hybridfree/eevblog-posts huggingface dataset:
Zhongdi ZD-982,Aoyue 968A+ (rework/soldering station recommendation thread) - Page 1
Forum section: electronics / beginners

author: Pikker
author_rank: Newbie
timestamp: December 08, 2014, 08:49:23 am
content: Can anyone recommend me a cheap normal solder station?From Aoyue 968A+ ive heard that their soldering handles are bad and usual experiences from others ranges from good to shit.But about ZD-982 ive heard nothing.Can anyone give input on them?Or better recommendations?
ZigBee - Page 1
Forum section: electronics / beginners

author: Tony R
author_rank: Regular Contributor
timestamp: May 12, 2012, 04:53:16 pm
content: Can anyone point me to a source that breaks down ZigBee real well? Books? Websites? Videos? anything

author: Codemonkey
author_rank: Regular Contributor
timestamp: May 12, 2012, 09:11:30 pm
content: Here ya go:http://www.jennic.com/elearning/zigbee/index.htmPlenty of ZigBee & ZigBee PRO documentation on the Jennic site.

author: Tony R
author_rank: Regular Contributor
timestamp: May 13, 2012, 09:32:38 pm
content: Quote from: Codemonkey on May 12, 2012, 09:11:30 pmThanks, that is very informative, but I would still like more resources so if you have anymore I would like to see them...

author: Codemonkey
author_rank: Regular Contributor
timestamp: May 14, 2012, 07:33:01 am
content: What specifically is it you're looking for ? Also, what flavour of ZigBee ? (ZigBee or ZigBee PRO) ? Any profiles ? (Smart Energy, Home Automation etc) ?

author: Tony R
author_rank: Regular Contributor
timestamp: May 17, 2012, 01:20:18 am
content: Quote from: Codemonkey on May 14, 2012, 07:33:01 ama general sense of zigbee, which I think I have down now, ZigBee PRO and Smart Energy. I have been reading the spec sheets from the ZigBee Alliance, but one can only stand that for so long before going crazy.What I really want right now is something that gives more in depth but is not a spec sheet.I found this book:http://www.amazon.com/gp/product/0750685972/ref=oh_details_o00_s00_i00and it is very helpful and easy to read. For anyone else who wants to learn ZigBee I would say this should be first stop. I bought it because i have gotten several books from this publisher and they have all be very good.

author: Codemonkey
author_rank: Regular Contributor
timestamp: May 18, 2012, 01:11:45 pm
content: If there's anything specific you need to know, pm me, for my sins I work with this stuff daily!

author: Avidrugi
author_rank: Newbie
timestamp: June 17, 2012, 07:21:51 am
content: Hi Tony R.,I am not sure you are there yet but you might find it useful to look into the Peryton ZigBee sniffer -www.perytons.com.They provide a 30 days free evaluation download of their SW that includes pre-captured data files (SE profile included) and also some features that are usually included in their licenses Add-Ons (traffic Generator) that enables you to 'theoretically' build messages based on a desired profile, encrypt it with a key and security level of choice, and look at the way the message actually would look like if transmitted over the air.Hope this info helps ;-).

author: montcler
author_rank: Contributor
timestamp: June 17, 2012, 10:17:14 pm
content: Hello,Perhaps this book you can help others you can download it from internet"Oreilly Building Wireless Sensor Networks"Greetings.
Zigbee adapter - Page 1
Forum section: electronics / beginners

author: larangel3
author_rank: Contributor
timestamp: January 12, 2016, 09:57:14 pm
content: Are there any low priced zigbee usb adapters for PC out there?Are there any alternatives other than using a usb adapter?

author: ataradov
author_rank: Super Contributor
timestamp: January 12, 2016, 10:25:58 pm
content: What do you want to do with it?

author: larangel3
author_rank: Contributor
timestamp: January 12, 2016, 10:42:07 pm
content: Quote from: ataradov on January 12, 2016, 10:25:58 pmI want to transfer numerical data from a zigbee based device to a computer.

author: ataradov
author_rank: Super Contributor
timestamp: January 12, 2016, 10:48:18 pm
content: There is no standard generic ZigBee payload format. Do you know what target device is? Do you know what protocol it uses? There are also differences between different profiles.

author: larangel3
author_rank: Contributor
timestamp: January 12, 2016, 11:16:24 pm
content: Quote from: ataradov on January 12, 2016, 10:48:18 pmI intend to use this microcontroller on the devicehttp://www.digikey.com/product-detail/en/JN5168%2F001,515/568-10145-2-ND/3881885How could I set up a wireless interface with a PC with it as you would with a bluetooth adapter?

author: IconicPCB
author_rank: Super Contributor
timestamp: January 12, 2016, 11:22:47 pm
content: Are you looking for a point to pint ( peer to peer) or a meshed solution?What data rate and how much of it?Would a serial (TTL) link be acceptable?EDIT: point to pint ... peer to beer?

author: ataradov
author_rank: Super Contributor
timestamp: January 13, 2016, 12:37:02 am
content: Quote from: larangel3 on January 12, 2016, 11:16:24 pmNote that MCU by itself will not do much, you will need to have ZigBee stack. NXP/Jennic provides one, but typically ZigBee stacks are not the easiest things to use.Quote from: larangel3 on January 12, 2016, 11:16:24 pmThe easiest thing is to take the same controller and connect it to PC via UART (use FTDI or equivalent IC for USB connectivity).

author: coppice
author_rank: Super Contributor
timestamp: January 13, 2016, 01:30:24 am
content: Quote from: ataradov on January 13, 2016, 12:37:02 amIts worth noting that most ZigBee stacks are somewhat buggy, and with the ZigBee market not very active developers aren't putting a lot of resources into changing that.
ZOOM H1 *no power*  - Page 1
Forum section: electronics / beginners

author: odik
author_rank: Newbie
timestamp: January 20, 2013, 08:26:33 am
content: Hello guys need help! I have a Zoom h1 which lately doesn't power up anymore and guys from eevblog help me out finding the culprit and now i cant find any replacement for these smd capacitors. however i found some close match for these capacitors in here is the link..-->http://www.aliexpress.com/item/Free-shipping-1000-pieces-lot-Wholesale-New-Chip-Tantalum-Capacitor-6-3V-330uF-SMT-Capacitor-105c/597993982.htmlUploaded withImageShack.usdefective smd capacitor areW4 330UF 6Vthe capacitor i found in ebay is330UF/6.3Vare those i found online can be my replacement for my Zoom h1 defective capacitors?1 more problem is that they don't ship here in the Philippines if you have other options where i could purchase my replacement please leave me a message..Thanks a lot guys hope you can help me out with this one!!! More Power!!

author: SeanB
author_rank: Super Contributor
timestamp: January 20, 2013, 09:29:23 am
content: Hunt up a few dead CDROM or DVD drives, they use the same size capacitors. Salvage a pair, test them for capacitance and try them first to see if they solve the problem.

author: odik
author_rank: Newbie
timestamp: January 20, 2013, 02:21:48 pm
content: Thanks for the info SeanB. i have 3 dead dvd drives and havent found a compatible specs for the replacement i found 2 smds 100uf 16v which is way to high as replacement..i have a match for the spec i need will these be a good replacement?http://www.ebay.com/itm/KEMET-T310-SOLID-TANTALUM-330UF-6V-CAPACITOR-FD2J72-/400267127060?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item5d31c7a914

author: Bored@Work
author_rank: Super Contributor
timestamp: January 20, 2013, 02:31:37 pm
content: A higher voltage rating (6.3V instead of 6V) is not a problem. Capacitance should be the same (100u is too low), unless you have studied the circuit and checked if a lower/higher capacitance is ok, too. Same for ESR.

author: cwalex
author_rank: Frequent Contributor
timestamp: January 21, 2013, 04:47:12 am
content: you could just use some through hole caps and lay them down. use some glue to keep them from moving around.
ZOOM H1 recorder (No power) - Page 1
Forum section: electronics / beginners

author: odik
author_rank: Newbie
timestamp: November 26, 2012, 04:27:36 pm
content: guys can anyone help me with my zoom h1 recorder?problem: No Power(already change diff batteries) / Computer cant detect it1st i opened it & checked it visually for burns but its clean. cleaned the switch and still no powerone thing i have notice is once u have connected it tru usb on a computer the middle 1 capacitor of those 3 capacitors with the black marker heat up fast.**see attached photo** not the actual photo of my unitthe capacitor present in my unit is aW4 330 6vsince i have noticed it heat up and since the computer cant detect it I disconnect it instantly..pls help me guys..thanksi saw some forums that some zoom h1 had bad capacitors.i also wanted to check the capacitor but i dont know how.

author: peter.mitchell
author_rank: Super Contributor
timestamp: November 27, 2012, 06:22:05 am
content: Check the resistance across the capacitor, it should start at 0 ohms and climb up. If it doesn't climb upwards, it just stays low or stays still, it definitely needs replacing.

author: Fraser
author_rank: Super Contributor
timestamp: November 27, 2012, 09:31:12 am
content: Hot smt capacitors are bad news. Remove and fit a new one.Change any others that appear to have fluid under them or are associated with the power circuitsFraser

author: odik
author_rank: Newbie
timestamp: November 27, 2012, 06:12:02 pm
content: Thanks a lot guys!!! i will try to check on that and will update you soon.. i got to check local stores for parts replacement..

author: odik
author_rank: Newbie
timestamp: December 14, 2012, 05:19:09 am
content: Bad news... ive checked all local electronic stores and could not find any smt/smd capacitors with the same specs for my h1 as replacement. can i purchase from any of you guys?..
Zoyi ZT703s multimeter buged - Page 1
Forum section: electronics / beginners

author: firulais
author_rank: Newbie
timestamp: July 26, 2024, 03:52:27 pm
content: Hello, I have a problem with the multimeter mode, in oscilloscope mode it works perfectly, as you can see in the photos in multimeter mode the needle, the battery icon and the measurement numbers do not appear, it does not respond to any key from f1 to f4, it does respond to the menu key, but the function keys do not respond; I have updated the firmware to the latest version, I downgraded it to a version prior to the one it came with and it is not solved. Has anyone had something similar happen to them? Do you know any hard reset method? I hope someone can help me, Regards

author: black6host
author_rank: Contributor
timestamp: July 27, 2024, 04:01:59 pm
content: Take a look at this post, someone else has had a similar problem.https://www.eevblog.com/forum/testgear/new-zoyi-multimeteroscilloscopes-zt-70xs-up-to-50mhz250msps-(nov-2022)/msg5571365/#msg5571365A couple of posts down @RAPo offers up another link with something you might be able to try.I haven't had this problem so I'm afraid I can't be of more help.

author: redlopa
author_rank: Newbie
timestamp: August 27, 2025, 10:44:09 pm
content: I have a unit with the exact same problem. The cause is dry joints on the chip under the on/off switch, and I found a video of the fix (in Polish I think, but it’s obvious what to do) here:https://youtu.be/P6QntvNAdx8
ZTP-135SR and pic16f1933 - Page 1
Forum section: electronics / beginners

author: tonysallen
author_rank: Newbie
timestamp: November 26, 2010, 10:25:09 pm
content: hi all. this is my first post here so be nice or not you choice. OK here is my question. i have a ZTP-135SR GE and i was wondering how i can get a signal out to feed into the ADC on the pic. there pdf on the part does not say anything about powering the part of where to take reading from. if anyone could help or suggest a more useful part that does the same job i would be great full.im trying to read the temp of a surface about 10cm below the IR sensor

author: armandas
author_rank: Frequent Contributor
timestamp: November 26, 2010, 10:58:05 pm
content: The pinout (see attached) as well as other data is provided in the datasheet. You don't need to power the device, it will produce voltage corresponding to the temperature. There is also a thermistor for compensation/reference.As for reading the voltage, you might need to amplify the signal first.Start by reading here:http://en.wikipedia.org/wiki/Thermopile

author: johnmx
author_rank: Frequent Contributor
timestamp: November 27, 2010, 12:04:33 am
content: Tony Sallen, check this application note (schematic included):http://www.thermometrics.com/assets/images/thermopile.pdf

author: tonysallen
author_rank: Newbie
timestamp: November 27, 2010, 01:17:53 pm
content: thanks a lot guys that was a big help. will make that circuit next week and see how it goes.
ZXBM5210 (PWM DC motor controller) question - Page 1
Forum section: electronics / beginners

author: mribble
author_rank: Regular Contributor
timestamp: March 07, 2021, 02:45:35 pm
content: My question is about what Vref does for this part. I want it to rage the PWM duty cycle between 0% and 100% approximately linearly (though I don't care if it's not exactly linear) as Vref increases.I plan to run this at 5V and on page 10 there is a graph of output duty vs Vref voltage that acts kind of like I want. On page 3 it says the min Vref voltage is 3V. Is that a typo or can someone explain what that 3V is supposed to mean?Here is the datasheet.https://www.mouser.com/datasheet/2/115/ZXBM5210-335426.pdfI've also attached a schematic of how I plan to use this part. If anyone has any suggestions I improvements I'm open to suggestions. Thanks for your feedback!

author: mvs
author_rank: Frequent Contributor
timestamp: March 07, 2021, 04:32:51 pm
content: Quote from: mribble on March 07, 2021, 02:45:35 pmIt is a bit strange spec. On "OutputPWM Duty vs VREF/VDD Ratio" chart you can find a curve for 3V supply, which is senseless if min Vref voltage is also 3V.You may contact Diodes inc. tech support to clarify this.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: March 09, 2021, 03:08:10 pm
content: I did a small search for Vref in the datasheet. and then, on page 5 found:In the forward or reverse mode, for VREF speed control, the output drive duty ratio is generated internally based on the voltage on the VREF pinWhich is as I expected.I've seen something similar with a PT4115, which is a cheap SMPS LED driver. The output can be controlled directly via PWM, or with an analog voltage, and in that case the chip generates it's own PWM internally.

author: Terry Bites
author_rank: Super Contributor
timestamp: March 11, 2021, 02:50:25 pm
content: The controller has two modes, internal or external PWM. See table on page 5 of data sheet. Tie Vref to Vdd (100% Duty) for external PWM.
ZXW, for Laptops, PCs, TVs ETCs - Page 1
Forum section: electronics / beginners

author: Neshco
author_rank: Contributor
timestamp: December 17, 2023, 02:20:07 pm
content: I have seen ZXW schematic system recently and needless to say that it is really nice to have it visualised that way.Is there some similar solution for other type of the electronic?Is there also some database for semiconductors replacements?Paid or free, whatever.
Zynq Xilinx overheating - Page 1
Forum section: electronics / beginners

author: AjayS
author_rank: Newbie
timestamp: May 31, 2019, 04:13:04 pm
content: I was working with a Zynq Xilinx FPGA running at 3.3V. For some reason, I did not realized that my power supply was shorted and I stopped getting the output. I tried checking by taping my finger on the FPGA and it nearly burnt my finger. I have no idea why it was too hot. I immediately turned the main power supply off. I am still figuring out why it was shorted but is the FPGA ok? I did no see any smoke coming out from it. Once I figured out the short with the power, I will plug the power back in. Also, how long do we have (if something is heating up) to turn the power off and the chip is still safe?

author: wraper
author_rank: Unknown
timestamp: May 31, 2019, 04:27:48 pm
content: Quote from: AjayS on May 31, 2019, 04:13:04 pmThere is no predetermined time. If something goes wrong, chips may be bust in milliseconds or survive for hours.

author: 0culus
author_rank: Super Contributor
timestamp: May 31, 2019, 04:45:43 pm
content: Not an FPGA, but I recently had an LM386 survive quite a bit of trying to find where the output was shorting to ground. Like wraper says, it might blow instantly or survive for hours.

author: Fred27
author_rank: Unknown
timestamp: May 31, 2019, 04:52:02 pm
content: Getting hot is not a good sign, but you might be lucky.

author: mikerj
author_rank: Super Contributor
timestamp: May 31, 2019, 05:25:57 pm
content: Quote from: AjayS on May 31, 2019, 04:13:04 pmDo you not think the two issues are very likely related? Something has probably killed the Zynq which then started drawing a very high current from your supply.

author: dmills
author_rank: Super Contributor
timestamp: May 31, 2019, 06:46:23 pm
content: I hope that 3.3V was only applied to the HR IO pins... 3.3V on the core or PS supply lines is an expensive mistake in a time measured in factions of a millisecond.Regards, Dan.
$10. Cheap outdoor solar LED driver, lighting system! - Page 1
Forum section: electronics / projects

author: rickey1990
author_rank: Regular Contributor
timestamp: May 15, 2015, 10:23:35 pm
content: Well il start off with why i needed such a device, Yesterday my mum asked me if i could light up her garden with some mains 240v LED light's,which she liked so she was keen on me using them, problem was she didn't want to run a extension lead to the bottom of the garden. So yesterday, I went to Asda (Walmart) picked up a disposable camera and a solar garden light. Two things iv used for different things in the past. which i fort they would work together. So today took them apart and played around with them until it was working. From other projects i knew a camera flash circuit with a AA battery will easily powered 4 ,240v 60 smd bulbs. (240smd's) for 4hours. So some LED lights would be fine.Its not pretty but it works. Hooked up a LED bulb for testing the circuit.FinshedSome final words of wisdom, Prototyping doesn't have be expensive,I was told one of my projects would cost £20,000, when all the components for that project cost £70 and im not exactly paying myself to build my own prototype. In the real world of business, The cheaper it is to build a product, the more money there is to made from it. Thats what boss's like. Also going to experiment with using it as a mini electric fence generator to keep slugs and cats off my boarders.
$20 QFH GPS :) - Page 1
Forum section: electronics / projects

author: @rt
author_rank: Super Contributor
timestamp: October 12, 2016, 02:51:12 pm
content: Hi Guys,I guess there's not much more to sayEdit,,This was supposed to be attached as well, but the image was too large.This is my second go at a QFH antenna for GPS (1575 MHz), a little nicer than the first this time.

author: DaJMasta
author_rank: Super Contributor
timestamp: October 13, 2016, 02:13:41 am
content: Well it certainly looks nice, but how's performance? How does it stack up against your standard ceramic antenna?

author: @rt
author_rank: Super Contributor
timestamp: October 13, 2016, 04:31:05 am
content: Hi, I think the U-Blox module can tell you, but I'm not talking to it serially yet to ask. They both get a lock faster than a Garmin GPS-18 indoors. It does have to be close to vertical though.

author: dannyf
author_rank: Super Contributor
timestamp: October 13, 2016, 09:55:05 am
content: you can get gps-equipped smartphones for less, with screen to boot.

author: Pjotr
author_rank: Frequent Contributor
timestamp: October 13, 2016, 11:22:54 am
content: Quote from: @rt on October 13, 2016, 04:31:05 amYep, all those modules do. Can't imagine U-Blox hasn't a standard win monitor application. Simply hook up a RS232 <--> USB to it.My own experiences with the Sarantel helicals where not better indoors compared to the standard 1" ceramic ones.

author: @rt
author_rank: Super Contributor
timestamp: October 13, 2016, 01:38:43 pm
content: I've got a lot of different eBay ceramics on the way, as the module has an SMA connector to change them.

author: @rt
author_rank: Super Contributor
timestamp: October 15, 2016, 12:02:31 am
content: This can get a position fix sitting horizontally, it just takes more time, so I assume that’s a good thing.All that there is to do is parse, and software connect the serial NMEA to the vector mapping,and it’s a functional GPS, which I think is a World first for these resources… otherwise please show me before I run to HackadayI can see a few traps if the online QFH antenna calculator was used.* Not accounting for the radius of the metal stem. The calculator assumes the loop will pass through a PVC stemwhen providing the result length of the loop wires. For this one, the radius of the stem needs to be trimmed from all elements.* The bending radius input to the calculator includes the radius of the tube being bent, not just the radius of the former.* It’s a loop antenna, so using any ferrite material nearby, or in construction including the coax sheath will probably detune, or break it.
$49 labview - Page 1
Forum section: electronics / projects

author: ehughes
author_rank: Frequent Contributor
timestamp: May 29, 2015, 11:51:41 pm
content: Not a bad deal if you use Labview.https://www.digilentinc.com/Products/Detail.cfm?NavPath=2,1301,1450&Prod=LABVIEW-HE

author: Obin
author_rank: Contributor
timestamp: May 30, 2015, 07:54:55 am
content: AwesomeIf only the application builder would cost the same...

author: DavidDLC
author_rank: Frequent Contributor
timestamp: May 30, 2015, 11:24:36 am
content: Quote from: Obin on May 30, 2015, 07:54:55 amExactly right. But still is a super deal with all the power integrated on it already, sometimes good sometimes bad as Dave mentioned on the EEVBLAB when something is already done you don't learn a lotDavid.
(-40)-(40)V P Channel Based Reverse Polarity Protection   - Page 1
Forum section: electronics / projects

author: electronx
author_rank: Regular Contributor
timestamp: March 13, 2023, 07:16:44 am
content: Hello everyone, I'm building a circuit and I'm building a pmos based reverse polarity protection circuit. The input requirements are as follows. It needs to carry 8-40V input voltage to the output and it needs reverse polarity protection up to -40V. I predict that the system consumes a maximum of 8.8 watt of power. For this application , using this p channel mosfet DMP6023LFGQ-7https://www.digikey.com/en/products/detail/diodes-incorporated/DMP6023LFGQ-7/6187315, and using that zener diode BZX84-A10,215 (Zener Diode 10 V 250 mW )https://www.digikey.com/en/products/detail/nexperia-usa-inc/BZX84-A10-215/2119643,and I'm using a 10kohm 1/8watt resistor. I understand how it should work in theory, but I'm a junior engineer. I'm afraid of not seeing overheating and other problems. or can you suggest other configurations that are in active stock on digikey?
[ measuring load voltage using minimum current ] - Page 1
Forum section: electronics / projects

author: texane
author_rank: Regular Contributor
timestamp: March 14, 2014, 07:10:14 am
content: Hi,I am implementing a carrier board for the TEENSY3.1microcontroller to measure both voltage and currentof an external DC load. With this circuit, I am interestedin seeing voltage and current transients related to loadcurrent peaks. The MCU 2 integrated 16 bits ADCs areused for measurements. Attached is a functional view.To measure the load current, I use a high side shuntresistor and a INA210 (powered by the MCU). This hasbeen validated, I have no questions on this part.The external DC load voltage may be within 0 - 12V.Thus, I will use a voltage divider to scale the voltagebefore feeding it to the MCU ADC (blue path on picture).The resistor sum is large, as I want to minimize thecurrent used for the measure: the DC load current resolutionis in the uA order, and I do not want to influence theexternal DC load supply (a 3v coin battery typically).Is a resistor divider well suited at all ? If not, whatdo you propose ? Otherwise, I am aware that the currentused for the measure should be large in respect to theADC internal current. But I also want it low to notperturbate the measure. How do you solve this ?Thanks very much for your help !Cheers,f.
(AHD?)Cabling consolidation feedback requested - Page 1
Forum section: electronics / projects

author: alaskanb3arcub
author_rank: Newbie
timestamp: January 01, 2023, 08:52:27 am
content: The CCTV system at work needs maintenance, and I'd like to see if I can try and reduce the rat's nest. As part of that, I'd like to condense the cabling as it gets back to the recorder. I have an idea for gradually combining (up to) 4 camera feeds on a single cat 5/5e cable, and would like to see what you guys think. One potential issue I could see is potential signal issues stemming from the difference in power cable length vs video. Hopefully the scan of my sketch makes sense.Quick rundown: each module with 2 1X8 screw terminal blocks, with jumpers in the middle, so I can: 1) inject video signal via balun, 2) have it pass through on to the next point, or 3) do nothing on select lines. The same modules would have 3 1x2 screw terminals that would receive power, split it, and then pass it on. On the receiving end, it would be a single 1x8 terminal block that would terminate the run, with the matching baluns at the DVR end of things.Equipment in use: Qsee HD DVR, up to 16 inputs, not that we even have that many functional cameras at this time. I am looking into wither just replacing the imaging sensors in them, or outright replacement. Any thoughts on that are appreciated.

author: Terry Bites
author_rank: Super Contributor
timestamp: January 02, 2023, 09:59:51 am
content: That should work. If I understand correctly this is your scheme:

author: alaskanb3arcub
author_rank: Newbie
timestamp: January 02, 2023, 10:02:10 am
content: That's the simplified version. I'm wondering if I'm adding more complexity/introducing more errors than necessary for the goal.
(An attempt at) turning a pile of e-waste into a weather radio. - Page 1
Forum section: electronics / projects

author: Vincent
author_rank: Regular Contributor
timestamp: October 20, 2021, 03:30:59 am
content: Back after several years of absence!I'm one of those weirdos who finds building things out of trash more satisfying than with brand new parts. Anyway...I used to have several large boxes full of old circuit boards, now down to one smaller box, but I still have enough of them to try and build a proper weather radio (that is, one that doesn't grab all the interference sources around and make me goevery time).Now I only have very, VERY basic knowledge of radio receivers, so trying to build an RF amp, local oscillator and mixer with discrete components probably wouldn't be a success LOL. But it turns out I still have the boards from an old hi-fi system, and there's this FM tuner module on one of them, Y'know, the little tin canister. With a bit of reverse-engineering (in the form of an incomplete, rather mediocre schematic) and the datasheets of the surrounding ICs I was able to figure out how to make it spit a 10.7 MHz IF signal. At least I think so.It's a Mitsumi part (EAF 2203-001) for which I couldn't find any information.If all goes well, a TDA1220B (from some other AM/FM radio) would receive this IF and generate audio for an AN5265 audio amplifier, to a 2W speaker, both from an old TV.The one big question remaining is whether or not I can make this FM tuner module reach ~162 MHz. It uses 1SV103 varactors which have a capacitance ratio of 2.6-2.8 over their voltage range. At first sight it seems to allow a pretty wide range of tuning frequencies. But maybe it's not that simple...It's probably not even designed for anything outside the broadcast FM band. I guess it won't harm anything to give it a try, unless it starts emitting interference or something.Otherwise the only brand new component is the prototyping board I'll solder everything on. Even the enclosure is one from an old cable TV terminal LOL.Maybe some of you guys know a bit more about those varactor-based tuners? The rest of this project looks relatively straightforward (unless I'm trying something that's bound to fail LOL), so not having a deal with RF and mixers would save me quite a bit of work! I don't feel quite confident enough to try to design RF circuitry just yet.

author: bob91343
author_rank: Super Contributor
timestamp: October 20, 2021, 03:42:07 am
content: You seem to know what varactors are. Now you want to raise the local oscillator and front end tunings from about 99 - 120 MHz to something around 175 MHz for the first and from 88 - 108 to 163 MHz for the second.That's not really such a big stretch, so go ahead and try it. You may want to pad the varactors to achieve both the ranges, by adding a series capacitor to each of them. Remember that to increase the frequency by, say, 50% you must decrease the capacitance by quite a bit more than that, unless you want to muck with the coils as well.Good luck; I think it's possible.
[Arduino Circuit Question] Using a Capacitor to Smooth Out the Messy Noise or Un - Page 1
Forum section: electronics / projects

author: AlexUAS
author_rank: Newbie
timestamp: December 16, 2022, 11:18:25 am
content: To whom it may concern,Hello. I have a question about how to smooth out the noise/messy signal using a capacitor when it comes to controlling a joystick with an Arduino.The link is pasted down below to view a photo. There are three photos within a link; Arduino/joystick diagram, photo, and signal wave.LINK :https://imgur.com/a/dARk6hXAs you can know, the signal is not always constant as shown in one of the photos. The signal is received by a pin A4 (Analog Pin) on Arduino Mega.My goal here is to get rid of the unstable-messy signal wave and to smooth it out using a capacitor.Does anyone have any ideas on how to wire a capacitor to smooth out the messy signal? And also, what type of capacitor should I use?If someone could paste the diagram on how to wire a capacitor and also show an electrical calculation with a detailed explanation, that would be very helpful.Best Regards,Alex

author: Abdurrahman YAMAN
author_rank: Newbie
timestamp: December 16, 2022, 11:25:38 am
content: Hi Alex,The data that you shared is not messy, it moves around 342 and 344. With 10Bit ADC there shouldn't be a problem.How accurate do you need to measure the signal?Regards.

author: pcprogrammer
author_rank: Super Contributor
timestamp: December 16, 2022, 12:00:58 pm
content: You can use a small capacitor like 100nf connected from the arduino pin (A4 in this case) to ground. That can smooth the signal, but it might not kill the small noise you are seeing. This can be addressed in software, by using a moving average filter.

author: Nusa
author_rank: Super Contributor
timestamp: December 16, 2022, 06:07:39 pm
content: I agree, the data you are showing is very normal for a digitized analog input, for the most part changing between two adjacent values. That's not noisy, that's just the result of digital being digital -- there's no between value to report. You'll have better luck smoothing this in software if it's even a problem for your application.
[DONE] Help to identify TSOT23-6L controller chip used in AC/DC adaptor - Page 1
Forum section: electronics / projects

author: BravoV
author_rank: Super Contributor
timestamp: March 23, 2017, 11:06:27 am
content: Help needed to identify this AC to DC adapter, with common input at AC 100-240V 50/60Hz 1.2A and output of DC 12V 3A.The chip labeled as :73H06a240AAttached photo of the whole board bottom/solder side, single layer.The left part is the primary and secondary is on the right, and there is no special IC at the component side, only common discrete like transistors, diode, caps, transformer etc.My google fu failed me.TIA

author: amyk
author_rank: Super Contributor
timestamp: March 23, 2017, 12:07:58 pm
content: If you search "2273 PWM controller" you will find a bunch of (clones?) nearly identical products with similar datasheets and markings, all beginning with 73xxx. This may be one of those.

author: BravoV
author_rank: Super Contributor
timestamp: March 23, 2017, 02:07:33 pm
content: Quote from: amyk on March 23, 2017, 12:07:58 pmThat is it, spot on !I'm impressed, how did you know to add the "22" prefix ? Is that common for the heavily cloned each other pwm controller chips out here ?Thank you.
[ASK] RUG-Z , Precision shunt resistor with TCR of +/- 1 ppm/K - Page 1
Forum section: electronics / projects

author: BravoV
author_rank: Super Contributor
timestamp: February 15, 2018, 03:46:21 pm
content: While browsing for precision current shunt, spotted at these two manufacturers :- PCN Corporation, a Japanese company ->http://www.pcn.co.jp/pcn-English/index.html- Isabellenhütte , USA branch ->https://isabellenhuetteusa.com/Noticed on a particular product called RUG-Z resistor, both companies has same product name, very similar physical/foot print and also specifications.PCN Corp, ->http://www.pcn.co.jp/pcn-English/Images/seihin-02.html#02-03Isabellenhütte ->https://isabellenhuetteusa.com/products/precision-and-power-resistors/RUG-ZEach specifications available in PDF at both links above.Are these identical resistors ? If they are, who manufactured it ?Is it PCN Corp. or Isabellenhütte, or maybe joint venture developed ?Personally I am aware or at least heard of Isabellenhütte, but PCN Corporation, is it well known ?

author: BravoV
author_rank: Super Contributor
timestamp: February 15, 2018, 04:09:52 pm
content: Answered my own question, just found it at Isabellenhütte website for Japan's branch, the PCN Corp. is one of their distributor.http://www.isabellenhuette.co.jp/disributors/index.html

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: February 15, 2018, 04:16:41 pm
content: Pretty nice. Can't be cheap.

author: BravoV
author_rank: Super Contributor
timestamp: February 15, 2018, 04:25:39 pm
content: Quote from: Conrad Hoffman on February 15, 2018, 04:16:41 pmYou bet ... > 500 bucks a pop.
[AU] Alternative MOSFETs? Or have some hiding away? - Page 1
Forum section: electronics / projects

author: User80
author_rank: Newbie
timestamp: March 22, 2021, 01:05:26 pm
content: Hey All,Attempting to find some suitable MOSFETs to replace the Light control module in our BMW, not overly keen on spending $300+ for a second hand unit or $2000+ for a new oem one.When I can hopefully replace a handful of FET’s and get it back up and running and therefore the lights working on the damn car. (Thank you Sydney rain for drowning the car the other day)I’m looking for:ST VN750-E in a pentawatt packageOrSiemens BTS426L1, BTS425L1 (looks like the only difference is the operating voltage)Naturally, they’re all obsolete, and while I can get them ex China, I really would like to buy them locally or via international expressWould anyone in Australia have a handful they would be willing to part with? I don’t seem to be able to find any through board 5 pin FET’s that suit via mouser/digikeyhttp://pdf.datasheetcatalog.com/datasheet/siemens/BTS425L1.pdfhttp://pdf.datasheetcatalog.com/datasheet/siemens/BTS426L1.pdfhttps://www.st.com/resource/en/datasheet/cd00044424.pdfFor reference the module I’m trying to find parts for.http://bimmerboard.com/members/cn/Repair%20of%20LCM%20on%20an%20e39.pdfThanks All!

author: Jo
author_rank: Contributor
timestamp: March 22, 2021, 04:13:31 pm
content: Hello,first of all I have to admit I can't offer you any parts.Not sure if you are aware of it, but if you buy any obsolete parts from shady (mostly, but not limited to chinese) sellers test them on arrival. Most importantly test them before using them. I was looking for a similar High-side driver and it has been a lottery with 100% duds so far. I received completely different parts only relabeled as High-side drivers, they had nothing in common an could, depending on your circuit, blow up other parts.AFAIK the replacement parts from STM are all SMD and using them takes some kind of adapter pcb.Have you checked that they are actually blown, because while they do fail, they are robust and take some abuse.

author: larsdenmark
author_rank: Regular Contributor
timestamp: March 22, 2021, 04:37:00 pm
content: RedTide says that have 1000 in stock. And they are super cheap.https://www.redtideonline.it/en/integrated-circuits/186-vn750-e.htmlI have never done any business with them before, but it may be worth a shot?!
(Audio) Amplifiers: attenuation + fixed gain OR no attenuation + variable gain - Page 1
Forum section: electronics / projects

author: trevortjes
author_rank: Contributor
timestamp: February 17, 2020, 04:08:38 pm
content: Hey everyone,I was wondering which of the two following ways to achieve audio amplification is best:1) Signal -> Attenuator (voltage divider) -> amplifier (fixed (high) gain)2) Signal -> amplifier (variable gain)What are the pros and cons? As far as I know many audio amplifiers use (1) to achieve audio amplification but other's say that (2) might be better for SNR.EDIT:For example the LM386. It is possible to add an attenuator in front of the input, but it's also possible to utilize the gain pins.

author: Benta
author_rank: Super Contributor
timestamp: February 17, 2020, 06:42:19 pm
content: The main issue with option #2 is stability and frequency/phase response.

author: TimFox
author_rank: Super Contributor
timestamp: February 17, 2020, 08:03:45 pm
content: The main problem with no. 1 is noise. Attenuating the signal before the gain stage will always increase the effect of the amplifier noise. If the amplifier noisereferred to its inputis very small (compared with the signal level) then this may not be important.

author: fcb
author_rank: Super Contributor
timestamp: February 17, 2020, 08:14:48 pm
content: If audio quality is the prime concern then attenuate+fixed gain.If audio quality doesn't matter then attenuate+fixed gain.The increased noise from the attenuate+fixed gain setup matters if it's perhaps a mic amp (they tend to have attentuatorsandvariable gain stages) - but if it's just plain old audio (you reference an LM386) the noise won't matter and stability is more important. Also, difficult to make an amplifier have a gain of 0 (when you want zero volume) and be adjustable for a gain of say x30 (max volume).

author: David Hess
author_rank: Super Contributor
timestamp: February 17, 2020, 09:23:21 pm
content: Attenuation is usually used with a fixed gain amplifier because altering the gain of the amplifier changes its frequency response which has implications for stability. However at audio frequencies, active volume and tone controls where amplifier gain is variable are very feasible and commonly used. Their chief advantage is that a wide non-linear control range can be achieved with linear potentiometers.Look up Baxandall volume controls and Baxandall tone controls.

author: Kleinstein
author_rank: Super Contributor
timestamp: February 17, 2020, 09:37:05 pm
content: The usual audio amplifiers have a rather limited range the gain can be adjusted. This is because of stability issues at to low a gain. The more common non inverting configuration can not go below gain 1 anyway.So a variable gain for the output stage can not be used for the full range. It may be an option for something like 2 overlapping ranges in addition to a divider in front of the amplifier for fine adjust.
[Bathroom TV hack] TFT Monitor PSU capacity - adding ARM board as media player - Page 1
Forum section: electronics / projects

author: faekjarz
author_rank: Regular Contributor
timestamp: June 23, 2017, 04:52:42 pm
content: Hey there, Enginerds and DIY afficionados!I really like watching videos while enjoying a hot tub in my bathroom. I happen to have an oldSamsung 940NW(click "SEE FULL SPECS") TFT Monitor which i'd like to convert into a VESA wall mounted media playback appliance according to the following spec:some low power ARM board, what for running the operating system"SJW/Linux"OS with X GUI for VLC, MPV or Kodi on a low-spec desktop env like openbox or xfcecapable of 720p60 playback, preferably 1080p30 minimum (up/downscaled to 900p, the native TFT res)ARM board has VGA output (i haven't researched the TFT input board yet, for now that's the only available input)maybe use of a (bus-powered) external HDMI-to-VGA converterwireless LAN, what for mounting my main rig's storage via sshfs …onboard or external via USB dongle?tiny USB keyboard, maybe touch panel and on-screen-keyboard, capacitive, none of that resistive rubbishall powered via the original TFT monitor PSU ...preferablyi might even tap the mains supply and add a secondary PSU for that ARM board ...just in case the TFT PSU isn't strong enoughboot from USB or SD cardi'm not afraid of crimping / soldering stuffi'd even replace the TFT / LVDS input board to accommodate a non-VGA ARM board video output...composite to VGA converter? (least favourite option / last resort)Experiences / comments?I'm sure a RaspberryPi is one of the first recommendations, thank you …what else?Is it feasible / could the PSU have sufficient reserves to power an additional ARM board?Which in-spec low-power ARM board would you recommend?Links to existing projects / logs?Maybe a furious rant about my utter stupidity, followed by a tremendous spillage of enlightened wisdom …LOLMUHARHARHAHAHAROFLMAO…the project progress (my decisions) will be logged in this thread (with photos and explanations).
(Beginner) From a single LiPo cell to a stable 3V (part 1) - Page 1
Forum section: electronics / projects

author: Moriambar
author_rank: Unknown
timestamp: June 02, 2022, 01:07:27 pm
content: Hi,Recently I've been asked to try and substitute a 2xAAA battery supply for a portable game with a lipo battery.Not thinking about recharging rn, just the concept of supplying a stable 3V throughout the whole discharge curve of the battery.From what I know and see from thedatasheetthe battery has overcharge/discharge/current protection circuits embedded.What I need3.0V (idk about ripple, 50mV I think would be great)300mA max currentWhat I thoughtVin varies from 3.9 to 3VSwitching reg, inverting (so to keep the stable 3V)So am I thinking the right way? Selecting an appropriate switching is kinda painful but I would like at least to start with the right foot.Are there any mistakes or things I have to know or pointers to select the reg?Thanks

author: tunk
author_rank: Super Contributor
timestamp: June 02, 2022, 01:52:03 pm
content: A new alkaline is around 1.6V, and depending on the application,it can discharge to below 1V. So you don't need a constant 3.0V.No experience with this, but you could look at an LDO or maybe acouple of diodes in series to drop around 1V (have no idea if thiswill work or is recommended).
(Beginner) Making a circuit to charge a power bank - Page 1
Forum section: electronics / projects

author: BRetonDP
author_rank: Contributor
timestamp: May 13, 2015, 01:26:05 am
content: Hello, EEVBlog members!I am making a circuit which charges a cell phone power bank and have stumbled upon an issue.I am using a very simple center tapped full wave rectifier and a 7805 IC to get the 5V output that the power bank takes as input. Of course, two things come to mind:My power bank says it takes a maximum of 800mA as input. Since I don't really know what's inside the power bank, I think limiting the current in the circuit is a good idea, but how would I go around doing that? I opened my textbook and found a circuit, which I added to my build, but I'm pretty sure it is not working.Even if I do manage to limit the output current, would that be all I need to have a functioning circuit? Is the bank ready to be plugged? Do i need the current limit in first place? Am I missing somethingEvery little observation and criticism is appreciated. Thanks guys!

author: moffy
author_rank: Super Contributor
timestamp: May 13, 2015, 01:43:00 am
content: Can't work out what the TIP32C is doing except act as a series diode? The LM7805CT already has a 1 to 1.5 Amp current limit, as well as overtemp, do you really need more protection?

author: BRetonDP
author_rank: Contributor
timestamp: May 13, 2015, 01:47:41 am
content: That's the issue, I'm not really sure if I need itI would like to try and limit the current that actually goes into the bank to around 700mA, even if its not really necessary to have it. The transistor is there because I was trying to built a circuit that I saw in my textbook but it didn't work and I just left it there.

author: moffy
author_rank: Super Contributor
timestamp: May 13, 2015, 02:15:32 am
content: The following circuit is a rough guide. Hope it helps.

author: BRetonDP
author_rank: Contributor
timestamp: May 13, 2015, 02:26:37 am
content: Hey, that's pretty neat, thanks!Will Vin be the output of my regulator? Also, just to be sure, R1 is a 1ohm resistor?

author: moffy
author_rank: Super Contributor
timestamp: May 13, 2015, 11:42:23 pm
content: Vin is the output of the bridge rectifier, you don't want the current limit voltage drop in normal operation to mess with your regulator output voltage, that's why it's on the input side. Yes, 1 ohm/1watt will do the trick. The PNP power transistor needs to have enough gain for the 470 ohm resistor to saturate it in normal operation, so a Hfe/Beta of about 100 or better should be fine.
[Big pics.] MicroSd - Footprint question - Page 1
Forum section: electronics / projects

author: Spikee
author_rank: Frequent Contributor
timestamp: October 10, 2012, 05:41:55 pm
content: Hello all , I have a question about a footprint of the ALPS SCHD3A0100 Micro sd connector .I made the footprint but i'm not sure if there is a pad or not. As I'll show in this picture:footprint alone:footprint + 3d :ALPS website:http://www.alps.com/WebObjects/catalog.woa/E/HTML/Connector/microSD_Card/SCHD/SCHD3A0100.htmlDatasheet: Page 2 , NO. 2http://www.mouser.com/ds/1/15/SCHD-22488.pdfI hope you guys can clarify this.Thanks,Spike

author: 8086
author_rank: Super Contributor
timestamp: October 10, 2012, 06:47:35 pm
content: There is a legend on that page with the answer.

author: AndyC_772
author_rank: Super Contributor
timestamp: October 10, 2012, 07:27:11 pm
content: It says "no parts area", ie. it's a keepout, where the connector's own spring terminals might touch the PCB. Keep vias and traces out of that region, and don't include a copper pad there or it could short the connector pins together.

author: Spikee
author_rank: Frequent Contributor
timestamp: October 10, 2012, 07:28:32 pm
content: Thanks for the knowledge / tip !

author: Ribster
author_rank: Frequent Contributor
timestamp: February 13, 2017, 11:15:30 am
content: Can i ask where you found this 3d model ?

author: Spikee
author_rank: Frequent Contributor
timestamp: February 13, 2017, 07:34:04 pm
content: Can't find the model anymore on my pc. I assume I got it from alps. Ask them directly or ask trough a distributor (this works wonders).Or try to get it from here:http://www.epartfinder.ne.jp/en/eparts/55450