hybridfree/eevblog-posts huggingface dataset:
Need help with choose QC charger IC for custom powerbank - Page 1
Forum section: electronics / projects

author: az113
author_rank: Newbie
timestamp: September 05, 2021, 11:25:24 pm
content: Hello everyone.How i experience in this year's two-weeks bike travel, me and my friends needs a powerbank with 30-40Ah capacity, and QC function to charge the devices and powerbank itself.What we need: a abstract powerbank, that can in 30-60min charge battery at least that much, so that the charge is enough for one phone charging, or so (within riding a bike we stops from time to time in a Roadside stores to rest or buy water).How i imagine a concept:A "single-cell" Li-ion (or Li-pol) battery with capacity 30...40000mAh, based on Tesla 18650, Tesla 21700 or flat-pack LiPol cells like mobile batteries.Stand-alone step-up DC-DC for QC a devices like mobile phone or other user devices like GPS.Stand-alone module for charge inner battery, that must give at least 1/10C for battery capacity (i.e. 3A) from regular wall charger with QC2, QC3 or QC4, that can deliver 22-27W (my MI wall charger delivers 12V2.25A or 20V1.35A as example)(optional) DC IN cirquit for use a solar panels with 12...24v output (if this function not supported by charger natively), or custom AC adapter like notebook's 19V 4.75A(optional) charge indicator or voltmeter to monitoringSo, i begin to search suitable step-up DC-DC to support QC for devices, and found a cheap and very useful chinese board, based on TPS61088, so this part of project is closed now.But in search of charger for main battery i was screwed up: all cheap (or not so) chinese boards draws only 1-2 amps output from wall, even with QC enabled.It is a critically not enough for reasonable charge time.Here is a Fast Charger Module based on IP5328 (theoreticaly, it must draw up to 5A, charging battery, so i bought some to test), but it won't enable QC, try on 4 different chargers, also 100% QC capable. Only 5V, only 11W total. It is critically low for my goal. May be i don't know something?Because i failed with IP5328, so i continue to search charger, that will draw 4.2V@3+A from regular QC wall charger.Sure, i can use a 90W notebook adapter and one of wide available chinese buck regulators, but goal is a compatibility with any regular charger from modern phone.Any ideas, please?
Need help with code to add a button to change array speed - Page 1
Forum section: electronics / projects

author: c3d20
author_rank: Contributor
timestamp: August 16, 2012, 03:16:37 pm
content: Arduino Uno.Help is very much appreciated.Put this into a case:This is what I had when first writing the script which I dont even think would have worked and anyway is now uncompatible to do this action:you get the idea though of what I was trying to doCode:buttonPin2State = digitalRead(buttonPin2);if((buttonPin2State== HIGH) && (digitalRead(ledPin3) == HIGH)) {for (count=0;count<5;count++ ) {digitalWrite(pinArray, HIGH);delay(timer*2);digitalWrite(pinArray, LOW);delay(timer);}}else if ((buttonPin2State == HIGH) && (digitalRead(ledPin5) == HIGH)) {for (count=0;count<5;count++) {digitalWrite(pinArray, HIGH);delay(timer);digitalWrite(pinArray, LOW);delay(500);}}else if((buttonPin2State== HIGH) && (digitalRead(ledPin6) == HIGH)) {for (count=0;count<5;count++) {digitalWrite(pinArray, HIGH);delay(400);digitalWrite(pinArray, LOW);delay(200);}}}

author: c3d20
author_rank: Contributor
timestamp: August 16, 2012, 04:58:41 pm
content: I found this which might workhttp://leaflabs.com/docs/lang/api/hardwaretimer.html
Need help with component values for rc & lc filter - Page 1
Forum section: electronics / projects

author: bigjoncoop
author_rank: Regular Contributor
timestamp: June 22, 2019, 01:04:14 am
content: I need to create a RC filter and LC filter for a 5 volt circuit with around .5amp draw.I tried to make an RC filter with a 1k resistor and 330uf cap also tried a 1000uf cap but didnt help clean the 5v signal.This is to power a 5.8 GHz receiver module. I have only been able to get a clean signal using a linear regulator but using it by itself is not an option since it gets so hot. I'm trying to create a capacitance multiplier using the 5 volts from a buck regulator. And I want to create an LC filter as well but I'm not sure of the value of components I need to use for it or a rc filterThx u

author: bob91343
author_rank: Super Contributor
timestamp: June 22, 2019, 04:19:51 am
content: First you need to write a specification for the filter. What frequencies do you want to reject and what frequencies do you want to pass?Armed with that information you then can proceed to design a filter. You will have to decide how much attenuation you want and how much loss you can tolerate. And, in the process, how many stages of filtering will be required.There are lots of books on the subject. It's not something you can shotgun, as you have discovered. There are also cookbook calculators available online but these may not satisfy your needs.Maybe a simple RC filter will do, or maybe you will need a five stage job with M derived end sections. Or a Sallen-Key active filter.
Need help with converting power on 650 watt atx psu - Page 1
Forum section: electronics / projects

author: jamessinghal
author_rank: Contributor
timestamp: April 19, 2017, 10:08:10 pm
content: I am currently looking into options for my new higher current power supply for my workshop, andI came since I am into building computers, I found an ATX power supply to power it, as it has the higher quality than if it was froma non-name brand company in China.The link to the PSU is:https://www.newegg.com/Product/Product.aspx?item=N82E16817139200Since computers don't need a power rail above 12v, the highest there is, is a 12v 54a rail. This would be perfect if it was 54v and 12v, but I am not sure about how to do that.My main question is, how can I convert it to higher voltage, and lower amperage (with decent efficiency), and if this isn't possible, is there another money friendly way to get about 54v and 12a max on a power supply. (I will be turning it into a variable supply)Thanks!

author: wraper
author_rank: Unknown
timestamp: April 19, 2017, 10:22:57 pm
content: No way modifying it to 54V. But you could attach boost converter to 12V output to get 54V.
Need Help with Eltek Flatpack 1500 24 Volt Supply - Page 1
Forum section: electronics / projects

author: DRBuck
author_rank: Contributor
timestamp: July 26, 2021, 11:20:06 pm
content: I have an Eltek 1500 24 Volt Flatpack Rectifier Module I want to use to power a 1296 MHz amplifier. The full part number is FP1500 and it is available in 24V, 48V and 60V versions. The 24V version is the Flatpack 1500, 241114.300.I have been completely unsuccessful at locating a service manual for it. I did come across the schematics for the 48 volt version which is supposed to be similar.When I connect AC power to turn it on, the Red 'ALARM' LED lights up and the 'POWER' LED does not light. This state is listed in the fault table of the user manual but none of the possible errors seems to be the problem. I am getting 24 VDC at the output connector both with and without a load. So, it appears to be working but with the FAULT light on the load current indicator does not function. I would like to make this work like its supposed to.Any one have the Eltek Service Manual? Or, is anyone familiar enough with these supplies to have an idea on where the problem might be?EDIT -- I attached the 48V schematic, image of the unit I am having issues with and the user manual "Fault Table".

author: TheMG
author_rank: Frequent Contributor
timestamp: July 27, 2021, 03:24:43 am
content: As these are not really intended to be used as a stand-alone unit (without the shelf system that it slots into), it's highly probable the alarm state is caused by a missing signal.What exactly is making it unhappy though will take some trial and error, and/or careful reverse engineering. Of course, a lot easier if you have the proper shelf for the unit.

author: trobbins
author_rank: Frequent Contributor
timestamp: July 27, 2021, 03:53:56 am
content: I agree that the rack system may provide a control line - you may need to look for operational system level docs to see what controller is used for such rack systems, and whether the rectifier modules can operate standalone (eg. if the control module is hot-swap). Such telco systems often require return of the rectifier to official service outlet, and any schematics/repair docs are only available in-house.You could fairly safely confirm correct operation of most of the control circuitry, such as by connecting in say 20Vdc to input of VR1, and 12Vdc to its rail, and then probing all related circuit functions (assuming the 48V module schematic is accurate for the 24V module for the control sections).
Need help with my IoT Project ESP8266 NodeMcu to ESP12-E - Page 1
Forum section: electronics / projects

author: Osfuco
author_rank: Newbie
timestamp: March 27, 2021, 09:20:38 pm
content: Good evening, I am doing a project in which I want to measure air quality. I started the project with the ESP8266 NodeMcu board and three sensors, temperature (DHT22), VOC's (CCS811) and PM (PPD42).I have it all assembled with a breadboard and the NodeMcu and it works fine.The fact is that I want to pass it to PCB and I am a little lost. From what I've been reading, I have to use the same board but without NodeMcu, so I use ESP12-E.I have tried to make a design on the webhttps://easyeda.com/, (I attach images). I copied the connections that I already have working and grouped all the GND connections in a single point.The 3V3 pins I still have no idea how to do it, if anyone can give me a hand I would appreciate it.Am I wrong or am I on the right track?Thanks a lot! (::
Need help with name of a connector/socket - Page 1
Forum section: electronics / projects

author: homemadecpu1986
author_rank: Contributor
timestamp: June 26, 2020, 03:50:43 pm
content: Hello friends!I need some help in knowing the name of this socket. I need to buy a socket that will connect to these pins on myboard, but I am having trouble finding this. Do you know the name of the connector I need ? On the photo the pins I meanare just the ones on the white supports. You see there are a bunch of them going down.Here is a photo of the pins. These are all power pins. Some 5V, some 12V and some grounds.So I need this only for power connections. Thank you so much guys.

author: bateau020
author_rank: Frequent Contributor
timestamp: June 26, 2020, 05:56:54 pm
content: What is the pin spacing and the pin length?By the looks of it, I would guess 2.54mm pin spacing. In that case, molex kk-254 would fit just fine.Probably the most common connector type in hobby electronics.

author: tonyh88
author_rank: Regular Contributor
timestamp: July 06, 2020, 12:19:56 am
content: As mentionned by bateau020 measure the pin pitch on the connector and have look on digikey by doing a parametric search with the pin pitch.These are just standard pin headers so anything could fit really and the most common is 2.54mm pitch but do measure just to be sure.This Molex one could probably work:https://www.digikey.com/product-detail/en/molex/0022013067/WM2004-ND/26439Or if you want more option here is the digikey parametric search for 6 positions 2.54 pitch housings:https://www.digikey.com/products/en/connectors-interconnects/rectangular-connectors-housings/319?k=&pkeyword=&sv=0&pv2172=i1&sf=1&FV=-8%7C319%2C88%7C249730%2C89%7C9726&quantity=&ColumnSort=0&page=1&pageSize=25

author: MarkMLl
author_rank: Frequent Contributor
timestamp: July 09, 2020, 11:14:53 am
content: Those look more like some variant of 0.15" Molex. Other relevant dimension is the pin thickness, which is going to be somewhat larger than the 0.1" (2.54mm) that everybody loves.OP: you probably need vernier calipers to measure this. Digital ones are cheap and readily available these days.MarkMLl
Need help with power rating for active equalizer components - Page 1
Forum section: electronics / projects

author: hummusdude
author_rank: Regular Contributor
timestamp: June 28, 2020, 03:34:13 am
content: I'm building this 5 band active EQ for my home hi fi. I'm putting together a PCB and because I'm making it stereo there are a lot of passive components. Although I have minimal experience using SMD parts I starting thinking this may be the way to go to keep the size of the board from getting too big. But then it occurred to me that since this isn't a strict logic circuit that the power rating could be a factor. I'm comfortable with small circuit analysis but this one is quite complex for my experience. I'm not at all confident I could figure out the max power draw, or potential current hot spots that need a little more capacity. Is there a rule of thumb for this sort of circuit?

author: dmendesf
author_rank: Frequent Contributor
timestamp: June 28, 2020, 03:58:45 am
content: Your ICs will consume like 10mA each, not a big deal. You can use 0603 resistors and capacitors. Large value capacitors may be better served by 0805 size.

author: jdthorpe
author_rank: Newbie
timestamp: July 02, 2020, 08:20:44 am
content: So, it looks like the Vs+ and Vs- for the opamps are left out (for brevity), but one thing I think mightbe an error is highlighted in in green in the attached schema. My read is that the highlighted node should not beconnected, but I'm a total noob so I'd be equally happy to find out that I'm wrong

author: hummusdude
author_rank: Regular Contributor
timestamp: July 07, 2020, 05:12:54 am
content: Great observation. I have to agree it seem odd that the virtual ground would be tied to the output of the input buffer.

author: hummusdude
author_rank: Regular Contributor
timestamp: July 07, 2020, 06:03:58 am
content: Also wondering if it's necessary to keep signal ground and power ground separate in a low power circuit like this. I know it's good practice on a power amp to prevent ground loop hum issues, but this is very low gain so not sure if that matters. The person who made the schematic seems to have gone out of his way to show signal ground and power ground as separate.

author: jdthorpe
author_rank: Newbie
timestamp: July 12, 2020, 12:50:38 am
content: The virtual ground is held at 6v (b/c of the 100K resistors), which is (for example) connected to the reference pin (pin 3) of IC3(B) opamp. I believe this is important because the power pins (4 and 8 ) are connected to 0 and 12v, and the bandpass circuit requires that the voltage on the reference pin of the op amp be half way between the power pins...
Need help with programming I2C ADC using arduino - Page 1
Forum section: electronics / projects

author: OM222O
author_rank: Frequent Contributor
timestamp: December 07, 2018, 09:30:43 pm
content: HelloI made a board using an atmega328p-au (arduino nano) , an ADS1219 and a voltage reference.I'm not very good with programming, especially for I2C communication. Can somebody help me get the circuit to work?

author: archnemesis
author_rank: Contributor
timestamp: December 07, 2018, 10:58:17 pm
content: Try Google.I hope that answer was as frustrating for you as reading your question was for me.

author: OM222O
author_rank: Frequent Contributor
timestamp: December 07, 2018, 11:00:58 pm
content: I tried googling , searching github and even the arduino froum

author: archnemesis
author_rank: Contributor
timestamp: December 07, 2018, 11:03:36 pm
content: But you offer no indication of anything you've tried, what you're even having issues with. Did you write any code?

author: OM222O
author_rank: Frequent Contributor
timestamp: December 07, 2018, 11:22:00 pm
content: I found some codes which are for the ADS1115 (a very similar product, 16 bit I2C ADC) and tried modifying it to work with the 24 bit ADS1219 but I had no luch tbh. My main issue is using the register maps given in the data sheet and writing / reading data to / from them.

author: rstofer
author_rank: Super Contributor
timestamp: December 07, 2018, 11:28:19 pm
content: Maybe start here:https://www.arduino.cc/en/Reference/WireOr here:https://playground.arduino.cc/Main/SoftwareI2CLibraryOr just Google for 'arduino i2c library' = there will be about 1,460,000 hits.Or, Google for 'arduino ads1219' There won't be anything directly on point but there is a hint that code exists for a similar device.I2C is my least favorite protocol. It is a real problem child to bring up unless you have the tools - like a logic analyzer or scope with I2C decoding.

author: rstofer
author_rank: Super Contributor
timestamp: December 07, 2018, 11:57:37 pm
content: The biggest mistake people make with I2C is dealing with the address. If both A0 and A1 are grounded, the address of the device is 40h as a 7 bit quantity. The value is shifted left one spot to make the address actually sent over the wire as 80h or 81h where the low order bit is the R/W' value. In effect, you write the commands to 80h and read the status from 81h. Those are the only addresses and there is only one register in each direction. See page 29 here:http://www.ti.com/lit/ds/symlink/ads1219.pdfSome libraries will handle the shift internally and mask in the R/W' bit so you tell them to use address 40h and the code knows what to do with the R/W' bit. Other libraries want you to shift the address (to 80h) and still allow them to mask in the R/W' bit. Getting this part right is the main difficulty with I2C.For a first approximation, I would write code to read the status register and look for some kind of ID code in bits 0..6. I'm hoping they didn't leave the field 0x00 or 0xff. If I could get a consistent ID, I would know I'm on the right track. Just print the value to the terminal.
Need help with protection circuit for a single cell lithium battery - Page 1
Forum section: electronics / projects

author: Metalloid
author_rank: Newbie
timestamp: November 10, 2020, 06:48:47 pm
content: Hello, I'm a designing a small wearable device with a 15mAH single cell lithium battery and I'm having some problem with the design of the protection circuit.The standard approach is using a specific IC like for example the AP9211 or BQ297xx, the problem of this solution is that all the protection IC that I found have a typical consumption of 3uA or more which is a lot considered that the entire system consumes 7.5uA at the nominal 3.7V .The PMIC I'm using has already: under voltage, overcurrent and overcharge protection.Should I rely on the PMIC protections and connect the bare cell directly to it? The only component before the PMIC is a 10uF ceramic cap, so in case of failure of this cap the cell will be short circuited before the PMIC.The battery has a 1C maximum discharge rate so I was thinking of using a small surface mount fuse before the PMIC like one of this series by AVX:http://datasheets.avx.com/AccuGuardLC_0402.pdf, the smallest has a 70 mA fusing current, which I'll have to test.What do you recommend?Should I even be this worried about a "small" cell? My main concerns arise from the fact that it's wearable and I want to be extra safe.Thanks a lot for the help.

author: bob91343
author_rank: Super Contributor
timestamp: November 10, 2020, 10:07:55 pm
content: Safe from what? If you can define the threat you are better equipped to devise protection from it.

author: Metalloid
author_rank: Newbie
timestamp: November 11, 2020, 01:02:02 pm
content: I’m not an expert in lithium protection. In past project I’ve always used a specialized IC. It is my understanding that a lithium cell could catch fire due to short circuit and overcharge.Also a deep discharge could damage the cell.Being the product a wearable that is worn close to the body a fire or a big rise in temperature is a big hazard.Right now I don’t have the sensibility in this field to decide if a fuse and the pmic is a good decision or if I must use an IC.

author: Peabody
author_rank: Super Contributor
timestamp: November 11, 2020, 03:13:17 pm
content: Could you provide a link to the PMIC you're using, and perhaps a diagram of your power circuit?The protection chips I know about, such as the DW01, run the battery's negative terminal through mosfets to ground. So a shorted capacitor from the positive terminal to ground would trigger the protection ciruit and one mosfet would be turned off. If your PMIC doesn't include something like that, then I think you would need a protection chip (preferably one built into the battery), and I think 3uA would be pretty typical. But I don't know what's available that works with a battery that small.
never mind - Page 1
Forum section: electronics / projects

author: GaMtnMan
author_rank: Newbie
timestamp: October 23, 2014, 10:16:29 pm
content: thanks

author: GaMtnMan
author_rank: Newbie
timestamp: October 23, 2014, 11:17:42 pm
content: for nothing

author: DenzilPenberthy
author_rank: Frequent Contributor
timestamp: October 24, 2014, 03:15:45 pm
content: I'm going to be Buzz Killington here and point out the obvious safety implications of a home made remote control system for a sawmill. I don't know which country you're based in but here in the UK the HSE would throw the book at you if there was an incident. Unless that is you can show that your system complies with all the relevant safety standards. e.g. PUWER, Machinery Directive, god knows what else? Presumably there are specific standards for remote control industrial equipment like this.Obviously if it's for your own personal use then you can do what you like but no one has a Wood-Mizer just to cut stuff up for their own personal domestic use.
Need help with RF communication - Page 1
Forum section: electronics / projects

author: rea5245
author_rank: Frequent Contributor
timestamp: January 20, 2015, 03:25:40 am
content: Hi,What's a good option for RF communication between microcontrollers, with a range of at least 100 feet?The project is a mailbox detector, with the transmitter outside in the mailbox by the street, and the receiver indoors. I've been using cheap 433MHz transmitter/receiver modules from eBay, with 1/4 wave helical antennas. They were working at first, but the range has dropped dramatically recently, so the system no longer works. I don't know why - maybe there's some new RF interference in the area. The problem does not appear to be temperature-related: if I bring the transmitter indoors, the range is still bad. The battery also appears to be OK: the transmitter is powered by a 9V battery that currently reads 8.5V.The messages are sent from the microcontroller's UART at 300 baud to the transmitter, and they are sent redundantly.Any suggestions for improving communication?Thank you,Bob

author: KM4FER
author_rank: Regular Contributor
timestamp: January 20, 2015, 04:34:20 am
content: Everybody laughs at troubleshooting step 1, "Is the device plugged in?" but it's step 1 for a reason.In your case, have you tried a new battery even though you think the one you have is still good?earl...

author: w2aew
author_rank: Super Contributor
timestamp: January 20, 2015, 05:28:59 am
content: Quote from: KM4FER on January 20, 2015, 04:34:20 am^^above^^The battery may read 8.5v, but you have to remember that these 433MHz modules transmit with a very low duty cycle, thus you're likely not seeing how low the battery voltage drops during the transmission. And, transmit power may be proportional to the square of the supply voltage.
need help with shipping 3 I.C. chips from U.S. to Lithuania - Page 1
Forum section: electronics / projects

author: xwarp
author_rank: Frequent Contributor
timestamp: November 02, 2015, 09:05:12 pm
content: I am confused about the HS codes.I am sending an envelope from the U.S. to Lithuania using USPS. The items are 3 identical I.C. chips from a Fluke 8840a.Value is $10.USPS is asking for a 6 digit code. Best I can find so far starts 8542. What are the last two digits going to be?

author: Ian.M
author_rank: Super Contributor
timestamp: November 02, 2015, 09:21:59 pm
content: http://www.foreign-trade.com/reference/hscode.cfm?code=8542You need to know if the chips are purely digital or analog/mixed sig.

author: xwarp
author_rank: Frequent Contributor
timestamp: November 02, 2015, 09:24:47 pm
content: As a matter of fact, the service manual/schematic shows them to be simply op amps.It appears to be 4 per chip. Fluke's manual shows LM339 amps.

author: Ian.M
author_rank: Super Contributor
timestamp: November 02, 2015, 09:27:51 pm
content: So that's obviously "854219 Other Monolithic Integrated Circuits"

author: xwarp
author_rank: Frequent Contributor
timestamp: November 02, 2015, 09:29:52 pm
content: O.K. thanks!also, these chips appear to be a custom made LM339.
Need help with solar lamp project - Page 1
Forum section: electronics / projects

author: ElectricPower
author_rank: Frequent Contributor
timestamp: November 18, 2022, 05:16:26 am
content: I have designed an simple PCB with EasyEda thats smaller then tha PCB inside my cheap Garden solar LED lamp.Here is the example circuit in datasheet for the QX5252 component that i followed. (I only use one LED diode)And here is the schamtic i made PCB from:Here is link to Chematic:https://www.mikroshop.ch/pdf/QF5252F.pdfSo what is my problem?The lamp works when i give it some light before placing it in the dark. it's lights up fine and works, for a while. I do not know how long time it works, but under one hour. When i give the solar cell light again (just for one second) it works for about one hour again before the led stop working. I have measured the battery and that shows 1.17V. Brand new battery.My only explanation is that i have done something wrong when i copied the schematic from datasheet, but i'm not an expert and i need som help to see what i'm missing.I have tried to change to a new QX5252 driver component, with no luck.I can't see what i can have done wrong here.Can somebody please give me an helping hand?

author: Unica_Research
author_rank: Contributor
timestamp: November 19, 2022, 02:14:43 pm
content: it's a potential faultiness of chip designer, you should try YX8018.

author: ElectricPower
author_rank: Frequent Contributor
timestamp: November 20, 2022, 06:03:35 am
content: Quote from: Unica_Research on November 19, 2022, 02:14:43 pmI think YX8018 has an different pin configuration.

author: Electroplated
author_rank: Regular Contributor
timestamp: November 20, 2022, 09:31:39 pm
content: Try changing the inductor, data sheet ranges indicate between 33uH and 330uH I have never seen these type of circuits using a 470uH inductor, then give the battery a real charge if possible or leave it in light for a few hours and test it again, if it only runs for a short time you either have oddball IC's or your IC is cutting off the battery, it should run down to just above 0.7v before it gives up.You could use the 8018 or one of its variants or you could just buy a cheap solar light and rip the PCB from it if your projects not a garden light, its sometimes cheaper to salvage then piddle about with parts, PCB design and assembly, more so for such a small project.Edit to correct uH values.
Need help with solar light PCB design. - Page 1
Forum section: electronics / projects

author: convoy84
author_rank: Newbie
timestamp: September 14, 2022, 05:44:52 pm
content: Hello all!I am trying to design a simple solar light PCB to use when I make projects. This is the first time I have attempted Circuit design and I’m not very good at making schematics yet. I recently got in the first prototype batch and I can’t get it to work after soldering my components to it. I tried troubleshooting it myself but have had no luck. Can anyone take a look and see if they can see any obvious mistakes or point me in the right direction?I started with the QX5252f datasheet and added a capacitor, diode and switch. I think I must have a connection wrong, I have successfully made this circuit on a breadboard.I have included pictures of the board and the schematic from EasyEDA.Any help would be appreciated!

author: strawberry
author_rank: Super Contributor
timestamp: September 14, 2022, 06:37:30 pm
content: joule thief circuit

author: Marco
author_rank: Super Contributor
timestamp: September 14, 2022, 07:30:37 pm
content: The way you draw schematics hurts my brain. You make life difficult on yourself by not drawing the voltage rails similar to the datasheet, that's probably what caused you to connect the solar panel wrong, Strawberry has it right.

author: convoy84
author_rank: Newbie
timestamp: September 15, 2022, 03:10:29 am
content: Thanks for the help!Now I can clearly see I connected the negative solar panel to battery positive.I broke the trace and bodged a wire to the negative and now it works! In the revised schematic what advantage is there to moving the switch to ground instead? The diode and LEDS are flipped also, is this just better for routing?

author: strawberry
author_rank: Super Contributor
timestamp: September 15, 2022, 06:56:49 am
content: IC leakage currentswitch contact arc can produce some over voltage spikes (need voltage clamp circuits RC/RCD)to shorten PCB inductive loop. some 100n across powersupply near IC

author: rooppoorali
author_rank: Regular Contributor
timestamp: September 17, 2022, 03:58:45 pm
content: You can also see these designs:https://www.pcbway.com/project/share/Solar_light_Board.html

author: floobydust
author_rank: Super Contributor
timestamp: September 17, 2022, 07:46:38 pm
content: OP, I see a couple mistakes in your circuit, and unfortunately your PCB.The two LED's, C1 should connect to BATT(-) not to BATT(+). edit: solar cell as well. The circuit won't operate.Your inductor value is huge at 1mH, it is more typically 33-100uH.D1 1N4148 loses more voltage than a Schottky part like 1N5817, so the 1N4148 is not as efficient.
Need help with Sony Vaio VGC-RM1N Access Unit hack! - Page 1
Forum section: electronics / projects

author: deltawars
author_rank: Contributor
timestamp: November 17, 2013, 04:42:55 pm
content: Hi my brothers old sony vaio PC broke so he chucked it out but throwing the acces unit seemed like a waste so i thought i would try to hack it.In the main PC case there was a PCI-E card but it has a special plug socket so i looked up the datasheet for the PCI-E chip to see if i could make a adapter that would plug into a normal PC.I Found the datasheethttp://www.alldatasheet.com/datasheet-pdf/pdf/136694/PERICOM/PI2EQX4401ZFE.html?But What Pins on the chip go to what pins on a normal PCI-E Slot?Many Thanks-Ethan

author: SeanB
author_rank: Super Contributor
timestamp: November 17, 2013, 04:54:16 pm
content: Probably a one to one correspondence with a regular PCI slot. Sony likes to do that using odd connectors, but best is to look up the specs of the PCI standard and look as to where the power pins on the card connect and where the pins on the PCI chip go on the card, then you can make an adaptor to mate them.
Need help with the Jay_Diddy_B Transmission Line Avalanche Pulser - Page 1
Forum section: electronics / projects

author: rodd
author_rank: Regular Contributor
timestamp: May 21, 2023, 04:07:47 pm
content: Hi Folks,I am taking the liberty to re-open an old thread about building a Jim Williams type fast rise pulse gnerator.The thread is:https://www.eevblog.com/forum/projects/transmission-line-avalanche-pulse-generator/msg606142/#msg606142.Jay_DiidY_B kindly posted the gerber files and a schematic drawing of his design at this thread.However, I am having some problems trying to build it.For example:I could not find the place to install L1 (10nH choke) and could not locat R9 on the schematic.I am enclosing the photos of the board manufatured accoring the files he attached as well as the latest version of the schematics that I could find.Did anybody built this project?Is there a BOM for it available?Thanks to all.

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: May 23, 2023, 02:44:19 am
content: Hi rodd,The pictures are in this message:https://www.eevblog.com/forum/projects/transmission-line-avalanche-pulse-generator/msg606142/#msg606142The PCB was not updated.Also read:https://www.eevblog.com/forum/projects/transmission-line-avalanche-pulse-generator/msg3037828/#msg3037828Regards,Jay_Diddy_B

author: rodd
author_rank: Regular Contributor
timestamp: June 01, 2023, 08:48:42 pm
content: Hi,Thank you for the reply.I have another question: the LTC1799CS5 comes in a SOT-23-5 package, which has 5 pins.However the pcb has a footprint for this IC with 8 pins.What is the correct part number to be used in this project?Thanks

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: June 01, 2023, 09:21:18 pm
content: rodd,I think it is a 555 timer.See the attached schematic.Jay_Diddy_bTransmission Line Avalanche Pulse - Nov 28 2013.pdf(28.83 kB - downloaded 100 times.)

author: rodd
author_rank: Regular Contributor
timestamp: June 12, 2023, 05:59:33 pm
content: Hi,I finally got all the parts that are needed.After assembly I noticed that this design uses two sepparate power supplies.One for the uA7805 (probably +7.5V or higher) and another >= 30V.I was thinking of powering this device from a USB connection for the +5V (bypasing uA7805) and using a Lm2596 boost regulator module to get the +30V required.Is that a reasonable idea?I wonder if the noise introcuded by the boost regulator (that would be close to the Pulser PCB) would cause any problem.Any comment will be welcome.Thanks
Need help with tiny unknown RC-aircraft GPS pinout - Page 1
Forum section: electronics / projects

author: cdev
author_rank: Super Contributor
timestamp: August 03, 2017, 10:32:29 pm
content: I just picked up a used RC aircraft module (ublox m8n) and it has a very small inline six pin connector that connects to a very small six connector plug Y-cable which splits off to two separate 4 conductor plugs of the same type.It actually appears to not be one of the common GPS pinouts, as far as I can tell.(rest of my ruminations no longer relevant, deleted)--------So, to make a long story short, the cable the vendor gave me fit the GPS but was wired for another GPS, with the four essential non-compass connections divided between two plugs.Thats what was confusing me.The ground and TxD was on the 2nd connector. The connector on the GPS itself is wiredSCL ---> (compass i2c) (usually these are on their own 2 wire plug)SDA (compass)5volts Vcc for all (usual wiring)RxD GPS "TxD ----> GPS " (two wire plug now)Gnd Gnd for all " "So, that solves my problem.For future reference in case anybody else ever encounters this GPS board, I am attaching a photo I found giving the proper order.Why did I want an older M8N and not a newer one?To do RTK (super accurate GPS) with it, a capability which was never supported by Ublox on their cheapest GPSs, but which they had, due to a special test mode. .
Need help with TPS56921 Voltage Converter - Page 1
Forum section: electronics / projects

author: CorbPeters
author_rank: Newbie
timestamp: January 19, 2013, 06:48:44 am
content: Hello,I have been struggling with making this thing work. I am working on a project that needs anywhere from 3 to 10 amps at 6 volts from an 8 volt source. I have read through the datasheet and tried several attempts to make this thing work but I have not gotten any good results. I have used the example circuit as a template and run through the calculations and am still unable to get even a regulated output. The best I have gotten is around 2 volts out but and this is dependent on the input. As I turn up the input voltage the output voltage also increases. If anyone is interested I can provide the values I have calculated. I have no experience with switching regulators and need some help getting started.Thanks for the help,Datasheet:http://www.ti.com/general/docs/lit/getliterature.tsp?genericPartNumber=tps56921&fileType=pdf

author: BravoV
author_rank: Super Contributor
timestamp: January 19, 2013, 08:29:33 am
content: Assuming all you've been through only in software simulation, then that was probably 0.001% of your problem.Quote from: CorbPeters on January 19, 2013, 06:48:44 amThe above quote is the rest of your nightmare. The ic you pointed switches at Mhz range is not an easy ic to work with especially without any experience at all.Suggesting you to read this thread throughly, try not to focus on the IC since it doesn't meet your need, but rather than the OP's journey, yours problem might be harder than this one ->https://www.eevblog.com/forum/beginners/still-trying-(and-failing)-with-the-lm2588-5v-gt-12v/

author: sorin
author_rank: Frequent Contributor
timestamp: January 19, 2013, 03:00:01 pm
content: the maximum output voltage of TPS56921 is 1.48V

author: CorbPeters
author_rank: Newbie
timestamp: January 19, 2013, 04:32:29 pm
content: First off I have not done the software simulation I have done all my design based on the datasheet. Second the chip has an I2C interface that sets the voltage from .72 to 1.48 in 10 mV increments but it also has an external output voltage control using a resistor divider to get up to 15 volts.Thanks for taking time to help me out.
Need hobby electronic enthusiast to build voice modulators in NZ - Page 1
Forum section: electronics / projects

author: Trackhappy
author_rank: Newbie
timestamp: October 21, 2017, 11:08:04 pm
content: Hi all,Firstly, I apologise if this is the wrong place to post, but it seemed the best fit.I currently build voice modulators in Australia for Dalek enthusiasts. Occasionally, I get a request from New Zealand and send one over. Obviously the postage and time delays make it difficult to support them and I am hoping there may be somebody over the pond who likes building such devices and can build and support them going forward. I do them no profit, but whoever takes it on is free to set their own rules. There are several proven designs we offer (USA, UK, Canada suppliers as well) and my new fully digital one, details and support of which are available to the right person. Check out projectdalek.co.uk for some more information, search for trackhappy.Thanks,Glenn.

author: vk6zgo
author_rank: Super Contributor
timestamp: October 22, 2017, 01:35:21 am
content: Quote from: Trackhappy on October 21, 2017, 11:08:04 pmWhy do you need voice modulators?I can do a pretty good imitation without one.

author: frog
author_rank: Contributor
timestamp: October 22, 2017, 01:51:13 am
content: I might well be up for it - I'll message you.
Need info: co-opting the analog PID of an HDD - Page 1
Forum section: electronics / projects

author: Orpheus
author_rank: Regular Contributor
timestamp: March 29, 2013, 12:07:57 am
content: I should preface this by saying that I don't know the detailed PCB layout, chip choice, etc. of any HDD controllers. Normally, I'd just keep my mouth shut and file this idea with all the other promising tidbits, but it occurred to me that some of you DO know this stuff, so I could advance my notion further by asking.HDD controllers have very interesting precision mechanics. I don't have a specific use in mind at the moment, but I work a fair bit with microscopy and other projects on a micrometer or millimeter scale, so I could envision even the native mechanics of an HDD may span sufficient range to be directly useful to some precision positioning project I might use someday.Today, I was reading some literature and a passing reference to theanalogPID on HDDs just leapt off the page at me. I'd always been interested in using HDD mechanicals. I'd hacked a positioner from some mysterious surplus specialty FDDs whose origin I never learned (and could therefore never restock on) and have seen a few interesting projects on Hack-a-day, but somehow it just hadn't hit me that HDD voice coils would need analog PID for positioning, unlike the mechanical positioning on my FDDsFirst question is: how tightly integrated in the PCB on an HDD. Is the analog loop likely to be separate or buried in a specialty MCU?Second question: Would it be strictly analog voltage levels or some form of pulsed signal like PWM?Even if you think my notion is hopelessly unpromising (it may well be) I'd appreciate any help in learning.

author: marshallh
author_rank: Unknown
timestamp: March 29, 2013, 12:13:57 am
content: Look up old magnetic encoding formats like MFM and work from there. Every hard drive will have analog conditioning and DSP on it. Modern consumer drives are very highly integrated. My unedcuated best guess would be to put a very fast ADC on the heads.Look up the discferret project
Need info on Motorola SC71280K...... - Page 1
Forum section: electronics / projects

author: jsantoro
author_rank: Regular Contributor
timestamp: May 25, 2020, 10:56:15 pm
content: This is a +15V regulator in a TO3 can. Specifically interested in operating temperature range. I can't find a datasheet anywhere for them. Is it some Mil Spec device?Thanks,jim

author: srb1954
author_rank: Super Contributor
timestamp: May 27, 2020, 08:03:26 am
content: Motorola used the SC prefix on customer-specific parts. This was typically for mask ROM programmed micros but it may also apply to other parts designed, tested or selected to a specific customer requirement.It may be difficult to get any published information on this part although you could always saw the top of the can and see if there is any marking on the die.

author: jsantoro
author_rank: Regular Contributor
timestamp: May 27, 2020, 05:41:08 pm
content: Thanks. I was curious,they work just fine. Do you know if they made anything TO-3 that was rated less than 125deg C?

author: srb1954
author_rank: Super Contributor
timestamp: May 29, 2020, 05:18:57 am
content: No, not without doing a search through every item in the Motorola catalog(s).However, I do know that there are some devices rated for more than 125deg junction temperature when packaged in a metal can. For example, the 78xx series regulator was available in 2 grades tested for operation at 125deg junction temperature or at 150deg.

author: jsantoro
author_rank: Regular Contributor
timestamp: May 29, 2020, 02:36:13 pm
content: Thanks again. This can is the equivalent of a 7815. I'll just assume it's a 125 deg device.
Need J-TAG or not ? - Page 1
Forum section: electronics / projects

author: Md Mubdiul Hasan
author_rank: Regular Contributor
timestamp: April 29, 2019, 06:35:49 am
content: Currently I am working IAR 7.80.2 1 months trial version.I need some help.Currently I am trying to download firmare of WIFI module through a USB serial COM port.I have SDK firmware for this wifi module.This module wifi module has...1. On-chip PA, LNA, and RF Switch2. Connection Manager for Autonomous and Fast Wi-Fi Connections3. Built-in Hardware Crypto Engines for Advanced Security4 . 16-bit Sigma-Delta ADC : Differential 2 Channels12-bit SAR ADC : Single-Ended 4 Channels5. Supports Various Interfaces– eMMC/SD Expanded Memory– SDIO Host/Slave Function– Quad-lane SPI for External Flash Control– 2 Universal Asynchronous Receivers and Transmitters(UARTs)– Serial Peripheral Interface(SPI) Master/Slave Interface– Inter-Integrated Circuit(I2C) Master/Slave Interface– I2S for Digital Audio Streaming– Pulse-Width Modulation(PWM)– Individually Programmable, Multiplexed GPIO Pins– JTAGRight at the moment, I need to check weather my WIFI module can split its data in smart phone APPs or can be connect in AWS cloud.In the Debugger category, generally the driver selects an available debug probe via the SWD or JTAG interface.It can not be used when writing firmware via serial communication.Practicaly I have connect this module to serial port by SECUIRE CRT,but no data has recieved !To activate the 4 image files are necessary. This image has SFDP (Serial Flash Discoverable Parameter) of the serial flash which is installed on WIFImodule and runs the active RTOS image.Secondary bootloaderRTOSRAM LibraryPTIMI think, UART is not a possible for bootloading, what do you think ?JTAG is not necessary?

author: bson
author_rank: Unknown
timestamp: April 29, 2019, 03:58:34 pm
content: Depends on the primary bootloader as installed from the factory. Anything that runs over a UART is a firmware feature; JTAG/SWD is a hardware feature.

author: Md Mubdiul Hasan
author_rank: Regular Contributor
timestamp: April 30, 2019, 12:43:51 am
content: So kind of you Mr.bson!Form factory in case of mass production, boot-loader is must I think even my co-worker does not believe GTAG is necessary.This WIFI module datasheet is confidential as I heard.I think it has enough memory,ROM : 192KBytesSRAM : 1664KBytesOTP : 16KBytesRetention Memory : 28KBytesThis company also provide an EVM board, but right at this moment I dont have it.This module is connected with that EVM board which has also a main MCU.I think that MCU talk in SPI/UART mode to that WIFI module.
Need JRC CCA-390 GPS Info or datasheet. - Page 1
Forum section: electronics / projects

author: Isad
author_rank: Frequent Contributor
timestamp: October 09, 2015, 10:56:34 am
content: Hello all.So i got this gps module out of a old s class comand 2.5E sat nav.And as i have been able to get some kinda of pinout from this website :http://dl4aas.de/jrc-protocol.htm#inputI still dont bealive thats correct i have connected that to a usb to rs232 converter and i am reading iton the arduino serial read but in any baude rate its giving random crap.I have read that this thing givesjrc protocol but could it be posible to change it to nema.I hope anyone know anything about this module would really like to make it work.

author: PA0PBZ
author_rank: Super Contributor
timestamp: October 09, 2015, 11:15:27 am
content: This could help (sorry for the strange url, could not get it to work after sanitizing ):http://www.google.nl/url?sa=t&rct=j&q=&esrc=s&source=web&cd=12&cad=rja&uact=8&ved=0CCYQFjABOApqFQoTCKmW4KSgtcgCFcs4FAodtN8FAQ&url=http%3A%2F%2Fread.pudn.com%2Fdownloads3%2Febook%2F6866%2FJRC%25E8%25AF%25B4%25E6%2598%258E%25E4%25B9%25A62.10S.doc&usg=AFQjCNGB87VgnVT2MlJX-GWiZzsxCejVzQ&sig2=83Xv0B27CBIzk2g2D5qxOg

author: Isad
author_rank: Frequent Contributor
timestamp: October 09, 2015, 01:23:20 pm
content: Quote from: PA0PBZ on October 09, 2015, 11:15:27 amWell i have tryed that but it not outputing any of that data.Its random data in any baud rate i try.

author: PA0PBZ
author_rank: Super Contributor
timestamp: October 09, 2015, 02:37:51 pm
content: Do you have a scope? In that case you could measure the duration of the bits and find out what baudrate is used.

author: Isad
author_rank: Frequent Contributor
timestamp: October 09, 2015, 06:58:14 pm
content: Quote from: PA0PBZ on October 09, 2015, 02:37:51 pmYes a rigol ds1074z with all option hacked.How can u finde out what baudrate is used.

author: PA0PBZ
author_rank: Super Contributor
timestamp: October 09, 2015, 07:12:53 pm
content: Quote from: Isad on October 09, 2015, 06:58:14 pmbaud = bits per second, so find one bit (not a glitch, not 2 or more bits) and do the math.
Need MatLab Help (Solved) - Page 1
Forum section: electronics / projects

author: abrarbaig
author_rank: Contributor
timestamp: March 01, 2018, 12:51:05 pm
content: Hello everyone. Anybody around here to solve my Matlab issues.Thx (Solved)

author: Andy Watson
author_rank: Super Contributor
timestamp: March 01, 2018, 12:56:26 pm
content: Probably.If you want a more specific answer you will need to ask a more specific question.

author: abrarbaig
author_rank: Contributor
timestamp: March 01, 2018, 01:23:42 pm
content: Thanks for your quick response. I was not sure that this forum is suitable for MatLab help. I will post my .m file soon.

author: rstofer
author_rank: Super Contributor
timestamp: March 01, 2018, 02:42:59 pm
content: Or the Mathworks Community help system Or, more often than not, Googlehttps://www.mathworks.com/matlabcentral/answers/When you post your actual question, it might be better over in the Beginner's Forum. Not because it is a Beginner's question, it's just that this forum is supposed to be related to Projects. Unless you are using MATLAB to control a project - that's always cool!