hybridfree/eevblog-posts huggingface dataset:
Help needed working out the size needed for a power supply - Page 1
Forum section: electronics / projects

author: badwolf84
author_rank: Newbie
timestamp: August 27, 2016, 10:24:14 am
content: Hey guys,I'm currently rebuilding my NAS built from a Raspberry Pi and 3 external HDD. The NAS side of things works well, slow as crap but suites my needs. Using a Pi because its what I had laying around and I had the external HDD spare. It's Just annoying when I need 4 power points to run everything, so I'm wanting to replace them with a Power Supply.I'm not sure on what size power supply I need. the 12v wall adaptors are all rated to 1A,and the Pi is supplied with 5V@2A.(using a buck converter for the 5v needed for the Pihttp://www.ebay.com.au/itm/191731851020). My research suggests 20w max during power up for each USB HDD and 10w for the Pi. So my maths suggests a 12v 6A 70w Power Supply . If someone could check my figures, before I release the magic blue smoke along with all my data, that would be awesome.I was thinking of using one of these power supplyhttp://www.ebay.com.au/itm/AC-110-220V-TO-DC-12V-24V-Regulated-Transformer-Power-Supply-For-LED-Strip-Light-/400469998223or if you have a recommended supplier let me know.
help needed  - Page 1
Forum section: electronics / projects

author: electronics technician
author_rank: Regular Contributor
timestamp: March 06, 2014, 08:47:20 pm
content: i need some advice on this power supply im going to make i saw it here on this forum but im not seein it here anymore so here goesi did some research and found thsi circuithttp://www.thebackshed.com/windmill/articles/VariablePowerSupply/TheBackShed723Reg.gifim going to buy a dual voltmeter and ammeter with current shunt rated at 300a and 300vi rewound a (mot) microwave oven transformer to get 27v ac and i need some advice on it thanks
Help on I2C controller, GPIO expander, and switch - Page 1
Forum section: electronics / projects

author: bhj99
author_rank: Contributor
timestamp: August 29, 2023, 06:10:31 pm
content: Hi all, newbie here.I would like to get some advice on the best ways to test the following circuits in the schematic snippets attached from an evaluation board. There is a USB to I2C master controller using the FT232H chip to generate the 2-wire wire serial interface, which are used by the downstream devices (GPIO expander and I2C fanout switch that provides serial lines to a retimers and SFP transceivers).For the FT232H chip, I am thinking of observing the output SCL/SDA waveforms on a oscilloscope, but I suppose I could also use an Aardvark header and the Aardvark Total Phase software to verify if the SMbus is recognized. I could follow the same approach for the I2C fanout switch I suppose while also verifying read/write to the target devices. As for the GPIO expander, I don't have much experience dabbling with the config registers to set I/O as outputs, etc. or doing read/writes. Could I get some help here? I appreciate any comments.
Help on MEMS Microphone Boards - Page 1
Forum section: electronics / projects

author: Seren200018
author_rank: Newbie
timestamp: July 09, 2020, 08:16:46 pm
content: Dear Readers,I currently got a project to create an (or rather around 100) microphones for acoustic measurement. The first idea was to just bruteforce it using a multi channel system. After considering the number of wires needed we redecided to use multiple digital microphones with build in microcontroller and a shared data channel. I do not think reading all of them at the same time is really feasible.So I think its best going for a buffered approach where every microphone board is buffering a full measurement and afterwards the boards are sequentially read.Currently, I am not sure if I should go for a SPI RAM or a Flash solution (QSPI possible but i do not know if QSPI write is possible).The measurement has the following parameters:smaller or equal to 24 bit Dataaround 5-15 kspsif possible one additional byte for status informationwrite time maximum of halve the sample ratesmall if possibleWith those parameters I get around 320kbit/s to 960kbit/s Save rate. I would like to buffer as much as possible. While RAM is fast enough it has to little space at low prices. I would like to keep it cheap. NAND-Flash is fast enough but first it can only be wrote a limited amount of times (i do not think we will do 10.000 measurements), and i fear it is to slow.What would you suggest? Are there any bigger ram ICs? I know of PSRAM like ESP-PSRAM64H but I can only buy it from ali express not mouser or farnell and i didn't find anything similar. Are there other feasible chips?Best RegardsChristian
help on Optical Fiber Communication System  - Page 1
Forum section: electronics / projects

author: Moturki
author_rank: Newbie
timestamp: March 07, 2018, 06:36:57 pm
content: I'm asking about an ideas about design an optical fibers communication system project for Bachelor's degree or any recommended website that could be helpful for communication systems.thanks.....

author: jbb
author_rank: Super Contributor
timestamp: March 07, 2018, 06:50:46 pm
content: You may need to be more specific. There is a lot of scope; international telecoms backhaul, city-scale backhaul, fancy physics stuff, industrial etc.Avago (now Broadcom) make a nice line of industrial modules (modest bandwidth and range).https://www.broadcom.com/products/fiber-optic-modules-components/industrial/The White Rabbit is a crazy precision synchronised system for physics experiments.https://www.ohwr.org/projects/white-rabbit

author: nctnico
author_rank: Super Contributor
timestamp: March 07, 2018, 06:59:34 pm
content: Not just that but there are also many industrial busses which use optical fibers.

author: Moturki
author_rank: Newbie
timestamp: March 07, 2018, 07:29:32 pm
content: thanks for your response, the truth i'm interested on wdm optical networks design but i need a good project idea of this field........could be "audio transmission over optical fiber cable" good project or not ??

author: jbb
author_rank: Super Contributor
timestamp: March 08, 2018, 12:08:04 am
content: WDM as in Wavelength Division Multiplexing? Isn’t that super high bandwidth stuff?It’s not clear what you want to research.
Help on schematic - Page 1
Forum section: electronics / projects

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: December 15, 2014, 07:40:12 pm
content: So, we built up this schematic on a PCB for a project. The idea is to have a UPS-style supply for a automatic shuttle prototype on small scale. Theoretical max load is 8A peak, 4A average.When testing, as soon as the batteries were connected, the LT1512 decided to destroy itself. The issue was clearly the current in the Vsn pin (since half of the pin decided to vaporise).What caused this? is there something obvious I'm doing wrong here?EDIT: I would like to add that since we revisited the datasheet, we placed a 7812 with the neccisary caps to power the Vin of the charging IC. All the other parts (the 22uF cap and the inductor on that same line as Vin) are still at 24V. Is this the issue? this is the first time I ever used a charge pump.

author: PA0PBZ
author_rank: Super Contributor
timestamp: December 15, 2014, 08:18:58 pm
content: Quote from: TheUnnamedNewbie on December 15, 2014, 07:40:12 pmIs that because of this line in the ds:*Maximum Input Voltage = 40V – VBAT?I think it refers to not only Vin but also Vsw (connected via the 33uH inductor). I'm also not sure if you are actually allowed to give Vin a lower voltage than Vsw.Maybe trying to charge a 24V battery with a 24 volt supply (for 48 volt total) is just not the thing for this chip. You could try to charge a 12V battery by changing your resistor divider just to see if the rest of your circuit is ok.

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: December 16, 2014, 08:46:57 am
content: Yes, that was because of that line. I think we should try to run the rest of the charging circuit of of 12V aswell, since it's a charge pump, it shouldn't matter.

author: ptricks
author_rank: Frequent Contributor
timestamp: December 16, 2014, 11:49:21 am
content: The LT chip you used isn't the best choice for what you want to accomplish, it is complicating what could be a very simple design as it sounds like you have enough power to charge the battery. Most UPS I have taken apart seem to go the comparator or opamp route, often using the cheap lm324.

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: December 16, 2014, 12:40:49 pm
content: Quote from: ptricks on December 16, 2014, 11:49:21 amWe went for the charging IC route because we didn't have the knowledge to design our own CV/CC charger, and a lab assistant here told us we should just look into a prebuilt IC. However, turns out that charging IC's in a DIP package that can power 24V batteries are hard to find.Since this has to work for 8 hours tomorrow at a demonstration and then never work again, we don't really have time to redesign and build an entire new schematic - so I just need to try and get what we have to work.

author: Zero999
author_rank: Super Contributor
timestamp: December 16, 2014, 02:02:57 pm
content: I got a sore neck trying to read your schematic so I've flipped it and increased the contrast.There's no VSNpin, don't you mean VSW? I agree, it looks like you shouldn't make VSWhigher than VIN
Help on UPS fan modding - Page 1
Forum section: electronics / projects

author: bitwelder
author_rank: Super Contributor
timestamp: January 10, 2015, 09:10:31 am
content: I recently got a new UPS for home, Eaton 5SC750i.The problem that I have is that relatively noisy, due to the fan that *never* stops.The fan is a 60mm, high speed (4500 rpm), ~36 dB type and as wrote, even when battery is fully charged it doesn't stop spinning, although it goes into 'low speed' mode, but for a relatively silent home it is still quite noisy.So I wonder if it would be possible to mod the unit and put a slow-speed silent 100-120 mm fan.The issue that I see is that the UPS logic detects and alerts if the fan is malfunctional, so I would need to make some kind of converter from the 'low rate' signaling that the low speed fan offers to the 'high rate' that the UPS logic expects (the fan is a F-type).Any suggestions how to do that?

author: Seekonk
author_rank: Super Contributor
timestamp: January 10, 2015, 10:43:16 am
content: Not familiar with that unit but at my camp I removed the fans form my inverters and allowed better ventilation. That may not be practical for you but adding a temp control might be the solution. I have a half dozen of these and I love them, only $3.65. Place the sensor on a heat sink and let the fan cycle when it needs to.http://www.ebay.com/itm/141442045768?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

author: bitwelder
author_rank: Super Contributor
timestamp: January 12, 2015, 06:39:03 am
content: Quote from: Seekonk on January 10, 2015, 10:43:16 amHow would a temp control system solve the problem that the fan is monitored by the UPS controller and so it would trigger the UPS alarm when it sense the fan is not spinning?

author: Seekonk
author_rank: Super Contributor
timestamp: January 12, 2015, 10:59:26 am
content: I doubt the fan itself is monitored. These three wire fans generally attach to some temperature sensor or more likely just go to a higher speed when when the microprocessor knows it is doing something that will cause heat.
help please with design problem - Page 1
Forum section: electronics / projects

author: KTP
author_rank: Frequent Contributor
timestamp: April 12, 2010, 04:25:18 pm
content: Hi guys,I have a bit of a problem. I want to build up a light battery to use with a Minn Kota Riptide saltwater 55 pound thrust trolling motor which has a digital maximizer control instead of using speed coils (in other words, it pwms the motor instead of dropping voltage in resistance coils like the cheaper 5 speed models). The problem is I want to use some of the many Lithium Manganeese sony US26650VT cells I happen to have (4.1V fully charged, 2600mA, capable of 50A discharge) to build up a pack. The LiMn battery voltage drops from about 4.1V full to about 2.5V empty (don't discharge below this voltage) so if I make a 20 cell ~200Wh using 5p4s pack it will have a fully charged voltage of 16.4V and a fully drained voltage of 10V.The problem is I cannot get Minn Kota to tell me if the Riptide 55 pwm electronics would be tollerant of 16.4V, and the electronics are all potted (for salt water protection). I assume since the trolling motor is normally connected to a battery which may be charging via an alternator at something around 14.5V that the components are at least rated that high. I could build the pack as 6p3s with a 12.3V full and 7.5V empty, but I don't think the motor would work well below about 10V.Since the battery would only be at 16.4V for a few minutes until it has drained somewhat, I could run the output through a series string of 3 honkin diodes, dropping the output to under 15V, and then maybe have a circuit to bypass these diodes after the unloaded battery voltage has dropped below 15V? I guess this way I would only have the wasted power (50 amps max times 1.8V = 90 watts) for a few minutes, then have a low Rds on mosfet bypass the three diodes.Any suggestions for a better way?

author: Zad
author_rank: Super Contributor
timestamp: April 12, 2010, 05:05:13 pm
content: Any idea what frequency the PWM runs at? I'm thinking you could feed the output through an inductor and drop the voltage using impedance rather than resistance. The power delivered would be the same, just at a lower peak voltage.

author: rossmoffett
author_rank: Regular Contributor
timestamp: April 12, 2010, 05:06:05 pm
content: Test at 7.5V and get back to us. If it's the easiest way, don't just trash it because of unknown variables.
help reading datasheet logic levels - Page 1
Forum section: electronics / projects

author: stern0m1
author_rank: Contributor
timestamp: July 02, 2018, 08:58:13 pm
content: Could someone explain me what this data sheet means where its defining the logic levels? Whats 0, 7xVGPIO? Whats the zero comma?Thanks

author: tautech
author_rank: Super Contributor
timestamp: July 02, 2018, 09:07:43 pm
content: The clue will be listed in the datasheet somewhere else.0, is just 0.x0 where x represents a %.Sometimes comma is used for 'point'.

author: stern0m1
author_rank: Contributor
timestamp: July 02, 2018, 09:17:28 pm
content: Not sure I understand...VGPIO = 1.8vSo, Vih = 7% of 1.8?Thanks

author: tautech
author_rank: Super Contributor
timestamp: July 02, 2018, 09:26:27 pm
content: Quote from: stern0m1 on July 02, 2018, 09:17:28 pm0.70
Help Reading this - Page 1
Forum section: electronics / projects

author: docmur
author_rank: Regular Contributor
timestamp: September 23, 2013, 11:58:27 pm
content: Okay maybe I'm an idiot and just missing it entirely.I'm using this Micro-controller in my design:http://ww1.microchip.com/downloads/en/DeviceDoc/39897c.pdfI can't find the UART Pins or the SPI Pins! I'm using the 100 pin TQFP package. Can anyone point them out to me? I thought the UART pins were labelled Ux but I can't find any. The product webpages lists:Digital Communication Peripherals 4-UART3-SPI3-I2CThanksAndrew

author: dannyf
author_rank: Super Contributor
timestamp: September 24, 2013, 12:00:10 am
content: It has remappable pins - a remarkable feature in those chips.

author: docmur
author_rank: Regular Contributor
timestamp: September 24, 2013, 12:02:26 am
content: I know you can remap the pins, I'm trying to figure out what Pin's the UART and SPI are on.

author: c4757p
author_rank: Super Contributor
timestamp: September 24, 2013, 12:12:44 am
content: Read section 10.4: Peripheral Pin Select...

author: docmur
author_rank: Regular Contributor
timestamp: September 24, 2013, 12:20:47 am
content: Thanks thats what I was looking for :-)

author: dannyf
author_rank: Super Contributor
timestamp: September 24, 2013, 12:25:38 am
content: QuoteSince those pins are "remappable", they are not associated particular pins - otherwise, they wouldn't be "remappable".
Help reading/writing 2-Kbit serial presence detect (SPD) EEPROM - Page 1
Forum section: electronics / projects

author: flyrod
author_rank: Contributor
timestamp: September 29, 2019, 12:41:07 pm
content: Hello. I've got a computer project that I've run into a problem with. There are some little EEPROM chips that I need to adjust. I could buy a programmer, just for this project, but I figure there are people here who already have them and know how to use them. The chip is a ST M34C02 2-Kbit EEPROM for DDR1, DDR2 and DDR3 serial presence detect in a TSSOP8 package. I have several of them that I would like to read, compare the values, adjust, and write. I'm in the USA; can anyone help with this?

author: flyrod
author_rank: Contributor
timestamp: April 01, 2020, 02:48:15 pm
content: Anyone with a reader able to help?

author: coromonadalix
author_rank: Super Contributor
timestamp: April 01, 2020, 03:27:56 pm
content: you should adjust your location in you profile, you say you're in usa but it is set to afghanistan ??

author: Ian.M
author_rank: Super Contributor
timestamp: April 01, 2020, 03:44:10 pm
content: Its a bog-standard 2kbit I2C serial EEPROM..What you can use to read and program it depends on what PC you have, its available ports and what OS you are running. Linux offers the most flexibility, but if you have a legacy PC with a real parallel port running Windows XP, Win9x or even DOS, there are various minimal hardware options. Anything more recent, and you are likely to need to invest in some sort of USB serial EEPROM programmer that can do I2C, though you could also access it using an Arduino and a sketch to dump it to the terminal and another sketch to write it back after editing, or (assuming you are a competent programmer) you could write an interactive I2C EEPROM editor sketch.

author: magic
author_rank: Super Contributor
timestamp: April 01, 2020, 04:02:37 pm
content: On Linux I literally used i2cget/i2cset to manually write a few bytes to some EEPROM once. It's relatively simple and wouldn't be hard to automate. On the hardware side, any VGA/DVI/HDMI port supported by open source drivers can do.
Help, can I use another oxygen battery instead? - Page 1
Forum section: electronics / projects

author: daisizhou
author_rank: Super Contributor
timestamp: May 28, 2022, 02:44:06 am
content: One of my test instruments originally used psr-11-75-ke oxygen battery, because psr-11-75-ke is hard to buy, I plan to replace it with ordinary oom202 oxygen battery.I inquired about their 2 kinds of oxygen batteries, the output voltage is different, I don't know if they can be used instead?If it can't be used directly instead, can a voltage conversion circuit board be added to change their output voltage, and then connected to use?I mean add a small circuit board, adjust the new battery to the same linear range as the original battery and use it again.If you know please help me, thanks

author: free_electron
author_rank: Super Contributor
timestamp: May 28, 2022, 05:00:50 am
content: These are all made by Figaro.

author: daisizhou
author_rank: Super Contributor
timestamp: May 28, 2022, 06:41:35 am
content: Can I use oom202 instead of psr-11-75-ke?Their output voltages are somewhat different

author: daisizhou
author_rank: Super Contributor
timestamp: May 29, 2022, 01:27:01 pm
content: please, who can help me
Help replacing crystal on RTL SDR with 28.8mhz TCXO - Page 1
Forum section: electronics / projects

author: rwgast_lowlevellogicdesin
author_rank: Frequent Contributor
timestamp: August 06, 2014, 01:03:23 am
content: So I bought this through hole TCXOhttp://www.ebay.com/itm/1pcs-TCXO-28-8MHz-28-800M-Ultra-precision-Crystal-Oscillators-DIP-0-5ppm-NT-/131129276731?pt=LH_DefaultDomain_0&hash=item1e87e9f93bto replace the cheap crystal on the RTL SDR dongle. I fed it 5v and 3.3v then connected the ouput to where the crystal output on the dongle was. The issue im haveing is it is cutting my signal strength WAY down like over 2/3. I cant figure out what I am doing wrong here. I thought maybe my wires for testing were to long, but when I solder the crystal to long wires the dongle works just fine.

author: dannyf
author_rank: Super Contributor
timestamp: August 06, 2014, 11:01:30 am
content: QuoteTo achieve what goal?
Help: repurposing a lcd power supply - Page 1
Forum section: electronics / projects

author: dany-boy
author_rank: Contributor
timestamp: February 03, 2016, 07:14:30 pm
content: Hello everyone:The other say I was shopping in downtown Mexico city and scored these power supplies for dirt cheap (50 pesos / 2.8 USD). All of them work fine, both in voltage and current specs. Among them, there is an lcd power supply which has a high voltage output to drive the back-light. I would like to use this high voltage output to easily drive a clf in another electronics project. However, the HV output shuts down after a few seconds of turning it on. I suspect that the PSU has some sort of feedback mechanism that shuts it down if certain conditions are not met.Here is the datasheet for the entire LCD:http://www.go-gddq.com/upload/2009_10/09102412529181.pdf. PSU schematics are in pages 22 and 23. High voltage supply is in page 23. With my limited electronics knowledge (I'm a high-school student) I can't quite figure out which conditions must be met. I don't just want to short the terminals in the HV output in case something blows up. Any help towards getting continuous HV would be amazing.Should you need any more information I will be happy to reply.Thanks for reading my post.

author: rf+tech
author_rank: Frequent Contributor
timestamp: February 03, 2016, 09:18:52 pm
content: Hello dany-boy,You are correct that there is a feedback path. Most supplies such as this require both CFL to be present. If one is missing/broken/dead, the supply senses this abnormal condition and turns itself off. If you have two CFL, try the supply again with both lamps.As a learning exercise, I'll give you this hint: check the voltage present at the point where R853 and C853 connect to the base of Q806, when the one lamp lights briefly and when the lamp is off. What happens here?Can you follow the schematic and see where this control signal comes from?RF+ Tech
Help req to drive led's to backlight panels in simulated cockpit. - Page 1
Forum section: electronics / projects

author: v81
author_rank: Regular Contributor
timestamp: May 10, 2020, 08:52:00 am
content: Working with some friends on an A-10C Warthog cockpit.The software/arduino firmware is DCS BIOS for Digital Combat Simulator which spits out integers for backlight brightness levels.I'm pretty inexperienced at driving multiple LED's and captain obvious says the Arduino will not be able to sink or source enough current without external assistance.So we're looking at physically having a bunch of green or green/yellow colour leds either in series, parallel or a combo of both.The cockpit will be made of multiple boards behind panels all connected by a powered USB hub (with attention to combined current of all).One idea, if sourcing all of the power for an entire cockpit over USB hubs gets a bit much is to have a separate 12v supply distributing power around the pit and to each board to do the heavy lifting (lighting, servos(via 5v pre-regulation) LCD's etc..).To get the lighting into the pit i was hoping to have one arduino (Electronic Warfare / countermeasures panel) feed 3-4 different lighting circuits on other sub panels (engine instruments, consoles etc...).I think it might be most efficient to power each panel from a 12v bus and have a PWM signal from the main board over a signal wire hit a mosfet or something on the sub boards to control lights on/off/brightness.So if the above makes sense.. Some questions...Are there any issues sending a PWM signal directly from an Arduino pin over a meter or 2 (3-6ft) distance?Any issues daisy chaining that same signal to multiple related boards (eg all fo the backlights for the left and right consoles will be on one signal).Any idea to vary / calibrate brightness on a per sub panel basis? Goal will be to build them as close as possible match others, but it might not work out that way.Should i have anything on the Arduino end of the wire to protect the Arduino or ensure signal integrity over a few feet?How would one go about actually powering the LEDs? I'm thinking transistor or mosfet, but I'm not real clever with semiconductors.I think strings of 4 or 5 LEDs could be run fairly efficientlyI feel like I've left a bunch of questions here, if anyone made it through all that then i very much appreciate it.I'll leave some pics below of the real pit, and of the on screen simulated pit, the lighting panel will also be attached just for context really.
Help requested identifying something (antenna?) - Page 1
Forum section: electronics / projects

author: Moonchild
author_rank: Newbie
timestamp: March 17, 2022, 11:30:27 am
content: Hey folks.I recently got into the possession of a bunch of cables and sundry, and included with those were three items I can't identify (identical). Potentially an antenna? It was suggested I ask on this forum.I'm thinking they are antennas of some sort but any of you experts can probably make more educated guesses than I can!So, can you please help identify the thing I attached a photo of? It has no markings anywhere, a single metal connection plate at the base running into 3 capped, sealed leads that have wires running through them. All of it is tightly sealed in cast rubber except the single metal base plate. The three leads sprouting from the flat base are ~4.5m long.

author: Terry Bites
author_rank: Super Contributor
timestamp: March 17, 2022, 05:59:04 pm
content: Its a mystery. Could it be a sensor from a dryer or AC system?

author: Moonchild
author_rank: Newbie
timestamp: March 17, 2022, 07:36:14 pm
content: Quote from: Terry Bites on March 17, 2022, 05:59:04 pmI'm not sure that makes much sense. There's no electronics in it and the leads are 4.5m long -- and why 3 of them for a sensor?...

author: Moonchild
author_rank: Newbie
timestamp: March 19, 2022, 08:20:24 am
content: Since I'm still no closer to identifying, I tore down one of them to have a closer look.Attached some pictures of that.Base plate is just metal with the three (what looks like tinned copper) leads soldered directly onto it. The leads are wrapped in a cloth sheath.All of it tightly sealed in soft, insulating rubber. Grime on it suggests they have been used in an outdoor environment.It really does look like some kind of antenna but really not sure. If only it had markings!
Help reverse engineering this circuit - Page 1
Forum section: electronics / projects

author: reflejo
author_rank: Newbie
timestamp: August 23, 2021, 06:43:46 am
content: Hello, I'm trying to reverse engineer a circuit that has 3 functions:Turn on/off a matrix of 6 6.3v incandescent lights (Outputs of the 4435 / IRF7303)Control a stepper motorOutput a photomicrosensor informationBear with me since my electronics foundations is not strong. I'm doing this to learn more and connect it to a RPi. The board has multiple layers and no visible tracks, so I reversed it by doing a continuity test. I think i pretty much got the schematics reproduced (attached) as well as all resistor values (ask if needed for the analysis) and I have a few questions:1. There are two voltages that need to be supplied, I guessed the values as 5.5v (this one based on the IC specs, pretty confident it's between 4v and 5.5v) and 24v (this one I'm a bit less sure, but the motor that was attached to it is rated 24VDC). Here is the issue: The bulbs are incandescent 6.3v and connected to the same line as the source of the motor hence the 24VDC doesn't make sense. Is there any voltage multiplier I don't see? Hence I should supply 6-7v ?2. I don't know what most of the capacitors are doing, except for D1-D8 which seem to be transient suppressors.3. Seems like the cathode of the power LED goes to the board socket, which means I need to provide ground to the LED, is this normal? I guess you could have a switch to control the LED but seems weird they didn't hook it up to the +-5v.Note: J1 goes to the motor, J2 goes to the lights matrix and J3 goes to the photomicrosensor. J4 is the board socket where I'll be connecting toThanks!

author: Terry Bites
author_rank: Super Contributor
timestamp: August 23, 2021, 06:04:45 pm
content: You'd have less bother forward engineering this on an arduino or similar platform.

author: reflejo
author_rank: Newbie
timestamp: August 23, 2021, 06:20:31 pm
content: I know; I mostly want to use the existing boards for a restoration project and also want to understand what I'm missing. Mostly academic at this point.
Help setting up a coil test bench. - Page 1
Forum section: electronics / projects

author: automech12
author_rank: Newbie
timestamp: May 01, 2018, 03:24:57 pm
content: Hi all,I am setting up a test bench to test automotive ignition coils. came here for some help with the same.im getting interferance and induced voltage on my trigger signal from the function generator every time the coil fires. can anyone please help me figure out how to filter that noise?thanks

author: ahbushnell
author_rank: Frequent Contributor
timestamp: May 01, 2018, 06:08:05 pm
content: What is your setup? What are you trying to measure and what are you using to measure it with?

author: floobydust
author_rank: Super Contributor
timestamp: May 01, 2018, 06:23:42 pm
content: Strong RF interference is always there from car ignition coils, and raises havoc with oscilloscopes and test gear.What is your coil secondary load? Are you using an arc or a SAE J973 ignition coil test jig? That is what I use because you can measure arc current. There is also an aircraft magneto test jig.Generally, resistance spark plug wire and resistance spark plug help a lot. A direct arc is very noisy.

author: Circlotron
author_rank: Super Contributor
timestamp: May 03, 2018, 09:47:00 am
content: I’ve spent LOTS of time playing with coils.Most canister and E-core coils have one end of the secondary terminated at the (+) primary terminal. Make sure you are drawing the spark between the HV wire and a wire connected to the (+) primary terminal. If you draw the spark to ground as per normal automotive installation, the spark current will find its way back to the (+) terminal via whatever random path that it can find. The leading edge of this spark current (more so than voltage) has a nanosecond rise time and consequently will find its way into all sorts of unwanted places, dumping noise everywhere.

author: StillTrying
author_rank: Super Contributor
timestamp: May 03, 2018, 11:51:16 am
content: I think the interesting question is, why is the large spike 1.5ms after the spark.

author: Circlotron
author_rank: Super Contributor
timestamp: May 03, 2018, 11:00:16 pm
content: Quote from: StillTrying on May 03, 2018, 11:51:16 amProbably that’s when the arc finishes and then the secondary is feeding an open cct so the HV wire flaps around unloaded a bit?

author: floobydust
author_rank: Super Contributor
timestamp: May 04, 2018, 07:32:57 am
content: OP should have some ringing and burn time unless he put a diode across the primary?I've been using automotive IGBT's to drive them, they have an internal 400V zener crowbar to limit switch and output voltage.A lot of oscilloscopes can't take the EMI, depending on circuit grounding. Most blips seen I take lightly, especially with Rigol.
Help Simulating Application Circuit #5 of LTC3350 Datasheet using LTspice - Page 1
Forum section: electronics / projects

author: joe306
author_rank: Newbie
timestamp: April 05, 2019, 10:21:09 pm
content: Hello, I am trying to simulate a circuit found on page 41 of the datasheet for the LTC3350. I am using LTSpice and when I run the Simulation get the message "Pseudo-Transcient Analysis that runs forever until I hit the ESC button. That's my first problem the second is that I'm not getting the correct Vout voltage. I have all my parameters set like the datasheet.I'll upload the datasheet and LTSpice design.Thank you,Joe

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: April 05, 2019, 10:56:32 pm
content: Hi.Check these two boxes:And it will add startup and uic to the simulation command.Everything will work nicely.Also:Regards,Jay_Diddy_B
Help: Snubber circuit for AQH3223 - Page 1
Forum section: electronics / projects

author: Jayy
author_rank: Contributor
timestamp: May 30, 2020, 06:02:37 am
content: Hi,I have attached a PCB layout. The Circuit works fine if snubber circuit is not added. If the Snubber circuit is added the load remains onalways.I have pcb layout according to datasheet. please help.attached datasheet AQH3223.Thanks.Jai.

author: Jayy
author_rank: Contributor
timestamp: May 30, 2020, 07:59:25 am
content: I need someone to verify the reason below:If you take a look at the ti_ssr_cautions document on page 2 ssr AQ-H model it is clearly seen that snubber is across terminals 8 and 6.if that is done then there is a connection made by capacitor and resistor with AC terminals which completes the circuit for the load and hence the load is on.I believe the snubber should be across load. but this error is seen in a lot of schematic in the net.

author: itdontgo
author_rank: Regular Contributor
timestamp: May 30, 2020, 11:12:05 am
content: What are you switching? If it only takes a small current your snubber will conduct enough to appear on. You'll need the snubber on the high current triac if that's what you're driving.We had a mystery problem once that I couldn't figure out. We had a circuit that would spontaneously fire. It was a photo-triac driving a high current triac. When we had one motor connected it was fine. When we connected up a second motor to an identical parallel circuit on the same PCB, both circuits would randomly fire when both motors were supposed to be off. With snubber, with snubberless triacs it didn't matter.The only fix for that was to put two photo-triacs in series. The breakdown voltage was 400V on that part and we were controlling 230V. Somehow two motors was causing it to breakdown.Anyway my point is that you put the snubbers in where you need them. You'll know about it when you do.
help solve the STP1612PW05 Ardino driver issue - Page 1
Forum section: electronics / projects

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: February 13, 2017, 06:41:29 am
content: HiI have written a driver for this cheap Excellent LED Driver, The problem with my code is that I can only turn on all outputs counting from 1-14 and when I set the value for the 15 output the output 0 and 15 would have the same output! and output 0 wouldn do anything! Help me solve this issue and we will have a nice open source library for this little cheap beast.Code:void init_STP1612PW05(void){//set outputspinMode(RGB_LE, OUTPUT);pinMode(RGB_SDI, OUTPUT);pinMode(RGB_CLK, OUTPUT);digitalWrite(RGB_LE, HIGH);}volatile uint16_t RGB_Data;void STP1612PW05_write(void){int i=0;uint16_t RGB_Data_temp;for(i=0;i<16;i++)RGB_Data_temp=RGB_Data;//Load first 15 datafor(int j=0;j<15;j++){for(i=0;i<16;i++){digitalWrite(RGB_LE, LOW);if(i==15)digitalWrite(RGB_LE, HIGH);digitalWrite(RGB_CLK, LOW);if(RGB_Data_temp & 0x8000)digitalWrite(RGB_SDI, HIGH);elsedigitalWrite(RGB_SDI, LOW);digitalWrite(RGB_CLK, HIGH);RGB_Data_temp <<= 1;}}//Global latch all datafor(i=0;i<16;i++){digitalWrite(RGB_LE, LOW);if(i==15 || i==14)digitalWrite(RGB_LE, HIGH);digitalWrite(RGB_CLK, LOW);if(RGB_Data_temp & 0x8000)digitalWrite(RGB_SDI, HIGH);elsedigitalWrite(RGB_SDI, LOW);digitalWrite(RGB_CLK, HIGH);RGB_Data_temp <<= 1;}}

author: obiwanjacobi
author_rank: Super Contributor
timestamp: February 13, 2017, 07:07:20 am
content: In the datasheet I see a CLK, SDI, SDO and LE. That sounds like SPI to me. The chip can work at 30MHz. There is no way you will even come close to that using digitalWrite bit-banging.If you want to write a good (reusable) library you should:- separate the pin-connections from the protocol. This will allow the user to choose where the chip is connected in his design and not force him to comply with your choice. Ofcourse using MCU-hardware (SPI) will fix pin assignments.- look into using other functions to setup the MCU registers etc. The top-level Arduino API (digitalWrite etc) is too slow. Using the Arduino API for setup is no problem, that is executed only once.Hope it helps.

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: February 13, 2017, 11:00:54 am
content: Thanks for the suggestions, I wanted to do a bit banged version for now,and please forget the Speed issue for now. How should we solve the software algorithm?

author: obiwanjacobi
author_rank: Super Contributor
timestamp: February 13, 2017, 12:16:45 pm
content: I think you're missing some setup code. Read Chapter 6 of the datasheet...
Help sourcing datasheet (photo inside) TO-92 559-1310  - Page 1
Forum section: electronics / projects

author: eevblogfan
author_rank: Frequent Contributor
timestamp: March 01, 2016, 06:34:49 pm
content: Hello( the picture is attached)I bought 3 sensors from some reseller, he told me only words, i need datasheet to confirm pinouts and working temperatures, please help me firstly by the logo , i've googeld it up ? Also found this :http://how-to.wikia.com/wiki/Howto_identify_integrated_circuit_(chip)_manufacturers_by_their_logos/U-ZAnd maybe i've missed the symbol (i'll rechek myself)Thank you in advance !

author: bktemp
author_rank: Super Contributor
timestamp: March 01, 2016, 06:57:59 pm
content: http://www.secsemi.com/products/Hal-Effect-Bipolar-Latches-Switches/SS559.html

author: eevblogfan
author_rank: Frequent Contributor
timestamp: March 01, 2016, 09:12:41 pm
content: That was Quick !How did you identified it ?Thank you very much

author: bktemp
author_rank: Super Contributor
timestamp: March 02, 2016, 06:19:02 am
content: This type of package is widely used for hall sensors, because they are often mounted inside motors, so they must be as thin as possible to fit.So I tried entering 559 hall sensor into google and it gave me link.
Help stop patent trolls... - Page 1
Forum section: electronics / projects

author: JoeyP
author_rank: Frequent Contributor
timestamp: January 22, 2013, 09:19:39 pm
content: Here is a way to at least increase awareness of the problem. If the petition gets enough "signatures", the President's administration has vowed to research/respond and possibly take action.I definitely wouldn't hold my breath for any earth-shattering legislation, but this petition system gets quite a bit of publicity on news channels when petitions get large numbers of signatures. Nothing will happen on this issue until/unless the public becomes more aware of how much it costs them in lost jobs/innovation/products.To "sign" the petition takes little more than a functional email address:https://petitions.whitehouse.gov/petition/make-patent-trolls-pay-all-costs-associated-their-frivolous-lawsuits-if-they-lose/gWPpVYMt

author: digsys
author_rank: Unknown
timestamp: January 22, 2013, 09:34:34 pm
content: Is this only for US citizens ? It's not clear.

author: Kremmen
author_rank: Super Contributor
timestamp: January 22, 2013, 09:49:20 pm
content: Only in America

author: JoeyP
author_rank: Frequent Contributor
timestamp: January 22, 2013, 10:30:21 pm
content: Quote from: digsys on January 22, 2013, 09:34:34 pmIn theory it's only for US residents and/or citizens, but they're really only interested in the final number of signers. I'm sure they won't be going to a lot of trouble to validate the signatures because it's not regulatory in nature. It's just an "attention getter" which is supposed to give them ideas of what people are concerned about.Even US citizens living outside the US would be perfectly eligible, and their process does nothing to prove eligibility. So, I would say go for it, no matter where you are.
Help to find out the function of the resistor and diode in the open-drain switch - Page 1
Forum section: electronics / projects

author: washburn961
author_rank: Newbie
timestamp: December 26, 2024, 05:04:19 pm
content: Hi everyone,I'm analyzing a low-side switch circuit that uses a BSP75NTA MOSFET from Diodes Inc to control a 24 V load, and I’m trying to understand the specific roles of two components: R1 (1k resistor) and D1 (1N5819 Schottky diode). Here’s the circuit schematic:Circuit Overview:The BSP75NTA is used as a low-side switch.The gate is driven by an NPN BJT (2N3904), which is controlled by an input signal.R1 is connected between the source and ground.D1 is placed across R1.My Observations and Questions:I suspect R1 is there to ensure the source is not left floating.For D1, I assume it blocks reverse currents, possibly protecting against transients. Could D1 be moved to another position, such as in series with the drain, to achieve the same functionality?I don't understand why the people who designed this couldn't just connect the source directly to ground, since at the supply section of the board that contain this cirucit there is a giant unidirectinal TVS diode that could protect against negative transients.Could anyone provide insights into the function of R1 and D1 in this configuration? Would removing or repositioning them make sense, or are they essential for proper operation and protection? Note this circuit is used in an automotive ECU.Thanks in advance for your help!Best,GabrielEdit: had previously linked the wrong image.

author: inse
author_rank: Super Contributor
timestamp: December 27, 2024, 06:53:07 am
content: In automotive electronics there is often a requirement for reverse battery protection.Haven‘t figured out why it’s in the source, maybe to avoid transient negative gate overvoltage in case of reversed battery.I wonder why there is no protection against inductive kickback or is it a purely resistive load?Edit: ah, it‘s a smart switch, so inductive clamping is integrated.
Help to identify a SOT23-6 from its marking? - Page 1
Forum section: electronics / projects

author: Romain
author_rank: Regular Contributor
timestamp: February 15, 2018, 09:49:19 pm
content: HiI'm trying to fix a LCD driver board. It's a LCD kit I bought and I do not have any datasheet nor schematic with it...One of the power supplies capacitors is microphonic and the noise is just terribleAt first I tried to swap the 1µF capacitor with a new 4.7µF capacitor but it made the matter worse. I'd like to get to the bottom of this, and have a look at the converter's datasheet.The component is most likely a Buck converter converting the 12V in to 9V out, probably driving the LCD backlight.The device marking is "W659".Anyone who could help me with that?

author: sstepane
author_rank: Regular Contributor
timestamp: February 15, 2018, 10:43:12 pm
content: Hi,I do usually check the sites for smd markings:http://www.s-manuals.com/smdhttps://www.semicon-data.comhttp://kazus.ru/datasheets/smd/index.htmlhttp://www.smdmark.com/en-US/smd-code-fd2.htmlThere are some more sites if You google with smd markings.However, another very good source for smd markings is taobao. I would search like "W659 SOT23-6" or what is chip packages size and if it sells there - there will be partnumber.Hope it helps. It did many times for me.

author: Romain
author_rank: Regular Contributor
timestamp: February 17, 2018, 07:16:06 pm
content: Thanks sstepane. I could not find anything on the websites, but I'll keep them for future referenceI found a drop-in component on Mouser :https://www.mouser.com/ds/2/115/AP3211-271560.pdfI'm almost certain that it's not the exact same one, but probably close enough to start tinkering with !
help to identify audio transformer - Page 1
Forum section: electronics / projects

author: tinytim
author_rank: Contributor
timestamp: June 14, 2014, 01:22:33 pm
content: Hi guysi have a pair of Superex PRO BV headphones on the bench from the 70'sI have a naff winding on one of the transformersDoes anyone know the spec for this?regardstim

author: SeanB
author_rank: Super Contributor
timestamp: June 14, 2014, 01:52:40 pm
content: That probably is just a simple iron cored choke. Look for a broken wire at one end of the coil most likely.

author: SeanB
author_rank: Super Contributor
timestamp: June 14, 2014, 05:56:54 pm
content: Did a quick chockolate factory search and it seems a common fault is the capacitor failing open or short and the tweeter unit burning out.
Help to identify component!! beyer TG D57c - Page 1
Forum section: electronics / projects

author: angelothewolf
author_rank: Contributor
timestamp: July 07, 2016, 10:40:16 pm
content: hi!Im working on this beyer condenser drumkit mics, i have six of them with the same component shorted, It´s a SOT363 or SOT26 6 pin package and I have one working perfectly so I could compare and Im sure this component is shorted. the thing is i dont know what it is>I mesured the working component and it doesnt have any low resistance betwen any pins. with the diode test it seems to have two parallel diodes in the first two pins going the cathodes to a common pin, and another diode from one pin to another, very strange arrangement to be a diode package I thing.the marking on it is " T4 "

author: Buriedcode
author_rank: Super Contributor
timestamp: July 07, 2016, 11:37:07 pm
content: possibly a dual transistor?http://rohmfs.rohm.com/en/products/databook/datasheet/discrete/transistor/bipolar/imt4.pdf

author: angelothewolf
author_rank: Contributor
timestamp: July 08, 2016, 12:48:52 pm
content: Quote from: Buriedcode on July 07, 2016, 11:37:07 pmwell was my first guess but I fit two PNPs in there and it doest work

author: angelothewolf
author_rank: Contributor
timestamp: July 08, 2016, 01:17:48 pm
content: It is a IMT4!! i was confusing the pinout!thanks!