hybridfree/eevblog-posts huggingface dataset:
[circuithology] Symmetric 4 transistors (audio) driver - Page 1
Forum section: electronics / projects

author: RoGeorge
author_rank: Super Contributor
timestamp: June 28, 2023, 07:24:39 am
content: Found this amplifier on a qsl.net projects webpage, don't recall from which call sign, so no link. IIRC it was used as a power amplifier for a small speaker or a headset. Looked interesting for its symmetry, low parts count, 4 transistors 4 resistors, and for not needing any idle current adjustment if the transistors are matched.Does this topology have a dedicated name?

author: moffy
author_rank: Super Contributor
timestamp: June 28, 2023, 07:35:16 am
content: I thought it looked familiar, it is called a 'Diamond Buffer':https://en.wikipedia.org/wiki/Diamond_buffer.Burr Brown made an IC around it, the OPA660 with a current output stage.

author: magic
author_rank: Super Contributor
timestamp: June 28, 2023, 07:56:36 am
content: That's what it is, also known as "folded darlington". A common type of unity gain buffer, also commonly used as output stage in opamps (at least in the '80s or so, before R2R became mainstream).Has the same β² current gain as complementary Darlington pairs, but better matching between the low and high side if identical transistors are used for outputs and drivers. Transconductance and output impedance is determined by the output pair, which would benefit from emitter resistors dropping exactly one thermal voltage each, as do all complementary emitter follower output stages.It obviously does run idle current in the output pair. The sum of their Vbe equals the sum of driver Vbe and hence their current is the same, unless they heat up due to driving a load, then it may increase. Possibly another good reason to include emitter resistors.

author: RoGeorge
author_rank: Super Contributor
timestamp: June 28, 2023, 08:06:07 am
content: Indeed, the circuit has an idle current, I was thinking idle currentadjustmentbut mangled the word adjustment, adding it now to the first post.

author: Terry Bites
author_rank: Super Contributor
timestamp: June 28, 2023, 08:07:47 am
content: Its a diamond amp as moffy says but its not the Burr Brown diamond transistor.That's a different beast, a current conveyor.

author: moffy
author_rank: Super Contributor
timestamp: June 28, 2023, 08:31:47 am
content: Quote from: Terry Bites on June 28, 2023, 08:07:47 amIf you look at:https://www.ti.com/lit/an/sboa071/sboa071.pdfpage 2, Figure 6 the equivalent BE of the Diamond transistor is the Diamond Buffer, The C becomes a current mirror, current output of the Diamond Transistors E, so it looks like a bidirectional transistor hence its name.
[Concept] Siberian methane combustion quadrocopter mosquito - Page 1
Forum section: electronics / projects

author: robin_
author_rank: Newbie
timestamp: August 14, 2015, 11:41:33 am
content: This videojust gave me an idea how to weaken the greenhouse effect of methane being released from perma-frost. The idea is basically to build swarms of methane consuming quadrocopters that combust the methane into the weaker greenhouse gas CO2 (and water vapor). Something like this:It would detect methane leaks with aTelpos Hyper-Cam Methane. The needle could possibly be made of a light heat resistant plastic or carbon-carbon composite fibers.Perhaps other designs are conceivable, for example a very light, gliding aircraft that simply pierces the ground, ignites the methane directly and uses the explosion for uplift.

author: unitedatoms
author_rank: Frequent Contributor
timestamp: August 14, 2015, 02:14:57 pm
content: You can drive over ice on the truck for miles in winter there. There is also a history of seasonal temporary rail roads put on top of the ice. The plastic mosquito has to be 5 ton may be to fall from 100 m to break that ice of this thickness.
[dumb request] please help me identify mcu from picture - Page 1
Forum section: electronics / projects

author: cbc02009
author_rank: Regular Contributor
timestamp: March 21, 2020, 07:28:18 pm
content: I'm going to apologize in advance, because this is really dumb, but I'm running out of ideas, so I figured I'd at least ask.I have a keyboard I want to buy, the varmillo va87m, but I want to know what chip is on it before I buy it. The only place I've been able to find a picture of the PCB is this set here:https://imgur.com/a/TQI5j. I'm pretty sure the mcu is in the second pic, but I don't recognize the logo, and I can't read enough of the part number on the silkscreen to give me a good guess.I was hoping someone would at least recognize the logo, so I'd have a starting point in my search, but any help at all would be greatly appreciated!

author: ataradov
author_rank: Super Contributor
timestamp: March 21, 2020, 07:55:22 pm
content: The logo is Holtek. But it is impossibles to see any other markings.The PCB skil screen starts with HT68F0, which does match some Holtek MCUs.Ok, it looks like it actually is HT68FB560. And it is available in QFP-48, just like the device in the picture.

author: cbc02009
author_rank: Regular Contributor
timestamp: March 21, 2020, 08:02:45 pm
content: Quote from: ataradov on March 21, 2020, 07:55:22 pmThank you so much! I want to try programming my own keyboard firmware just for the heck of it. I was hoping it would be arm or avr since I know those toolchains, but maybe I can still make it work.
[Eagle] 10W RGB Led Flasher (Photo-coloring) - Page 1
Forum section: electronics / projects

author: expertmax
author_rank: Regular Contributor
timestamp: January 06, 2014, 01:07:33 am
content: Hi folks!My friend wants this 10W RGB Led Flasher that I built.It mainly consists of a ATtiny84 which controls the 3 color channels (npn darlington transistors), depending on the values of 5 potentiometers.It's my first time designing a board (ever) and I would like to have your advice regarding my work.I've attached the schematic and the board.Tell me what you think, Thanks!https://www.dropbox.com/s/7brm47ts97zja6k/main.brdhttps://www.dropbox.com/s/n460xsh4948syh8/main.schCode:/** led_flasher_adc_tiny84.c** Created: 05/01/2014 8:37:58 PM* Author: Maxime Clermont*/#define F_CPU 1000000U#include <avr/io.h>#include <util/delay.h>int _ADC_Read(int pin);int main(void){ADCSRA |= (1 << ADEN) | (1 << ADSC) | (1 << ADPS1) | (1 << ADPS0);DDRB |= (1 << PINB1) | (1 << PINB2) | (1 << PINB3);DDRA |= (1 << PINA6) | (1 << PINA7);TCCR0A |= (1 << COM0A1) | (1 << COM0B1) | (1 << WGM00) | (1 << WGM01);TCCR0B = (1 << CS00);TCCR1A |= (1 << COM1A1) | (1 << WGM10) | (1 << WGM11);TCCR1B = (1 << CS10);while(1){if(bit_is_set(PORTB, 0)){int duration = _ADC_Read(4) / 2;do{int brightness = _ADC_Read(5);OCR0A = _ADC_Read(1) - brightness;OCR0B = _ADC_Read(2) - brightness;OCR1A = _ADC_Read(3) - brightness;duration = duration - 1;}while(duration != 0);}_delay_ms(100);}}int _ADC_Read(int pin){ADMUX &= 0xF0;ADMUX |= pin;ADCSRA |= (1 << ADSC);while(ADCSRA & (1 << ADSC));return ADCL;}

author: Odysseus
author_rank: Regular Contributor
timestamp: January 06, 2014, 06:00:14 am
content: Your LM317 is configured to output 27V, and I assume you have four 9V batteries in series to provide ~36V, which is the input to the 7805 and 317. This is near the absolute maximum rating for both regulators.You will need to move the darlington transistors "below" the LED's if you hope completely switch then on, since the micro can only drive the bases to +5V. I.E. Connect emitters to ground and collectors to the series resistors R11-R13. Otherwise you'll just be wasting the majority of your power in the transistors.Then again, I don't know why you need 27V to drive some LED's. 10W you say? Are these LED strings, because they look just like normal 5mm LEDs. What is the forward voltage at rated current for your LEDs?Also, mounting holes are always a good idea.
[FYI] Effects of reference plane slots/"broken" return paths on SI and EMC - Page 1
Forum section: electronics / projects

author: DutchGert
author_rank: Frequent Contributor
timestamp: February 20, 2017, 09:56:50 am
content: Hi guys,Last week I did some design verification and performed some EMC tests on a product and the results I got showed very clearly the effects of reference plane slots on LVDS signals in regard to signal integrity and EMC.This is something we all of course already knew but in this case the results u get from a "bad" pcb layout are very clear and visible: (see attachment)I thought this could be a good example of how important a 'proper' reference plane/return path is when dealing with high-speed LVDS signals.
[Graphics] Microcontroller needed to update TFT display frame buffer at 75Hz - Page 1
Forum section: electronics / projects

author: sentry7
author_rank: Regular Contributor
timestamp: December 14, 2015, 11:58:18 pm
content: Hey guys,I'm starting a graphical project. The display is a QVGA TFT, 320x240, 16bpp @ 75Hz. The display already has an integrated display controller (ILITEK ILI9341) and a frame buffer, but I need a microcontroller that can update the buffer at the refresh rate of 75Hz. If my math is correct, the throughput I need is,bandwidth = num_pixels * color_depth * refresh_rate = 320 x 240 x 2 (bytes / pixel) * 75 ~ 12MB/s.Does anyone have any microcontrollers in mind that can achieve this? Or maybe a different idea in mind?

author: NiHaoMike
author_rank: Super Contributor
timestamp: December 15, 2015, 05:57:39 am
content: How about a Raspberry Pi Zero? At $5 each (if you can get one), you'd have a hard time finding anything cheaper that can do it.
[Guidance required] Want to generate RF... but - Page 1
Forum section: electronics / projects

author: BadeBhaiya
author_rank: Regular Contributor
timestamp: May 13, 2025, 02:05:55 pm
content: What is the easiest (and most reasonable) way to generate RF (let's say 500MHz) without just buying a VCO, DDS or PLL chip or oscillator.Clapp's or Colpitt or Hartley oscillator? Are they stable though?Ring oscillator + harmonic bandpass filter + amplifier?This is only for playing around with my rtl-sdr and nothing serious, so drift, jitter etc i don't mind much. I have a bunch of dev boards so i don't mind using microcontrollers either

author: tggzzz
author_rank: Super Contributor
timestamp: May 13, 2025, 02:25:48 pm
content: Quote from: BadeBhaiya on May 13, 2025, 02:05:55 pmHow about a 2N3904 plus 1kohm circuit?https://entertaininghacks.wordpress.com/2024/03/16/practical-traps-with-a-one-transistor-audio-amplifier-solderless-breadboards-and-oscilloscopes/Use the RTLSDR to characterise its instability.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: May 13, 2025, 10:50:47 pm
content: How about a crystal oscillator with a lot of harmonics and then a SAW filter for somewhere near 400 MHZ (cheap) then a few MMIC amplifiers?I needed an over 400 MHz signal to align a piece of equipment so I used the output of a GPSDO and amplified it after using a SAW filter I purchased on ebay.

author: jonpaul
author_rank: Super Contributor
timestamp: May 14, 2025, 05:14:53 am
content: become a ham, join ans read ARRL publicationsSee fine text on RF oscillatorsj
[HACK]Adding a constant current pot to a power supply to work as CC CV (TL494)? - Page 1
Forum section: electronics / projects

author: MikeLemon
author_rank: Contributor
timestamp: August 04, 2017, 01:38:01 pm
content: Hello,So I have this SMPS unit:and would like to add a variable resistor to a TL494 based power supply I've seen other people do it but on another types and would like to know how to do it in here where is the resistor that controls the current limiting and what value pot should it be replaced with?Help is very appreciated.Thanks for your time.Here is the reference schematic in the datasheet.

author: David Hess
author_rank: Super Contributor
timestamp: August 04, 2017, 04:15:44 pm
content: A 1 kilohm variable resistor in place of R1 would do it.

author: MikeLemon
author_rank: Contributor
timestamp: August 04, 2017, 04:31:28 pm
content: Quote from: David Hess on August 04, 2017, 04:15:44 pmAight Thanks I'll try it out and send a feedback.

author: MikeLemon
author_rank: Contributor
timestamp: August 04, 2017, 06:06:13 pm
content: Quote from: David Hess on August 04, 2017, 04:15:44 pmSo I located that resistor on my PSU and it was 68KOhm so I replaced it with a 50KOhm Pot now when connecting a 2A load to it and turnin the pot to min or max it doesn't have any affect on voltage or current you sure it's that resistor?Also what is the math for the current behind it?

author: MikeLemon
author_rank: Contributor
timestamp: August 04, 2017, 07:49:46 pm
content: Quote from: MikeLemon on August 04, 2017, 01:38:01 pm

author: David Hess
author_rank: Super Contributor
timestamp: August 04, 2017, 10:01:03 pm
content: Quote from: MikeLemon on August 04, 2017, 06:06:13 pmThat is the resistor on the schematic which can be used to alter the current limit.Resistor divider R2 and R1 apply a 1 volt reference to the inverting input of the current error amplifier at pin 15. When the voltage across R13 reaches 1 volt indicating that 10 amps are present, the current error amplifier takes over and limits the current. Lowering the value of R1 lowers the reference voltage applies to pin 15 lowering the maximum current.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 05, 2017, 01:43:25 am
content: I don't see a current transformer, nor an auxiliary power supply for the controller.I doubt you'll be able to get much adjustable range before the controller starts hiccuping, and no such thing as CC operation.Tim

author: MikeLemon
author_rank: Contributor
timestamp: August 06, 2017, 11:30:51 am
content: Quote from: T3sl4co1l on August 05, 2017, 01:43:25 amSo you say leave it?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 06, 2017, 12:08:16 pm
content: If you want to go to great lengths, it could be used as a starting point, perhaps -- but if you just want a thingy, yeah, better to leave it.Tim
[HELP] 1512a voltage regulator manufacture! - Page 1
Forum section: electronics / projects

author: allenpan
author_rank: Contributor
timestamp: September 06, 2015, 10:28:57 pm
content: 1512a voltage regulator manufacture!i have a regulator, TO-263 package... for life of my i cant find out who makes it...Cll <----reversed C and l is 2 broken in the middle1512A1108cLthanks...

author: codeboy2k
author_rank: Super Contributor
timestamp: September 07, 2015, 07:17:45 am
content: Reversed CII is the Diodes, Inc. logo.You have the AP1512A
[help] Adafruit's Bluefruit SPI - Page 1
Forum section: electronics / projects

author: WillHuang
author_rank: Contributor
timestamp: December 19, 2016, 04:13:05 am
content: I'm trying to understand how to work with Adafruit's Bluefruit SPI module so I can write a small driver for my next microcontroller project. I am having a hard time following theirSDEP protocoland using it to write some small program tests in Arduino (shown below). In this code, I'm attempting to send an AT command. According to Adafruit's protocol, after sending a message to the BLE, the Bluefruit would prepare a response back. The IRQ line is set high to indicate that a response is ready to be received. However, I can't seem to be able to properly read back the reponse packet and bring the IRQ line back low.If anyone has some insight, that be great and very helpful! Thanks in advance.Code:#include <SPI.h>#define BT_CS 8#define BT_IRQ 7#define BT_RST 4unsigned char fifoBuffer;unsigned char locFifoBuffer;unsigned char sizeFifoBuffer;unsigned char Flag;void setup() {// put your setup code here, to run once:pinMode(BT_CS, OUTPUT);pinMode(BT_IRQ, INPUT);pinMode(BT_RST, OUTPUT);// Setting SPI clock to 2 MHZSPI.setClockDivider(SPI_CLOCK_DIV8);SPI.begin();SPI.setBitOrder(MSBFIRST);Serial.begin(115200);locFifoBuffer = 0;sizeFifoBuffer = 0;// Resetting BLE ModuledigitalWrite(BT_CS, HIGH);digitalWrite(BT_RST, LOW);delay(100);digitalWrite(BT_RST, HIGH);Serial.println("BLE Resetted");}void loop() {Serial.print("AT Command> ");while(!Serial.available()); //Wait for a command Inputwhile(!Flag){if(Serial.available()){fifoBuffer = Serial.read();if(fifoBuffer == '\n'){Flag = 1;}locFifoBuffer++;}}fifoBuffer = '\0';sizeFifoBuffer = locFifoBuffer;locFifoBuffer = 0;Flag = 0;SerialWriteString((const char *)fifoBuffer); // Echo back the commandSerial.print("\r");sendATCommand((const char *) fifoBuffer, sizeFifoBuffer); // Write the command to BLE// If IRQ line is high, BLE has a packet for us...if(BT_IRQ){SPI.beginTransaction(SPISettings(2000000, MSBFIRST, SPI_MODE0));digitalWrite(BT_CS, LOW); // Chip SelectdelayMicroseconds(100);while(BT_IRQ){SPI.transfer(0xFF);}digitalWrite(BT_CS, HIGH); // Chip SelectdelayMicroseconds(100);SPI.endTransaction();}}void SerialWriteString(const char *s){while(*s){Serial.write(*s++);}}void putString(const char *s){while (*s){putChar(*s++);}}void putChar(unsigned char ch){SPI.transfer(ch);}void sendATCommand(const char *cmd, unsigned char len){SPI.beginTransaction(SPISettings(2000000, MSBFIRST, SPI_MODE0));digitalWrite(BT_CS, LOW); // Chip SelectdelayMicroseconds(100);SPI.transfer(0x10); // Message Type: CommandSPI.transfer(0x00); // AT Wrapper Command IDSPI.transfer(0x0A);SPI.transfer(len);while(*cmd){putChar(*cmd++);}digitalWrite(BT_CS, HIGH);delayMicroseconds(100);SPI.endTransaction();}

author: LeonV
author_rank: Contributor
timestamp: December 21, 2016, 03:10:23 am
content: Usually when i get that behaviour, the MISO pin on the master is setup incorrectly or some other preferential is using it, or the mode is wrong and the data read / clock timing is wrong.
[Help] Any analogue Geek Out there? - Page 1
Forum section: electronics / projects

author: Mousam Upadhyaya
author_rank: Newbie
timestamp: May 25, 2021, 02:19:40 pm
content: Recently I was repairing a Chinese rechargeable Emergency light (solar/Mains) and the problem certainly was the Battery itself. I fixed it and thought a glimpse on this circuit. All was going well until I stumbled on this (Attached picture). Is this an Undervoltage/Overcurrent protection? Because AMS1117 adj (U.S.B 5V Regulator in this case) on this circuit can handle Everything Right? If someone Explains me with Theory of operation I will be happy Forever

author: pqass
author_rank: Super Contributor
timestamp: May 25, 2021, 04:52:19 pm
content: First of all, it would be easier for most if the GND was on the bottom, Vcc on top, IN from the left, and OUT on the right. ie. flip vertically.The 1K/330R divider at the regulator adjust pin normally sets OUT to be 5V as per the formula: OUT=1.25(1+1K/330R)The transistors will short the 1K resistor so OUT=1.25 until the input goes above 5.6V.See attached. I've used an LED to indicate when the second transistor is on or off; ie. when the 1K resistor is shorted or not, OUT=1.25 or 5V, respectively.Basically, the circuit doesn't produce 5V until there is enough source voltage to compensate for the drop-out of the regulator and only then produce a clean 5V out. However, the datasheet says there is a 1V drop-out! Oh well.Play with the simulator here. Use the Voltage slider on the right to change Vcc.http://www.falstad.com/circuit/circuitjs.html?ctz=CQAgjCAMB0l3BWcMBMcUHYMGZIA4UA2ATmIxAUgoqoQFMBaMMAKGwBYQAvOgOzoBODdtGzhw0DGHbYEKPGGLyw8FI3JUUseDt35OIsay4gU7KtjSnzphIVPc+g4aJYDrFq2Yt5OVdhiQbh4g2L4h7Ox4UKHEQQDmEVEReFRpLABKISh22fgx-rTQhNFpUNAILAAuoZCcYfXY9g0xEDAI2IF28mhyYJjlhP05hER27ISQckgqVAAmdABmAIYArgA2VSyJ2E0g5hZ7UWVB7rvNJaF7IzG7cCwA7lf2N9629kE156GXMig-pXEDAQFSUkCa5kICEUig+sAw0NIxDwsmI2CUCHYxGQ8yWa02232llC4T++1SBUeRP+sn+x1CcigwXptPJmjwgNmQTAozZ7z58mi-wWKw2VQY6zoc3EJ1grCe9Ju3xuQQADuB5CTOP1opFom0mU8dftkm89YaNdEWm8WmrQjSrMTzQagk9iZZNDYPRancljeagp1PT56nUtTKmWF9jFtf8AGoAe02y3idBYQAAlso, C is wrong.Both emitters are grounded and so are both pins of C?

author: Mousam Upadhyaya
author_rank: Newbie
timestamp: May 25, 2021, 06:45:58 pm
content: Thank you @pqass for your precious time rearranging, creating a simulation, further explaining and evaluating components. Yes, the circuit I dawn is ''a bit how you doing" and the capacitor shown in the figure is connected to Q2 base and GND, my bad. Yes the Device has a threshold voltage similar to that of the simulation, now I'll be happy forever 😀
[HELP] Found an interesting optical device - Page 1
Forum section: electronics / projects

author: SamCZ
author_rank: Newbie
timestamp: June 14, 2020, 12:59:28 pm
content: Hi,Im new in this forum so exuse me if this is posted in wrong thread.I was searching in my old stuff for some scrap electronics and i found this interesting device.I think it is some optical device, but i cannot find any information regarding that serial number.Doest anyone know what that can be ?Any help woud be appreciated.Thank you.
[HELP] I cannot find the manufacture of this chip. Help me find it, please. - Page 1
Forum section: electronics / projects

author: learner1245
author_rank: Newbie
timestamp: October 08, 2015, 08:40:37 pm
content: Hi, I am trying to reverse engineer this Field Camera Processor. I cannot find the manufacturer of the chip, highlighted in the picture.Can you guys help me out? My friend told me it is from Texas Instruments, I know it is impossible because the logo does not say so.

author: LaserSteve
author_rank: Super Contributor
timestamp: October 09, 2015, 12:10:18 am
content: Start with Chip Logo sites:http://www.classiccmp.org/rtellason/logos/semiconductorlogos.htmlhttp://how-to.wikia.com/wiki/Howto_identify_integrated_circuit_(chip)_manufacturers_by_their_logos/A-ESteve

author: Deathwish
author_rank: Unknown
timestamp: October 09, 2015, 01:41:26 am
content: I have been looking for the last couple of hours for the logo etc, no luck so maybe a brand and model of the actual camera might give us a better clue if there happens to be a manual out there.
[Help] Identification of connector from image - Page 1
Forum section: electronics / projects

author: Fire Doger
author_rank: Regular Contributor
timestamp: January 25, 2018, 09:49:39 pm
content: HelloDoes anyone knows the type of 5 pin connector of the photo below? Its 2.54mm (100mil) pitch and it has a weird way of fitting which I haven't seen before and leads are very short its exactly like: -LAnd there is no sign of brand on it....I want to buy the male (pcb mount) part, If anyone knows manufacturer, part number, digikey link or anything else it would be very useful!*I have attached and a pic of the male (cables) if it helps from a stick for that spot from the same manufacturer but pic quality is .....Thank youStefanos

author: Fire Doger
author_rank: Regular Contributor
timestamp: January 25, 2018, 10:16:54 pm
content: Quote from: blueskull on January 25, 2018, 10:13:03 pmIts possible, caliper doesn't fit in there and 0.04 is a bit hard to judge with eyeI will check them out! Thank you
[HELP] Looking for Yatour YT-M06 “Pioneer 1” firmware (.bin) - Page 1
Forum section: electronics / projects

author: EduCabral
author_rank: Newbie
timestamp: July 08, 2025, 06:49:32 am
content: Hello everyone,I've been trying for over 10 years to make my Yatour YT-M06 (CD changer emulator) work properly with my **Pioneer DEH-P5950IB** head unit. The radio detects the device as “MULTI-CD” and shows “CD-ROM,” but unfortunately, it doesn’t play anything from the USB, SD card, or AUX input.After opening the device and researching online, I discovered that my Yatour uses the **MB89F202 MCU** and is supposed to use the "**Pioneer 1**" firmware version.Unfortunately, the official Yatour site is down and I haven't been able to find a reliable source to download the correct firmware (.bin file) for reprogramming.Here’s what I’ve tried:- Two different Yatour units.- Confirmed correct connection to the iBus.- Head unit recognizes the device.- No playback from any media.- Could not contact Yatour (all emails bounced).- I have a photo of the mainboard and MCU.🖼️ Board image:https://obrazki.elektroda.pl/2434145000_1751771284.jpg📻 Head Unit photo:https://obrazki.elektroda.pl/2333091500_1751771284.jpg---If anyone has a copy of the **“Pioneer 1” .bin firmware**, or a full flash dump of a working unit (MB89F202), I would be incredibly grateful.Even a lead or dump from a similar working unit would help.Thank you all in advance!— Eduardo (Brazil)

author: EduCabral
author_rank: Newbie
timestamp: July 09, 2025, 03:34:36 am
content: Just bumping this thread to see if anyone might have access to the “Pioneer 1” firmware (.bin) for the Yatour YT-M06 using the MB89F202 MCU.Still hoping someone out there has a working unit or a firmware dump. Any help would be greatly appreciated!Thanks again!
(HELP PLZ!)What is this signal (video from O'scope)? - Page 1
Forum section: electronics / projects

author: jstpie5
author_rank: Newbie
timestamp: February 22, 2017, 04:18:40 pm
content: I posted this in the microcontrollers board too, and I am new to the forum so someone tell me if i need to delete one or the other!As the subject implies I need help identifying the waveform on the video link below (and possibly recreating it later).The signal is the feed to a John Deere hydraulic solenoid. The signal and return wires were connected to a load resistor with the same value as the solenoid for testing purposes (5.5 ohms).I was expecting it to be PWM and it looks more like a rectified sine wave that increases in voltage and decreases in frequency as the joystick is pulled further back (more power).I am trying to take control of the hydraulic solenoid with an Arduino and MOSFET (or similiar) and I would like to use a similar signal as what John Deere uses. PWM works ok to control the solenoid but I am now curious what John Deere is doing and why.Any help is appreciated!Video starts with solenoid getting full power. Then the power is varied by moving the joystick back and forth.Low power signal frequency is ~22kHzLow power voltage is from 0 to ~10VHigh power signal frequency is ~20kHz.High power voltage is from ~2.5-10V-James

author: MickM
author_rank: Regular Contributor
timestamp: February 22, 2017, 09:11:46 pm
content: Hi;That timebase seems awfully fast.Try slowing it way down.I have a feeling that you are looking at just the top of something, e.g. ripple.Mick M

author: rstofer
author_rank: Super Contributor
timestamp: February 23, 2017, 01:48:00 am
content: Is it a solenoid or a servo valve? I wouldn't be surprised to see a 'dither' voltage on a servo valve. This keeps the spool from freezing in one spot yet won't actually move the spool enough to change the hydraulic circuit.
[Idea] Electronic Frequency Spectrum Chart - Page 1
Forum section: electronics / projects

author: Cyberdragon
author_rank: Super Contributor
timestamp: June 29, 2017, 07:16:10 pm
content: I had an idea for an interesting project for anyone that wants to tackle it.Take a frequency allocation chart in a thick frame and put a fine array of SMD LEDs behind the bars. These would connect to a few controllers and extremely simple multiband scanning recievers that detect frequencies and output the data to light the corrosponding LEDs on the chart (basically each control chip would know what frequency it's scanner is on and would listen for any signal). It would go from the bottom of the AM band all the way up to wifi using different detectors for each set of bands. The LEDs would be multiplexed and stay on (well, get relit each multiplex cycle) unless the scanners lost those frequencies. All of the antennas might fit coiled up inside the frame but you might want to include external antenna jacks and a digital gain control.

author: Benta
author_rank: Super Contributor
timestamp: June 29, 2017, 07:31:00 pm
content: A spectrum analyzer with LED display? Could be done, of course, but somehow not worth the effort...

author: mdszy
author_rank: Unknown
timestamp: June 29, 2017, 07:41:41 pm
content: Quote from: Benta on June 29, 2017, 07:31:00 pmThat's pretty subjective. I think it'd be really neat to have as a bit of an art piece. I think it's a fascinating idea.

author: Benta
author_rank: Super Contributor
timestamp: June 29, 2017, 08:07:28 pm
content: As an art piece or conversation piece, I'm with you. Perhaps I was thinking too commercially.

author: Cyberdragon
author_rank: Super Contributor
timestamp: June 29, 2017, 08:21:14 pm
content: I wouldn't really called it an "analyzer", it would't need any ADCs or anything, just some sort of simple amplifiers and digital tuners with a dirt simple detector and amp that just makes a logic 1 when any signal at all is detected. Signal integrety is of no importance so not to much fancy RF engineering, just make sure it has good reception and doesn't interfere with itself.Yes, this is only meant as an electronic decoration for your lab, hence the idea for framing it then hanging it on a wall. It would also be a bit useful for HAM guys to see what bands are currently active. You could have smaller ones too that just show specific bands of interest which would only have a single band tuner.
[Led Lamp Pjr] 7020 in series wire bridge replacement, better solution? - Page 1
Forum section: electronics / projects

author: ESXi
author_rank: Regular Contributor
timestamp: September 27, 2018, 11:08:45 am
content: Hi,I have made this project of 7020 leds, using a aluminuim back plate with special 3m tape to keep the leds in place.The question I have now is there a better solution for the wires that you can see in the picture below. I want a small pcb bridge or other solution, so I don't have to strip & cut wires on the correct lenght (saves a lot of time).Looked on online markets and on mouser but I am unable to find something that works in this application. I was thinking to cut out a copper trace with a laser cutter but meh, this isn't really great because there will need to be placed isolation material under the traces.
[LED RETROFIT]50W LED 3000LM for just US $13.27 incl. driver board!I smell BS... - Page 1
Forum section: electronics / projects

author: Zucca
author_rank: Unknown
timestamp: November 14, 2014, 04:56:26 pm
content: Yes I don´t have too much experience on LED stuff...I need to retrofit 15-20 lights in my home.Plan A:eBay auction: #201099334536Do you think this board will work properly (of course with a proper heat sink on the LED)? If yes for more than one year? This is to me too fishy.You know when something is too cheap, a weak point should be there somewhere... (maybe I am just crazy)Unless someone of you dragons tell me you bought it and it is working fine, I will NOT pull the trigger for this LED system.Plan B:eBay auction: #321445378659always made in China but more reasonable quality/price, I like also the 600mA regulated output. I am still wondering why so many LED driver (according to my investigation) just regulate the voltage and not the current.http://www.mouser.com/ProductDetail/Cree-Inc/CXA1520-0000-000N00P250F/?qs=sGAEpiMZZMt82OzCyDsLFG0GbtaLX%252bUmFiybp3GNG50%3dDamn I like the CREE CXA1520 so much, it should be like comparing chocolate and shit (we use to say in Italy) with the LED in Plan A.Any suggestions?Thanks in advance guys...

author: sleemanj
author_rank: Super Contributor
timestamp: November 14, 2014, 05:10:13 pm
content: Quote from: zucca on November 14, 2014, 04:56:26 pmBuy LED bulbs, plug led bulbs into socket, put ladder away. Filament LED bulbs are all the rage these days.The LEDs you are looking at in those links are high power LEDs in small flat packages, they require BIG heatsinks if passive, or a smaller heatsink and active cooling. They are not what you would use if you just want to "retrofit 15-20 lights in my home". They are used more for floodlight type applications, not really home lighting.

author: Zucca
author_rank: Unknown
timestamp: November 14, 2014, 05:17:01 pm
content: sleemanjit makes so much sense.But you know my old lights are soo big and they have a huge metal plate on the back (diamter 20-30cm), so I thought let´s use it as a heat sink.Quote from: sleemanj on November 14, 2014, 05:10:13 pmI think you are right, I already see my mother screaming at me to take them down because she don´t want to use sunglasses at home.You know sometime you just want the best, and the overkill is always a risk in my case.Thanks buddy.

author: Kjelt
author_rank: Super Contributor
timestamp: November 14, 2014, 06:47:27 pm
content: I agree , buy the A brand dimmable light bulbs, they are becoming cheaper everyday.At least you don't have to explain the whole story to the insurance company that some unreliable Chinese pcb set the home on fire.
[Finished]Weekend project -- design and build a battery analyzer - Page 1
Forum section: electronics / projects

author: blueskull
author_rank: Unknown
timestamp: November 07, 2015, 02:53:08 pm
content: I have 3 credits this semester, physics and chemistry of energy storage devices. This course is graded by a lab assignment and a final presentation.The lab session is rather simple -- to measure efficiency and capacity of a given unknown battery.The battery given is a 6F22 battery, with 12mA max charging current. Assuming the capacity is 600mAh, then I need to charge this thing for 50 hours assuming 100% efficiency.I also need to do a discharge cycle, which takes 25 hours to do. To liberate my time, I decided to automate this process.I will try to finish the design of this project within 4 hours, from concept to PCB layout, then use OSHPark swift service to prototype it, in the meanwhile, purchase parts from Mouser.//Used another approach instead. Quick and dirty. Experiment data attached below.

author: Len
author_rank: Frequent Contributor
timestamp: November 07, 2015, 05:27:43 pm
content: Quote from: blueskull on November 07, 2015, 02:53:08 pmWill you live-blog that part too?
[LTspice] - Bode asymptotes lib - Page 1
Forum section: electronics / projects

author: RoGeorge
author_rank: Super Contributor
timestamp: February 11, 2024, 06:43:08 pm
content: From one link to another, landed to thiswebpagewhich points to a download link of a Bode asymptotes for LTspice library by Dr. Vahe Caliskan:Bode-20120215.zip.The library might come handy in many ways, for example to draw Bode plotswithoutrounded corners, for learning and experimenting with idealized filters, etc., so wanted to let others know about its existence, and also to say thank you to the author(s), very useful library.

author: VaheCaliskan
author_rank: Newbie
timestamp: February 18, 2024, 10:13:46 pm
content: Thanks for using the Bode asymptote building block library for LTspice. I use this in a course that I teach on filter synthesis. It is mainly used for verification as you can look at the s-domain transfer function, the filter response and the asymptotic Bode plot simultaneously.--Vahe

author: pifouille
author_rank: Newbie
timestamp: October 10, 2025, 08:18:19 am
content: Hi,I would love to use this library but the links seem to be broken.Is there another link to get it by any chance??I am quite curious about how you did that. I tried to plot the final asymptote by drawing the asymptotes for each region of the diagram,and then using min/max functions to combine them.I didn't have much success...Thxpif

author: Ian.M
author_rank: Super Contributor
timestamp: October 10, 2025, 12:44:34 pm
content: Internet Archive:https://web.archive.org/web/20241028221928/https://vahe.people.uic.edu/spring2016/ece412/ltspice.html
[NEED IDEA & ASK] Securing SOT-227 mosfet to heatsink base & Mosfet's FBSOA - Page 1
Forum section: electronics / projects

author: BravoV
author_rank: Super Contributor
timestamp: May 17, 2016, 04:19:22 am
content: Any idea how to secure SOT-227 mosfet to the cpu heatpipes heat sink base ?Cause drilling two holes for the standard SOT-227 mount is not possible I'm afraid, just look at the attached photos below as the base thickness to the heatpipes is quite thin.I don't have any metal workshop here, so making a special custom metals thingy to secure this, is not easy for me.Also the securing mechanism must be easily detached in order to clean the heatsink once in a while, I bet most of you know how dusty and dirty a cpu heatsink with fan attached running for months can be, right ?Also another question, the plan is to use this fet for DC dummy load, say assuming this heatsink can maintain the Fet's Tcase below 90 C, targeting at 300 watt max dissipation is not too ambitious right ? CMIIW or suggest even other numbers. Fyi, its IXYS IXTN46N50L linear mosfet and the FBSOA chart also attached below.TIA
[Optical Fiber] Coupling 106.5um fiber into 105um fiber - Page 1
Forum section: electronics / projects

author: blueskull
author_rank: Unknown
timestamp: August 17, 2020, 02:38:54 pm
content: I was just lurking on Taobao, and found a brand new JDSU 140W pump laser diode for only $400.While it is a great deal, its output fiber is 0.22NA, 106.5/125um fiber, but all my current fibers and other fiber-coupled optical toys are 105/125um.I wonder what do I need to couple energy from 106.5um fiber into 105um fiber, and can I just splice them and expect the joint not to set itself on fire (at 140W!!!)? Or do I need some fancy optical setup to match just 1.5um of difference?FYI, 1.5um looks like just error, that's I wanted to give it a try.On paper, a standard cheap 105um fiber is actually 105um +- 3um, and a 106.5um fiber is 106.5um +- 1.5um, so technically they do overlap. If I stay with quality manufacturers, I can expect 105um fiber to be bang on, so it falls within the 106.5um fiber's specified range.Any suggestions if this is a good idea or I'm risking with my $400?
[Please Pin] CH340G datasheet translated. - Page 1
Forum section: electronics / projects

author: technix
author_rank: Super Contributor
timestamp: August 11, 2015, 04:30:58 pm
content: So I have heard lot of guys complaining the lack of a good English datasheet of WCH CH340G chip. Here I made one translating from the original Chinese datasheet. (WCH's CH340 Series Datasheet in English does not cover CH340G, only CH340R and T)The PDF file should be in all vector format and should be able to be printed out nicely.Moderators when you see this please pin.

author: brabus
author_rank: Frequent Contributor
timestamp: August 11, 2015, 05:51:23 pm
content: Dear Sir,You are a very nice person.Thank you and Best Regards!

author: jimmc
author_rank: Frequent Contributor
timestamp: August 11, 2015, 06:07:43 pm
content: Nice work, thanks for taking the trouble.Jim

author: amyk
author_rank: Super Contributor
timestamp: August 12, 2015, 05:11:34 am
content: Which one is the "please pin" and what does it do...? I can't find any mention of it in the datasheet.
(Potentially stupid) crazy BGA pad design - Page 1
Forum section: electronics / projects

author: blueskull
author_rank: Unknown
timestamp: February 25, 2017, 08:41:59 am
content: Hi all. I'm working on a ultra small form factor design which has a goal of using as TINY parts as possible.As part of the challenge, I need to find a PMIC that can power my CPU while being as small as possible.All WLCSP parts I can find are offered in 0.4mm pitch, not 0.5mm, therefore standard 0.1mm/0.1mm PCB process without microvia cannot layout this.I only need to bring a few balls out, not all.Essentially, I cut 1/4 of the 0.2mm ball pad to satisfy 0.3mm spacing between 2 pads, so that I can route 0.1mm trace in between.Do you think this is a viable solution, or a stupid one?

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: February 25, 2017, 05:14:44 pm
content: Wouldn't the ball just re-form into a sphere when reflowing?

author: nctnico
author_rank: Super Contributor
timestamp: February 25, 2017, 09:24:16 pm
content: I'd keep the total pad area equal so there is a chance the solder blobs are at least the same in height.

author: Scrts
author_rank: Frequent Contributor
timestamp: February 26, 2017, 03:36:24 am
content: I'd keep the pads, break the routing rule and let PCB manufacturer to eat it...

author: Someone
author_rank: Super Contributor
timestamp: February 26, 2017, 05:21:08 am
content: Quote from: blueskull on February 26, 2017, 03:46:55 amBoo hoo hoo, you poor struggling student who can't afford a mid priced board house....Quote from: blueskull on November 25, 2016, 06:15:09 amQuote from: blueskull on December 04, 2016, 09:06:51 amIt pays to be careful when you've got a public profile that keeps all this visible. Showing off about wealth is particularly repellent in most cultures, and then to cry poor just makes you seem entirely insincere.

author: hendorog
author_rank: Super Contributor
timestamp: February 26, 2017, 07:35:08 am
content: No idea if there are any other issues but I just checked PCBCart and they do 3mil trace width and spacing. That is 0.0762mm.http://www.pcbcart.com/pcb-fab/standard-pcb.html

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 26, 2017, 08:09:09 am
content: I asked around the DFM guys and was recommended to use LDI (Laser Direct Imaged) soldermask for fine CSPs.I wouldn't recommend putting a trace inbetween pads (fortunately I didn't have to; the central pins were power connections in parallel with the sides, so no trace-weaving was necessary).If you have to, the tighter alignment of LDI should help at least. Try making the solder mask expansion small (0 to 2 mils).Shaving pads I think would be okay, as long as you adjust the overall diameter to keep the same pad area. It's kind of getting into the realm of the superstitious though... who knows.For sure, regular fab mask isn't going to cut it. See if LDI adds much cost.Tim
[Project] Drawer light automatic system - Page 1
Forum section: electronics / projects

author: Liknus
author_rank: Newbie
timestamp: July 24, 2018, 09:55:08 pm
content: Hello everyone!I'm new not just to this forum, but to the electronic world too, so thanks a lot in advance for all the help you'll provide me with.I'm here 'cause I'd like to replicate the IKEA OMLOPP Drawer light systemto demonstrate what I'm talking about).I've got a new IKEA (damn cheap) television stand, with 4 doors.. no drawers, only doors. The project aim is to have one or two small LEDs that automatically turns on when the door is opened.The problem for me is that I've got NO idea of where to start..What king of LEDs should I buy? And (considering 4 'drawers') what PSU to cope with?What sensors? A photoresistant? So that the lights turn on when the sensor 'sees' an increase in the amount on light?Do I need a Transistor to control the sensor and switch on/off the lightsIs it possible to control the light so that it stays on for X seconds if the door is open, and if the door is closed before a determined amount of time, the lights switch off nontheless?Would you be so kind to make a scheme as easy as possible so that i can implement it?What parts / sensors do you suggest?CheersCiao

author: NiHaoMike
author_rank: Super Contributor
timestamp: July 24, 2018, 11:07:00 pm
content: Some LED strips would be easy to install and most run on a common 12V PSU. For sensing when the door is open, use microswitches. Add up the amperage of all lighting installed and make sure the PSU is at least that big. Keep it nice and simple...
[project] - Inductor Saturation Current Tester - Page 1
Forum section: electronics / projects

author: Gregory
author_rank: Regular Contributor
timestamp: April 23, 2019, 03:24:17 am
content: Hey guys!I would like to share with you a project I`m currently making. It is a inductor saturation current tester.Here a youtube videoIt will work by discharging a capacitor bank over the inductor on test and show on a scope the current waveform.The saturation will be seen when the current stops to grow linearly and shootup to the sky.The equipment have a selector with three current shunts for diferent current ranges.Also, I have integrated an external trigger input and a trigger output for better triggering of the scope.I will be updating this post with the progress.When I get the equipment working, I will share with you the design.Thanks!
[ASK] About old Sanyo OSCON polymer caps - Page 1
Forum section: electronics / projects

author: BravoV
author_rank: Super Contributor
timestamp: October 23, 2015, 06:59:59 am
content: Bought bunch of these at local store, as they're industrial excess stock. Even I don't need them now, its just the price was so damn cheap, just < $5 for this 50 pcs of purple caps.Measured capacitance are spot on with LCR meter, with ESR at 0.045 Ohm (45 mOhm) @100KHz.Size is 5mm tall and 10 mm diameter.Questions :1. Which type of OSCON is it ? For sure its rated at 105 C as printed, but I can't spot the type.2. As these are old model, looking at the packaging style, do they rot over time ?Attached cap's photo below.

author: SeanB
author_rank: Super Contributor
timestamp: October 24, 2015, 02:31:05 pm
content: Haven't heard of these degrading with time, and they are used a lot in older server boards, so must be a reliable unit.

author: Pjotr
author_rank: Frequent Contributor
timestamp: October 24, 2015, 03:41:22 pm
content: The only point is that they have silver plated wires. Over time they become unsoldarable due to oxidation/sulphurization. You can overcome this by scraping the wires blank again with a scalpel or something.

author: BravoV
author_rank: Super Contributor
timestamp: October 24, 2015, 07:08:27 pm
content: Quote from: SeanB on October 24, 2015, 02:31:05 pmQuote from: Pjotr on October 24, 2015, 03:41:22 pmThanks, noted.Wonder why they had to use silver, is that common ?

author: DanielS
author_rank: Frequent Contributor
timestamp: October 24, 2015, 08:36:44 pm
content: Quote from: BravoV on October 24, 2015, 07:08:27 pmThe main reason is most likely solderability: clean silver plating wets very easily with most solder alloys.

author: BravoV
author_rank: Super Contributor
timestamp: October 26, 2015, 04:32:04 am
content: Quote from: DanielS on October 24, 2015, 08:36:44 pmWhats wrong with tin plating as normal/common lower priced electrolytic cap, does silver is much-much better ?But yeah, you watch the above photo carefully, I did scraped the pins with sandpaper as they're sort of dull/powdery white looking.I guess these are > 10 or 20 years old aren't they ?

author: TiN
author_rank: Super Contributor
timestamp: October 26, 2015, 04:34:36 am
content: Never see these fail, they are solid electrolyte, like modern low-esr caps.I have them high ranked in my "good stuff" list.And due to environmental issues production of these caps are long gone, unless I miss something. Just so you know before you fit them into your xxxx pieces design (cap sizes/pitch is not same as most other electrolytic caps).P.S. woa, 1000th post

author: BravoV
author_rank: Super Contributor
timestamp: October 26, 2015, 05:11:26 am
content: Quote from: TiN on October 26, 2015, 04:34:36 amWhat production environmental issues ?Mind elaborate more ?Btw, congratz on your #1000 post.

author: Psi
author_rank: Super Contributor
timestamp: October 26, 2015, 08:11:45 am
content: Yep Sanyo OSCON caps are A class.
(Questions) Designing a cheap high speed ADC for analyzing inductors - Page 1
Forum section: electronics / projects

author: Fireflaker
author_rank: Newbie
timestamp: September 14, 2019, 08:20:05 pm
content: Hi everyoneI am working on designing a high speed ADC frontend to measure the rising edge slope of the inductor current. Just wondering if there can be a way to do it without needing high speed FPGA.

author: Marco
author_rank: Super Contributor
timestamp: September 14, 2019, 09:08:21 pm
content: You can just read out an oscilloscope capture, or a DAQ cature.Why would you design your own device for what is I assume an experiment? Your requirements aren't special and the one off nature doesn't really justify all the effort.