hybridfree/eevblog-posts huggingface dataset:
Problem with 5V rail on Dell Workstation PSU - Page 1
Forum section: electronics / beginners

author: taste_tester
author_rank: Regular Contributor
timestamp: June 11, 2024, 04:16:21 am
content: Hi all,Today after shutting off my Dell T3610 it wouldn't power back on. The power supply passed the self test (it would make all fans spin) but the computer still wasn't powering on at all. (It's a Dell D685EF-00).I measured the voltages at the connector and then took out the power supply to measure the voltages directly from the pins of the power supply.From the attached image you can see the pinout of this power supply. When I measure it, the 5V at Pin 13 comes on, and the 5VSB at Pin 18 comes on until I push the self-test button where it goes to 0V. Pins 9 & 10 (red wire) stay at 0V.The problem is I can't find any schematic of this power supply or any repair logs about it. I took it apart and nothing is obviously wrong from a visual inspection. The +12V outputs are clearly labeled, but the ground and 5V is not labeled. There is a small section over on the bottom side which is separated from the other ground pins and I was thinking this might be the 5V.The power supply is supposed to be able to put out 4A of 5V on 5VSB, but the single pin of the power supply labeled 5VSB is going through a 220 uF capacitor - I can't imagine this is for the full 4A if it's going through such a tiny capacitor?If anyone could help identify if this mystery section of the edge connector is in fact for 5V then i can begin attempting to track down the problem in my power supply.Thank you if you read this far!

author: aliarifat794
author_rank: Regular Contributor
timestamp: June 11, 2024, 11:19:30 am
content: Check the capacitors, especially those in the 5VSB and 5V circuits, using an ESR (Equivalent Series Resistance) meter.Test diodes and transistors for shorts or open circuits.

author: CaptDon
author_rank: Super Contributor
timestamp: June 11, 2024, 12:48:35 pm
content: I can't imagine any power supply for a P.C. style computer being designed to provide 4 amps at 5 volts of 'standby' power? 20 watts isn't exactly standby! Maybe 40ma. or at the most 400ma.? Even 400ma. would seem excessive for standby.

author: HwAoRrDk
author_rank: Super Contributor
timestamp: June 11, 2024, 12:53:30 pm
content: Quote from: CaptDon on June 11, 2024, 12:48:35 pmThe 5V SB is typically also used to power the USB ports, so modern PSUs often have capability to supply several Amps on that rail.

author: CaptDon
author_rank: Super Contributor
timestamp: June 11, 2024, 01:12:55 pm
content: You have a point about the USB stuff!! I was thinking more along the lines of the older supplies where the standby circuit sort of evolved from the old 'Keep Alive' term which basically kept the 'soft' power on button alive and then woke up the main power.

author: tunk
author_rank: Super Contributor
timestamp: June 11, 2024, 01:34:29 pm
content: Have you tested that the on/off push button works?
Problem with "automatic" high/low flashlight mode... - Page 1
Forum section: electronics / beginners

author: MyHeadHz
author_rank: Regular Contributor
timestamp: October 17, 2017, 11:55:24 am
content: I just bought aCoast PX1(on sale at a local store). I bought it to use with my rechargeable AAA batteries. It works with the batteries, but it will only go into "low" mode. There is no manual way to adjust high/low. There is one button that somehow decides what mode to go in to. With regular (not rechargeable) AAA batteries it generally toggles back and forth between the low and high modes. There is no manual (online or with the light) that explains when or why it chooses low or high modes. :/I'm guessing there is some sort of voltage meter that only allows it to go into high mode if it has over a certain voltage... but that makes rechargeable useless as they generally run at 1.2v instead of 1.5v.Any ideas on how to force it into "high" mode? or am I probably screwed?edit: title originally said "auromatic" instead of automatic

author: kalel
author_rank: Frequent Contributor
timestamp: October 17, 2017, 12:00:34 pm
content: Some type of joule thief for batteries? No, there's probably not enough place to stuff a step up module in there, plus it might cause undesired operation.There are some specific rechargeable batteries with zn that have a higher voltage, 1.6v (and more when charged up), but then there's the risk of having too much voltage and causing something to overheat. There might be other technologies that provide 1.5 in the desired package.Other than this, if there's an internal MCU that chooses the modes (and toggles between them) I'm not sure there's much that can be done.It does sound like when the battery is low (probably low voltage like you mentioned), the lamp doesn't want to go into high mode. It likely considers the battery to be low at the voltage of the rechargeable batteries.

author: MyHeadHz
author_rank: Regular Contributor
timestamp: October 17, 2017, 12:35:38 pm
content: Rechargeable batteries I've had in the past charged to 1.2v. I decided to test these and they charge to 1.4v. Well, two of them did. The third cell was dead! No wonder I had issues...I replaced that dead cell and the light functions normally now with my rechargeable batteries. After 5+ years, seven out of eight cells I originally bought are still good.Sorry for the wild goose chase

author: kalel
author_rank: Frequent Contributor
timestamp: October 17, 2017, 12:36:55 pm
content: Good that you solved the problem, it would have been annoying to get a moderately priced flashlight just to find out you can't use it without wasting batteries.
Problem with ADG2128 in EVAL-CN0565-ARDZ - Page 1
Forum section: electronics / beginners

author: hiepss12
author_rank: Newbie
timestamp: March 30, 2025, 08:32:34 am
content: Hi everyone, I have trouble with ADG2128. My objective is 4-wire BIA measuring in 'EVAL-CN0565-ARDZ' using Arduino Wemos D1. Specifically, after configuring AD5940 depending on this code:(https://github.com/analogdevicesinc/ad5940examples/blob/master/examples/AD5940_BIA/BodyImpedance.c)It worked, there was a sine waveform at CE0 (capacitor C1). But I tried many ways to configure ADG2128 but it didn't work. At first, it cannot communicate to ADG2128 (I2C). I reconfigured AD5940's GPIO, and then it can. But up to now, there has been no signal or waveform at CN0565's pins (in the picture). I don't know why. My full Arduino code version in .zip file.Someone can help me :'( :'(. Thank you very much. I'm really grateful for that.

author: ahsrabrifat
author_rank: Regular Contributor
timestamp: March 31, 2025, 07:01:57 am
content: Run an I2C scanner and see if the ADG2128 responds.

author: hiepss12
author_rank: Newbie
timestamp: March 31, 2025, 01:06:19 pm
content: Yes, I did. It worked properly. I did read ADG2128's addresses were 0x70 and 0x71
problem with arduino code - Page 1
Forum section: electronics / beginners

author: little_carlos
author_rank: Regular Contributor
timestamp: May 15, 2015, 05:12:12 pm
content: hello guys, im trying to do a digital counter, from 1 to 128, but i get an error, this one, could someone tell me what is itint n = 0int 1 = 3int 2 = 4int 4 = 5int 8 = 6int 16 = 7int 32 = 8int 64 = 9int 128 = 10int a;int b;int c;int d;int e;int f;int g;int h;void setup() {pinMode(1, OUTPUT);pinMode(2, OUTPUT);pinMode(4, OUTPUT);pinMode(8, OUTPUT);pinMode(16, OUTPUT);pinMode(32, OUTPUT);pinMode(64, OUTPUT);pinMode(128, OUTPUT);}void loop() {a = n;digitalWrite(1, a%2);b = a/2;digitalWrite(2, b%2);c = b/2;digitalWrite(4, c%2);d = c/2;digitalWrite(8, d%2);e = d/2;digitalWrite(16, e%2);f = e/2;digitalWrite(32, f%2);g = f/2;digitalWrite(64, g%2);h = g/2;digitalWrite(128, h%2);}the error is :Arduino:1.6.0 (Windows 7), Placa:"Arduino Uno"sketch_may15a.ino:2:1: error: expected ',' or ';' before 'int'sketch_may15a.ino: In function 'void loop()':sketch_may15a.ino:30:3: error: 'a' was not declared in this scopeError de compilación

author: ctz
author_rank: Contributor
timestamp: May 15, 2015, 05:20:11 pm
content: - numbers aren't valid identifiers in C++.- statements end in a semicolon. you have some of these, but some are missing.as a style issue, you probably don't want a-h to be globals. declare them inside loop().

author: Aodhan145
author_rank: Frequent Contributor
timestamp: May 15, 2015, 07:08:26 pm
content: Give some background in what you are looking to and we will be able to help you fix your problems.Try to include:What you are trying to achieveWhat each pin doesWhat board you are usingAdd comments in your code saying what each line does, what you are defining etc.Please try to use the "[ code][ /code]" tag to make it look cleanCode:It will be formatted like this. It makes it easier to read

author: tron9000
author_rank: Frequent Contributor
timestamp: May 15, 2015, 10:21:18 pm
content: Quote from: ctz on May 15, 2015, 05:20:11 pm+1 this

author: zapta
author_rank: Super Contributor
timestamp: May 15, 2015, 11:52:17 pm
content: You can simplify the code by listing the pounds in an array of IBT and then update then in a loop, one pin at a time.(Reading on my phone, can't write sample code)
Problem with audio system 2.1 - Page 1
Forum section: electronics / beginners

author: Laur
author_rank: Newbie
timestamp: February 15, 2015, 12:38:20 pm
content: Hello, i have a problem with a audio system 2.1, Sole S350 , it's not a popular brand and i don't found the schematic online.The system stop working when i listened music, few years ago, and since then i let it in the garage, but now i want to see if i can repair it.First them before the system stop working, i gived to someone who claim to knows how to repair so... he removed 2 stabilization transistors and gived to me, but i lost them, and now i don't know what type are...So i will put the pictures here with the system.The pictures with the main board:http://postimg.org/gallery/12fyekway/And here are the pictures with the mini-board who is connected with a cable to the main board, you can see there are no more that transistors at Q6 and Q8:http://postimg.org/gallery/n1esrtj6/And here it's the picture with a wanna-be schematic, someone who had experience in electronic maked this for me, and he thinks the alternatives for the missing transistors are BD138 or BD139 but it's not sure what type NPN or PNP:http://postimg.org/image/snxbza6uz/My question is, if i put BD138 NPN and on the board the missing transistors was PNP, i can damage all the PCB?Please reply if you have any ideas, thank you very much.
problem with c code for pic (0-99 counter, multiplexing 7 segment) - Page 1
Forum section: electronics / beginners

author: little_carlos
author_rank: Regular Contributor
timestamp: May 27, 2016, 12:17:52 am
content: hello, i made a code for a pic 16f628a to count from 0 to 99, the thing is that the left digit turns on, and counts as it should be(every time i == 10 j increases), its displays that, but the units doesnt display on the 7 segment.ive measured with the multimeter and a scope to see if ra2 turns on, but it doesnt, ive tried with other ports as well but it doesnt go high, so i suppose is a code problem.here is the code:Code:int i;int j;int var;int conmutador;void main() {TRISB = 0;TRISA = 0;PORTA = 0;PORTB = 0;var = 0;i = 0;j = 0;conmutador = 0;while(1){Delay_ms(300);i++;Delay_ms(300);if(i==10){i = 0;j++;}if(j==10){j = 0;}if(conmutador == 0){RA2_bit = 1;RA1_bit = 0;var = i;Delay_ms(10);conmutador = 1;}else{RA2_bit = 0;RA1_bit = 1;var = j;conmutador = 0;}switch(var){case 0 : PORTB = 0x3F;break;case 1 : PORTB = 0x06;break;case 2 : PORTB = 0x5B;break;case 3 : PORTB = 0x4F;break;case 4 : PORTB = 0x66;break;case 5 : PORTB = 0x6D;break;case 6 : PORTB = 0x7D;break;case 7 : PORTB = 0x07;break;case 8 : PORTB = 0x7F;break;case 9 : PORTB = 0x6F;break;}}}i stands for unitsj stands for dozensim doing the multiplexing by using 2 bc547'sthe transistors are working fine, as well as the resistors, the problem is on the pic not activating the pin for unitsthanks for your time

author: Andy Watson
author_rank: Super Contributor
timestamp: May 27, 2016, 12:31:39 am
content: Have you disabled the analogue inputs? I believe the default state is analogue, which takes precedence over logic in/out.

author: little_carlos
author_rank: Regular Contributor
timestamp: May 27, 2016, 12:47:27 am
content: Quote from: Andy Watson on May 27, 2016, 12:31:39 amhow do i do that in code?

author: Andy Watson
author_rank: Super Contributor
timestamp: May 27, 2016, 12:53:49 am
content: This chip does not appear to have the usual ADC, but it does have analogue comparator inputs. I am looking at Microchip's datasheet DS40044F (probably out of date now), example 5.1, "Initializing PortA". It is suggesting that the comparators need to be disabled by writing 0x07 to a register called CMCON.

author: Skimask
author_rank: Super Contributor
timestamp: May 27, 2016, 01:17:49 am
content: Quote from: little_carlos on May 27, 2016, 12:47:27 amSame way you do everything else in code, or a PIC, or electronics, or a car, or a baby crib, or breakfast...RTFM.If you have a problem with an I/O pin, you look at the section in the datasheet about...you may have guessed already...I/O pins.If you have a problem with Port A, maybe you want to read the section that talks all about Port A.
Problem with comparator circuit for drum machine triggers - Page 1
Forum section: electronics / beginners

author: belzrebuth
author_rank: Frequent Contributor
timestamp: April 11, 2023, 02:30:14 pm
content: I'm trying to mod a Yamaha MR10 drum machine to have trigger inputs and I've got a problem with the circuit I'm using.This drum machine has a peculiarity that is it needs -9V triggers and it has no positive power supply rail so it's a bit trickier to deal with.The individual sounds are also triggered by some trigger pads on the front so when the individual triggers are not firing they need to sit at 0V (more on this later) in order for the pads to send their -9V pulses.I tried to make a circuit hoping to make all this work and I came with what is attached below.The circuit takes a positive pulse which is isolated from the drum machine power supply just in case the trigger inputs are coming from a grounded source.The positive pulse short the collector to -9V where the emitter is attached.The collector is at the non-inverting of the opamp and that essentially brings the comparator low because the (-) input of the opamp sits at about -4.5V so we've got a nice -9V trigger.It works as a simulation as well but it doesn't work in real-life.All I get is a very short pulse of about 5V at the output of the opamp which is not enough to trigger the sounds.I'm more worried about the amplitude the width of the pulse is irrelevant in this case (should have been about the same length as the trigger input thought).Any ideas of what might be going on here?I attached a schematic of the drum machine section as well although I get the same behavior with the outputs of the opamps disconnected from the base of the input transistors.

author: Terry Bites
author_rank: Super Contributor
timestamp: April 12, 2023, 10:26:29 pm
content: True - you don't actaully need the comparator. But if you want clean pulses and some output drive for a cable, its a good idea.The TL022 has a total output swing of abut 5V.Check your sim with a real load on the opampConsider using a real comparator or single supply opamp.Note that you don't need an opto. You can use a level shifter instead- much cheaper.Any small signal transitors will do. I should work out at about $2 per channnel including the comparator.BTWAdd some hysteresis as shown, you'll avoid false triggers.

author: Kim Christensen
author_rank: Super Contributor
timestamp: April 13, 2023, 12:41:10 am
content: I don't know why you'd need a comparator anyway. Why not something like this:(You could maybe eliminate R1, R2, and Q1 and drive the trigger directly with the opto if it has enough current gain)
Strange problem with composite(CVBS) video system - Page 1
Forum section: electronics / beginners

author: Logan
author_rank: Frequent Contributor
timestamp: February 08, 2022, 05:35:49 pm
content: Hi friends.I have a strange problem. The devices in question are 6 cameras, 4 power supplies, and 1 monitor.At first, I found some combination don't work well, then I isolated the issue to a specific PSU.If that specific PSU is used, the video signal will be at best, distorted and having horizontal moving strips; or at worst, just show "no signal"; or in the middle, showing flashing horizontal bars(no usable picture), indicating bad sync.The strange part is the PSU is new, and works well anywhere else, ONLY being a bad guy when I connect the monitor and a camera to it at the same time.I'm thinking, is it possible that some signal make their way into the power line, and that PSU don't filter them well, so somehow gets crosstalk? Or the PSU itself is not giving a clean output? Without a scope I cannot tell...Thank you.

author: CaptDon
author_rank: Super Contributor
timestamp: February 08, 2022, 09:40:25 pm
content: Is this questionable power supply the same make and model as the ones that work properly? Sounds like it has poor regulation or little filtering on the output.

author: Logan
author_rank: Frequent Contributor
timestamp: February 11, 2022, 04:38:31 pm
content: Quote from: CaptDon on February 08, 2022, 09:40:25 pmThanks!No they are very different, otherwise I'll know it's just a bad one.I fell it's just bad design problem.

author: Terry Bites
author_rank: Super Contributor
timestamp: February 11, 2022, 08:14:44 pm
content: You mean when the FEDs are in your shop?
problem with dc-dc converter mc34063 "inverting " - Page 1
Forum section: electronics / beginners

author: poohpary
author_rank: Contributor
timestamp: July 08, 2013, 10:03:13 am
content: well ..i designed boost regulator with mc34063 and that worked well (input:7.8 ,output :22, ground:0.3V and....) but i deigned inverting converter with that ic....and does not work...i need output -22V but its output is -8V...design seems correct (due to datasheet)...i dont know what to do....is there anyone who can help me??? plz?

author: planet12
author_rank: Regular Contributor
timestamp: July 08, 2013, 12:15:08 pm
content: As it happens I'm in the middle of working on one of these at present. Don't worry if you can't answer all my questions, just do your best.Please point to the exact schematic you are using along with component values, diode types, etc. Be as specific as possible about the inductor, as that's a very core part of all such circuits - eg. is it purchased, scavenged, homemade? Have you confirmed the value? Any idea what the saturation current of it is?Double check that pin 4 is _not_ connected to ground, as that's a rather important part of the inverting configuration (although if you're getting -8V out this is highly unlikely).Do you have access to an oscilloscope? If so, screenshot/photograph and post the following measurements: pin 2 referenced to ground (switch output), pin 3 referenced to pin 4 (timing capacitor), and pin 6 referenced to pin 7 (voltage across current sense resistor).

author: poohpary
author_rank: Contributor
timestamp: July 10, 2013, 03:34:10 pm
content: thanks for reply...it worked with capacitor exchange..!!but leme ask a Q ...if i want to calculate input power i need average input current or rms? what current is my source voltage showing? when i used that current showing on source voltage to calculate efficiency , it became over 100%!!
Problem with driving a circuit using boost converter from Li-ion Battery - Page 1
Forum section: electronics / beginners

author: nitish111
author_rank: Contributor
timestamp: May 25, 2017, 02:39:29 pm
content: Hi All,I have a device that runs on 9V battery. It consumes about 100 mA @ 8.5 V. I am trying to replace 9V battery with rechargeable Li - ion battery (1 cell nominal 3.7 V). I have connected Li-ion battery to input of LT3580 (schematic attached). The circuit works fine when the load is not connected. The output of LT3580 is around 9.56 V. When I connect the load output voltage of LT3580 drops to battery voltage. According to data sheet this configuration should give me around 500 mA but I am not getting expected output.http://cds.linear.com/docs/en/datasheet/3580fg.pdf

author: bktemp
author_rank: Super Contributor
timestamp: May 25, 2017, 02:44:34 pm
content: It sounds like current limit is tripping to early, maybe a bad pcb layout?

author: sanwal209
author_rank: Regular Contributor
timestamp: May 25, 2017, 03:29:32 pm
content: are you using the right inductor? There are few mentioned in datasheet

author: nitish111
author_rank: Contributor
timestamp: May 25, 2017, 03:47:42 pm
content: Thanks for the reply. Here is my PCB layout. All traces are 10 mil. Do you think there is a problem?I took a inductor I had handy with me. I will order inductors specified in datasheet. Any other suggestions?

author: bktemp
author_rank: Super Contributor
timestamp: May 25, 2017, 05:29:20 pm
content: The layout is most likely the problem.Look at page 15 in the datasheet. It describes all important traces: The switching node must have short and thick traces, much shorter than your ones. Compare the high frequency switching path between your layout and the layout in the datasheet.

author: Neilm
author_rank: Super Contributor
timestamp: May 25, 2017, 06:39:42 pm
content: Quote from: nitish111 on May 25, 2017, 03:47:42 pmCalculate the current that is flowing in the inductor. If you don't know the parameters of what you have it could easily be saturating. Be aware that manufacturers all specify the current capability of their inductors in different ways, some might say the value has reduced by 5%, others use 10%. 10mil sounds a bit thin for this but I would not expect this failure mode.
Problem with driving MOSFETs using IR2113 - Page 1
Forum section: electronics / beginners

author: src94
author_rank: Newbie
timestamp: August 23, 2017, 07:51:59 am
content: I'm trying to run 2 IRFZ44N mosfets in push-pull configuration(powered through a 15V supply). The PWM signal is provided through a TL494, which is configured for push-pull mode (it works properly). But the HO pin of IR2113 is always low and the LO pin is always at 15V.I'm using a 0.1uF bootstrap capacitor. VDD and VCC are at 15V, and VSS is ground.I've attached the datasheet.Thank You.

author: sean87
author_rank: Regular Contributor
timestamp: August 23, 2017, 08:41:22 am
content: Please read the How to ask question topic!Where is your schematic?

author: The Soulman
author_rank: Super Contributor
timestamp: August 23, 2017, 08:50:22 am
content: SD Logic input for shutdown

author: src94
author_rank: Newbie
timestamp: August 23, 2017, 09:30:14 am
content: Ive attached the schematic. Please tell me whether the voltages for VCC, VDD and VSS are correct.What should be the voltage at SD.Thank you.

author: jmelson
author_rank: Super Contributor
timestamp: August 23, 2017, 07:50:31 pm
content: I use the 2113 in a servo amp I make. After SD is removed, the 2113 needs a pulse on both of the inputs to reset the shutdown latches. The 2113 is NOT designed for push-pull, it is designed for half-bridge drive. The two terminals of J1 should be connected together, and the output is from that junction to ground.Jon

author: The Soulman
author_rank: Super Contributor
timestamp: August 23, 2017, 09:07:19 pm
content: It depends on your application but you may need a floating (second) supply of approximately 15 volts between Vs and Vb to be able to drive the top side mosfet properly.

author: Seekonk
author_rank: Super Contributor
timestamp: August 24, 2017, 04:30:07 pm
content: That is the same schematic they show in the data sheet. You can't do a damn thing with that schematic, it has no useful purpose. It is totally useless for anyone trying to learn how to use this chip. Lets see how you hooked it up.

author: fourtytwo42
author_rank: Super Contributor
timestamp: August 24, 2017, 05:48:51 pm
content: Your schematic is incomplete! How do you expect an answer when you don't show what is driving the inputs.

author: src94
author_rank: Newbie
timestamp: August 25, 2017, 10:13:38 am
content: i have uploaded the schematic again with the pwm IC (TL494).I'm probing at J1 to see the output.Earlier I connected a 10ohm load across J1, and connected probes at HO and LO to observe the output. I could see the desired square waves on both the pins.Could any one tell me the difference between IR2113 and IR2184.
Problem with Fluke 28-ii  - Page 1
Forum section: electronics / beginners

author: DS-LABOR
author_rank: Newbie
timestamp: December 09, 2012, 02:12:02 pm
content: hi all!i bought a?new28 II and i checked the number of calibrations - surprisingly it showed 2 - is it possible that fluke calibrates new devices twice, before they are being sold? It bought it from an official fluke reseller here in Europe and they claimed this model to be not second hand.can anyone help me?thanks, and best regards from AustriaDave

author: M. András
author_rank: Super Contributor
timestamp: December 09, 2012, 02:28:38 pm
content: my 289 shows only 1 calibrations

author: Unknown
author_rank: Unknown
timestamp: December 09, 2012, 02:32:09 pm
content: I wouldn't worry about it. It could easily be that the calibration expired before the meter was sold and the distributor recalibrated it.

author: DS-LABOR
author_rank: Newbie
timestamp: December 09, 2012, 03:15:03 pm
content: after what time period a calibration usually expires?are there any other significant signs to determine, if this meter is new or second hand?shouldn't there be a certificate of calibration somewhere?!cheersdave

author: M. András
author_rank: Super Contributor
timestamp: December 09, 2012, 06:25:34 pm
content: usually a year or so there are cal labs in every country where you can get a certificate as for the original papers ask fluke with the serial number of your unit
Problem with GW Instek GDS-1102B Digital Oscilloscope - Page 1
Forum section: electronics / beginners

author: sbdada
author_rank: Contributor
timestamp: February 13, 2018, 08:47:52 am
content: Hello,Today I got my first oscilloscope. It's a GW Instek GDS-1102B. According to the specification, it has a 10MPts memory depth. But, when I turned it on, the upper right corner of the screen shows only 10Kpts of memory depth. Unfortunately I've almost zero knowledge about digital storage oscilloscope, so I don't know how to fix it.So, is there any way or option in the settings to increase the memory depth or did I got the wrong product?Please help me. Thanks in advance.

author: wraper
author_rank: Unknown
timestamp: February 13, 2018, 08:59:08 am
content: Press "Aquire" button, set record length. There is nothing to fix, you don't want to use 10 Mpts unless you really need it.

author: sbdada
author_rank: Contributor
timestamp: February 13, 2018, 09:32:36 am
content: That's cool, I got it. Another question which i forgot to mention on my main post, sorry for that. It has 5 button's which just do nothing. Pressing those says, "Not supported for this model!". Those buttons are "Option", "Search", "Set/Clear", "Left arrow" and "Right Arrow". This looks odd to me. If this is not supported, then why they added these buttons?Anyway, thank you Mr. wraper
Problem with LCD controller board - Page 1
Forum section: electronics / beginners

author: sph
author_rank: Newbie
timestamp: November 02, 2020, 01:22:06 pm
content: Hi everyone,I want to use the screen of an old laptop as an external monitor.So I followed a tuto and I bought a LCD controller board on ebay (eDP HDMI LCD Controller Board for LTN156HL01 LTN156HL06 1920x1080 LCD Screen).My problem is that it doesn't work: when I plug in the adapter, the controller's LED turns red, and when I plug in the HDMI wire connecting my computer to the controller, the controller's LED turns green.However, the external screen (that I connected to the controller) doesn't turn on.I am not sure if I did something wrong (for instance, while plugin the controller's wire to the screen) or if it is because the adapter is not powerful enough: I'm using a 12V 3A adapter and it is written on the controller's page on ebay that the controller requires an adapter with 12V and "more than 3A", I'm not sure if "more than 3A" means 4A and more or 3A and more.I am sorry if it sounds confuse, I'm a total newbie in electronic stuff.Here's two pictures of the controller not plugged and the controller plugged.I would appreciate a lot any piece of advice.Thanks by advance !
Problem with lm35 and lm 358 - Page 1
Forum section: electronics / beginners

author: little_carlos
author_rank: Regular Contributor
timestamp: May 24, 2014, 11:46:46 pm
content: HelloI have a problem with the lm358, i have 2 lm35, both have good readings of temperature, ive tested both and they show what they should, the problem is, that when i connect any of these to a lm358, the output voltage is bigger than what it should, the voltage supply is 12 volts, the output voltage is always 6.23 volts, even when the temperature at the lm35 is almost 100º C , it never changes, or just a few milivolts.here is the circuitive thest 2 lm358 and both show the same problem, but one at 6.23 and the other at 5.4 voltswhat should i do, i need to amplify the signal of the lm35

author: c4757p
author_rank: Super Contributor
timestamp: May 25, 2014, 12:17:09 am
content: What are R1 and R2?

author: Paul Price
author_rank: Super Contributor
timestamp: May 25, 2014, 12:42:44 am
content: First of all you show a 5V power supply for the whole circuit..this will not allow an output >5V.
Problem with MAX14830 - Page 1
Forum section: electronics / beginners

author: dambo
author_rank: Newbie
timestamp: May 05, 2016, 10:53:39 pm
content: Hi allI want to have more UARTs on my Raspberry Pi. I have my own PCB with MAX14830 unfortunately i can't send anything. Problem is UART clock - when i set bypassing dividers and PLL then ClockReady flag is always 0. I can write to TXFIFO and read their counter but chip doesn't send anything. Maybe someone work with this chip and can give me some advice? Here is documentation:https://www.maximintegrated.com/en/products/interface/controllers-expanders/MAX14830.html
Problem with original PicKit3 - Page 1
Forum section: electronics / beginners

author: sairfan1
author_rank: Frequent Contributor
timestamp: February 09, 2024, 05:29:21 pm
content: MPLABX looks like a very poor IDE, its been long they redone it but still does not look like its stable.I'm working on a project where I'm communicating between two PIC MCUs (both are 16LF18324) I often need to switch betwen master or slave projects both projects are open in same IDE and can be seen on project tree. Whenever I switch between uC it gets crazy, sometime it does not detect device connected, sometime it reads device successfully but could not program and mostly I have disconnect it from USB and connect it back again to make it work. Even sometime i have to close IDE and then load the project again to make it work.I'm looking for if someone know a solution.

author: coromonadalix
author_rank: Super Contributor
timestamp: February 09, 2024, 05:46:47 pm
content: programming ...https://www.eevblog.com/forum/microcontrollers/pickit-plus-for-pickit2-and-pickit3-programmers-latest-news/msg3209826/#msg3209826and you have threads about pickit3 problems, just do some search here

author: fourtytwo42
author_rank: Super Contributor
timestamp: February 09, 2024, 07:10:35 pm
content: You don't say if you are using Winx or Linux, I believe from my experiences there are some differences in USB pickup.MPLABX is horrible in just about every way but we are forced to use it to support newer chips! MPLAB8 being a bit long in the tooth.I find with X it is soooooo damm slow I don't try doing anything fancy so just one thing open at a timeThe two problems I have encountered with PK3 are :-It has to be plugged in before you start XIf it reloads the PK3 firmware it will be incompatible with MPLAB8 firmware reloads! (Workaround is change FW if required under X then use it under 8If your not using C might I suggest sticking to MPLAB8, so much better and faster
Problem with panel meter - Page 1
Forum section: electronics / beginners

author: jeet55
author_rank: Contributor
timestamp: October 14, 2017, 02:57:12 pm
content: Currently iam working on a simple power supply project,It consist of a 12v 2A smps and a dc-dc convert , i used a panel meter to display the voltage and current but the problem with panel meter is it needs a isolated supply like from a battery , if i used a 9v regulator powered by smps the panel wont work and it just displays 1(overloading). But i dont wont to use a battery so what are my options?

author: Signal32
author_rank: Frequent Contributor
timestamp: October 14, 2017, 05:02:05 pm
content: Link to power meter ? Very strange that it would require an isolated supply. I think you may be doing something wrong, also perhaps post your schematic.1. You can use a different power meter that doesn't want isolated power supply2. You can get a DC-DC isolated converterhttp://www.ebay.com/itm/-/282666465349/https://www.digikey.com/product-detail/en/cui-inc/PEM1-S12-S12-S/102-2762-ND/4009686(similar to this, based on your requirements)

author: jeet55
author_rank: Contributor
timestamp: October 14, 2017, 06:20:54 pm
content: Here is a very curde block diagram / schematic , sorry iam just a beginner.

author: Signal32
author_rank: Frequent Contributor
timestamp: October 14, 2017, 06:57:15 pm
content: What model is the power meter ? Can you post pics of the setup ?If you don't use the battery, is the error happening when you try to measure current, voltage, or both ?

author: Vtile
author_rank: Super Contributor
timestamp: October 15, 2017, 07:36:50 pm
content: Yep, there is some of the "better range" digital meters that need a separate power to allow them to float. Only option I can think of is to make a small separate (floating) transformer circuit to power the meters.ie.http://www.peaktech.de/productdetail/kategorie/id-3-12-stellen-voltmeter-module/produkt/ldp-340.html

author: Brumby
author_rank: Unknown
timestamp: October 16, 2017, 05:00:53 am
content: Having a link to the actual meter module might be helpful in looking for ideas.Sometimesyou can play some games with sense connections to work off the same supply - but if you are doing current measurement as well, then that's pretty much off the books.Also, two things -1. Your voltage divider for the volts range is wrong. It will divide by 101 not 100. To divide by 100, the ratio of thesumof the upper and lower resistorsmust be 100 times the value of the lower resistor. For example, with the lower resistor being 100 ohms, the upper resistor needs to be 9900 ohms, not 10K.2. As wired, the current display will be negative. With current flowing, the meter's "negative" input will be at a higher potential than it's "positive" input. If you want it to show as positive (and still keep your voltage sense correct) you will need a DPDT switch and switch both sides of the meter input.
Problem with pressure transducer - Page 1
Forum section: electronics / beginners

author: spintinas
author_rank: Contributor
timestamp: February 08, 2018, 11:52:25 pm
content: Hello, my problem is related to pressure transducer. I have a pressure transducer Data Instruments (now Honeywell) AB model 25 psi. Datasheet is here:https://stevenengineering.com/tech_support/PDFs/31DTMAIN.pdf. (My transducer in datasheet is first, AB model). Problem is, that when I power this transducer from usb connector, transducer didn't work correctly. When there is no pressure, I get the 2.5V DC voltage in my multimeter, but according to datasheet Zero Output is 0 + 5 mV. Also, when I pressure transducer there is no change, anyway 2.5V from transducer. In my opinion power source is good, because voltage between Excitation+ and Excitation- is 5V. So, maybe anything of you know what problem it can be?

author: BradC
author_rank: Super Contributor
timestamp: February 09, 2018, 04:00:34 am
content: Quote from: spintinas on February 08, 2018, 11:52:25 pmWhere are you measuring from. You need to measure the voltage difference *between* the two signal wires. That should be ~0V at rest and ~100mV at full pressure. Their relationship to your excitation wires is arbitrary and not important, although they should be sitting somewhere around half (which they appear to be).

author: babysitter
author_rank: Frequent Contributor
timestamp: February 09, 2018, 09:45:14 am
content: If you are already measuring between both the signal pins, the unit is damaged. Sometimes pressure transducers die with one half bridge basically OK, the other half bridge tied to excitation + or -.

author: danadak
author_rank: Super Contributor
timestamp: February 09, 2018, 11:40:41 am
content: The xducewr is a bridge type interface -http://www.analog.com/media/en/analog-dialogue/volume-38/number-2/articles/bridge-type-sensor-measurements.pdfhttp://www.ti.com/lit/an/slyt640/slyt640.pdfhttp://cds.linear.com/docs/en/application-note/an43f.pdfRegards, Dana.

author: spintinas
author_rank: Contributor
timestamp: February 11, 2018, 08:51:28 pm
content: So, now I check again, and I see that voltage between data signals is ~65mV, in datahsheet i saw, that my transducer is absolute pressure. So, when I try to measure pressure from my blood pressure pump, I see voltage 65mV, which equal to 14,7 psi (atmospheric pressure). 25psi - 100mV, 14,7psi ~50mV, i came to conclusion, that transducer works correctly, but now I have a question, how to perform pressure measurement with this transducer? It's there some ways to callibrate them or any onther options? When I apply some pressure on transducer, still I get value of 65mV (atmospheric pressure).

author: babysitter
author_rank: Frequent Contributor
timestamp: February 12, 2018, 12:36:55 pm
content: Please state the exact type! The front membrane is the sensitive area.
Problem with Ramp signal Generator using IC 555 - Page 1
Forum section: electronics / beginners

author: Pr1y4n5hu
author_rank: Newbie
timestamp: May 09, 2022, 04:31:45 pm
content: According to theory the time period for ramp signal generated using the following circuit should be:2 Vcc. C1. RE. (R1+R2)T= - . -----------------------------3 Vcc. R2 - VBE (R1+R2)Now...putting the value of Vcc, R1, R2, VBE, RE... the time period comes out to be around 0.9ms.But from the simulation it appears to be around 3ms.Whats wrong here?

author: Zero999
author_rank: Super Contributor
timestamp: May 09, 2022, 05:43:56 pm
content: You've correctly calculated the rise time of the ramp, which is 1V/0.9ms. The period will be 3.3 times longer, since the 555 timer won't discharge the capacitor until the voltage on it reaches2/3VCC.If you just need to calculate the period, the VCCterm can be eliminated from the formula.EDIT:The bit about eliminating VCCis not quite true, because of VBE.
Problem with reducing the voltage below transistor's minimum  - Page 1
Forum section: electronics / beginners

author: ozan
author_rank: Newbie
timestamp: August 03, 2024, 06:08:01 am
content: Hello there,I am newbie here so my question will be accordingly. Please be gentleI have the following diagram on my breadboard and what I want to achieve here is to turn and off the led with an LDR. I want to place a resistor first where it would only allow voltage pass through to the base just slightly above 0.6v to close the circuit and light up the LED and then place an LDR in series with the resistor to make the circuit light sensitive where it turns on and off according to the daylight. No matter what I did with the resistors available at hand (the biggest I have is 80kohm) I couldn't get the voltage drop below 0.6v. I have also added a diode in series but still the same and I know I am getting something wrong here since I don't know much about electronics. So help me understand it please!

author: ozan
author_rank: Newbie
timestamp: August 03, 2024, 06:30:18 am
content: Okay guys I got it. I have placed the ldr in parallel with the transistor and I guess this is what you call voltage divider? See the attached picture pls.

author: Gyro
author_rank: Super Contributor
timestamp: August 03, 2024, 08:44:30 am
content: @quince, an LDR is a light dependent resistor.

author: ledtester
author_rank: Super Contributor
timestamp: August 03, 2024, 01:57:17 pm
content: Quote from: ozan on August 03, 2024, 06:30:18 amIt's being used in a voltage divider and the circuit is normally drawn like this to clearly show the divider:Putting the LDR on the high side of the divider will invert the behavior of the circuit, eg:

author: Kim Christensen
author_rank: Super Contributor
timestamp: August 03, 2024, 03:30:44 pm
content: Quote from: ozan on August 03, 2024, 06:30:18 amI see that you're powering this with 3.7V so I assume that the circuit is battery powered?Just want to point out that your circuit will draw approximately 3mA when the transistor/LED is turned off by the LDR. (3.7V across the 1200resistor)
Problem with Relay experiment (Make: Electronics #7) - Page 1
Forum section: electronics / beginners

author: OgreSwamp
author_rank: Newbie
timestamp: January 19, 2015, 12:57:30 am
content: Hi there,I'm reading Make: Electronics to recover my college electronics knowledge.I've assembled a circuit (using a breadboard, during it with alligators is a nightmare) and it doesn't really work.So here is a circuit I'm trying to do:Here is what I've done:Resistor is 680Omh, LEDs positioned properly (cathodes facing right - to the negative, green wires).When I press red button (bottom left corner) I can hear the relay is switching, top led goes off, but bottom one doesn't start.I've tried few things:1) replace a relay component2) replace LED3) tried to measure voltage at 2nd led pins when I press red button1 & 2 doesn't help.Voltage goes up to 0.4-0.6 for half a second and then drops to zero when I press/release the button.Can't figure out what's wrong. My only guess was that DPDT relay I've bought isn't the correct one, but I found the data sheet and it says that coil voltage is 12v - came as my circuit voltage.Here are few more pictures to get a better understanding what's happen there.Thanks!

author: digsys
author_rank: Unknown
timestamp: January 19, 2015, 01:31:22 am
content: Easy fix - check the drawing .. grobotronics.com/images/datasheets/HK19F-12V.pdfCommonis the centre pinsare the pins NEXT to the coil ! Always check drawings, pinouts can vary a lot.

author: peter.mitchell
author_rank: Super Contributor
timestamp: January 19, 2015, 02:13:29 am
content: if that is real carbon fiber i'd avoid doing electronics work on it - its quite conductive.

author: jahonen
author_rank: Super Contributor
timestamp: January 19, 2015, 11:29:49 am
content: If all else is correct, it is possible that relay contacts are a bit oxidized and circuit voltage is too low to break through this oxide layer. This often happens if there is insufficient voltage/current through the relay to clean the contacts via contact sparking when switching happens.Regards,Janne

author: OgreSwamp
author_rank: Newbie
timestamp: January 19, 2015, 11:49:17 am
content: digsys, thanks! I switched red probe from the push button & non-working LEDs anode and now everything is working! That was one of my suggestions. I've checked drawing on the bottom of relay (it has it) but didn't quite understand it. Now I have much better understanding.peter.mitchell - good spot. This is a soldering pad, so most likely it is a carbon fibre. I think for now I can work on the table but when I will start to do experiments with ICs I may buy a anti-static mat.jahonen, thanks. I mentioned I've tried to change relay. Anyway thanks for the guess. I'll check in future that all contacts are clean.Cheers!
Problem with setting parameters VARISPEED V7 OmronV7 V7AZBOP7 1.1 KW  - Page 1
Forum section: electronics / beginners

author: IOAN
author_rank: Newbie
timestamp: September 22, 2014, 09:49:08 am
content: Hello,I write the first time in this forum and hope resolve with your help my problem.I bought (via EBAY) VARISPEED V7 OmronV7 V7AZBOP7 1.1 KWThe seller was setting parameters for him useI have driving (delta conexions) 3x220V/50Hz and current consummation it is 2,9 A. the drive use to mini latheMy Omron v 7 no good function the drive have noise sound but no start , distance drive ----varispeed it is 6 meters.not understanding setting parameters for a good function.so, when command ,, RUN,, the driving start for 0,5 " secundes and stopthe display information cod faulty OL3Best regardes and please replay me.IOAN

author: AlfBaz
author_rank: Super Contributor
timestamp: September 22, 2014, 10:14:17 am
content: What are the motor specifications?Looks like you are at the vfd's max kilowatt rating

author: cs.dk
author_rank: Unknown
timestamp: September 23, 2014, 05:21:20 am
content: From the manual:OL3 (Overtorque detection)Motor current exceeded the preset value in constant n098.Overtorque detection level was exceeded because of increased leak current due to excessively long wiring.Reduce the load, and increase the acceleration/deceleration time.Refer to the paragraph of Carrier Frequency Selection (n080)14kHz max on page 93.Check the wiring (increase of current caused by rare shortcircuit, etc.).Whats the data on the motors nameplate?Your acceleration time is 1,5 sec. Try increase is to ie. 5 sec. and see. (menu n19)For a testrun you can disable the overtorque detection, set n096 to 0 (The feature is disabled when factory settings are loaded)
Problem with SSD1306 OLED  - Page 1
Forum section: electronics / beginners

author: PeterFW
author_rank: Frequent Contributor
timestamp: March 26, 2016, 03:19:22 am
content: Edit:Never mind, incorrectly labeled, different controller.... SH1106 instead of SSD1306, works now. The cheap price allways comes at a cost. (No pun intendet)Hello!I have 3 pieces of this display, two identical and a third that is from a different batch.The two identical both show the same problem, as seen here:Has someone got an idea why? I would say, they are broken... but, who knows.They are controlled by an AtMega328P, at 5V over SPI and with the u8glib routines.Both should be 5V tolerant.Greetings,Peter

author: bktemp
author_rank: Super Contributor
timestamp: March 26, 2016, 11:07:31 am
content: It looks like you need to increment the horizontal address by 2 when writing data: On the right side there are two colums showing random data (non initialized RAM data).

author: danadak
author_rank: Super Contributor
timestamp: March 26, 2016, 11:47:34 am
content: Consider looking at the write timing with oscope to the display. Alsoexamine logic levels correct at display.The spec does not mention 5 V tolerance, in fact page 35 of spec shows maxVih of Vdd1.Regards, Dana.

author: PeterFW
author_rank: Frequent Contributor
timestamp: March 26, 2016, 02:32:18 pm
content: Hello and thanks for your reply!Quote from: danadak on March 26, 2016, 11:47:34 amThe problem was wrong labeling, the controller on the display is not a SSD1306, it is the SH1106, it works now like it should.QuoteThe boards both have a regulator and what appears some level shifting and were sold as 5V compatible. Should have checked to make sure but...Greetings,Peter

author: amyk
author_rank: Super Contributor
timestamp: March 26, 2016, 02:52:26 pm
content: The SH1106 is a 132x64, whereas the SSD1306 is 128x64. Command set appears nearly identical. Did you get 256 extra pixels?

author: bktemp
author_rank: Super Contributor
timestamp: March 26, 2016, 03:19:36 pm
content: Quote from: amyk on March 26, 2016, 02:52:26 pmThe 128x64 pixels are centred in the 132x64 RAM area. That's why a 2 pixel adress offset is necessary.I have no idea why there are so many 132 pixel wide controllers, almost all displays only have 128 pixels.