hybridfree/eevblog-posts huggingface dataset:
Linear technology power supply design - Page 1
Forum section: electronics / projects

author: qpit3a
author_rank: Contributor
timestamp: October 13, 2014, 12:30:28 am
content: I was sent this design from Linear Technology for a power supply that I think is interesting as it has 3A output capacity from linear regulators without heatsinking and without large capacitors.https://drive.google.com/file/d/0Bz-LaovGlmDOa1d0ak5xOHhyMGM/view?usp=sharing

author: Marco
author_rank: Super Contributor
timestamp: October 13, 2014, 12:56:54 am
content: I get that they want to push their ICs, but the two parallel linear regulators I find a bit iffy.

author: qpit3a
author_rank: Contributor
timestamp: October 13, 2014, 02:16:21 am
content: Perhaps this idea of the parallel regulators could allow easy design alterations to allow larger current supplies to be built.My main interest would be to see if all the components could be obtained for a through hole implementation and if it could then be made cheaply without a pcb...The populated board turns out to be $200 from LT...

author: Smokey
author_rank: Super Contributor
timestamp: October 13, 2014, 02:30:50 am
content: I bet they are showing two parallel linear regulators to point out the fact that you can do that. Unless you matched old 7805s, if you put them in parallel one would take all the current and overheat.That's cool that they made the new chips parallel-able.

author: Unknown
author_rank: Unknown
timestamp: October 13, 2014, 03:16:28 am
content: Quote from: qpit3a on October 13, 2014, 02:16:21 amAFAIK only the LT3081 comes in a TH (TO220-7?) package.c.f.This earlier discussionon the LT3081, which includes a similar circuit.

author: nowlan
author_rank: Frequent Contributor
timestamp: October 13, 2014, 03:23:00 am
content: Also Here.linear-technology-dc2132a-cvcc-adj-bench-power-supply-board

author: qpit3a
author_rank: Contributor
timestamp: October 13, 2014, 03:25:15 am
content: Thanks, should have checked.

author: David Hess
author_rank: Super Contributor
timestamp: October 13, 2014, 06:06:59 am
content: Quote from: Marco on October 13, 2014, 12:56:54 amIt is no more iffy than using parallel output transistors. In both cases resistive ballasting is used to enforce current sharing even if that only exists in the output resistance of the devices and the circuit wiring.
Linear Technology SMD Collection Kits - Page 1
Forum section: electronics / projects

author: Trailboss
author_rank: Contributor
timestamp: May 03, 2015, 07:14:00 pm
content: Looking for info on these SMD kits, I can't seem to find much info on this stuff, I can't seem to find pricing on the individual SMD's.Hate to throw em away if someone can make use of them,any info appreciated,thanks,Vin

author: SArepairman
author_rank: Frequent Contributor
timestamp: May 05, 2015, 05:52:59 am
content: looks cool, you can find the pricing on digikeyhttp://www.digikey.com/product-search/en?x=0&y=0&lang=en&site=us&keywords=lt1167seeems like a useful thing to have in case you wanna spurt of the moment build some kind of analog system. i certainly have used some of those chips before.It would be nice to have a sample of every product that TI/Linear/Maxim/Analog/etc has made in the last 15 years in a "proper" high end rapid prototyping laboratory. you can also quickly figure out the specs of the chips that are not listed, which would be nice.my version is a large box filled with like 15 lbs of mylar packagingare you giving this away? I'm not sure you can sell it considering their excellent free sample service, though, there are some people who refuse to order free samples based on principles, so maybe you have a market.

author: Trailboss
author_rank: Contributor
timestamp: May 05, 2015, 10:50:25 am
content: Yes, I would like for someone to have it, doing spring cleaning in my shop (vacuum tube amp repair). Also SMD's frighten me!

author: TiN
author_rank: Super Contributor
timestamp: May 05, 2015, 10:59:27 am
content: Would love having such a kit for analog voltnutting

author: JoeN
author_rank: Frequent Contributor
timestamp: May 05, 2015, 11:34:03 am
content: That's actually worth something. You could sell it on eBay if you have ever done that before. It would sell. It's not that hard.There is no part number on that thing at all? It seems like a very nice kit. Maybe they gave it out some time back to very qualified customers. I can't see them just shipping that off to any asking party. Though they will send you like 2 each of 4-5 parts if you ask nice on their site. Linear are good people on the sampling front. Then again, so are a lot of companies these days.

author: Trailboss
author_rank: Contributor
timestamp: May 05, 2015, 12:28:43 pm
content: I put them up for sale in classifies misc section here on EEV. Hope someone can make use of them.
Linearization of a fiber optic transmitter/receiver - Page 1
Forum section: electronics / projects

author: ezalys
author_rank: Frequent Contributor
timestamp: March 28, 2022, 06:13:17 pm
content: The signal recovery 7124 is a lock-in amplifier with two separate boxes: one is an analog frontend and the other does DSP, handles the user interface, all these things. They're coupled with a handful of fiber optic links.Crucially there's no clocks in the analog frontend box -- they make a pretty big deal of this. There's therefore no modulation or encoding. There's a calibration screen for calibrating the gain of the fiber chain for goo on the fiber ends or attenuation due to bending, so I'm inclined to believe they're just transmitting pure analog signals. This is certainly what the block diagram suggests. I popped one open and saw a few OPF322A and OPF472 transmitters and receivers in the main section -- so nothing terribly special.If you look at the manual, it quotes a truly incredible -90 dB THD. I'm curious how one goes about linearizing and temperature stabilizing a pair of these. There's an analog subsection box, but this is enclosed and I didn't have the cojones to take apart the rest of the instrument to get at it. Maybe there's a splitter and a receiver in there and the transmitter runs in a feedback loop -- I don't know.Has anyone tried to transmit analog signals over a fiber link with high linearity and no modulation?

author: moffy
author_rank: Super Contributor
timestamp: March 28, 2022, 11:23:52 pm
content: It sounds a bit off as the OPF322a doesn't even have a power feedback detector to keep the output power constant.There is a general article:https://www.digikey.com.au/en/articles/linear-optical-isolation-for-safe-sensor-operationI might just say that THD is purely a measure of linearity of the transmitter/receiver pair, I would be more interested in gain stability, which is what will vary most with temperature.
linking current sensing feedback with variable DC-DC output question - Page 1
Forum section: electronics / projects

author: john23
author_rank: Frequent Contributor
timestamp: June 15, 2024, 04:55:03 pm
content: Hello, As you can see below I have a simple Mosfet where a current goes threw R1.(its 0.1Ohm)In real life my mosfter is a power amplifier PMA5-83-2W shown in the link below and my V2 in real life is a relay system shown below.The relay outputs voltage "V2" on a certain time period where all the feedback action needs to taken place.In the final united photo below I have the current sensing chip and the relay with variable output.I want some how to get the the relay system of LTC1261LCS8 to change the output voltage according to the feedbacl from the current sense chip LT6119.Is there a way?Maybe some feedback mechanism that will control the output of the DC-DC?LTspice files are attached.Thanks.https://www.minicircuits.com/pdfs/PMA5-83-2W+.pdfhttps://www.analog.com/media/en/technical-documentation/data-sheets/611912f.pdf

author: xvr
author_rank: Frequent Contributor
timestamp: June 15, 2024, 06:12:08 pm
content: You still trying solve simple problem in a most complex wayYou don't need regulated DC/DC for negative voltage. Maximum load current of this circuit is 2.5mA. Just use negative voltage (you say that you have -12V in system?) for power opamp and get required negative voltage from it's output. In this case you also don't need switch and discharge on this voltage rail.Another point - gateing of 12V supply also wrong, you should use high side switch. You can try to find switch with current sense and get rid of separate current sense circuit.
Linking together VHDL codes! - Page 1
Forum section: electronics / projects

author: pyrohaz
author_rank: Regular Contributor
timestamp: February 23, 2015, 11:33:55 pm
content: Hey all,I've decided to splash out on an FPGA (finally!) as I'm really interested in learning to program in a parallel manner, along with the whole reconfigurable hardware stuff seems absolutely awesome! So I've got myself a Altera Cyclone IV development board, it features a couple of onboard devices like SRAM, 16bit R2R VGA DAC amongst a USB UART converter etc.I've never actually used an FPGA, merely a CPLD so it took me a couple of attempts to learn how to use the PLL megafunctions etc. but most of the Altera tutorials were pretty useful. What I'm wondering however is:After writing a simple VGA generation function, I want to match it to a ROM megafunction so I can display a simple image on my LCD. I've got the sync and timing working, I'm struggling however matching up my VGA section to the ROM section. I'm using the Altera block diagram method, along with writing all my parts in VHDL. The problem I'm coming across though is I'm trying to interface my VGA block with a ROM block. I've set my ROM address, clock and data pins as inputs/outputs (respectively) but quartus seems to think that I want to use these as dedicated digital pins, messing up my hopes of using any other peripherals. I've got a feeling I'm doing my VHDL wrong by declaring the I/O for the ROM in the entity port section but any form of help would be really beneficial!Code:library ieee;use ieee.std_logic_1164.all;use ieee.numeric_std.all;entity VGATest1 isport(ClkIn: in std_logic;R, B: out std_logic_vector(4 downto 0);G: out std_logic_vector(5 downto 0);HSO, VSO: out std_logic;VRomAddr: out std_logic_vector(14 downto 0);VRomDat: in std_logic_vector(7 downto 0);VRomClk: out std_logic);end VGATest1;The sections labelled VRomXXXX are what I want to internally connect to my ROM megafunction.Cheers!
Linux for Samsung J7 Prime ? - Page 1
Forum section: electronics / projects

author: Swaroop 21
author_rank: Regular Contributor
timestamp: January 03, 2025, 04:06:15 am
content: I have a J7 Prime wondering if I could install a linux server image to host home assistant etc ? I don't want any desktop environment and use ssh. One I could find was with a desktop environment was the "PostMarketOS"
Using MIPI Displays with SoMs - Page 1
Forum section: electronics / projects

author: 99
author_rank: Newbie
timestamp: November 26, 2018, 07:02:47 am
content: I have looked at building a handheld with the form factor of a phone and want to use an SoM with a custom carrier board that possesses the correct MIPI or DSI connector for a specific but yet unchosen display. Considering that I am looking at SoMs that are MIPI/DSI aware, I was thinking about routing the connection straight from the pins on the SODIMM connector to the MIPI/DSI connector. I am not knowledgeable with PCB design just yet but that probably means I have to read up on impedance matching, spacing, etc to make sure the connections are solid. Other than that, is there anything wrong with routing from the gold fingers to the connector in this way?Other than routing, I'm also wondering about the process of speaking with a DSI/MIPI display. From what I have read, the process of interfacing with these displays requires knowledge of MIPI commands and any initialization sequence required by a specific display. With those in hand, do I really need anything else to drive these displays? I'm still fuzzy on the overall process but I want to get the gist of the prerequisites before going further.
Linux terminal on a GLCD - Page 1
Forum section: electronics / projects

author: yashrk
author_rank: Frequent Contributor
timestamp: March 01, 2018, 07:41:27 am
content: Dear Friends,I am working on a personal project which is a handheld Linux system, I want to know if can get Linux terminal on a GLCD and what will be the steps to get it working on an Ubuntu distribution?Thank you,Yash RK

author: yashrk
author_rank: Frequent Contributor
timestamp: March 01, 2018, 04:04:10 pm
content: Anyone?

author: Photon939
author_rank: Regular Contributor
timestamp: March 01, 2018, 09:09:22 pm
content: AFAIK there are two main ways you could do this - either find or write a kernel driver to run the GLCD as an output display (there are tons of raspberry pi examples for this) or have something like an Arduino running a terminal emulator connected to a serial port on the Linux system.

author: yashrk
author_rank: Frequent Contributor
timestamp: March 02, 2018, 12:00:26 pm
content: Quote from: Photon939 on March 01, 2018, 09:09:22 pmThanx for replying.I won't like to use any micro for this thing as I am doing this project to learn and not to get anything working asap.I found that there are many tutorials on how to get glcd working on the Pi but I am not sure how get terminal data on to the glcd. I don't expect a step wise break down on how to do it but just few pointer and things I might have to read to get this thing working.As an example friend of mine pointed out that I should see what socket programming is, to get low level access to Ethernet communication.That kind of general pointing out will be helpful.

author: Photon939
author_rank: Regular Contributor
timestamp: March 02, 2018, 02:41:55 pm
content: Quote from: yashrk on March 02, 2018, 12:00:26 pmWell if you already have a kernel driver for the LCD then the LCD should act as a terminal on boot assuming you are not running a GUI.
LinuxIoT Board with add-on modules - Page 1
Forum section: electronics / projects

author: sanwal209
author_rank: Regular Contributor
timestamp: March 21, 2017, 08:47:21 am
content: Hi all,I am one of the founders of LinuxIoT Project and would like to introduce our Opensource project which is under active development. We plan on updating our website in about two (2) weeks from now. The update is planned to show Project Timeline, Roadmap, Contribution Guidelines, Feature and Bug Tracking.LinuxIoT is an Opensource Project started by two individuals. The product is a complete IoT Eco-system of Hardware, Software, Webservices, and the necessary Interfaces.The Product include necessary Hardware and Software for a fully functional IoT Infrastructure. You can build an entire Universe of tiny beasts with it - Unattended Ground Sensors (UGS) to UAVs, and much more depending on if you can think straight.http://www.linuxiot.org/Hardware:1. End-point Board (IoT EP Board as we call it)2. Debug & Program Board3. Gateway Breakout Board (designed for C.H.I.P Linux computer)4. Heart Rate Pulse Oximeter Sensor - Add-on5. Navigation Unit - Add-on7. Optical and Thermal Vision Sensor - Add-on8. 40-pin Flex Board-to-board ConnectorFirmware:1. Firmware for IoT End-point board2. Firmware for IoT Router & Forwarder (EP Board also functions as dedicated Router/Repeater)3. Firmware & Middleware for IoT Gateway (Linux only)Applications1. Webservices Stack2. Minimal Dashboard Stack (Web UI)3. Mobile Apps for iOS and Android mob4. These boards are WIP (work in progress):Add-on BoardsSeismo-acoustic sensor with on-board Signal Processing Unit - UGS Boardwe would love to hear from you
Lion Battery Packs,  BMS's Chargers... - Page 1
Forum section: electronics / projects

author: mrpackethead
author_rank: Super Contributor
timestamp: November 20, 2023, 12:36:38 am
content: Hello Folks, who know stuff i dont.I'm got a need to build 2 Lithium Ion Battery Packs using 18650 battery packs. One will be 10s, 5p, ( 36V nominal ). I want to use this to power up my Makita Lawnmower, which flattens the LXT batterys quite quickly and i need ~10 to get through my lawn. I'm building it with a JK BMS ( BD4a17S4P ), that is appropriately rated for the job. I have a very low capacity charger, but it will take 3 days to charge it up!The other will be a 12s, 4p, ( 44V nominal ) which i want to use for a heavy lift ( well, 6kg ) drone. Have not yet started this, and dont' have a BMS for it.What i'm wondering about is a charger.. I have several Meanwell RSP-48-2400 PowerSupplies, which can be adjusted up to around 56V, and down quite a long way..Does anyone know of a ready made DC input charge controller that might be suitable?

author: p.larner
author_rank: Frequent Contributor
timestamp: November 20, 2023, 05:20:33 am
content: look for ebike chargers on aliexpress,i just got a 54.6v 3a unit for 12 pounds delivered.

author: XxMandragoraxX
author_rank: Contributor
timestamp: January 14, 2025, 07:16:18 am
content: Hellow mrpackethead.I saw you were making battery packs for applications that need a lot of power. You can’t use standard batteries because you need a high C-rate for those, especially for the Makita. I know the post is old, but I’m also interested in making efficient BMS, like u. Did you manage to get any info in the end?
LiPo Batteries - Mechanical strain considerations - Page 1
Forum section: electronics / projects

author: Nikos A.
author_rank: Regular Contributor
timestamp: October 12, 2020, 01:17:47 pm
content: Hi everyone,I am desing an insole and I am going to integrate a LiPo battery to supply a PCB. The LiPo and PCB will mounded at the inner of the insole. I am wondering if LiPo batteries is suitable for this kind of application.. I mean could they withstand the body load, friction etc. I am going to install it under the instep flap. I cannot find any information regarding mechanical strain in the datasheets..Do you have any experience with that?Nick

author: tooki
author_rank: Super Contributor
timestamp: October 12, 2020, 02:02:38 pm
content: Mechanical strain is part of what caused Samsung to have to spend $5 billion to recall the Galaxy Note 7.I wouldn't entertain any design that didn't completely, 100%, redundantly, rigidly protect the battery from any kind of forces whatsoever. It's not worth the risk.

author: StefanHamminga
author_rank: Contributor
timestamp: October 12, 2020, 02:09:24 pm
content: Besides the whole liability mess of such a thing (and you've stepped in quite a biggie), I'd start by looking at multiple small cells encased in stainless steel enclosures. Strong and small enough to stop or divert a nail when jammed in with 2kN. Engineer from there.

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 12, 2020, 02:59:14 pm
content: LiPo can bulge so consider that into your design...
Lipo battery charger and monitoring module - Page 1
Forum section: electronics / projects

author: akis
author_rank: Frequent Contributor
timestamp: April 19, 2016, 08:51:37 pm
content: I have made an arduino based module that monitors my 6S lipo battery, it looks at individual cell voltages and current draw and pulls the plug if anything went wrong.I am thinking of adding a small lipo battery charger as well, all into that module, nothing extravagant, say 1A or 2A max. But the battery in question is 6S and am not sure what the proper method is to balance lazy cells. Do we try to charge them to a certain level individually (with all the problems that entails) or do we bleed the other cells to match them down (I seem to have read this somewhere) or do we bleed them while they are being charged so somehow they do not really discharge but they just do not charge as fast?Has anyone got any experience on the matter? Many thanks

author: Zbig
author_rank: Frequent Contributor
timestamp: April 19, 2016, 10:02:09 pm
content: Both are valid approaches. The basic charger that came with my RC helicopter used the method you've mentioned first: charged each cell separately via the balancing plug. The main power lead was left dangling. It was meant to be used with relatively low capacity packs so neither the balance harness gauge nor the balance plug rating wasn't posing much of a problem. My slightly more advanced Turnigy Accucell-6, as well as other "big boys'" RC hobby chargers, do the other thing you've described: pump the charging current through the main power lead (so, effectively, the cells are being charged in series) and "bleed" through the balancing connector the individual cells that approach their terminal voltage sooner than others.

author: Siwastaja
author_rank: Super Contributor
timestamp: April 20, 2016, 05:22:15 am
content: How are you monitoring individual cells? This is where things usually fail catastrophically; the designs sometimes (often) draw different current from the taps, resulting in accumulating inbalance, and finally, over-discharge destruction of the cells with highest current draw during a storage period.

author: sleemanj
author_rank: Super Contributor
timestamp: April 20, 2016, 06:32:12 am
content: I think i would go with bleeding down cells as the simplest solution, a mosfet and series resistor across each cell, sized to draw maybe 100ma. Balance at top of charge, or if any hit say 4.3v before then.
LiPo battery connector - assembly options - Page 1
Forum section: electronics / projects

author: Nikos A.
author_rank: Regular Contributor
timestamp: November 26, 2021, 09:20:31 am
content: Hi,I am ordering some LiPo batteries, and the manufacturer is asking for details such as the PCB protection circuit, cable length, and connector type.I told him that I wanted the part number ACHR-02V-S connector. Now he asks me if I wish the connector to be either positive or negative (type A or B as shown in the picture below). Is there a reason that should force me to select type A or B?? That could make sense, maybe if you know the battery placement and orientation beforehand and already have a PCB design with the battery male connector in place, right?
Lipo battery suppliers in the US? - Page 1
Forum section: electronics / projects

author: mgwalker95
author_rank: Contributor
timestamp: December 07, 2022, 12:38:23 am
content: Has anyone found good Lipo battery suppliers/distributers in the United States? I usePowerstreammost of the time but, they have a limited selection of batteries. Any help would be appriciated!
LiPo charge in circuit 2S1P 7.2V stack - Page 1
Forum section: electronics / projects

author: SL4P
author_rank: Super Contributor
timestamp: April 12, 2014, 03:49:13 am
content: I'm working on a project where I have to use 5V0 rather than 3V3 as VccI could use a converter to push a (larger) 3V6 cell up to 5V/regulated, but would rather use 2x 2000mAh 3V6 Li-Xx cells to start high and regulate down.Load is around 1200mA sustained from the battery pack, so a 500mA charge would be desirable.All the integrated charger chips I see online are for single Li-Xx cells.Does anyone have a hook into a multi-cell charger chip / schematic for cell balancing etc.Batteries are not removable in this application (an IP rated hand-held enclosure)--- or I could consider an OEM charger brick + cell kit that slides in to the handle like power tools. ??Thanks

author: ohmineer
author_rank: Contributor
timestamp: April 12, 2014, 01:36:52 pm
content: There are some integrated chips that charge 2S1P cell stack.No sure if this is what you need but Take as an example these models:- Microchip MCP7384X (http://ww1.microchip.com/downloads/en/DeviceDoc/21823D.pdf)- TI BQ24133 (http://www.ti.com/lit/gpn/bq24133) and TI BQ24170 (http://www.ti.com/lit/gpn/bq24170)Regarding to cell balancing, AFAIK it is not very used in battery packs with only two cells.In any case, you can also take a look at BQ29200 (http://www.ti.com/lit/gpn/bq29200) model from TI.Depending on the balancing current you want, the circuit can be very easy to implement.

author: kaindub
author_rank: Regular Contributor
timestamp: April 15, 2014, 03:39:17 am
content: Hi SL4Phave a look in Silicon Chip magazine April 2014 (www.siliconchip.com.au)I published a circuit that charges 2S Lipo from 5V (USB) and has cell balancing. Charging current is 250ma ( matched to the capability of USB ports)You can adapt it to any input voltage and output current with a few component changes. Uses an MC34063 chip.I designed it to be incorporated into equipment, similar to your needsRobert

author: SL4P
author_rank: Super Contributor
timestamp: April 15, 2014, 01:02:13 pm
content: Thanks - both excellent refernces.I was trying to get April SC - but everyone's out of stock.Cheers

author: amyk
author_rank: Super Contributor
timestamp: April 15, 2014, 01:11:21 pm
content: Quote from: SL4P on April 12, 2014, 03:49:13 amWhy is that? Parallel cells don't require any balancing (as long as they're balanced to start with, they'll stay balanced) and you'd have to use a boost converter anyway if you wanted to charge from USB (500mA).

author: SL4P
author_rank: Super Contributor
timestamp: April 16, 2014, 01:00:05 am
content: 2S = serial
LiPo charger 5-28V in, 5V out - convoluted system? Or the only way? - Page 1
Forum section: electronics / projects

author: 8086
author_rank: Super Contributor
timestamp: November 12, 2015, 10:18:38 pm
content: Hi guysI'm designing a product that will operate from 5-28VDC and have a LiPo battery backup (3.5-4.2VDC). The system will operate at 5VDC.I can't find a charger IC that will take up to 28V without tripping the overvoltage protection.The only solution I can see is to have a buck converter on the input to provide 5VDC, then have the charger IC running from that, and then a boost converter to power the system (5VDC).Does anyone know of a more elegant solution?

author: Paul Price
author_rank: Super Contributor
timestamp: November 13, 2015, 02:30:48 am
content: If your system runs at 5V, then you cannot have a 5-28V input voltage range and maintain regulation at 5V power in with a buck converter.
lipo connectors - Page 1
Forum section: electronics / projects

author: artag
author_rank: Super Contributor
timestamp: December 02, 2019, 09:58:57 pm
content: I'm familiar with several of the 2mm and 0.1" JST connectrors such as XH and PH.However, a lot of small LIPO cells (especially when packaged for micro quadcopters) have a 2 or 2.5mm connector with tiny flanges. What connector is this ?

author: Monkeh
author_rank: Super Contributor
timestamp: December 02, 2019, 10:18:12 pm
content: I believe that's a Molex 51005.
lipo pack monitering - Page 1
Forum section: electronics / projects

author: merlinuk32
author_rank: Newbie
timestamp: September 24, 2021, 12:17:41 am
content: hi there all now befor anyone say it yes i know there are already units out there that are stand alone to do this task but thats the issue there they are stand alone and not intergratable i am wanting to moniter a 72v lipo pack with current peaks of 300a for voltage and current (bidirectional (charge and discharge)) as acuratly but cheaply as posible due to this being such a high voltage and current i thought i would see what others with more exspariance have to say now i plan on useing a teensy micro controler for the job as i am also wanting to moniter 9 tempriter points (but thats not what this is about) also want it to be as safe as possible

author: m3vuv
author_rank: Super Contributor
timestamp: October 18, 2021, 09:21:36 am
content: I assume its a 20s pack,ive a homebrew ebike using a 13s 18650 homemade pack,i use a bluetooth smart bms,do just about everything you can wish for.
Lipo to "SLA" adapter (for UPS battery replacement) - Page 1
Forum section: electronics / projects

author: chaseadam
author_rank: Contributor
timestamp: April 14, 2021, 06:35:15 pm
content: I am getting ready to replace the battery pack in my 48VDC APC UPS. Before I go out and purchase new batteries, I am exploring if I can adapt some very large LiCo02 Lithium Cells from a decommissioned Chevy Volt battery pack I have laying around.The UPS supports external battery packs in addition to an internal pack consisting of 2x 4s 12V SLA batteries. I do not (believe) I have direct control over the charging circuitry.I can imagine several situations where we may want to safely drop in a LiPo battery as a replacement for SLA or other battery technologies.Are there existing "adapters" (preferably circuit) which would allow a LiPo battery to interact with a system which is expecting to be charging an SLA battery?Any obvious issues with a "simple" solution such as prevent "charging" from the UPS (i.e. a diode in front of the battery assuming the UPS charger is "satisfied" when it reaches float voltage) and use a separate dedicated charger?Thanks!AdamReference Material:https://www.eevblog.com/forum/projects/converting-2200va-ups-from-sla-to-li-based-batteries/https://www.powerelectronics.com/markets/mobile/article/21858074/replace-sla-batteries-with-liion-technology

author: Pineapple Dan
author_rank: Contributor
timestamp: April 14, 2021, 07:02:16 pm
content: Like your reference material suggests, LiFePo4 lends itself better to this. It would be possible to convert I suppose but it will be a complicated affair involving a cacophony of TI bqXXXX chips, power mosfets and pesky sensors to prevent the much-dreaded exploding battery event from happening. You can probably shoehorn a bunch of off the shelf BMS into it but then you're still stuck with the different charging voltages. Ideally you would boot out the existing charging circuit and replace with your own

author: chaseadam
author_rank: Contributor
timestamp: April 16, 2021, 03:39:53 pm
content: Quote from: Pineapple Dan on April 14, 2021, 07:02:16 pmYep, had those datasheets up already for this and another project.I will try the large diode and dedicated charger and see if the UPS stays happy.

author: ajb
author_rank: Super Contributor
timestamp: April 16, 2021, 06:17:16 pm
content: Assuming you can incorporate a sufficient BMS to prevent catastrophe, the discharge curve of the Lithium battery is going to be different from the SLA, so any state-of-charge or capacity/runtime estimates the device does may be thrown off. Whether or not that's a problem I guess depends on the application and how finicky the particular device is.I just came across this site, which is interesting, it discusses using lithium batteries in parallel with lead acid, which maybe could be a good option to extend the runtime of a UPS that supports external batteries:https://www.zwerfcat.nl/en/open-hybrid-bms.html
LiPo to USB charger project idea - Page 1
Forum section: electronics / projects

author: ajasmin
author_rank: Newbie
timestamp: December 03, 2012, 09:17:04 pm
content: After watching Davetest discharge that 5000mAh LiPo cell, I thought of ordering a few of them to build myself a beefy portable USB power pack.Hobbyking also sells aLiPo to USB chargerbut if the customer's comments are to be believed it has two major issues:No undervoltage protection to preserve the batteryDoesn't charge Apple devicesSo I'm thinking of building my own LiPo to USB charger. It would have a switch to select the number of LiPo cells and a cut-off circuit (perhaps a modified version ofthis). And two USB ports. One of themApple compatiblewith the proper voltages on the data pins.That could make for an interesting blog post. And if it works well enough perhaps I could sell a couple of them on an eBay store or something.Any thoughts?Edit:"Low voltage cutoff circuitry to protect your battery" is listed as a feature of the Hobbyking product. Perhaps it was just that one customer who had a problem.
Lipoly discharger - troubleshooting - Page 1
Forum section: electronics / projects

author: IrejectYourReality
author_rank: Contributor
timestamp: July 27, 2016, 10:52:29 pm
content: Hello! I am working on a simple project, a device to discharge my lipol batteries. Fully charged, they have 4.2V per cell, and I need to discharge them to 3.85V per cell for storage. I am using 2 cell batteries, so they have 8.4 V fully charged. This is my circuit, which I built on a breadboard:The idea is, that the TL431 will provide 3.85 volts, which is compared by the comparator(LM2903) to the battery voltage divided by two (2 cell battery). If the battery voltage is higher than 3.85 V, the mosfet will turn on and burn the energy on a power resistor (the resistor is actualy only 4.7 ohms, forgot to update the schematics). The problem is, that the comparator only puts about 2-4 volts on the mosfet gate, which is not enough to turn it fully on. If I disconnect the mosfet and measure the comparator output voltage, it is at saturation, about 8V, but when I connect it to the mosfet, it drops. I measured the voltage drop of the battery when directly connected to the 4.7 ohm rezistor, it dropped from 8V to 7.99V, so the voltage drop of the battery should not play a significant role. And another observation, I just tried to connect my only 3S battery (11.1V) to the circuit, which basically means that on the noninverting input, there will be about 6V instead of 4V and it worked flawlessly, mosfet turned on completely. So the problem seems to only arise when the voltages on the comparator inputs are close to each other. What am I doing wrong?
LIPUS (Low Intensity Pulsed Ultra Sonic) circuits - Page 1
Forum section: electronics / projects

author: terrygm
author_rank: Newbie
timestamp: March 29, 2025, 02:16:18 pm
content: Any circuits for a LIPUS (Low Intensity Pulsed Ultra Sonic) device.They are used for healing bone fractures and other tissue types.They cost $4000 (and more) but there is bugger all circuitry in them, (a 1.5MHz oscillator pulsed at 1kHz 20% duty cycle).Hardest part is finding a suitable ultrasonic transducer, but well worth it to save thousands of $$.

author: Terry Bites
author_rank: Super Contributor
timestamp: March 31, 2025, 05:32:44 pm
content: I'd be thinking about the cheap as chips transducers used in beauty machines.See "1MHZ Ultrasound Transmitting Transducer Ultrasonic Beauty Instrument Probe Replacement for Beauty Introducers" on Aliexpress.

author: Marco
author_rank: Super Contributor
timestamp: April 01, 2025, 09:37:38 am
content: Without a way to calibrate delivered power, i'd pay the 4000.

author: terrygm
author_rank: Newbie
timestamp: April 03, 2025, 12:52:51 pm
content: Already on it.Relibility unknown.Can probably calibrate it on a 100MHz scope.thanks

author: Marco
author_rank: Super Contributor
timestamp: April 03, 2025, 09:38:31 pm
content: Delivered ultrasonic power is not electrical power, most of the electrical power is heating the Piezo.

author: DaJMasta
author_rank: Super Contributor
timestamp: April 03, 2025, 11:01:14 pm
content: I think the point being made is that most expensive medical stuff is that way because of being built with a whole set of requirements designed to keep you safe. The basic principles or circuitry may be fairly trivial, but they have to be accurate, predictable, without side effects, properly isolated, and targeted in a verifiable way or they won't be allowed on the market.I'm all for tinkering around and designing something similar, but don't go trying to use it on someone unless you can be sure of everything that is coming out of it, that potential avenues of misuse are designed to be protected against, and when you are a suitably trained medical professional who can confirm that it's being used as intended and is being effective.As for the ultrasonic element, have you looked at piezo elements? Any physical movement will generate acoustic waves and you probably don't want much power, so things sold as ultrasonic transducers for normal applications may not be what's sought out for the professional designs either.

author: thm_w
author_rank: Super Contributor
timestamp: April 03, 2025, 11:15:03 pm
content: You can buy an exogen setup on Ebay for $100. You might find some locally as well.So either re-use the transducer only, or re-write the eeprom and reset the electronics in the unit and re-use it.https://www.reddit.com/r/AskElectronics/comments/1fuk4cy/what_chip_could_be_keeping_count_of_uses_remaining/

author: EggertEnjoyer123
author_rank: Frequent Contributor
timestamp: April 04, 2025, 01:30:20 am
content: Quote from: Marco on April 03, 2025, 09:38:31 pmYou could probably use another ultrasonic transducer to convert the vibrations back to an electrical voltage which could be measured.
liquid nails silicone for electronics? - Page 1
Forum section: electronics / projects

author: CopperCone
author_rank: Super Contributor
timestamp: December 01, 2017, 02:41:54 am
content: Is liquid nails silicone ok for electronics?It contains polysilane, and it does not have a vinegar odor. I like it because its at home depot.Things like GE Silicone 2 emit acetic acid on curing...

author: CJay
author_rank: Super Contributor
timestamp: December 01, 2017, 07:09:26 am
content: If the manufacturer doesn't specify non corrosive in their data why take a chance on an unknown?You can get neutral cure silicones from a lot of the DIY/home depot like places, Dow corning 799 is one example of a non corrosive silicone, GE SSG4000 is another and there will be many others.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 01, 2017, 10:12:25 am
content: Uhhh, hmm,http://products.ppgac.com/products/msds?culture=en-US&productcode=00407650says it's based on an oxime formulation. Which will hydrolyze to something that'll corrode electronics, I think (if not ammonia, then hydroxylamine or something along those lines).The ones based on alcohols, I think, are the least corrosive? And there are many more carefully crafted formulations (that I don't really know about) that are also safe to use. And of course two-part mixes, if you happen to have them.Tim

author: xavier60
author_rank: Super Contributor
timestamp: December 01, 2017, 10:41:31 am
content: I like to use flowable silicone sealants because they give a smooth finish. One such product is Permatex Flowable Silicone Windshield & Glass Sealer.

author: james_s
author_rank: Super Contributor
timestamp: December 02, 2017, 12:08:21 am
content: The "Sensor Safe" RTV is non-acidic and should be fine.That said, I've used ordinary clear RTV on electronics before and despite the acid I never had any problems with corrosion. That may not always be the case though, especially if the device you use it on is enclosed and collects the vapor.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 02, 2017, 02:20:04 am
content: I once had a control board returned from a customer, who glued the board into its enclosure with a heavy layer of acetic acid based silicone. The underside was covered in white corrosion.(Probably mixed lead and tin basic acetates.)Tim

author: james_s
author_rank: Super Contributor
timestamp: December 05, 2017, 12:14:46 am
content: Yeah that sounds like asking for trouble. I've never used it in huge quantities in electronics, just a blob here and there to stick something together or insulate a HV connection.
Liquid Nitrogen Chilled Beer - Page 1
Forum section: electronics / projects

author: CaptnYellowShirt
author_rank: Frequent Contributor
timestamp: February 25, 2014, 02:49:28 am
content: Guess who bought himself $7.53 worth of LN2? That's right... me.And who -- after conducting some interesting semiconductor science -- decided to super freeze some beer? Again... me.Below you'll see what happens to Heineken when poured into a dewar filled with liquid nitrogen.When I sober up, I'm guess I'll post the results from that science I was doing... maybe.

author: orion242
author_rank: Unknown
timestamp: February 25, 2014, 03:04:04 am
content: Quote from: CaptnYellowShirt on February 25, 2014, 02:49:28 amSounds like the creation of a hangover...

author: Tinkerer
author_rank: Frequent Contributor
timestamp: February 25, 2014, 04:21:22 am
content: So how much does that buy you anyway? Dont know how much they charge for that stuff.

author: CaptnYellowShirt
author_rank: Frequent Contributor
timestamp: February 25, 2014, 05:06:10 am
content: Here's the serious side to this beer endeavor:https://www.eevblog.com/forum/projects/the-cryogenic-p-n-junction/Oh and it bought me 2L. Considering the stuff should be basically free -- I think I was more paying for the guy's time to fill my container.

author: Legit-Design
author_rank: Frequent Contributor
timestamp: February 25, 2014, 05:08:40 am
content: Quote from: Tinkerer on February 25, 2014, 04:21:22 amhttp://benkrasnow.blogspot.fi/2008/08/diy-liquid-nitrogen-generator.htmlThis comes out to 9.6 kWh/liter or $1.15/literBen has the coolest and most original projects in the internets.

author: CaptnYellowShirt
author_rank: Frequent Contributor
timestamp: February 25, 2014, 05:16:01 am
content: Quote from: Legit-Design on February 25, 2014, 05:08:40 amOh my god. Will somebody shut those hippies up? I can't even hear the man speak.Ben needs to invent a death-ray next.But seriously, that's epic. I mean... The bank gave me a credit card... I just went and bought mine.
List of (less standard) components? - Page 1
Forum section: electronics / projects

author: mathmatic
author_rank: Newbie
timestamp: August 25, 2017, 02:17:36 pm
content: So, I'm trying to compile a list of less well known components (probably largely, but not necessarily exclusively, passives) that tend to be fairly common in practical use, but not typically taught in your standard EE program / textbook (eg. PPTCs, ferrite beads, TVS diodes, etc - honestly, we could probably just about say anything other than resistors, inductors, caps, diodes, and transistors qualify). I've tried searching around and can't really find much in the way of a "list". Anyone know of a good internet resource, book, or just want to make component suggestions? Thanks!

author: colorado.rob
author_rank: Frequent Contributor
timestamp: August 25, 2017, 05:57:12 pm
content: Photodiode, photoresistor, piezo-electrics (sensors, buzzers) -- just a few that come to mind.

author: chris_leyson
author_rank: Super Contributor
timestamp: August 25, 2017, 06:27:47 pm
content: Isolator and circulators either RF or optical

author: SeanB
author_rank: Super Contributor
timestamp: August 25, 2017, 07:19:27 pm
content: Zero ohm resistors, and why do they have negative tolerances......

author: DBecker
author_rank: Frequent Contributor
timestamp: August 27, 2017, 05:35:05 am
content: I don't think that photodiodes or photoresistors should be on the list. They are common enough in example circuits.But definitely include the whole range of protection/isolation devices. Optocouplers are increasingly being replaced by digital isolators, which have better aging and temperature extreme characteristics.Piezo devices aren't that obscure, but aren't typically covered as anything but buzzers.

author: Zom-B
author_rank: Regular Contributor
timestamp: August 27, 2017, 09:40:00 am
content: Quote from: SeanB on August 25, 2017, 07:19:27 pmI've got 0 ohm resistors with both 1% and 5% ratings
List  of common logic levle MOSFETS N-Channel /  P-Channel? - Page 1
Forum section: electronics / projects

author: spinnaker
author_rank: Regular Contributor
timestamp: December 24, 2012, 03:33:46 am
content: Does anyone have a comprehensive list of common logic N-Channel and P-Channel MOSFETS (through hole)? Trying to find them on a site like mouser can be difficult. Searching for "logic level FET" does not bring up all of the choices. I can't recall the part number right now but one particular FET was not coming up on logic level but came up when the part number was used to search. Also only one p channel comes up with a search on logic level.

author: c4757p
author_rank: Super Contributor
timestamp: December 24, 2012, 03:35:53 am
content: Digi-Key has a very well-curated "logic level" category that brings up loads of results. I get 143 pages of logic-level P-channel FETs.

author: hlavac
author_rank: Frequent Contributor
timestamp: December 24, 2012, 07:42:06 pm
content: Why don't the parametric searches usually include Vgs(th)?
List of Medical Grade Power Supply Manufacturers - Page 1
Forum section: electronics / projects

author: ANTALIFE
author_rank: Frequent Contributor
timestamp: February 20, 2020, 02:11:04 am
content: Another list from me, this time medical grade power supplies:AdvantechArtesyn Embedded PowerB&B ElectronicsCincon ElectronicsCUI IncDelta ElectronicsDIGIEOS PowerETA-USAFRIWOGlobTekHDP PowerIEIInventus PowermascotMEAN WELLPHIHONGQualtekSL Power ElectronicsTDK LambdaTriad MagneticsTri-MagTT ElectronicsUE ElectronicXP Power

author: marcelo.digital
author_rank: Newbie
timestamp: March 31, 2021, 03:37:16 am
content: Olá, saberia me indicar onde fazer downloads de esquemas eletrônicos ou fóruns que trate a respeito dessas fontes de alta complexidade e alto custo, principalmente TDK lambda ? Estou me especializando nelas aqui no Brasil e a demanda é grande. Obrigado, AbraçosHello, could you tell me where to download electronic schemes or forums that deal with these sources of high complexity and high cost, mainly TDK lambda? I am specializing in them here in Brazil and the demand is great. Thanks hugs
List of Stepper Motor Manufacturers - Page 1
Forum section: electronics / projects

author: ANTALIFE
author_rank: Frequent Contributor
timestamp: February 11, 2020, 01:17:47 am
content: Hi AllI want to make a list of stepper motor manufacturers, so if anyone has any ideas feel free to throw them inAdamant Namiki Precision JewelAllied MotionAmer Electric MotionAMETEK Advanced Motion SolutionsAnaheim AutomationApplied Motion ProductsARC Systems IncAstrosynChangzhou Fulling MotorChiaphua ComponentsCROUZETCUI DevicesDunkermotorenElectric Motor SolutionsElectroCrafteMinebeaEmpire MagneticsErntecFAULHABERFESTOHansen CorporationHaydon Kerk PittmanHurst MotorsJohnson ElectricJVLKOLLMORGENLin EngineeringMagmotor TechnologiesMAMCOMcLennan Servo SuppliesMicroKinetics CorporationMOONSMTINanotecNidecNippon PulseNMB Technologies CorporationOriental Motor (Vexta)PhytronPortescapPrimoPal MotorSanyo DenkiSchneider Electric MotionSOYOSpecialty MotorsSPGTeco Electro Device CoTorque Systems

author: H.O
author_rank: Frequent Contributor
timestamp: February 11, 2020, 11:24:27 am
content: Quite possible/likely that at least some of these are just rebrands but never the less here are a few that springs to mind:AnaheimChangzhou Fulling MotorGlobal Electric Motor SolutionsMoonsOriental Motor / VextaPhytronPrimoPal Motor Co. LtdTeco Electro Device CoTrinamic
Lithium batteries and charging - Page 1
Forum section: electronics / projects

author: ricko_uk
author_rank: Super Contributor
timestamp: July 09, 2020, 04:05:55 pm
content: Hi,couple of questions:1) can you put multiple Lithium batteries in parallel and charge them as a single battery?2) if so, does that apply to all Lithium types? i.e. Lithium Poli, Lithium Metal Hydrate, Lithium Ion etc)?3) are there any "classic/good" Lithium battery charging IC? Ideally universal ones which can do multiple chemistries too?Thank you

author: Peabody
author_rank: Super Contributor
timestamp: July 10, 2020, 02:50:28 am
content: The TP4056 is probably the most popular charger I/C for single-cell lithiums, and most of the modules from the Far East use that chip.
Lithium battery charging connector - Page 1
Forum section: electronics / projects

author: fedimakni
author_rank: Regular Contributor
timestamp: September 25, 2025, 02:55:04 am
content: HelloI am willing to purchase a Lithium battery from aliexpress 24V25Ah (XT60-DC)they mentioned in their product spec: Connector: XT60 for discharge, DC5.5*2.1mm for chargethe issue is that i want to use it in a product where i already implemented a battery charger so the same connector used in the discharge should in theory used for charging the battery too.Will that cause an issue if we use the XT60 to charge the battery?Thank youLink to the battery page:https://ja.aliexpress.com/item/1005008393759603.html?spm=a2g0o.productlist.main.17.29351133rIB6XD&algo_pvid=42835298-c134-4852-baa3-7c112070ff15&algo_exp_id=42835298-c134-4852-baa3-7c112070ff15-16&pdp_ext_f=%7B%22order%22%3A%221%22%2C%22eval%22%3A%221%22%7D&pdp_npi=4%40dis%21JPY%2111637%216639%21%21%2178.59%2144.83%21%402151e6dc17506059649945526e403b%2112000044837086323%21sea%21JP%212410287245%21X&curPageLogUid=O7olNyw97qpn&utparam-url=scene%3Asearch%7Cquery_from%3A&gatewayAdapt=glo2jpn