hybridfree/eevblog-posts huggingface dataset:
ultra scope issues - Page 1
Forum section: electronics / beginners

author: p.larner
author_rank: Frequent Contributor
timestamp: September 28, 2023, 11:49:53 am
content: I have a rigol ds1052d scope,i am trying to get it to work with ultrascope,ive installed drivers from herehttps://www.ni.com/en/support/downloads/drivers/download.ni-visa.html#484351but no good,all i get is a windows error message run-time error 48 file not found :VISA32.DLL,its a win 10 64 bit pc,any idea how to get it to talk to my pc,its the same over rs-232 or with a usb to serial converter,will it work using the usb port on the scope or only rs-232?.

author: wasedadoc
author_rank: Super Contributor
timestamp: September 28, 2023, 01:34:46 pm
content: You already asked athttps://www.eevblog.com/forum/testgear/rigol-scope-issues/msg5082913/#msg5082913.Potential responders should read the responses there before deciding if they have any additional advice.
ultrasonic based voice announcement system - Page 1
Forum section: electronics / beginners

author: thama.eng
author_rank: Newbie
timestamp: August 29, 2014, 12:27:37 pm
content: I am working on a project includes ultrasonic sensors and voice guidance. I'm trying to implement a system when there is a object in various distance it will give recorded voice announcements calibrate with the distance. I need to know new ideas to make this project interesting. whether to use raspberry or ardino and how to program the voice chip. Any Ideas will be very helpful. thanx
ultrasonic cleaner for pcbs - Page 1
Forum section: electronics / beginners

author: pcm81
author_rank: Regular Contributor
timestamp: September 22, 2025, 02:48:41 am
content: I have a 9Liter Kendal ultrasonic cleaner. Bought it 15 years ago. It is advertised as 550W. Using power meter i have determined that 260W is the ultrasonic and 290 is the heater. My question is this: is 260W in 9L volume too much for electronics like PCBs?Thanks ahead

author: XxMandragoraxX
author_rank: Contributor
timestamp: September 22, 2025, 07:06:23 am
content: That works out to roughly 28–29 watts per liter, which is pretty strong for cleaning electronics.I keep the cycles short just a couple of minutes at a time and don’t crank the temperature past about 30–40 °C. Higher heat plus that level of cavitation can get aggressive fast. Always keep the board in the basket instead of on the tank bottom, since the vibration is strongest there, and use a mild cleaning solution like distilled water with a drop of gentle detergent or an electronics-safe cleaner. After the run I rinse with distilled water, give it a splash of isopropyl alcohol to push out any moisture, and then dry the board thoroughly, sometimes with a low-temp bake around 50–60 °C.

author: ahsrabrifat
author_rank: Regular Contributor
timestamp: September 25, 2025, 03:15:23 pm
content: Quote from: pcm81 on September 22, 2025, 02:48:41 amNo. 260 W in a 9 L tank is not automatically “too much”, but it’s on the high side and you must treat populated PCBs with care. With the right procedure it can be used safely; done wrong it can damage parts.

author: LooseJunkHater
author_rank: Frequent Contributor
timestamp: September 29, 2025, 02:37:20 pm
content: Just curious, my ultrasonic cleaner is about 1L with around 50w ultrasonic power. I also typically boil water (around 90C) and then use it in my ultrasonic cleaner, to improve the PCB/component cleaning.What problems can arise from the higher power + higher temps?I'm not using any super-sensitive components like MEMS microphones nor thin PCB's. I haven't yet damaged any components (resistors, ceramic/electrolytic caps, op-amps, QFN audio codecs) from the 12+ times I've used my ultrasonic cleaner + 90C hot water.I've noticed that one PCB cleaning solution that I use in my ultrasonic cleaner (similar tothis one) removes most of the PCB flux from components/the PCB, but can slightly remove the solder mask around solder joints (unless I thoroughly clean the PCB afterward with water). Using a weaker cleaning solution does not cause any damage to the solder mask, but instead leaves more flux residue behind.
Ultrasonic detector - Blind zone - Page 1
Forum section: electronics / beginners

author: nForce
author_rank: Frequent Contributor
timestamp: January 18, 2019, 07:57:29 pm
content: I would like to know why is there a Blind zone in ultrasonic detectors? I know what is Blind zone, but I don't know why is there. (Physics)Thanks.

author: StillTrying
author_rank: Super Contributor
timestamp: January 18, 2019, 09:52:38 pm
content: Minimum sensing distance ?Here's the audio from a cheap ultrasonic distance measurer, at about 40 cycles of 40kHz the pulse is about 32cm long in the air, so using the same sensor for TX and RX it can't measure less than half the pulse length 32/2 cm, because the echo starts to arrive while it's still transmitting the pulse and not yet listening/receiving.I've no idea why the 40kHz pulse is that shape.

author: nForce
author_rank: Frequent Contributor
timestamp: January 19, 2019, 09:21:34 am
content: Ok, but why can't we sense less then some amount of length? Why is there a blind zone?

author: ogden
author_rank: Super Contributor
timestamp: January 19, 2019, 10:23:54 am
content: Quote from: nForce on January 19, 2019, 09:21:34 amYou measure time delay between chirp and it's echo, by measuring silence period between two. When echo arrives BEFORE end of the chirp, there's no silence between two.

author: Berni
author_rank: Super Contributor
timestamp: January 19, 2019, 11:31:50 am
content: Ultrasonic distance sensors tend to use the same piezoelectric element as both the transmitter and receiver.To transmit with it a large AC voltage is applied to it making it flex and act as a speaker to create sound, then quickly the AC voltage is removed and a amplifier listens for voltage across the terminals. Some time later the echo sound comes back and the vibration from it flexes the piezo element causing it to act like a microphone and create voltage on the terminals.So obviously there is a minimum length of transmitting time in order to create a loud enough sound, during that time you can't use the piezo element as a microphone since you are forcing voltage into it. So if a echo comes back before you are done transmitting the sound you will not be able to hear it.To somewhat get around this a separate transmitting and receiving element has to be used, but even then care must be taken so that the receiver does not directly hear the transmitter next to it and interpret that as an echo. If you need it to operate at short distances then design your system for it, or use a different technology all together.
Ultrasonic piezo atomizer - how to use? - Page 1
Forum section: electronics / beginners

author: josem
author_rank: Regular Contributor
timestamp: September 16, 2015, 07:11:26 pm
content: Dear all,I thought I'd try using this ultrasonic piezo liquid atomizer part, but it's proven to be more complicated than I thought. After extensively looking around the web I'm still unsure how to use it.The datasheet is not exactly rich in detail:http://www.farnell.com/datasheets/81205.pdfThe resonant frequency is quite high 1.65 MhzI'm guessing I need to generate some sort of high frequency AC signal, but not sure where to start. The only examples I found were for much lower frequencies, in 20Khz..I'm also not sure what sort of voltage is needed to drive this.Can anyone give me some pointers or recommendations please?Thank you

author: Tom45
author_rank: Frequent Contributor
timestamp: September 16, 2015, 07:19:10 pm
content: You can find app notes here:http://www.prowave.com.tw/english/item/qa.htm

author: josem
author_rank: Regular Contributor
timestamp: September 17, 2015, 06:24:21 pm
content: Thanks Tom that was helpful although for a different range of piezo elements.I did find this circuit online precisely for atomizers that should drive the piezo at the required 1.65Mhz, the schematic included some suggested values for L1, L2, L3.However the value of C1 is odd, 1100? Not sure what to use there. C1 and C2 set the oscillation amplitude so the choice seems quite critical.Can anyone shed some light please? Thanks so much!

author: josem
author_rank: Regular Contributor
timestamp: September 17, 2015, 07:10:46 pm
content: I found this other schematic that seems simpler, but it's for a piezo resonating at 2.4Mhz, not 1.65Mhz as mine is.I wish I could understand what to change to make it work for my case

author: Cliff Matthews
author_rank: Unknown
timestamp: September 17, 2015, 11:08:59 pm
content: Quote from: josem on September 17, 2015, 07:10:46 pmTDK has some physics and application data athttp://product.tdk.com/en/techjournal/tfl/sensor_actuator/NB/I tried searching for circuit layouts for the NB-59S-09S unit (no avail, but it must be out there somewhere..)PDF of the articlehttp://product.tdk.com/en/techjournal/tfl/sensor_actuator/NB/pdf/sa12_nb_pe.pdf

author: dteck
author_rank: Contributor
timestamp: September 18, 2015, 05:45:06 am
content: Quote from: josem on September 17, 2015, 07:10:46 pmFun fact I tried to build this circuit once. I'm still a beginner and a business student as opposed to an EE student so I never did figure out why it wasn't working. I just moved on to other simpler projects. I scoped the output and was getting something like 600KHz instead of the 2.4MHz I was looking for. And the transistor got blistering hot after just a minute or two even when connected to a multiwatt heat sink. I always figured the best way to learn how to drive them would be to pull apart one of those Halloween fog makers you can get on ebay for like $5 USD but I never did it. But I hope you can figure it out Its a project I'd love to go back to.
ultrasonic transmitter H bridge - Page 1
Forum section: electronics / beginners

author: reyntjensm
author_rank: Regular Contributor
timestamp: October 28, 2021, 07:59:09 pm
content: So i'm trying to design an ultrasonic transceiver... I want to use a H bridge made from a few transistors to double the voltage across the transducer( this is R7 in my schematic since i couldn't find a good spice model for the transducer). The power supply voltage is 12V. My signal source has a 5V square wave at 40 kHz. I have already tried different configurations but i always encounter the same problem: So with a 5V input signal. My H bridge goes from 6v to -12V. As soon as i have a 5,5V input square wave the H bridge goes from 12V to -12V, this is what i want to achieve. I could use an extra transistor to generate a 12V square wave from the 5V square wave. But i don't understand why the circuit only functions as expected with a 5,5V signal and not with a 5V signal? I can't find the error, any suggestions?

author: Capernicus
author_rank: Frequent Contributor
timestamp: October 29, 2021, 05:23:58 am
content: whats the 100k resistor doing on the output line of the h-bridge? isnt that where the ultrasound emitter would go?

author: Berni
author_rank: Super Contributor
timestamp: October 29, 2021, 05:44:25 am
content: This arrangement of transistors needs a 0 to 12V input signal to work. That is why the extra transistor is needed shifting the 5V signal to 12V.Also careful with using this circuit at higher powers since cross conduction could become a issue.

author: magic
author_rank: Super Contributor
timestamp: October 29, 2021, 06:13:01 am
content: When the input is near 6V, both transistors are receiving about 0.5mA base current and conducting 100mA.It's a crapshoot where the output of the bridge will be.Furthermore, if you built this circuit IRL, it would surely blow up. Not only on the left side where it is driven with 5V, but possibly also on the right when it crosses 6V during switching.

author: jesuscf
author_rank: Frequent Contributor
timestamp: November 06, 2021, 04:55:09 am
content: It looks to me that both Q1 and Q4 may be on at the same time. It is not a good idea to just place resistors between the bases of the NPN and PNP transistors on the sides of the H-bridge and expect to have one transistor cut off and the other saturated with an arbitrary logic voltage. A better configuration uses two extra transistors as shown in the attached diagram. Since your source voltage is 12V, you may be able to just use a CMOS inverter IC (like the CD4069) configured as an H-bridge to drive the ultrasonic transducer... it is way simpler and most likely cheaper.
ultrasound scanner - Page 1
Forum section: electronics / beginners

author: Unknown
author_rank: Unknown
timestamp: April 25, 2014, 01:33:58 pm
content: hi... this is rather interesting.. bit scary but would be fun to scan your body. Promises to be 50$, but nowhere to be found.Wonder if components are available to build anywhere.http://www.radiologydaily.com/daily/abdominal-imaging/50-ultrasound-scanner-plugs-into-usb-port/(please do not hate me for starting so many topics. I just have so many ideas I never had time to implement/play/brainstorm etc.)
Ultraviolet sensor recommendation - Page 1
Forum section: electronics / beginners

author: jancelot
author_rank: Regular Contributor
timestamp: October 20, 2016, 04:40:01 pm
content: Hi, I need an UV sensor to use both indoor and outdoor, to detect radiation from sun or artificial light. Which sensor do you recommend me? Either standalone equipment or simple sensors which I can connect to a multimeter or oscilloscope.

author: KMoffett
author_rank: Regular Contributor
timestamp: October 20, 2016, 11:50:30 pm
content: GOOGLE: UV meterKen
ultrsonic transducer with built in driver - Page 1
Forum section: electronics / beginners

author: brownt
author_rank: Regular Contributor
timestamp: December 28, 2018, 08:47:35 pm
content: Are ultrasonic transducers available with built in circuitry so that only need a DC voltage is needed to operate it?How do I consider safety/ear damage, when using one?What would be the best way to have an ultrasonic output with variable frequency?
UMFT200XD USB-I2C Adapter - Page 1
Forum section: electronics / beginners

author: AcePeach
author_rank: Newbie
timestamp: February 07, 2019, 03:00:37 am
content: Hi,I want to use UMFT200XD USB-I2C Adapter with windows/Visual C#, simply testing out how it works and some functions, does anyone has experience with this and willing to give some advice?I just want to do a simple communication (e.g. read/write) with my windows. Thank you.-Adele

author: nsrmagazin
author_rank: Regular Contributor
timestamp: February 07, 2019, 06:54:08 am
content: I have not used it, but it should be like this: the MCU sends the information to the adapter, the adapter sends it to the computer wiht a USB and the computer has to read it with some software(IDE or custom built).Here is the application note:https://www.ftdichip.com/Support/Documents/AppNotes/AN_255_USB%20to%20I2C%20Example%20using%20the%20FT232H%20and%20FT201X%20devices.pdfHere is a short explanation:https://www.robot-electronics.co.uk/htm/usb_i2c_tech.htmHere are the circuits of the device:https://www.soselectronic.com/a_info/resource/c/FTDI/FT-X%20more_2.pdf
Unable to control LED current ZLED7020 driver - Page 1
Forum section: electronics / beginners

author: made2hack
author_rank: Frequent Contributor
timestamp: November 24, 2017, 02:51:19 pm
content: Hello all,I'm trying to use an external voltage source to control the current that the ZLED7020 drives in a LED application. My schematic is attached below. The datasheet example is also attached below as is the description about driving the current with an external voltage source. However, I'm not having any luck. When the switch is in position 1, the voltage on ADJ pin is 0 essentially and the LED is off. When the switch is in position 2, the ADJ pin has around 0.5V, but the LED is being driven at 1.45 Amps (how is it exceeding the max current of the ZLED chip?). When the switch is in position 3, the ADJ pin has around 1 - 1.1V, and the same current of 1.45 A. The Sense resistor is 0.09 - 0.1 Ohm, and I thought according to the datasheet that the current cannot go higher than the value set by the sense resistor, in my case around 1Amp (approx).So a few questions:1 - External Voltage source, does that mean a completely separate supply with a separate ground? So there is no "interference" ?2 - Am I overcoming the ADJ pin's input impedance of 500k? as per the datasheet?3 - Why is the current so high? It is exceeding what I thought would be the max?ZLED7020 Datasheet

author: tpowell1830
author_rank: Frequent Contributor
timestamp: November 24, 2017, 03:30:52 pm
content: First of all, your schematic does not match the datasheet, the ISENSE is fed to the LED load through the ISENSE resistor in the datasheet and the ADJ is listed as 0.3 VDC to 1.2 VDC, you are putting 12VDC and the equivalent voltage divider voltage (which, at a glance is over 1.2 VDC) to the ADJ.

author: made2hack
author_rank: Frequent Contributor
timestamp: November 26, 2017, 09:28:40 am
content: Quote from: tpowell1830 on November 24, 2017, 03:30:52 pmHi tpowell1830,Thanks for your input. You were correct, this got it working. The Sense resistor obviously has to be in the path of the current under measurement (like a shunt). I guess sometimes a fresh pair of eyes is what is needed.
Unable to find datasheet - Page 1
Forum section: electronics / beginners

author: mloo55
author_rank: Newbie
timestamp: August 26, 2021, 07:34:40 pm
content: Please, need to find the datasheet of PF7708CS, It is the controller for the leds of a tv.tksmloo55

author: radiolistener
author_rank: Super Contributor
timestamp: August 26, 2021, 08:34:23 pm
content: http://www.powerforest.com/upload/userfiles/14436898201158820213.pdffound here:http://www.powerforest.com/en/product_description_1.php

author: mloo55
author_rank: Newbie
timestamp: August 27, 2021, 01:37:29 am
content: Radiolistener,Appreciated your help.byemloo55
Unable to find this part using Google - Page 1
Forum section: electronics / beginners

author: bifferos
author_rank: Regular Contributor
timestamp: July 27, 2021, 11:25:48 am
content: I've tried: "119xB17-33", "D119xB17-33" nothing.Anyone know what they are? I am hoping they are 3.3v regulatorsI inherited them from someone with a load of other parts.

author: mbno
author_rank: Newbie
timestamp: July 27, 2021, 01:36:02 pm
content: That looks like a AP1117 voltage regulator from Diodes Inc -https://www.diodes.com/assets/Datasheets/AP1117.pdfThe DII is the logo. "9x" is the date code - Year 9 (assume 2019), Week 50. And "17-33" is for the 3.3v variety.
[SOLVED] Unable to identify smd component - Page 1
Forum section: electronics / beginners

author: fibaldy
author_rank: Newbie
timestamp: July 25, 2023, 08:38:25 am
content: Hi all,An electronics beginner here. In the attachment you can see the component I'm trying to identify, the black one with label "2 J U". There are three of them, connected to BrookTree458 RAMDAC's RGB-output pins. I've downloaded the Brooktree458 pdf but am a little confused. I thought they would be a BAV99-diode array but after measuring them I'm not so sure. Each measure differently with DMM in diode mode when removed from circuit. One of them seems clearly shorted between pins 1 and 3 when measured in diode mode.Can anyone help?

author: MathWizard
author_rank: Super Contributor
timestamp: July 25, 2023, 10:38:26 am
content: Do you know the circuit around them ? If not I'd make a little schematic of that area.

author: tooki
author_rank: Super Contributor
timestamp: July 25, 2023, 03:25:36 pm
content: It could also be an MMBT3640 PNP transistor. But I agree that a dual diode is a good possibility, too.

author: fibaldy
author_rank: Newbie
timestamp: July 25, 2023, 04:22:04 pm
content: Quote from: tooki on July 25, 2023, 03:25:36 pmThanks, looked up MMBT3640 datasheet and found this:Quoteat least the marking matches2Jso maybe those really are transistors!

author: tooki
author_rank: Super Contributor
timestamp: July 25, 2023, 05:53:52 pm
content: Quote from: fibaldy on July 25, 2023, 04:22:04 pmThat's why I mentioned it. I wouldn't have if the markings didn't match.

author: Jwillis
author_rank: Super Contributor
timestamp: July 26, 2023, 02:32:25 pm
content: Quote from: tooki on July 25, 2023, 03:25:36 pmtooki is correct. The U is a date code. Notice that the U slightly offset from the rest of the code. Unfortunately this can cause a lot of confusion when identifying many SMD components.Check this out for further reference in the future.http://www.marsport.org.uk/smd/datecode.htm

author: fibaldy
author_rank: Newbie
timestamp: August 07, 2023, 05:25:29 pm
content: I received the component, MMBT3640. Measured and compared to the other originally on the PCB, seemed to match. I then soldered it on the board and powered the machine on. To my surprise I now have a picture again, woohoo! Thanks for the help

author: tooki
author_rank: Super Contributor
timestamp: August 08, 2023, 02:37:55 am
content: Glad it worked out!!
Unable to locate Datasheet - Toshiba Solid State Relay 733W02932 - Page 1
Forum section: electronics / beginners

author: Mephitus
author_rank: Regular Contributor
timestamp: October 19, 2015, 06:16:52 pm
content: I need a SSR for a project and the only one I have was salvaged from an old Xerox copier. Its marked Toshiba 733W02932 (Picture below). I am completely unable to locate any information about it at all, let alone a datasheet. And of course its the last part I need to finish, haha.Project requirements are: triggering under 10V DC with the active output able to take 110V-10A AC mains. If no one else can find the datasheet for this one, would you think it OK to test? (With proper safety precautions of course)

author: SeanB
author_rank: Super Contributor
timestamp: October 19, 2015, 07:12:11 pm
content: That size SSR is typically rated for 2A at most, with mains being the leftmost 2 terminals and the low voltage control being the 2 closer spaced pins on the right side. They are pretty much not going to work well at 10A load, they burn out rather fast and go short circuit. Trigger side is the typical 5-28VDC trigger voltage, typically positive on the outside pin. Also probably not a zero cross device either, as the copiers microcontroller takes care of that in many cases, but it might be.

author: Mephitus
author_rank: Regular Contributor
timestamp: October 19, 2015, 07:39:19 pm
content: Quote from: SeanB on October 19, 2015, 07:12:11 pmThanks! This helps a lot. Specifically I am making a reflow oven controller and the SSR is used to regulate the on/off cycle of a toaster oven. Maybe I can find a tie in point within the oven electronics that would be within tolerance.

author: amyk
author_rank: Super Contributor
timestamp: October 20, 2015, 08:08:41 am
content: Have you tried looking in here?https://archive.org/details/ToshibaOptoelectronicSemiconductors1984Or perhaps here?https://archive.org/details/Toshiba-PhotoCouplersDataBook1988OCR

author: Mephitus
author_rank: Regular Contributor
timestamp: October 20, 2015, 01:57:40 pm
content: Quote from: amyk on October 20, 2015, 08:08:41 amGood resources. I found some of the other stuff I salvaged. But not the SSR. Thanks anyhow.

author: SeanB
author_rank: Super Contributor
timestamp: October 20, 2015, 06:44:35 pm
content: Careful with those Toshiba modules, I used one to control a 60W BELL linear lamp as an alarm wake up in winter, and the module failed after about a year of operation, flickering on intermittently then going short circuit. Seems the inrush current of the linear tungsten lamp was too much for the module.Replaced with an OPTO22 module, a little overkill to use a 20A SSR with zero cross switching to control a 60W lamp, later replaced with a 32 candlepower carbon filament lamp as a more appropriate light source. Just pulled out 3 at work this week, been hiding under a shelf unused for around 3 decades.
Unable to post images any longer. - Page 1
Forum section: electronics / beginners

author: DW1961
author_rank: Frequent Contributor
timestamp: November 09, 2020, 09:19:55 pm
content: I keep getting this error:"Your attachment has failed security checks and cannot be uploaded. Please consult the forum administrator."Is there an administrator to contact?

author: wraper
author_rank: Unknown
timestamp: November 09, 2020, 09:22:13 pm
content: Probably your images have non acceptable file extension.

author: Bud
author_rank: Super Contributor
timestamp: November 09, 2020, 10:29:43 pm
content: There have been a few posts like this since last few days and i saw a Mod's message saying it is a bug in the forum software. I guess you may need to wait.

author: Cerebus
author_rank: Super Contributor
timestamp: November 09, 2020, 10:34:54 pm
content: Quote from: wraper on November 09, 2020, 09:22:13 pmNo, this has been happening to me, with filetypes, sizes, extensions, tool chain and camera all the same as I've used successfully and regularly in the past.

author: ataradov
author_rank: Super Contributor
timestamp: November 13, 2020, 12:55:43 am
content: Broken for me as well on a small JPEG file.
Unable to post on buy sell wanted - Page 1
Forum section: electronics / beginners

author: Kalin
author_rank: Regular Contributor
timestamp: August 27, 2018, 12:38:31 am
content: I am trying to post an item for sale and it goes through the process of uploading but it never appears on the forum. Am I missing a step?Sent from my SM-G930W8 using Tapatalk

author: Kalin
author_rank: Regular Contributor
timestamp: August 27, 2018, 01:03:17 am
content: Apparently it works from my phone. Hopefully mods can remove this thread.Sent from my SM-G930W8 using Tapatalk

author: Brumby
author_rank: Unknown
timestamp: August 27, 2018, 05:06:23 am
content: The Modscanremove a thread - but they won't unless there is a really good reason.The generally accepted practice is to ignore the thread and it will descend into obscurity in time. (About a week.)
Unable to program an stm32 in a custom circuit - Page 1
Forum section: electronics / beginners

author: Moriambar
author_rank: Unknown
timestamp: August 27, 2023, 09:12:06 am
content: Hi there.This project of mine is from before covid but, including an stm32 you should know why I'm bringing it up now.So basically I had a test with a bluepill for a system that would write on a epaper/eink display (waveshare) the contend of two eeproms, fetching specific content for each day.Then I transfered the design onto a pcb, thinking about using an stm32 directly (got it in '22 from digikey or farnell, can't remember) and so I did, searching online for how the mcu is wired on the said pill. And I did.The problem is that the mcu is dead: when powered no clk signal is available, and the stlink doesn't recognize the board.So first thing: do you think there's anything wrong in the circuit? I honestly don't know better. If not I think it's my soldering job that sucks (although I buzzed everything I could think of and it works fine).Second of all, since this is one of my first really thought through schematics on kicad, doo you have any suggestions to make my circuit schematic better?cheers.

author: DavidAlfa
author_rank: Super Contributor
timestamp: August 27, 2023, 10:00:11 am
content: Because SWCLK is PA14, not PB14 !

author: Moriambar
author_rank: Unknown
timestamp: August 27, 2023, 02:00:46 pm
content: Quote from: DavidAlfa on August 27, 2023, 10:00:11 amdamn! Easy and painful!Cheers
Unable to program PIC12LF1572 with PICKit5 on EasyPIC 7 board - Page 1
Forum section: electronics / beginners

author: sairfan1
author_rank: Frequent Contributor
timestamp: September 15, 2023, 03:52:11 pm
content: I'm trying to run a basic LED blink program on PIC12LF1572 (low voltage programming option is disabled) to ensure everything is good I was able to program the uC with with MikorE programmer.But when I try to program it using PIC Kit 3/5 using MPLABx I get following errorQuoteMPLABx also spits out followingQuoteI configured low programming mode but no luck, while ensuring connections with PIC Kit everything is goot except VCC stays out, means uC poweres up through board's power system and VCC from PIC Kit is only connected to capacitor on the board please refer to attached schematic, that means that was excpected as well.

author: jpanhalt
author_rank: Super Contributor
timestamp: September 15, 2023, 06:18:39 pm
content: That is a frustrating error, and in my experience it is processor dependent. I program PIC16F1829 with wild abandon. Never a problem. When I switch to PIC16F1789 it works sometimes and at other times, I get a similar error. One of the ID's ID is ridiculous too. I was able to fix the problem by installing an earlier version of the .jam file. The other thing I have found is the connector. I use a straight 5(6)-pin*, single-row header. The pins get loose, and if one pushes back a mm or two, it errors. That is with ICD3.*I leave the "aux" pin blank. In fact, I plug it in the female connector and use that as an orientation key.

author: sairfan1
author_rank: Frequent Contributor
timestamp: September 18, 2023, 02:12:49 am
content: @PeDrethanks you point me to the right direction. I forgot its 3.3v uC after setting its config register to low voltage programming, set PICKit5 programming voltage to 3.3v when I tried it failed, then I close MPLABx IDE and opened it again and it worked this time, not sure if it was required to set voltage on PICKit posting here so that it could be helpful for others.Thanks
Unable to read ST 95640W EEPROM - Page 1
Forum section: electronics / beginners

author: sidlauskas
author_rank: Contributor
timestamp: January 28, 2021, 09:49:11 am
content: Hello all,I get bunch of 0xFF when I'm trying to read ST 95640W EEPROM desoldered from the car radio (see the photo). It's some kind of protection?Programmer - modified CH341A black edition (+5V)Software - AsProgrammer v2.1.0.13I have no problems reading ST 95320W with the same programmer and software.

author: Terry Bites
author_rank: Super Contributor
timestamp: January 28, 2021, 12:06:03 pm
content: Could you have killed it the heat of de soldering?An erased EPROM shows FF in all fields?

author: wraper
author_rank: Unknown
timestamp: January 28, 2021, 12:08:26 pm
content: If you try reading it as ST 95320W and it still reads FF, then IC is either empty or dead.

author: sidlauskas
author_rank: Contributor
timestamp: January 28, 2021, 12:29:42 pm
content: Quote from: wraper on January 28, 2021, 12:08:26 pmCould it be that the EEPROM is empty by design until the radio is coded?

author: wraper
author_rank: Unknown
timestamp: January 28, 2021, 05:09:03 pm
content: We don't know what's the radio, if it was ever used, what is stored in this EEPROM and why you want to read it to begin with. This EEPROM cannot have any read protection BTW.

author: sidlauskas
author_rank: Contributor
timestamp: January 28, 2021, 07:16:53 pm
content: You're all right. It seems the chip is dead. Probably due to desoldering. Thank you for the help!
Unable to set channels to analyze UART in PulseView - Page 1
Forum section: electronics / beginners

author: anking
author_rank: Newbie
timestamp: April 14, 2019, 08:06:12 pm
content: I'm trying to analyze data coming from my Rigol DS1054Z using pulseview but unable to assign any channels to the decoder.After I capture data from the scope it is being displayed on a screen as expected. Then i'm adding UART decoder that displays "no channels assigned"when i try to assign channels manually I cannot select any from the drop-down list. what am i doing wrong here?Screenshot attached.

author: anking
author_rank: Newbie
timestamp: April 15, 2019, 12:32:52 am
content: I found an answer(Thanks to L29Ah from #sigrok IRQ channel). I needed to digitize the channel first (Channel->conversion), once this was done I was able to connect it to the decoder.However it seems like I can onle decode very short messages because the sample rate is mot high enough. Is this a hardware limitation of my scope(1GSa/s)? or is it because it is connected to PulseView via Ethernet?

author: TK
author_rank: Super Contributor
timestamp: April 15, 2019, 01:24:30 am
content: Why not do the UART decoding on the Rigol DS1054Z itself?
Unable to write to eeprom at28c256 HELP PLEASE - Page 1
Forum section: electronics / beginners

author: Novacic
author_rank: Newbie
timestamp: August 12, 2017, 08:43:37 pm
content: I am trying to write atmel at28c256 on breadboard so I tied all address lines to ground, and all I/O lines also tied to ground. I untie I/O lines for reading, tie 'WE to high, 'CE to low, and 'OE to low for reading. I am reading all ones at I/O ports, no matter what address. So, when I try to write this eeprom I put 'OE high and with 'WE line I touch to ground so that should write stuff to memory but it does not, all I/O ports were connected. I also made small RC circuit with button on WE but that also does not work. Any toughts?

author: slambo511
author_rank: Newbie
timestamp: August 13, 2017, 09:03:16 am
content: Hi,I am no expert myself but am in a similar position, I found this videovery helpful - he uses the 16k version not the 256k one you have but they should have the same pin out. Hope it helps.

author: David Hess
author_rank: Super Contributor
timestamp: August 13, 2017, 08:04:57 pm
content: -OE must be high, and -CE and -WE must be low to start a write cycle. The falling edge of -CE or -WE latches the address and the rising edge of -CE or -WE latches the data and starts the write cycle. -CE or -WR must be low for at least 100 nanoseconds.

author: jfigge
author_rank: Contributor
timestamp: August 21, 2020, 04:26:41 pm
content: I know this is old, but wanted to post a response incase someone, much like myself, stumbles across this post while looking for answers...It seems some 28C256 EEPROM chips are being shipped with SDP (Software Data Protection) enabled. Technically Atmel doesn't ship the chip in this state, so it does make me wonder if my branded chip is a cloneAnyway, when I wrote the code to program the chip via a Nano I found I wasn't able to write to the chip, nor issue the required commands to unlock it. I 'believe' the problem was because the code I original wrote ran WAY too slowly to be able to send the unlock commands within a single page (bytes must arrive within 150us to keep the page going). Once I figured this out I re-wrote the code to use port manipulation and we able to remove SDP and update the EEPROM.Here's my code:https://github.com/jfigge/arduino-28c256-programmerGood luck, and this comes with no warrantees (but is free to use and abuse)

author: wraper
author_rank: Unknown
timestamp: August 21, 2020, 04:33:09 pm
content: Quote from: jfigge on August 21, 2020, 04:26:41 pmRecycled e-waste, and likely relabeled. Just date code and/or speed grade changed or even chip from another manufacturer relabeled.
Unattended testing - Page 1
Forum section: electronics / beginners

author: roginutah
author_rank: Newbie
timestamp: April 21, 2019, 12:07:21 am
content: I want to run a couple of waveforms through a circuit and find out when an event triggers. It may take a very long time to trigger the event. Hours, days... I expect it to trigger more than once. I do, of course, need to know what the particular circumstances are that trigger the event. So, as straightforward as this seems, I can't seem to assemble the project. Do I need just software to work with my DS1054Z? A USB scope? Perhaps some PC controlled waveform generator, too? Help, if you can. Thanks.

author: chagli
author_rank: Contributor
timestamp: April 21, 2019, 12:37:31 pm
content: Hi,I'd say you need a PC controlled generator, your scope and a PC. You also need to send commands to the instruments, typically with VISA.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: April 22, 2019, 05:24:44 pm
content: Dive into your scope manual.I have an older DS1052 and it can be setup for windowed triggering and record multiple events and show the trigger events in a "movie" like fashion, and you can also single frame scroll through them afterwards.If you want to keep track at multiple signals at the same time you may consider to buy some extra scopes.Oscilloscopes are becoming so cheap they are almost disposable.
Unbalanced audio wire inductance question. - Page 1
Forum section: electronics / beginners

author: drewt86
author_rank: Newbie
timestamp: December 07, 2017, 12:59:46 am
content: I'm getting my Uncle a 70V amplifier system for Christmas to install in his home. I'll be doing the installation myself. I ordered normal low impedance speakers and purchased the transformers separately. As I was laying out the materials, I considered a little thought experiment. It occurred to me that I have seen instances where wires inside tube amplifiers are tightly wound to increase their inductance and help minimize noise induced in the cables. So I have a hypothetical question that I'm hoping someone could confirm my guesses.Would there be any benefit in this installation to tightly wrapping the wires coming off of the transformer to increase their inductance and shield against EMI or RFI? Would there be a significant sonic disadvantage or would it have little effect at all with only 8 inches of wire? My initial assumption is that it would negatively impact the AC audio coming thru the cable by creating an HF filter. But I thought, as well, that it could minimize 60hz being induced into the cables. It is a concern as the speakers will be installed in the ceiling and in close proximity to electrical fixtures and line wires. Interested to hear some thoughts form the community.

author: Brumby
author_rank: Unknown
timestamp: December 07, 2017, 01:30:15 am
content: If you're going to use a 70V system, you aren't looking for audiophile quality. The signal is already running through step-up and step-down transformers, so a little more inductance isn't going to make a noticeable difference (IMHO).I'm not sure how much effect it might have on EMI/RFI either. I suspect not a lot. I would be more inclined to put a twist in the cable, keep it away from mains as much as possible - and when you did have to cross a mains cable, do it at right angles.
Unbalanced signal through balanced cable - Page 1
Forum section: electronics / beginners

author: elimenohpee
author_rank: Contributor
timestamp: August 29, 2017, 01:17:58 pm
content: Is it possible to use a balanced cable to transmit an unbalanced signal? I have a video signal that is 75 ohm unbalanced from a video camera and was wondering if I could use a 75 ohm twisted shielded pair in lieu of a 75 ohm coax to transmit that signal to the input of the video receiver.

author: 4CX35000
author_rank: Regular Contributor
timestamp: August 29, 2017, 01:31:56 pm
content: If the distance is short then it tends not to matter too much with composite video, just ground one of the cores. Longer distances it is possible to buy a BNC to twisted pair balun, popular in CCTV.
Unclear About This Illuminated Rocker Switch - Page 1
Forum section: electronics / beginners

author: cpsmusic
author_rank: Contributor
timestamp: April 30, 2019, 04:17:28 am
content: Hi,I have an illuminated rocker switch that was removed from the power supply of a tube guitar amp. The switch was acting as the main power switch and has three connections.The switch was wired as follows - the AC input connected to the middle contact (2), while the outside contacts were connected to (1) ground and (3) the rest of the power supply circuit.When I was looking at this in the circuit I thought it was odd as I expected one switch position to connect contacts (1) and (2) which would have shorted the mains to the chassis!Now that the switch has been removed from the circuit I've checked it and there doesn't seem to be a position that connects contact 1 to either of the other two contacts. From what I can see the switch is SPST. Anyone know anything about switches like this one?Cheers,Chris

author: helius
author_rank: Super Contributor
timestamp: April 30, 2019, 04:29:43 am
content: The key word is "illuminated". There is a neon bulb between "ground" (should be neutral but old equipment was wired unsafely) and the parallel switch contact. When the switch is operated, it acts like a DPST internally with the second pole connecting live to the neon bulb. Neon bulbs look like infinite resistance until the voltage across them reaches 90V.

author: floobydust
author_rank: Super Contributor
timestamp: April 30, 2019, 05:22:33 am
content: Maybe check your pin numbering or the connections 1 and 3 flipped. Illuminated AC switches are wired like this inside.

author: Brumby
author_rank: Unknown
timestamp: April 30, 2019, 06:33:03 am
content: While the form factor might strongly hintandat a SPDT switch - it is only a SPST, as you have determined. What it will have is (more than likely) a small neon lamp with a series resistor connected between pins 1 and 3.When power (pin 2) is switched to pin 3, both the supply circuit and the neon are powered - the neon needing an earth/neutral point for completing the circuit.Edit: Typo

author: cpsmusic
author_rank: Contributor
timestamp: April 30, 2019, 07:31:13 am
content: Quote from: Brumby on April 30, 2019, 06:33:03 amThanks, that makes sense.
Unconnected USB 5V? - Page 1
Forum section: electronics / beginners

author: Emil
author_rank: Regular Contributor
timestamp: January 29, 2015, 12:39:58 pm
content: Can USB +5V be left unconnected in a circuit which is not USB powered? Or should it be terminated in some way?

author: rexxar
author_rank: Frequent Contributor
timestamp: January 29, 2015, 04:11:23 pm
content: I don't think you need to do anything special. I've left the 5V line disconnected before with no ill effects, but I was moving very little, very slow data. Your mileage may vary.

author: Monkeh
author_rank: Super Contributor
timestamp: January 29, 2015, 04:23:02 pm
content: Quotehttp://compliance.usb.org/index.asp?UpdateFile=Electrical&Format=Standard#59http://www.usb.org/developers/docs/usb20_docs/usb_20_121314.zip

author: katzohki
author_rank: Frequent Contributor
timestamp: January 29, 2015, 05:00:54 pm
content: Quote from: Monkeh on January 29, 2015, 04:23:02 pmSo put a 1uF capacitor on 5V line and leave it at that. Good to know!

author: Monkeh
author_rank: Super Contributor
timestamp: January 29, 2015, 05:14:19 pm
content: Quote from: katzohki on January 29, 2015, 05:00:54 pmMinimum 1uF, acros the entire applicable voltage range (0-5.5V). Be mindful of your tolerances and DC bias.If you're building something USB I do suggest thoroughly reading the specification.
Undead 78L05. - Page 1
Forum section: electronics / beginners

author: JTechno
author_rank: Newbie
timestamp: January 30, 2015, 07:29:50 pm
content: I have a NTC-based temperature module which I connected in reverse causing its death. I thought that what was death was its 78L05 voltage regulator so I connected it again, correct polarity this time, and measured the voltage at the 78L05 output pin, nothing as expected.Before replacing it I decided to inject 5v directly to that pin, without disconnecting the 12v, to check that the rest of the circuit still worked. It still worked but to my surprise it continued working after disconnecting the 5v supply.Now it works normally and my question is: What caused this behavior?

author: bartm
author_rank: Newbie
timestamp: January 30, 2015, 07:41:51 pm
content: The classic 7805 is a integrated circuit that contains around 20 transistors. See this 'tear-down':http://www.righto.com/2014/09/reverse-engineering-counterfeit-7805.htmlOne or more internal components could be damaged, shorten or open-circuit, who knows.It's hard to predict it's behavior now, I guess.You could try to mock around with an ltspice simulation model of it :-). it would be a nice learning opportunity.Best thing to do is to replace it tough.
Underating Supercap charging to avoid balancing problem? - Page 1
Forum section: electronics / beginners

author: fc3000
author_rank: Regular Contributor
timestamp: January 13, 2022, 10:24:24 am
content: Hi all,I was exploring the use of supercapacitors for future projects. So I come up with this thought.Say i have two supercapacitors rated at 17F@5V.I am aware that if you connect them in series they need to be balanced, to compensate for the tolerance.If i connect them in series, and charge them to only 8V, will this resolves the problem of balancing them?This, of course, will result in lower capacitance. Is the new capacitance 20% less than before, since the voltage is 20% less?Thanks in advance.Regards

author: Gyro
author_rank: Super Contributor
timestamp: January 13, 2022, 10:40:39 am
content: Hi,No, the capacitance will halve (the resulting value of series capacitors is not related to voltage).You need to use some form of charge balancing to ensure that neither capacitor exceeds 5V - their leakage may not be identical so they may not share voltage equally. In the simplest form, this might be in the form of a pair of 4V7 Zeners, but that's a bit primitive.

author: Siwastaja
author_rank: Super Contributor
timestamp: January 13, 2022, 10:49:40 am
content: If the difference was only in different capacitance, voltage derating would indeed solve the balancing problem. The smaller capacitor would fill up faster, so if you rated your max voltage so that when Vsmaller = 5V, then Vbigger = say 4V, and Vtotal would be at 9V.But, balancing is also needed to account for different leakage currents. Think about it, if one of the capacitor discharges on its own faster than its buddy, the one who discharges less sees larger part of the total voltage as you keep charging the series.Classic options are,Parallel resistors: the idea is to simply increase the leakage of both capacitors significantly enough so that the original (smaller) leakage current becomes only a tiny part of the new, higher leakage current; explicit resistors dominate and form a voltage divider. Obvious drawback is, these resistors consume current all the time, discharging the capacitors. Good for very short storage periods only.Zener diodes / series diodes / etc. These devices have, unlike resistors, exponential current rise as a function of applied voltage. They are pretty good at preventing exceeding the maximums, but they are still not on-off devices (just exponential), meaning they discharge the capacitors significantly near their clamping voltage. Also, the voltage curve of zeners / diodes is highly temperature dependent.Active circuit. Now, with a voltage reference + comparator, you can build a circuit which behaver pretty much like "ideal zener": below threshold, leakage/quiescent current can be tiny enough not to matter, and above threshold, they can shunt significant current. Classic and simple implementation, see TL431.

author: fc3000
author_rank: Regular Contributor
timestamp: January 13, 2022, 12:07:22 pm
content: Thank you very much for the info.Learning all the time!Regards