hybridfree/eevblog-posts huggingface dataset:
Dumpster Dive audio amplifier - Page 1
Forum section: electronics / projects

author: seanhaz
author_rank: Contributor
timestamp: November 19, 2013, 06:38:40 am
content: got this Marantz audio amplifier for free from a end of year student rubbish drop off.forgot to take a before picture of it but it was really dirtytook it apart and temporarily hooked up a mains cable to test run it, had to put a new mains cable in it because at the rubbish drop off site they chopped off all the appliance cables for safety reasons.first fault i found was no display on the LCD screen, turned out to be an easy fix which was just the incandescent back lights had blown, replaced them with LED'sThe next fault was the plastic volume buttons broken and by pressing either of the volume micro-switches causes the volume to increase which is probability how the volume button got broken lol.first i tested the continuity of the micro switches and they were both around 0.5M ohm when on, so luckily i had a few spare ones laying around and replaced them and now works perfect, just need to try find a new plastic volume button.next problem is the amplifier has a "two system" speaker output and the first "system" works fine, but when push the button to select output to both "systems" i get no output. have tested the switch and all the contacts are fine and cannot see anything obvious, so im a little bit stuck on this fault so any ideas are very helpful, or is it still a bit of a vague fault with the info given?so after that i decided next to strip the whole thing down and clean it out as it was pretty dirty and needed to repair a break in the plastic on the front panalpushed the break in the plastic back in are straightened it out and glued it back togetherreassembled the unit and gave it a test run and decided to add an IEC socket to the rear of the unit to replace the mains cable that was cut offand heres the finished piece(just need a new volume button)so all in all a great free score with little problems (well one im yet to solve so any help is welcomed)oh and the main thing, the sound quality is good

author: David_AVD
author_rank: Super Contributor
timestamp: November 19, 2013, 08:10:23 am
content: Did you have two pairs of speakers connected when you pressed the "both" switch?Some cheaper units simply put the speakers in series when A & B sets are selected together.This is so the amplifier won't have the paralleled impedance (too low) of the two speaker sets.

author: calexanian
author_rank: Super Contributor
timestamp: November 19, 2013, 06:19:15 pm
content: Good luck with that one.. They are not that great to begin with.

author: seanhaz
author_rank: Contributor
timestamp: November 20, 2013, 03:39:42 am
content: Quote from: David_AVD on November 19, 2013, 08:10:23 amthat was the case =) thank you
Duplex (one wire) audio with power - Page 1
Forum section: electronics / projects

author: MrWifiHifi
author_rank: Regular Contributor
timestamp: August 30, 2022, 06:36:47 pm
content: Hello. In the picture I attach the circuit diagram for duplex audio. Would it be possible to send not only audio but also power over one wire? I would also like to ask if it would be possible to connect several such units together (more units on one line than with a telephone exchange) and if so, how? Would it be necessary to separate the audio from the power at both ends or could all units be powered from one voltage source? Alternatively, if the audio was separated, how would the separation of the power and audio be handled by the circuit, and how would the audio be mixed?

author: moffy
author_rank: Super Contributor
timestamp: August 30, 2022, 11:48:46 pm
content: Telephones powered from the exchange handle bidirectional audio and power as well as the ring tone but over two wires, you always need the return. Perhaps if you studied some of those circuits they might answer some of your questions.

author: jonpaul
author_rank: Super Contributor
timestamp: August 31, 2022, 12:30:44 pm
content: search téléphone circuit, theory2 wire / 4 wire hybridsidetonephantom powerPOTShttps://en.m.wikipedia.org/wiki/Plain_old_telephone_servicebon chanceJon

author: MrWifiHifi
author_rank: Regular Contributor
timestamp: September 01, 2022, 08:35:53 pm
content: I know how SLIC works, but I don't know, how to wire up the "phone", so I can get power from and audio signal from and on the line. Is there any specific circuit that I can use?

author: Benta
author_rank: Super Contributor
timestamp: September 01, 2022, 10:43:11 pm
content: An idea would be to AC couple the "K3" signal and inject a constant current on the connector side of the coupling capacitor.The receiving end I'm not sure about.
Duplicator Remote control rolling code - Page 1
Forum section: electronics / projects

author: Aster
author_rank: Newbie
timestamp: December 21, 2017, 05:06:25 pm
content: I'm electronic product manufacturer in Iran.I want to know, Is there anyone who has done the duplicator remote control rolling code project?If anyone has done this, please email me.Remote.aster@gmail.com

author: Benta
author_rank: Super Contributor
timestamp: December 21, 2017, 05:11:20 pm
content: Please do NOT post in multiple forums! It's bad form and extremely annoying, and it will NOT give you better answers.
Durability of acrylic PCB coatings for water immersion - Page 1
Forum section: electronics / projects

author: e100
author_rank: Frequent Contributor
timestamp: October 17, 2012, 01:36:48 pm
content: Can anyone comment on the durability of acrylic PCB spray coatings when constantly in contact with water?I need to make a thin insulating layer on a capacitive electrode in a water level sensor. I've used two part epoxy before, but it's messy and takes hours between coats.The PCB lacquer aerosol I have is by Servisol.Mike

author: SeanB
author_rank: Super Contributor
timestamp: October 17, 2012, 03:54:06 pm
content: It is alcohol based and will dissolve slowly in water. for a faster setting go to a boating supply or car paint supplier and buy either gel clearcoat and catalyst ( and a shedload of acetone and very disposable unpainted "blonde" brushes) or automotive clearcoat and hardener ( shedload of appropriate thinners and same "blonde" brushes). Then you mix up small batches as needed and do the painting very quick before it gels or cures. Gelcoat can be applied up to 1mmthick and the auto clearcoat is best applied thin and used as per instructions, generally 20 mins between coats and an 8 hour cure. Both are waterproof al;most unconditionally and pretty UV proof as well.
Durable air quality sensor for high temperature - Page 1
Forum section: electronics / projects

author: Dhanushka
author_rank: Regular Contributor
timestamp: July 24, 2019, 05:57:06 am
content: Dear all,I need to measure a air quality (CO2, CO, etc.) inside a stove. Therefore, please tell me me a available sensor according to following specs.1. Durable to high temperature 5. (1000 Celsius)2. Pre-calibrated3. Good resolution4. This must have direct digital output with I2C/RS232 etc.Thanks

author: nfmax
author_rank: Super Contributor
timestamp: July 24, 2019, 07:20:05 am
content: Have a look at a 'flue gas analyser'. These work by using a pump to draw a hot gas sample through a cooling coil to a chemical sensor operating at a much lower temperature. Provided nothing in the gas sample condenses, the composition will be the same. Should be much cheaper.
Duralast 7816M Schematic - Page 1
Forum section: electronics / projects

author: warywolfen
author_rank: Newbie
timestamp: April 28, 2013, 01:14:53 am
content: I am setting up a photovoltaic power system, and due to various considerations, am using Duralast 7816M 1KW power inverters. They're sold by Autozone in the U.S. I want to connect the outputs of several inverters in parallel. They must all be in phase, of course. I'll do that by having them all run off a single master oscillator. But to make the mods, I need a schematic diagram. I've spent a lot of time searching the Internet to find one, but no luck. Does anyone know where to find a schematic?
Dust on solar pannel - Page 1
Forum section: electronics / projects

author: victorgozman
author_rank: Newbie
timestamp: February 06, 2016, 05:20:38 pm
content: I need design ideas on how to implement a circuit that would detect when a solar panel is dirty, and gives an output signal to show that the panel needs to be cleaned.

author: HAL-42b
author_rank: Frequent Contributor
timestamp: February 06, 2016, 05:29:59 pm
content: Put a light sensor under a glass aperture and place it near the solar cell. When the glass gets dirty the cell should also be dirty.

author: Seekonk
author_rank: Super Contributor
timestamp: February 06, 2016, 06:15:47 pm
content: Same as a turbidity meter. Shine a light through glass and see how much light comes through.

author: Kleinstein
author_rank: Super Contributor
timestamp: February 06, 2016, 06:19:28 pm
content: One could use a system similar rain sensors used in some cars: Use a piece of glass as a kind of light guide. Dirt (and rain) on the surface will cause loss and thus reduce the light getting to the sensor. One might also detect the scattered light instead - so this measurement is likely best done at night / sunset.An alternative way would be having two equal light sensors. One one just covered with glass like the solar cells and the other most of the time with an additional protection to keep it clean.

author: bookaboo
author_rank: Frequent Contributor
timestamp: February 06, 2016, 07:10:26 pm
content: Angle IR transmitter & receiver such that it reflects off the panel, less reflected energy may be proportional to a duller surface.Or a lux sensor with a self cleaning mechanism, compare output to lux (and temp coefficient).

author: victorgozman
author_rank: Newbie
timestamp: February 09, 2016, 07:07:43 am
content: with regard to your reply on my idea of designing a system (electronic circuit) to monitor when a solar panel is dusty. Please I need more explanation in any of the methods you suggested for me. Hoping to receive your reply soon, thanks in advance.

author: victorgozman
author_rank: Newbie
timestamp: February 09, 2016, 07:12:29 am
content: with regard to your reply my question on how to detect when a solar panel is dirty, could you please give me a detailed explanation on how I can achieve that. Hoping to receive your reply soon, thanks in advance.

author: dwpatter53
author_rank: Contributor
timestamp: March 02, 2016, 12:09:51 am
content: Can you measure the voltage from 1 panel or a small group of panels? You could compare that value to a small similar PV cell inside facing a window.When the difference gets large enough the outside PV panels need to be cleaned.This report says that only flat PV panels need to be cleaned.http://goodcleantech.pcmag.com/solar-energy/279277-google-studies-how-dirt-affects-solar-panel-efficiency

author: collingtech
author_rank: Contributor
timestamp: March 02, 2016, 02:07:48 am
content: nothing like do one cleaning each month, i doubt diference in voltage could be a really good addin for this , cmon guys stop being lazy and go clean the solar panels :0)
DUT vs EUT? - Page 1
Forum section: electronics / projects

author: Pack34
author_rank: Frequent Contributor
timestamp: October 20, 2020, 01:50:25 pm
content: From what I've seen, Device Under Test and Equipment Under Test seem to be interchangeable terms. Is this true? always true? and is there a situation where one is more appropriate than the other?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 20, 2020, 02:45:52 pm
content: Yes, more or less. I think of devices like individual components, whereas equipment is made from many devices. It's kind of... being specific as a courtesy, I'd say.I don't think there are many places where both terms are in use, and distinct? For example, EMC regs are only concerned about EUT, and component testing is only concerned about DUTs. Either one could use "DUT" alone, given a suitable definition elsewhere.Tim

author: Siwastaja
author_rank: Super Contributor
timestamp: October 20, 2020, 02:54:45 pm
content: Such abbreviations are meaningless and only confusing if you expect the reader to understand them automagically.It's not a name, like "USB", so you are using it just to save keystrokes and pages, in the original sense of using an abbreviation.You choose whichever, and do not forget todefineit the first time you use it, and if you are writing a long piece of documentation, better to remind the reader about such terms every now and then - for example write the full phrase each time the term is used for the first time in each new chapter.Adding a section listing all abbreviations used is typical and recommendable.The question to be asked is, are you calling the thing to be tested "device" or "equipment"?

author: BravoV
author_rank: Super Contributor
timestamp: October 20, 2020, 03:00:07 pm
content: Quote from: Siwastaja on October 20, 2020, 02:54:45 pm+1 , and its just weird if a single transistor under measurement is called "equipment".

author: LaryPant
author_rank: Contributor
timestamp: October 20, 2020, 04:10:33 pm
content: Just to throw in a little curveball: There is also UUT - Unit Under Test.Although UUT seems to be completely interchangeable with DUT, where as the abbreviation/term EUT would not be used for things like a piece of software, HDL module or components as was mentioned previously.Lary

author: spudboy488
author_rank: Regular Contributor
timestamp: October 21, 2020, 12:20:49 pm
content: Call it whatever you want as long as you describe/define what the acronym is in the test procedure.I design test equipment for a living. I've put together systems that test small PCBs all the way up to cellular base stations. I've always used UUT and included "UUT: Unit Under Test" in the definitions section of the test procedure.

author: greenpossum
author_rank: Frequent Contributor
timestamp: October 21, 2020, 12:44:51 pm
content: Just call it a WUT. Expands to WUT Under Test.
Duty cycle device for a switching power supply? - Page 1
Forum section: electronics / projects

author: Plasmateur
author_rank: Regular Contributor
timestamp: April 17, 2019, 10:35:45 pm
content: Hello. I'm wondering if such a device exists, and if it can be remotely controlled.I would have a 48V 50A power supply, where I need to put some kind of duty cycle on the DC.I'm guessing I could use some kind of fast remote switch, but I'm not sure if that switch would go on the AC side or DC side of the power supply.Is something like this commonly used?

author: pwlps
author_rank: Frequent Contributor
timestamp: April 18, 2019, 02:27:53 pm
content: Look for solid state relays, for example here:https://www.mouser.com/Electromechanical/Relays/Solid-State-Relays/Solid-State-Relays-Industrial-Mount/_/N-ay0tw/

author: jonroger
author_rank: Regular Contributor
timestamp: April 18, 2019, 03:57:49 pm
content: But be sure to use only SSRs designed for DC output.

author: james_s
author_rank: Super Contributor
timestamp: April 18, 2019, 11:27:29 pm
content: How often do you need it to switch?You could switch the output with a mosfet. If low side switching is adequate then a single N mosfet can do this really easily.

author: Plasmateur
author_rank: Regular Contributor
timestamp: April 20, 2019, 02:01:05 pm
content: Thanks everyone! I'll check into the suggested devices. A solid state switching relay sounds great as I can probably just remotely control it with a function generator.
Duty cycle of 38KHz IR carrier - Page 1
Forum section: electronics / projects

author: Peabody
author_rank: Super Contributor
timestamp: April 01, 2018, 07:11:57 pm
content: I'm working on a controller to automate several things for my Sharp TV, and have found pretty much all the specs for the IR remote controller to accomplish that. I just assumed the duty cyle of the 38KHz carrier should be 50%, but then I found a Sharp protocol description that says the recommended duty cycle is 25-33%.I also found a Vishay PDF that has the following:"The duty cycle of the carrier frequency can be between 50 % and 5 %. A remote control system using a Vishay IR receiver is more efficient regarding battery power consumption on the emitter side if the carrier duty cycle is low. This is shown in the following example:• Carrier duty cycle 50 %, peak current of emitter IF = 200 mA, the resulting transmission distance is 25 m• Carrier duty cycle 10 %, peak current of emitter IF = 800 mA, the resulting transmission distance is 29 m"So you increase the transmit power four-fold, but reduce the duty cycle by 80% and the average current by 20%, and you get 16% more distance. Not bad. I don't need to know for my project, but just wondered what the math is behind this. Presumably the current limit of the transmitting IR LED would limit the distance improvement at some point, and I wonder if having the duty cycle too short might effect the performance of the receiver. I have no information on the Vishay receivers other than this PDF:https://www.vishay.com/docs/80069/circuit.pdfSo what is this all about?

author: Benta
author_rank: Super Contributor
timestamp: April 01, 2018, 07:19:53 pm
content: Simple.Switching speed of the IRLED and IR-receiver is waaaay faster than 38 kHz, so only the emitter power plays a role. By reducing the duty cycle, you can increase the peak power without increasing power dissipation in the IRLED.
dvd/cd drive optical pickup head - Page 1
Forum section: electronics / projects

author: alireza7
author_rank: Regular Contributor
timestamp: October 28, 2017, 07:11:27 pm
content: hii want to detect motion of particles in order of micro meter and for this purpose the best thing that i know is using a dvd/cd drive optical pickup head as it detects cd/dvd pits and lands which they are under micro meter.i have got one but it seems sophisticated to work with. it have some signals to control laser diods, some signals to control distance of lens to the surface in order to focus the laser beam , and also the detector signals named A , B , C, D.in first step i want to shake some object in front of lens and get some signal from detectorshave any one worked with one of these? if yes can you give me some help about how to drive these signals ? also can you introduce me any useful content?

author: tooki
author_rank: Super Contributor
timestamp: October 30, 2017, 02:07:18 am
content: Take a look athttps://www.repairfaq.org/sam/cdfaq.htmIt’s a lot of info, and most of it you don’t need, but I wanna say that in reading this faq a few months ago, I came across at least some of the info you need.That said, bear in mind that CD/DVD/BD pickups don’t exactly measure reflectivity as such; they aren’t general purpose sensors. They work on complex principles highly tuned for the systems they’re designed for. (For example, the detectors work on the destructive interference caused by the pit depth, which is carefully controlled. That’s why a BD player has to have three different lasers, it can’t just use the blue laser for DVD or CD. And for CD/DVD-RW discs, the pickups detect the difference inpolarization!!)
DVI-D Shielded Backshell Kit - Page 1
Forum section: electronics / projects

author: bugrobotics
author_rank: Regular Contributor
timestamp: February 23, 2019, 05:24:48 pm
content: I'm looking for DVI-D shielded backshell kits to build my own cable assemblies. Shielding is hit and miss with the countless cables we have purchased (DVI-D to HDMI). These cables are going into aircraft for a product so EMI needs to be kept to a minimum. I've built up a few cables using D-Sub backshells (https://www.te.com/usa-en/product-1-2308341-6.html) and although they will fit the DVI-D connector and reduce the noise significantly the fit isn't perfect and I was hoping to find something designed for DVI with the correct screws and accommodating of the DVI connector sheet metal housing crimps.Not finding anything specific other than the discontinued MicroCoss system from Molex (https://www.molex.com/mx_upload/family/microcross_dvi/056dvi.pdf). Any help would be appreciated. Thanks.
DW01 (Chinese lithium battery protection IC) – any good? - Page 1
Forum section: electronics / projects

author: microbug
author_rank: Frequent Contributor
timestamp: October 19, 2014, 01:59:47 pm
content: I'm designing a custom bike light system powered by 18650 lithium batteries. There are four of them, wired 2S2P (2 in parallel connected in series to another two in parallel). The pack itself will be completely watertight (wrapped in electrical tape, or maybe self-amalgamating silicone tape) and the 3-pin connector which connects it to the LED driver board (custom) is IP68 rated. Since the risk of the cells shorting inside the pack is very low, I'm putting the protection circuit on the LED driver board.I had trouble finding a lithium battery protection IC on Farnell UK (I prefer to use Farnell as they do free one-day shipping), so a cursory search on Aliexpress turned up the DW01 (datasheet), by Fortune Semiconductors. It looks like a perfect fit, but I'm a little wary of buying ICs from Aliexpress, having heard stories about counterfeits. I found alistingfrom a seller with a very good feedback rating – should I buy it?Previously I have bought several things from Aliexpress, and found it cheaper and faster (in shipping) than eBay.

author: amyk
author_rank: Super Contributor
timestamp: October 19, 2014, 03:49:29 pm
content: DW01 is pretty common, I wouldn't be surprised if there are clones of it but I doubt they'd perform all that differently; IIRC the DW01 is itself a clone of a similar Seiko part.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: October 19, 2014, 06:28:56 pm
content: Seiko S-8244 series?
Dynalite System Builder - Page 1
Forum section: electronics / projects

author: perdrix
author_rank: Frequent Contributor
timestamp: March 21, 2024, 08:38:21 am
content: Any one out there have a copy the Philips (Signify) Dynalite System Builder software?Signify/Philips don't provide a download link for the hoi-polloi like us...ThanksDavid

author: perdrix
author_rank: Frequent Contributor
timestamp: August 18, 2024, 01:48:20 am
content: Bump ... Anyone have a copy? With documentation ideallyThanks

author: perdrix
author_rank: Frequent Contributor
timestamp: August 29, 2024, 08:00:23 am
content: Anyone?

author: Doctorandus_P
author_rank: Super Contributor
timestamp: September 01, 2024, 07:29:43 am
content: I did a short:https://html.duckduckgo.com/html?q=+Dynalite+System+BuilderApparently it's some kind of home automation software. There are a a bunch of open source solutions for this. Some of those have huge communities around them and include support for hardware from nearly any manufacturer.

author: perdrix
author_rank: Frequent Contributor
timestamp: September 01, 2024, 12:33:35 pm
content: Which may be great if you are starting from scratch, but if you have an existing Dynalite setup that you want to modify a bit ...David
Dynamic comparator latch  ?? - Page 1
Forum section: electronics / projects

author: Nhan95
author_rank: Contributor
timestamp: November 13, 2016, 04:50:24 pm
content: I'm trying to study and understand the operation of Dynamic Comparator with the structure in picture. In latch block, there is a mosfet with voltage Phi. What's it for ? Why do we have this latch circuit like that ?

author: TheoB
author_rank: Regular Contributor
timestamp: November 13, 2016, 05:16:07 pm
content: When phi is high, the nodes are shorted/made equal. This is the reset/setup stage. The circuit compares once phi goes low. It's thus not a transparent latch as there is no usable output when phi is high.

author: David Hess
author_rank: Super Contributor
timestamp: November 13, 2016, 06:10:15 pm
content: Phi is where the strobe or latch signal is applied and like TheoB says, this design does not allow continuous comparator operation.

author: Nhan95
author_rank: Contributor
timestamp: November 13, 2016, 06:16:13 pm
content: Quote from: David Hess on November 13, 2016, 06:10:15 pmCould you suggest me to improve this design ?

author: David Hess
author_rank: Super Contributor
timestamp: November 13, 2016, 08:36:53 pm
content: Quote from: Nhan95 on November 13, 2016, 06:16:13 pmImprove how and for what?Clocked comparators have advantages when the highest performance is required; they are less prone to oscillation and largely solve problems with metastability which would otherwise require a separate clocked logic stage anyway.
Dynamic contrast ratio regions on OLED screens - Page 1
Forum section: electronics / projects

author: Muny
author_rank: Contributor
timestamp: March 08, 2019, 07:39:44 pm
content: I wonder if sometime in the future (or now?) it would be feasible to measure the forward voltage drop across individual emitters (or just certain ones in a region) in an OLED screen? Would this voltage be affected by sunlight/ambient light? If so, could this ability be useful in dynamically changing the brightness of complex regions of emitters based on varying amounts of light striking them? For example, would this produce a better experience for users using an OLED screen which is partially illuminated by strong sunlight?

author: amy
author_rank: Newbie
timestamp: March 14, 2019, 03:00:18 am
content: When the positive pole of the power supply is connected to the positive pole of the diode, and the negative pole of the power supply is connected to the negative pole of the diode, the voltage at this time is positive voltage.When the positive pole of the power supply is connected to the negative pole of the diode, and the negative pole of the power supply is connected to the positive pole of the diode, the voltage at this time is the reverse voltage.Diodes are the basis of semiconductor devices, semiconductor diode devices.When the positive voltage is added at both ends of the PN junction (that is, the positive pole of the p-side power supply and the negative pole of the n-side power supply), the resistance of the PN junction is very low and the positive current is large (the PN junction is in the conduction state).Equivalent to at both ends with a positive voltage, it is in the conduction state, the resistance is very small, this resistance is called the forward resistance, only a few ohms, if there is a bulb and it in series, the bulb will give light;When the reverse voltage is added at both ends of the PN junction (that is, the negative pole of the power supply at the P side and the positive pole of the power supply at the N side), the PN junction presents high resistance and weak reverse current (the PN junction is in the cut-off state), which is the unidirectional conductivity of the PN junction.When the reverse voltage is applied at both ends, it is in the cut-off state, and the resistance is very large. This resistance is called the reverse resistance, which has several thousand ohms.
Dynamic Load Design for Fuel Cell Testing - Page 1
Forum section: electronics / projects

author: tech_builder
author_rank: Contributor
timestamp: January 25, 2021, 02:32:36 am
content: Hi,I’ve designed a dynamic load for testing and characterizing a small 5W fuel cell, and I would really appreciate any feedback you may have regarding my design. The fuel cell I have is from the Fuel Cell Storehttps://www.fuelcellstore.com/fuel-cell-stacks/5w-100w-fuel-cell-stacks/flex-stak-fuel-cell-assembledSome of my specifications for this project are:• Voltage range 0-5V• Current range 0-5A• Power 25W (it won’t get close to this, but that’s ok)• Bandwidth of about 10kHz• Dynamic load current <2A• Constant current to bias dynamic load• Constant voltage operation <5VSome protection circuitry has been added to the circuit.• Input protection for reverse polarity of load• Over voltage protection on control inputsIn a nutshell the design consists of a two MOSFETs in parallel, with one of them being a low bandwidth DC load (‘precision load’), and the other being a smaller but higher bandwidth dynamic load (`~10kHz). I haven’t seen this sort of design split before, so I am hoping that I can get some feedback on the pro’s and con’s it may have. I was hoping to be able to get more precision for the DC current for other tests, but still be able to get higher bandwidth for some EIS (Electrochemical Impedance Spectroscopy) testing.One of the reasons I am doing this project is because I am interested in the analysis presented in a journal article titled “Equivalent electric circuit modelling and performance analysis of a PEM fuel cell stack using impedance spectroscopy” by Dhirde, Aparna M. Et al. DOI: 10.1109/TEC.2010.2049267 (which for copyright reasons I can’t put here...)Essentially I would like to build a small dynamic load capable of making the EIS measurements (using an external EIS tool), as well as function in a more conventional manner to be able to test and characterize the fuel cell.I have attached the schematic and look forward to any feedback that you may have.Thanks
Dynamic load test of PSU - Page 1
Forum section: electronics / projects

author: MacIntoshCZ
author_rank: Regular Contributor
timestamp: February 08, 2023, 02:56:27 pm
content: Hello, why there is A_level and B_level in current step, I mean why its switching from 0,4A to 0,7A and not why from 0A to 0,7A? What is purpose of that?Here is electronic load where it can be seen.https://youtu.be/SA293akE2kE?t=299I dont have such device for testing so i am thinking about making some hobby alternative to it.

author: MacIntoshCZ
author_rank: Regular Contributor
timestamp: February 08, 2023, 06:31:49 pm
content: I think its not neccesary to have this switching from one level to another but its good to work with that. When load is turned off there are some switching cycles that could ramp up voltage, and when there is still some load (in this case 0,4A from video) it could recover much faster. If there will not any load only think that sink current will be voltage divider and leakage current.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 09, 2023, 12:48:39 am
content: An initial level biases the supply into a normal operating regime.You really don't have a load resistor in parallel with a step generator??Tim

author: MacIntoshCZ
author_rank: Regular Contributor
timestamp: February 09, 2023, 06:42:37 am
content: I can connect some light bulbs parralel. Normal resistors will be expensive since output is 200V and full load is at 5A.I am using heater from boiler.
Dynamic logic level shifting? - Page 1
Forum section: electronics / projects

author: 5321488
author_rank: Contributor
timestamp: March 16, 2017, 07:28:49 am
content: Hi,I have a digital input that could have an anywhere from 3.3 to 12v high level feeding into CMOS logic that will run at 12v. What is the best way to convert the levels, ideally something better than a bunch of different voltage LLCs and a range selector?Thanks!

author: Ian.M
author_rank: Super Contributor
timestamp: March 16, 2017, 07:36:28 am
content: How fast?Is there an external reference voltage for the logic '1' level available?

author: 5321488
author_rank: Contributor
timestamp: March 16, 2017, 07:56:07 am
content: Quote from: Ian.M on March 16, 2017, 07:36:28 amIt needs to be able to produce a pretty much no delay square wave at max. 1kHzQuote from: Ian.M on March 16, 2017, 07:36:28 amPotentially, although it could result in a range-like setting which I would like to avoid

author: Ian.M
author_rank: Super Contributor
timestamp: March 16, 2017, 08:12:51 am
content: I was thinking simple comparators, with the hysterisis feedback clamped to the (buffered) logic '1' reference voltage, so the hysterisis tracks with the reference voltage

author: 5321488
author_rank: Contributor
timestamp: March 16, 2017, 09:15:40 am
content: As long as the waveform is the same shape, length, time etc. as input on output, any delay doesn't matter. Any comparator should do?Quote from: evb149 on March 16, 2017, 08:07:38 amI kind of understand what you are saying but probably don't have the technical knowledge to properly implement it. Are you able to post a schematic? Something with comparators and hysteresis, or with a diode clamp would be good.I'm not sure about impedance. It probably isnt an issue.
Dyson DC16 battery replacement - Page 1
Forum section: electronics / projects

author: aurmer
author_rank: Regular Contributor
timestamp: June 19, 2016, 05:10:53 pm
content: I have had this DC16 for years. When I bought it, the battery life was disappointing. I understand that with this kind of power, no battery will last all that long. You can get more context reading product reviews on amazon.http://www.amazon.com/Dyson-DC16-Handheld-Vacuum-Cleaner/product-reviews/B000I5Q1IC----------That said, I am wanting to convert this device to wall power by purchasing (or building?) a power supply for it. My problem is figuring how much power I need. Here is what I know.The battery is rated at 21.6V.The battery measures around 24V when charged.The battery measures around 12-15V while the vacuum is running.When I hook up my lab power supply at 24V to run the vacuum, it rails out at 5A and the voltage drops to about 12V. While powered this way, the vacuum motor sounds like it is running at half power compared to the noise produced when running off the battery.Is there any way for me to anticipate my power needs? Other than buying an expensive 'high-power' variable power supply for testing?https://www.amazon.com/dp/B00KTJE3L4/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=13WJQDDHQBIXA&coliid=I1PIV4Z1HJ88PTBy the way, I have tentatively selected this power supply. Can anyone tell me why this might be a bad choice? I understand that the motor is an inductive load, but I am using Dyson's original motor driver circuit which I assume handles any issues (I hope?). Experienced advice is appreciated before I waste money/blow something up. =P

author: NiHaoMike
author_rank: Super Contributor
timestamp: June 19, 2016, 06:38:41 pm
content: Look into converting some surplus server PSUs. Cheaper and higher quality.http://www.tjinguytech.com/my-projects/diy-24v-47aYou can also use 6 R/C lipo cells and reuse the existing protection board.

author: Buriedcode
author_rank: Super Contributor
timestamp: June 19, 2016, 07:12:08 pm
content: At 21.6V thats 6 3.6V cells - often "lipo's" are 3.7. The motor won't care but any charging or protection circuit should be rated for the cells you use.As for the motor, I'm not sure if these use BLDC because their silly marketing spouts all sorts of crap about 'v6 digital motor', but I'm assuming it is. I guess if the current battery is working, then just measuring the current draw to get an idea of power requirements - I suspect its pretty hard on the batteries because then they can charge a lot for replacement battery packs.
e-field ball probe design - Page 1
Forum section: electronics / projects

author: sarepairman2
author_rank: Frequent Contributor
timestamp: July 18, 2015, 01:01:57 am
content: I want to make a easy e-field ball probe.page 10http://www.testequity.com/documents/pdf/anritsu/2000-1689-guide.pdf3.5 cm ball, but, should the termination on it be series or parallel?
E-Fuse signals referenced to RTN and not GND but GND and RTN are connected? - Page 1
Forum section: electronics / projects

author: ricko_uk
author_rank: Super Contributor
timestamp: December 28, 2024, 03:47:18 pm
content: Hi,I am thinking of using the TPS26600 e-fuse (datasheet links below for both the dev kit and the IC itself).In the datasheet a lot of input signals look like they are referenced to pin RTN (labelled as "Reference for device internal control circuits").In the block diagram on page 18 of the IC datasheet it looks like RTN is connected to GND, which makes sense. But in the description it says to connect various signals to RTN not GND, and in the Dev Kit schematic (page 3 of the dev kit datasheet) it also shows most of the signals connected to RTNwhich is isolated from GND.It doesn't make much sense. Why not allow to connect/reference the signals to GND if they are connected anyway inside the IC(if I read the datasheet correctly)?IC Datasheet:https://www.ti.com/lit/ds/slvsdg2g/slvsdg2g.pdf?ts=1735388589544&ref_url=https%253A%252F%252Fwww.ti.com%252Ftool%252FTPS26600-02EVMDev Kit Datasheet:https://www.ti.com/lit/ug/slvuav3a/slvuav3a.pdf?ts=1735371264696Thank you

author: uer166
author_rank: Super Contributor
timestamp: December 28, 2024, 09:44:55 pm
content: It does not show them connected together. The absolute max rating also obviously shows that they're not.

author: ricko_uk
author_rank: Super Contributor
timestamp: December 30, 2024, 06:48:34 am
content: Thank you uer166,I misinterpreted the meaning of that block in the diagram.
e-ink display question - Page 1
Forum section: electronics / projects

author: BurningTantalum
author_rank: Frequent Contributor
timestamp: September 10, 2017, 08:36:23 am
content: I have just acquired a friend's Kindle Paperwhite to 'have a look at'.The e-ink display is badly corrupted and frozen, the power button is unresponsive, and the illumination LEDs cycle on and off every few seconds.I have managed to dismantle it and remove the battery, and was surprised when the display stayed the same even when separated from the PCB. I know nothing about this type of display, so it normal for the image to stay on the screen when power is totally removed?If not, I assume that the display has completely failed.Regards, BT

author: ElektroQuark
author_rank: Unknown
timestamp: September 10, 2017, 08:40:05 am
content: Yes. e-ink displays work like that, that's why they are so power efficient.

author: Twoflower
author_rank: Frequent Contributor
timestamp: September 10, 2017, 08:44:00 am
content: That is a feature of the e-ink: It keeps the content there for ever. It is driven only if a refresh is required. That's the reason why the battery lifetime doe e-ink readers is often given in pages rather in hours (unless there is are LEDs for reading in the dark).So a frozen display could be that the battery died. Try to charge the reader, I think there should be a LED indicating the charging. My Kindle PaperWhite indicates this with an LED: orange = charging, green = fully charged.Can you connect the reader to a PC? It should connect as a drive.

author: BurningTantalum
author_rank: Frequent Contributor
timestamp: September 10, 2017, 12:07:17 pm
content: Thanks for the info-I had connected the unit to a PC and it was not recognised as a drive.I left it to charge, with a steady orange light showing, all afternoon then I removed the battery and charged it at 100mA for a couple of hours on a bench PSU.I will have a more detailed look tomorrow and report back on the state of the battery, and power the unit with 3v7 from the PSU.BT

author: Ian.M
author_rank: Super Contributor
timestamp: September 10, 2017, 01:18:29 pm
content: If the corrupted area of the display has any curved borders its almost certainly a physically broken display. If the corruption is strictly vertical and horizontal lines and rectangles, it *may* be a faulty display but is equally likely to be the main board sending bad signals or sent bad signals and is now no longer driving the display. As the USB storage mode is non-functional, odds are its a main board related problem - either a hardware fault or its badly crashed with a corrupted filesystem.Ask about it over on theMobileread Kindle Forumas there are various recovery options that can be tried for a bricked Kindle.
E-Ink faded?!?!? - Page 1
Forum section: electronics / projects

author: mrburnzie
author_rank: Regular Contributor
timestamp: October 13, 2020, 03:35:55 pm
content: Hi everyone!I have a small problem with my E-Ink. After writing and testing the prototype, it was put aside in a box.I just took it out and wanted to change some values on the display, when all of the sudden it faded and it won't update. After connecting the serial on it, it just crashes.Info:Board:http://www.lilygo.cn/prod_view.aspx?TypeId=50031&Id=1149&FId=t3:50031:3The error:The faded display:P.S. yes it spells cock (as coca cola)
e-Paper displays - Page 1
Forum section: electronics / projects

author: David_AVD
author_rank: Super Contributor
timestamp: May 21, 2013, 02:25:28 am
content: I saw some e-Paper displays mentioned in one of the technical emails I subscribe to. Here's a link to the eval kits:http://www.pervasivedisplays.com/kits/ext_kitThe distributor in Australia isGlynand the eval kits are fairly low cost I believe. You still need a micro to drive it of course.Anyway, they look interesting and I'm looking to get one just to play with, as I never know what projects are on the horizon!

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 21, 2013, 08:40:14 am
content: Adafruit also stock these
E-paper / E-ink questions - Page 1
Forum section: electronics / projects

author: K3mHtH
author_rank: Regular Contributor
timestamp: May 21, 2016, 09:35:41 pm
content: Hey guys,This might be an odd question, but what happens if you drill or punch a hole through e-paper / e-ink displays?If bad things happen, do you think it would be possible to have the e-paper manufactured with a hole in it on purpose? And what do you estimate the overhead and minimums would be on getting something like that made?Cheers,

author: 6thimage
author_rank: Regular Contributor
timestamp: May 21, 2016, 10:49:31 pm
content: Quote from: K3mHtH on May 21, 2016, 09:35:41 pmYou break the display - an E ink display will go badly wrong if you have a small crack on it (even on the back), so drilling a hole through it is just going to hurt your pocket.Quote from: K3mHtH on May 21, 2016, 09:35:41 pmA hole in it sounds unlikely (or just very costly) as the screen is addressed in rows and columns. You'd stand a better chance with two arcs, or a grid of smaller displays. You might be able to find a company willing to manufacture a custom display for you, but I'm guessing you'll need to be ordering at least 1 / 10k.

author: K3mHtH
author_rank: Regular Contributor
timestamp: May 22, 2016, 12:59:05 am
content: Quote from: 6thimage on May 21, 2016, 10:49:31 pmI figured it worked in rows and columns, but I was more hoping it worked with magic. Can someone drill a hole into an old e-reader for me please?? Dave??

author: uncle_bob
author_rank: Unknown
timestamp: May 22, 2016, 01:16:17 am
content: Quote from: K3mHtH on May 22, 2016, 12:59:05 amHiDrill a hole in it? No problem at all. Send me the display and my trusty drill press will do the job. .... errr ... payment is cash in advance.Put a hole in the display *and* have the display work? Also not a big problem. Can be done. Tooling is probably in the $20M range.Bob

author: xrunner
author_rank: Super Contributor
timestamp: May 22, 2016, 01:19:26 am
content: Quote from: K3mHtH on May 21, 2016, 09:35:41 pmYou can, but it has to be an e-hole.

author: 6thimage
author_rank: Regular Contributor
timestamp: May 22, 2016, 02:46:30 am
content: Quote from: K3mHtH on May 22, 2016, 12:59:05 amSearch on google for 'e-ink broken' and hopefully you will understand why drilling into an e-ink display (or any display) is a pointless endeavour. There is no such thing as magic - sorry to disappoint you - there are only tricks and slights of hand. If you want a display with a hole in it, you'll either have to use smaller displays dotted around the hole, or you will have to get a company to manufacture a display where the rows and columns finish and start either side of the hole (essentially creating two sets of rows for the left and right of the hole, and two sets of columns for above and below the hole).Why exactly do you want a hole in a screen, surely there is an easier, and significantly cheaper, alternative.
E vs H field strength levels to ionize different gases? - Page 1
Forum section: electronics / projects

author: Deactivated-1
author_rank: Frequent Contributor
timestamp: September 16, 2024, 12:22:53 pm
content: Is there a chart or a book listing the different levels of E and H fields required to ionize different gases?

author: LaserSteve
author_rank: Super Contributor
timestamp: September 16, 2024, 10:29:27 pm
content: your looking for Paschen Curves, and once you find Paschen's Law for gas X, you can work backwards from there. Ionization Voltage in Ev is another method that can be worked backwards from the listed value to what you seek. This is very serious math, so start with Paschen's Curves. I long ago stopped doing the math and just put the tubes on the fill station after a first approximation, so I will not be much help.Tying in H is whole different can of worms, as inductive coupling to a gas is vastly situationally dependent, and generally requires a High Q resonant circuit with inductive coupling or nothing happens.Steve

author: TimFox
author_rank: Super Contributor
timestamp: September 16, 2024, 11:03:23 pm
content: Note that the Paschen curve for a given gas graphs the voltage between the electrodes for a glow-discharge tube as a function of the product of pressure x distance.The voltage increases quickly to the left (low pressure), shows a broad minimum for intermediate values of the product, and then increases again to the right (high pressure).The Wikipedia article on Paschen curves is a good start.

author: TimFox
author_rank: Super Contributor
timestamp: September 17, 2024, 04:17:09 pm
content: Back to the original question:For atoms (and molecules) the relevant parameter is the ionization energy, which is the energy required to extract the first electron from a neutral atom, leaving a positive ion behind.Chemists quote this in kJ/mol, and physicists in eV. See a list:https://en.wikipedia.org/wiki/Ionization_energies_of_the_elements_(data_page)One mnemonic from my student days is that the ionization energy of the hydrogen atom is 13.6 eV, just like the specific gravity of liquid mercury (13.6 g/cm3).The ionization energy of the H2molecule, the normal form of gaseous hydrogen, is higher, about 15.4 eV.It is possible to ionize atoms or molecules with a high electrostatic field, known as "field ionization" (q.v.).In my university days, we did this by applying up to 10 kV to a sharp tungsten point, achieving a (huge) field value on the order of 100 V/nm = 1011V/m near the tungsten surface in a hydrogen atmosphere (roughly 10-4Torr), where we increased the current by cooling the needle and its surroundings to 78 K (liquid nitrogen) to enhance the gas supply to the narrow region around the needle.Seehttps://physics.stackexchange.com/questions/384241/could-a-strong-enough-electric-field-tear-a-hydrogen-atom-apartField ionization is used to make a small-diameter source of ions for microscopes and microprobes, and as a source of ions for mass spectroscopy.
E-waste / ore crusher concentrator with MSP430 control - Page 1
Forum section: electronics / projects

author: superUnknown
author_rank: Regular Contributor
timestamp: June 09, 2013, 02:48:21 am
content: I built a hydraulic impact crusher to get gold out of old motherboards. I also use it to look for interesting minerals in rocks.It's all built from scratch and worked really well, but was a bit of a pain when it jammed (after I choked it feeding oversized rocks).That's all solved now that I'm using the MSP430 Launchpad (arduino-esk board) to control the hydraulics. The MCU monitors a pressure signal. When the crusher jams, the pressure spikes. The MCU de-energizes the forward solenoid coil, then energizes the reverse coil to clear the jam. Automatic anti-jam!More details on my blog:LaunchPad goes for GOLD!]

author: gxti
author_rank: Frequent Contributor
timestamp: June 09, 2013, 03:25:03 am
content: Lots of neat stuff going on in your blog. Thanks for sharing.

author: nctnico
author_rank: Super Contributor
timestamp: June 09, 2013, 06:55:08 pm
content: I wouldn't use it on e-waste. There is lots of nasty (unhealthy and corrosive) chemicals in various components.

author: superUnknown
author_rank: Regular Contributor
timestamp: June 09, 2013, 09:08:07 pm
content: Quote from: gxti on June 09, 2013, 03:25:03 amThanks!

author: superUnknown
author_rank: Regular Contributor
timestamp: June 09, 2013, 09:09:59 pm
content: Quote from: nctnico on June 09, 2013, 06:55:08 pm"not to worry folks; I'm a professional!"

author: David_AVD
author_rank: Super Contributor
timestamp: June 09, 2013, 09:59:38 pm
content: " What could possibly go wrong? "