generator would work better if the goal is to generate electricity from firewood.

author: james_s
author_rank: Super Contributor
timestamp: March 26, 2020, 01:04:07 am
content: Generating electricity with a thermopile and heat source has been around for a century or more, I remember seeing a kerosene lamp with thermocouples surrounding the flame, it wouldn't generate much but it's probably enough to do something marginally useful. The RTGs that power deep space probes use a thermopile heated by decaying plutonium and generate hundreds of watts.

author: langwadt
author_rank: Super Contributor
timestamp: March 26, 2020, 02:09:05 am
content: Quote from: james_s on March 26, 2020, 01:04:07 amI believe there is also some weather monitors powered by RTG in Siberia

author: David Hess
author_rank: Super Contributor
timestamp: March 26, 2020, 04:08:53 am
content: It is definitely feasible with a camping stove or lantern but power density is not particularly high. I have also seen add-ons for wood stoves that do this to directly make electricity for fans or whatever. Portable solar charging will be a better option unless you absolutely need to charge something at any time.

author: vk6zgo
author_rank: Super Contributor
timestamp: March 26, 2020, 05:16:52 am
content: Quote from: james_s on March 26, 2020, 01:04:07 amThe Soviets used the lamp with thermocouples to run domestic radio receivers in remote areas, back in the '50s.
Help recognizing a device [SOLVED] - Page 1
Forum section: electronics / general

author: YoniK
author_rank: Newbie
timestamp: March 24, 2020, 12:15:14 am
content: Hello,I found a device in an electronics recycling bin, that I am almost sure is an Amp meter.It has the "CADENCE ultrashock" writing on it, has only 2 terminals for a beefy cables,display and 2 trimpots.I was unable to found a Datasheet, although found that the company sell Audio related devices.Does someone recognize/able to finding usage data for this one?Thanks,Yoni

author: oPossum
author_rank: Super Contributor
timestamp: March 24, 2020, 12:23:26 am
content: Looks like a fuse holder with a voltmeter. Probably intended for 12 volt automotive use.

author: YoniK
author_rank: Newbie
timestamp: March 24, 2020, 12:49:52 am
content: Hi, thanks oPossum for the reply.I am a mechanical engineering student, so please understand if I am way off:I also saw the fuse in the back, but I think a fuse only make sense if it is in series, and a Voltmeter need to be in parallel. Also cables of that gage intended to carry high loads, not just sense voltage.What do you think?

author: oPossum
author_rank: Super Contributor
timestamp: March 24, 2020, 01:17:17 am
content: In the last picture it looks like there is a small diameter wire that has been cut. I think that is the ground wire for the voltmeter. The two large diameter connections would be for the high current positive side.

author: Nusa
author_rank: Super Contributor
timestamp: March 24, 2020, 05:35:14 am
content: So hook up a 12V circuit with a 12V lamp for a load. See what you get.

author: YoniK
author_rank: Newbie
timestamp: March 24, 2020, 08:37:47 am
content: Thanks, I missed the ground wire completely.I supplied 12 to the device, and a load (24 lamp), draw 1.2.The device displayed the Voltage, beeped when I lowered the Voltage under 10, but didn't show the Amperage.I was able to tune the Voltage display with the right trimpot, the left one I assume tune the Amp.Maybe it will beep if more than a certain Amperage will flow through it, I have no way to test that (I have a small power supply).Again, thanks oPossum and Nusa!

author: engrguy42
author_rank: Frequent Contributor
timestamp: March 24, 2020, 08:46:21 am
content: Mr. Google tells me it's part of a Cadence Ultrashock car audio amplifier.

author: YoniK
author_rank: Newbie
timestamp: March 24, 2020, 08:53:02 am
content: Yes, I assumed so, but I was unable to find the exact one, and didn't knew what was the function of it in the system.
high voltage generator circuit - Page 1
Forum section: electronics / general

author: xzswq21
author_rank: Frequent Contributor
timestamp: March 25, 2020, 08:08:28 pm
content: DearI have a problem with the circuit, actually there is a flyback transformer in the circuit and I think I have problem with it! this circuit should generate a signal within 25Vpp and 29KHz.I have attached LTspice file. could you please help me to find the problem?as you see I have set the mutual coefficient on0.01(I have worked on it for two weeks) I really have critical problem with the High voltage transformer. (even I don't know the HV transformer) the HV transformer is similar to television HV transformer:(I have changed the Vcc to 13.2V, the first LTspice file had a 10V voltage source)Thanks
Position of filter inductor at DCDC module  input? - Page 1
Forum section: electronics / general

author: ocset
author_rank: Super Contributor
timestamp: March 22, 2020, 10:10:24 am
content: We are using the DCM3623T50M53C2T00 DCDC module, and have the following question....Page 23 of the “DCM design guide” states that the SRF of the input filter capacitor must be higher than the switching frequency of the DCM module.However, page 35 of the “DCM design guide” states that a small inductor is needed just downstream of the input filter capacitor. This would seem to work toward cancelling out the effect of having a high SRF input filter capacitor bank. After all, adding the aforementioned inductor, effectively reduces the SRF of the input capacitor bank as “seen” looking back from the DCM module’s input.Do you agree, that this inductor (from page 35) is a bad idea?“DCM design guide"..link now confirmed and now works..my apologieshttp://www.vicorpower.com/documents/design_guides/DG-DCM-Design-Guide-VICOR.pdfDCM3623T50M53C2T00 datasheethttp://www.vicorpower.com/documents/datasheets/DCM3623x50M53C2yzz_ds.pdf

author: Zero999
author_rank: Super Contributor
timestamp: March 22, 2020, 11:04:17 am
content: The link to the design guide doesn't work.Do the calculations. As long as the resonant frequency is still above the switching frequency it should be fine. Another thing which can be done is a resistor can be added either in series with the capacitor or parallel with the inductor, to dampen and resonance.

author: ocset
author_rank: Super Contributor
timestamp: March 22, 2020, 01:20:13 pm
content: Thanks, The small inductor is required to be 150nH…the external capacitance of the module is required to be 20uF…so the resonant frequency cannot be made above the switching frequency.Do you agree this inductor (from page 35) is a bad idea?

author: dmills
author_rank: Super Contributor
timestamp: March 22, 2020, 11:45:46 pm
content: Don't know why it is there, ask the FAE for an explanation!This sort of thing is why those people are employed, and any one that is actually worth their pay (Not all of them are any use), should be able to get you an answer.My guess, but it would only be a guess, is that there is energy up in the VHF that they are trying to keep inside the module, crap up in the tens - hundreds of MHz.
voltage spikes causing monitor issues? - Page 1
Forum section: electronics / general

author: Domino
author_rank: Newbie
timestamp: March 18, 2020, 09:48:34 am
content: hi,i have a new monitor with built in power unit.i noticed that my screen sometimes just goes black for a couple of seconds and this correlates with-the time a small water pump(engine) in my home is being activated-the time when i plug in the powerplug in my oscilloscope in same roomi was thinking about buying a simple over voltage protection but those seem to be only usefull for high voltages (lightning etc)or am i wrong im my assumption ?thanks,

author: madires
author_rank: Super Contributor
timestamp: March 18, 2020, 11:33:28 am
content: Possibly a voltage sag?

author: fcb
author_rank: Super Contributor
timestamp: March 18, 2020, 12:13:23 pm
content: We've got an AOC monitor here, that seems to be very particular about momentary sags, certainly more so than anything else in the lab.

author: Domino
author_rank: Newbie
timestamp: March 18, 2020, 03:53:11 pm
content: a drop...yea thats possible, but strangely this is the only device that is behaving like thisit seems my monitor vendor is not the only one that should have contracted Dave before bringing something outa power plug with filter circuit might probably solve this as a cheap fix but for now i'll just take it as its only 1 time a day

author: wraper
author_rank: Unknown
timestamp: March 18, 2020, 03:58:58 pm
content: Ensure that computer and monitor are powered from the same phase. You could power them from the same extension cord. Also video cable connecting computer and monitor might be bad. I've seen this happen with crappy Chinese cables which had shields inside the cable but they were not connected to connectors. And it's not a monitor issue is such, it's that video signal gets corrupted enough that monitor loses sync.
Find Capacitor Voltage value ? - Page 1
Forum section: electronics / general

author: Brent88
author_rank: Newbie
timestamp: February 08, 2020, 07:32:00 am
content: How do i find the Capacitor Voltage? they are lableless aluminum cans .. big name brand OEM unitsI really want to get more and build a CapacitorFarmwith them (I can get 28 Cells prefabbed on a circuit broad with overvoltage protection 4 parallel x 7 serial strings with a pretty plastic housing for 25$) would it be safe to assume they are 2.5 volt 150F?All i have to do is bypass a middle man circuit broad and throw it away( it's connection via 6 wires to another circuit broad it makes it easy to bypass it ) sensor wire and positive and negativeI could get a "premade" unit from XS power but 1050$ is way out of my budget for 1500F@12vthis would help in my hybrid as the Accessory Power Module is slow to react and the battery can't provide enough power sometimes as it has VERY LARGE electrical Loads when in autostop. and the voltage sags pretty quickly just turning on the headlights drops the voltage by 0.3volts on a 7.5@14.6v amp load (110w) (to 14.3) and you can see it drop further when more things are turned on... I'll be replacing the wires as well to bigger copper ones as it does not help it uses aluminum wireswhen i had my old battery I lost 12v power in the middle of driving it happened twice (bad battery) this could have caused an accident.. i would like to "fix this problem " by having a backup power module ... it should have had one in the first place

author: thedoc298
author_rank: Contributor
timestamp: March 17, 2020, 12:48:14 am
content: With no label, you could just measure the voltage of what they came out of and buy same voltage but 20% or more higher voltage on the replacement.
Renault Zoe EV Power Electronics Block teardown - Page 1
Forum section: electronics / general

author: Gyro
author_rank: Super Contributor
timestamp: February 27, 2020, 06:56:15 pm
content: Nice teardown. Both impressive and rather scary!Ok, the control stuff is fairly normal smt, but those bare die power modules are really scary - how on earth do they manage to reliably bond those multiple heavy bond wires to the thin surface metallisation on the dies?. They also seem to have relatively little surface area exposed to the coolant flow. All in all, quite a large number of coolant seals and internal connectors.I'm glad my Niro has a nice long warranty! - 32kW main motor, 8kW hybrid starter-generator for the engine, and Aircon compressor, all high voltage three phase brushless, and running off the same inverter module.

author: f4eru
author_rank: Super Contributor
timestamp: February 27, 2020, 08:39:03 pm
content: Yes, true.It's a first gen, so it could be simpler today.Those seals are hopefully silicone, so they don't harden over time.The pressure and temp in this coolant are not as extreme as in an ICE.Also, I find the choice of passive rectification bizarre for a 12V/80A PSU. Yeah, the design is quite old. Today, the DCDC at least would probably be made very differently, when we see the huge evolution of power devices

author: ahbushnell
author_rank: Frequent Contributor
timestamp: February 28, 2020, 02:14:11 am
content: Quote from: Gyro on February 27, 2020, 06:56:15 pmThe wire bonding on the IGBT's is standard construction that's been around a long time. The sticky stuff we call snot. It's a silicone compound.

author: Gyro
author_rank: Super Contributor
timestamp: February 28, 2020, 10:02:59 am
content: Quote from: ahbushnell on February 28, 2020, 02:14:11 amOh I know it is. It's just when you see it close up and think of the relative thicknesses of the bond wire and the surface metallisation at these current levels, and ponder why it doesn't just tear it. It's only sputtered on after all.Edit: Not to mention the relatively small contact patch.

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 28, 2020, 01:53:46 pm
content: The cohesive gel potting compound is commonly used in all sorts of power semiconductors.http://techno-fandom.org/~hobbit/cars/ginv/i2compon.htmlHow they get it in without disturbing the thin (control) bond wires I'm not sure, but I would have to guess maybe it's very runny (like honey?) before curing.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: March 13, 2020, 08:25:48 pm
content: Battery Charger Block ( BCB) :https://youtu.be/argrHjADn8g
DC-DC Step Down Converter - Page 1
Forum section: electronics / general

author: dellsam34
author_rank: Regular Contributor
timestamp: March 14, 2020, 03:17:50 am
content: Hello tinkerers I have an electric question, I have a 4S/3P 18650 Li-Ion battery pack to power up a light stand for testing purposes that requires 14V (14V mimics the automotive alternator voltage output, 30A max).The battery pack outputs 16.8V at full charge and about 13V when low, I'm in need of a high efficiency step down converter that gives me a steady 14V throughout the discharge process of the battery pack, High efficiency is important because I want the batteries to run for longer times before the recharge is required. Ebay is full of them but it's hard to know which is good and which is bad, high price is not always an indication of high quality.

author: bob91343
author_rank: Super Contributor
timestamp: March 14, 2020, 06:22:52 am
content: I think you need to buy one and test it, assuming you can return it. Otherwise, contact the sellers with your requirements.I suspect you won't get there from here, so I assume you could try out a few units and see how they perform.Otherwise, build your own.

author: Siwastaja
author_rank: Super Contributor
timestamp: March 14, 2020, 09:31:32 am
content: At such high discharge rates, you want to drive the cells down to say 2.8V or even lower to get full capacity out of them. So 4s minimum voltage is around 11V. You would need a converter that can both increase and decrease the voltage, such as SEPIC. While possible, this is far from optimal and reduces your choices of converter.If at all possible, consider using a 6s (or at very least 5s) pack for a voltage range 16 .. 25.2V. Then you can step it down to 14.0V with a simple buck converter (preferably, but not necessarily synchronous), which will be way simpler than a SEPIC (and better than inverting buck-boost).

author: dellsam34
author_rank: Regular Contributor
timestamp: March 17, 2020, 05:08:17 am
content: After reviewing the spec of the test stand it actually works anywhere from 13V to 14V and fused by 10A circuit breaker, so I have a voltage range of 16.8-13V, I want the pack to work within 30% from full charge to increase battery life and avoid overheating, my BMS doesn't have temp sensors.So I guess I will have to get few buck converters and experiment with then.

author: dellsam34
author_rank: Regular Contributor
timestamp: March 17, 2020, 04:54:37 pm
content: I bought this converter:https://www.ebay.com/itm/DC-DC-15A-Buck-Adjustable-4-32V-12V-to-1-2-32V-5V-Converter-Step-Down-Module-DT/152675836256?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649I'll see how it performs.

author: Siwastaja
author_rank: Super Contributor
timestamp: March 18, 2020, 12:58:34 pm
content: For high-duty usage (thousands of operating hours), you may want to replace the electrolytic capacitors with a good-brand low-ESR long life ones (for example, Panasonic FR or FM series), and/or add fan cooling. For intermittent usage with not too many operating hours, it doesn't matter much.
Capacitor type for pulse-discharge ignition - Page 1
Forum section: electronics / general

author: ricko_uk
author_rank: Super Contributor
timestamp: March 12, 2020, 10:57:31 am
content: Hi,what is the best type of capacitor for applications such as pulse discharge, arc discharge, capacitive ignition for engines etc?I only need 1 to 2.2uF and high voltage (~600Vdc) and obviously very low ESR and high current pulsing capabilities.Thank you

author: jpanhalt
author_rank: Super Contributor
timestamp: March 12, 2020, 11:02:25 am
content: Polyester (Mylar) is commonly used. Not sure "best" can be determined. What works is good enough. Also, for some applications, you may want to add low weight to the specifications.

author: Gyro
author_rank: Super Contributor
timestamp: March 12, 2020, 11:18:18 am
content: I once had an electronic ignition (kit) that worked very reliably with a Rifa Metalised Paper discharge capacitor for many years(then the moisture got to it and it caught fire!) so not recommended.Polypropylene Film is the best bet for a high dI/dt job like this. Epcos do some specifically for pulse discharge use. Avoid any that are 'X cap' for across the mains use because they tend to have thinner metalisation for easier self-healing.RS have a bunch of suitable parts...https://uk.rs-online.com/web/c/passive-components/capacitors/polypropylene-film-capacitors/?sra=p&applied-dimensions=4293395558,4292049497,4292049469,4292048644,4292049454,4292049050,4292048632P.S. Check the individual family datasheets.

author: vk6zgo
author_rank: Super Contributor
timestamp: March 12, 2020, 01:34:49 pm
content: Back in the day, when a lot of these were built, the capacitor type of choice was Polycarbonate.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 12, 2020, 08:55:47 pm
content: Yep, PP, since PC and PS are basically gone these days. Or PPS, but they're quite expensive especially for these kind of values. Don't recommend PE, has higher losses.Anything rated for pulse / surge / snubbing should do. For best results, calculate the peak current, or voltage rate, in your application, and compare to the datasheet figures. (What if they don't give ratings? Keep shopping!)EPCOS/TDK has a number of good lines, I forget which numbers offhand though. Illinois Capacitor has PPB and others, or most of their parts have dV/dt ratings anyway so you might use something cheaper. CDE has 935 and 940 series parts, and I think a bunch of others.Tim

author: ricko_uk
author_rank: Super Contributor
timestamp: March 13, 2020, 12:03:31 am
content: Thank you all!!