hybridfree/eevblog-posts huggingface dataset:
MPPT controller IC with pwm output - Page 1
Forum section: electronics / projects

author: franciscoPT
author_rank: Contributor
timestamp: January 19, 2023, 06:06:00 pm
content: Hello im a electronics engineering student and i'm making a full analog solar tracker project, i've already made the controller to make the PV panels perpendicular do the sun and now im making a dc-dc converter to extract the power from the PV panels i want to use an mppt controller, but i cant use a microcontroller, the project must be fully analog, it had been told me that i can use an IC that already implements the mppt algorithm but i cant find one that outputs a pwm signal or an analog one so i can generate de pwm for the converter, does anyone know about a circuit that implements what i need?

author: joaoPT
author_rank: Newbie
timestamp: January 19, 2023, 06:40:19 pm
content: Im his partner and we need help

author: moffy
author_rank: Super Contributor
timestamp: January 19, 2023, 10:50:56 pm
content: Looks like TI have a chip available: BQ24650https://www.ti.com/product/BQ24650

author: schmitt trigger
author_rank: Super Contributor
timestamp: January 20, 2023, 02:57:37 pm
content: And as usual, no need to design your own board. You can find fully assembled BQ24650 modules on EBay, priced very reasonably.One could buy one of those to start experimenting right away.

author: David Hess
author_rank: Super Contributor
timestamp: January 20, 2023, 04:56:05 pm
content: Some analog only designs for MPPT controllers have been published in the past but are difficult to find now on the web. The way they work is by sampling the output current, and then perturbing the duty cycle of the converter to change the DC impedance presented to the solar array. Then the output current is sampled again and compared to the previous sample to decide if the duty cycle should be increased or decreased on the next cycle. In this way they "hunt" or "track" the optimum duty cycle which controls the input impedance presented to the solar array.The sampling is also done in the analog domain with the results of each sample stored in a sample-and-hold or track-and-hold.For some ideas on how this sort of circuit can work, do a search for how delta-Vbe temperature measurement circuits work.
MPPT for AC Source - Page 1
Forum section: electronics / projects

author: snoop33
author_rank: Contributor
timestamp: July 26, 2022, 01:50:27 pm
content: Hi all,Consider the following system -Inductive Fixed Current Generator -> Capacitance -> Rectification -> Buck -> Super-Capacitors -> Boost -> Output(Setting aside parallel resistance of the generator to model eddy losses and rectification losses, and assume the super-caps can sink anything the generator can provide)Impedance of LCR can be worked out. The ideal loadat DC(AC RMS) is the equivalent resistor.If the generator is fixed current one can generate the ideal voltage.1. Is it correct to say MPPT can be met by having the buck track the ideal input voltage, that is the duty will increase as the AC changes cycle and will essentially clamp the voltage?2. I could do this using hysteretic control (comparator) to vary frequency and dutyorpwm at a set frequency and ramp the duty until the point is met. I believe the later will be a challenge without a very high MHz CPU to give the required resolution or a large inductor to keep the frequency low.

author: snoop33
author_rank: Contributor
timestamp: July 27, 2022, 06:38:36 am
content: Shameless bump, desperate for confirmation on this as I've implemented a prototype solution and found the MPPT point to be off by quite a bit (like 50%).
MPPT solar charge controller - battery charge current at MPP - Page 1
Forum section: electronics / projects

author: fedimakni
author_rank: Regular Contributor
timestamp: July 09, 2022, 10:30:48 am
content: Hello,I am currently planning to design an MPPT solar charge controller and i am trying to follow a reference design from TI - TIDA 010042i am planning to use arduino as the microcontroller for this project.I tried to learn and make some research about MPPT and how it works but I still have some remaining principle not clear.I will start by the conditions: I will use 12V battery and my load contains a motor the motor works only if needed otherwise the system has a camera which take some pictures and do analysis ... (variable load)I have 2 approach for this:1 - use the same bloc diagram as TI and implement the charging algo in the uC2 - Remove the charging algo from the uC and add a dedicated charge IC between the MPPT block and the battery.I am not sure if the second method can work or not (i am currently in the first phase of the design)Here comes the important question: for the first approach let's take at a given condition the solar panel operate at Vp and Ip the MPPT bloc will try to change the duty cycle of the buck or boost or buck/boost converter to mimic the load which extract the max power (P&O algo) now the panel output Ipmax and Vpmax with that specific duty cycle the DCDC will output a correspondant Idcdc and Vdcdc let's assume that the Idcdc at max condition is 5A and the battery need to be charged at 3A (constant current phase) in that case we need to change the duty cycle to output 3A instead of the most efficient 5A and that let the solar not operate in the MPP region.Could you please provide me your support to understand better the logic behind it? (I attached the bloc diagram of TI)Thank you for your cooperation.
MPPT Solar charge controller using Buck converter (Perturb and Observe Method) - Page 1
Forum section: electronics / projects

author: Siddhat
author_rank: Regular Contributor
timestamp: February 26, 2020, 10:35:05 am
content: Hello everyone!I am designing a MPPT solar charge controller using Perturb and Observe Method (P&O method). Following the algorithm of the Perturb and Observe method, arduino code was successfully written.I measured the open circuit voltage of a 40W solar panel and the measured value which was around 20V under different illumination conditions. The rated open circuit voltage is 21.5V.I need to extract maximum voltage which is 16.9V at maximum power. So, a buck converter with closed loop control to implement P&O method is needed.IRFZ44N Mosfet was selected for switching. But I had problems while calculating the values for the inductor and capacitor and since I will be charging a 12 V lead acid battery by implementing another buck converter circuit in cascade with the 1st buck converter circuit that implements the P&O method, how do I know the input impedance of the buck converter circuit?How do I properly calculate the values for the inductor and capacitor of a buck converter that when used even works in practical cases.I tried watching a bunch of youtube videos for calculating the values for inductor and capacitor but while simulating I did not get the expected results. The video below shows the formulas that I used but the values that comes after calculating do not meet the expectations even while simulating in Proteus Design Suite.Anyone here an expert on buck converters? Need Help!Thank You!
MPPT Solar charge controller using P&O in matlab - Page 1
Forum section: electronics / projects

author: Sangharsh Sharma
author_rank: Contributor
timestamp: March 11, 2020, 04:36:11 pm
content: Hello everyone...I was designing the model of a MPPT solar charge controller in matlab. Then, I encountered an error. The current from the solar panel was highly oscillating as it rose up. Because of this, it affected the whole output. What caused this? What can I do to solve this? I'm using matlab 2019a and I couldn't insert time delay by breaking the algebraic loop but I found it was available in previous versions. Any help would be appreciated. Thank you.
MPS (Monolithic Power Systems), your experiences? - Page 1
Forum section: electronics / projects

author: DutchGert
author_rank: Frequent Contributor
timestamp: February 04, 2016, 08:02:50 pm
content: Hey guys,So far we have used mainly Linear Technologies or Texas Instrument parts for power related stuff in our automotive designs. Since Linear is superiour but way to expensive and Ti is not really offering the best specs in te market we started looking at other companies.So far we also used a few Micrel parts that perform quite nice but since Microchip bought them it's going downhill fast (part unavailible or leadtimes of 6 months....)Exar may have have something but they seem a small fishAnalog Devices is not really strong in power and also not very big in automotive parts.So we stumbled on MPS. Looking at there website I though hmm ok, you seem like an typical low cost, low tech company but after there FAE visited it seems they are actually a big company with very high tech pars for really nice prices.Question is: what is your experience with MPS and are they any good compared to the giants like Linear and TI in terms of specs, price, size, leadtimes, reliability, etc?

author: Scrts
author_rank: Frequent Contributor
timestamp: February 04, 2016, 10:03:47 pm
content: We use them a lot. Personally, I had some issues with one part, but in general all the devices worked fine.

author: brumbarchris
author_rank: Regular Contributor
timestamp: February 05, 2016, 06:56:00 am
content: I'm also in automotive design, but we have not used them at all so far. We did, however, come across them in the past. It will be interesting to see the various opinions of people who have worked with their products.Regards,Cristian
MPU6050 always giving -1 values - Page 1
Forum section: electronics / projects

author: quaternion00
author_rank: Contributor
timestamp: December 21, 2017, 05:01:38 am
content: The MPU6050 is calibrated but the values always popping in the serial monitor is -1 . I made sure that the connections were correct .What might be the problem?The arduino code is attached .
MPU6050 hangs on ESP32 when operated using a battery on custom board - Page 1
Forum section: electronics / projects

author: Sarthdave
author_rank: Newbie
timestamp: November 24, 2018, 06:39:13 am
content: We are facing a very peculiar problem. We are designing a board based on ESP32 with various peripherals like motor drivers, sensors etc. We are using GPIO 4,5 on the ESP32 as I2C lines and have hooked up three devices on the bus. The first one is the MCP23017 which is connected to the ESP32 using a bidirectional level shifter (it operates on 5v), other is the CAP1206 touch IC and finally we have the MPU6050 interfaced with it. For powering the board we have three options. - DC adapter in which the voltage from the adapter is lowered to 5v using a buck converter and supplied to the system. - USB port for power and programming (We are using the CH340G for programming the ESP32 module) - Finally we use a 18650 cell in conjunction with a TP5410 based circuit which functions as a charger and boost converter (Converting the 3.7V of the battery to 5V) The problem is that when we run our device on DC adapter or the USB power, everything runs fine. However, when using on a battery, the MPU6050 device suddenly seems to hang after some 10-20s. I will include the schematics of our USB,MPU6050 and charging circuit with this post. The problem only occurs when using the battery and does not occur in any case when using USB/DC as power source. What have we tried: - Triple checked that all the connections on the PCB were right - We found that when we remove the diode marked "D2"in the charger circuit, everything seems to work fine with battery too. We thank you for taking time in reading this and hopefully giving us some solution.

author: macboy
author_rank: Super Contributor
timestamp: November 24, 2018, 01:10:05 pm
content: Monitor voltage Vbus issuing a high impedance voltmeter while running from battery. You may see it slowly creep up. This is due to reverse leakage on the Schottky diode D2. Schottky diodes are leaky. I'd guess that this reverse leakage current slowly charges C12 (Vbus). When the voltage on C12 becomes high enough, the charge controller thinks the USB is plugged in and tries to switch to that, causing a power blip. Of course this is just a hunch, you will need to test if this is happening. If it is then try putting a resistor across C12 to bleed the charge, maybe 10k or higher is sufficient as the leakage current is small.

author: Sarthdave
author_rank: Newbie
timestamp: November 26, 2018, 05:46:14 am
content: Thank you very much for taking the time to analyze and respond. The capacitance was indeed the problem. I removed the capacitance over the VBUS line and voila! everything worked perfectly. However, a 10k bleeder resistor did not work. Any idea as how I can keep that 10u capacitor on the VBUS line while still solving the issue.

author: nsrmagazin
author_rank: Regular Contributor
timestamp: November 26, 2018, 02:12:11 pm
content: Try a 1k resistor.
MPXV5010GC7U pinout confusion - Page 1
Forum section: electronics / projects

author: Salatkurke
author_rank: Newbie
timestamp: October 27, 2018, 05:37:09 pm
content: Hi everyone,I want to use the MPXV5010GC7U Pressure Sensor in a project but can't find the correct pinout in the datasheet.Link to Mouser datasheet:https://eu.mouser.com/datasheet/2/302/MPX5010-1127094.pdfThe package in question is referred to as "CASE 482C-03" in the datasheet, but on page 9 there is no pinout to be found. Instead there are two different 8-pin pinouts described on page 14 titled "Style 1" and "Style 2". No idea what this means. If anyone less incompetent could take a look at it that would be greatly appreciated.Cheers

author: stmdude
author_rank: Frequent Contributor
timestamp: October 27, 2018, 05:43:51 pm
content: Looking athttps://www.nxp.com/docs/en/data-sheet/MPX5010.pdfinstead. Your link didn't want to load for me.The pinout is (in a quite non-obvious way) on page 4.For 482C-03 (which is a SOP package according to page 2), the pinout is:2 - Vs3 - GND4 - Vout1,5,6,7,8 are NC

author: Salatkurke
author_rank: Newbie
timestamp: October 27, 2018, 06:03:33 pm
content: Wow, totally missed that. Guess I stopped reading at "internal circuitry" ^^'Thanks for your help!
MQTT Porting - Page 1
Forum section: electronics / projects

author: jtronix
author_rank: Regular Contributor
timestamp: May 11, 2018, 02:27:59 pm
content: How to port MQTT to any microcontroller?I download MQTT code fromhttps://github.com/eclipse/paho.mqtt.embedded-cbut din't understand how to use it for different controller such as NXP,TI,ESP8266...etcAny body know how to get started with MQTT porting from embedded paho source code?

author: David Chamberlain
author_rank: Frequent Contributor
timestamp: May 11, 2018, 08:33:57 pm
content: Port to what?Have you read the README?https://github.com/eclipse/paho.mqtt.embedded-c/blob/master/README.mdGenerally just suck it through your tool chain and see what errors you get.

author: jtronix
author_rank: Regular Contributor
timestamp: May 12, 2018, 05:47:04 am
content: I want to use one common library for GSM, Wifi and Ethernet by just changing the lower level function such as TCP connect, send or receive.like we do for graphic library we just change the platform supported files and library got work.
Mr-SK50A sound light sensor switch - Page 1
Forum section: electronics / projects

author: mrrcomp
author_rank: Contributor
timestamp: November 28, 2023, 09:10:50 am
content: HII have this module mr-sk50A . It works but the timer is preset to approx 45 sec. It uses a chip called the KU5590A I cant find any technical info on it. I managed to find a site where the blogger managede to break down the schematichttps://www.electroschematics.com/light-sensor-2/but he also wasn't able to find info on the chip to be able to hack the board to make it more "user friendly'Suggestions?RegardsMeir

author: SeanB
author_rank: Super Contributor
timestamp: November 28, 2023, 11:10:50 am
content: Looks like the capacitor on pin 3, 1uF, is about the only part that sets time. The 10uF capacitor will be an internal power supply, as the triac drive is likely coming from the chip switching the input mains pulses via the 300k resistor to drive the triac gate.

author: mrrcomp
author_rank: Contributor
timestamp: November 29, 2023, 12:09:57 pm
content: Thanks for your input..I'll try to switch in a different capacitor you suggest larger value for longer time or smaller value?RegardsMeir
MS5611 "blips" - Page 1
Forum section: electronics / projects

author: hpmaxim
author_rank: Regular Contributor
timestamp: July 31, 2020, 04:45:14 pm
content: I have a weird, and unfortunately very open-ended question, but I'm not sure how else to put it or even where to start.I have an Opensource project which I am trying to get to work but it is being problematic. It is an embedded Linux machine running on a "CubieBoard2" (similar to a Raspberry Pi). The Linux box has a "sensor board" on it which has a number of I2C sensors, including two MS5611s.There is a daemon that is run on boot-up of the Linux box which periodically reads the sensor data and sends it out a TCP Port (and records it to the SD card). In particular, it polls both MS5611s at approximately 50 ms intervals. If I look at the data, I see "blips" in it. A blip is typically 1-3 samples of + .3 to.5 mbar, followed by several samples of -.1 to -.5 mbar (about 10 total). The blips appear to occur between 92 and 94 samples apart, pretty consistently. And the blips on both MS5611s are PERFECTLY synchronized in time, and pretty much in magnitude. As far as I can tell, if one MS5611 blips, the other does too. The program kicks off the two conversions, and then does a usleep (12500); before reading both out. Timing in the program is entirely controlled by usleep, which of course isn't exact. I suppose it's possible that some of the usleeps aren't waiting long enough, but the MS5611 documentation says that a read on an incomplete conversion will give 0 and that's not what happens. Temperature is sampled (but not recorded) every 9 or 10 pressure samples during the period between the pressure samples. Is it possible that a temperature conversion is getting messed up? Maybe... But it seems unlikely this would result in the pressure output consistently jumping up and then down.Now, it this point, I'd think... Okay, maybe there is noise on the power supply. Seems unlikely since it's two separate power supplies, but, maybe... Unfortunately, it gets weirder...If I kill the process, and re-start it, the blips either completely or mostly go away. I recorded data off a restarted process for 20 minutes and never saw a blip. I recorded data off a restarted process and saw one blip in 2 minutes (obviously it normally blips every 4-5 seconds).The sensors are both sampling atmospheric pressure outside, and they are not moving.I'll also add that the sensor board is powered by a 5V supply and there are multiple 3.3V linear regulators on it. Each MS5611 has its own regulator. So the 5V supply is shared, but the 3.3V is not.Schematic/layout/BOM for the board can be found here:https://www.openvario.org/lib/exe/fetch.php?media=projects:series_00:electrical_tests:pressure-sensor.pdfSoftware can be found here:https://github.com/Openvario/sensordThe bad news is, it's in a self-contained box and would be difficult to probe the hardware.
MSG-EQ7, anything similar out there? - Page 1
Forum section: electronics / projects

author: wire
author_rank: Newbie
timestamp: February 19, 2016, 03:09:29 pm
content: TheMSG-EQ7seems to be pretty hit or miss on quality. Every place I have ordered them from I usually get 2-3 duds out of 10 (including SparkFun).Is there anything similar out there? I recently found theBA3812L5 channel graphic eq, but it looks like I would need to use 3 of them to get the same function of 1 MSG-EQ7.
MSI laptop web camera to USB need pinout - Page 1
Forum section: electronics / projects

author: BATAS
author_rank: Newbie
timestamp: November 07, 2014, 03:45:59 pm
content: I have web camera removed from laptop MSI cx610. I want to connect the webcam on desktop pc via USB port and need pinout(+5v, D-, D+, G). Please look image from attachments.

author: NiHaoMike
author_rank: Super Contributor
timestamp: November 07, 2014, 04:20:48 pm
content: That twisted pair is the D+ and D-. There's also a ground and what appears to be two different supply voltages. Probably something like 3.3V and 1.8V.

author: SL4P
author_rank: Super Contributor
timestamp: November 07, 2014, 10:29:45 pm
content: The 'second' supply could simply connect to a status LED (some of the laptop cameras have them on board)

author: Jeroen3
author_rank: Super Contributor
timestamp: November 08, 2014, 11:52:04 pm
content: Ground shoud be black. D+ might be the red one, and D- the brown one.Measure the orange and the yellow one in the laptop to know what voltage is required. Good chance it is indeed 1.8V for the chips/camera and 3.3 or 5 Volts for usb communication.USB requires more than 2.8 Volts for the datalines.Or it is the led... measure and thou shall know.
MST703 LCD driver board,  VGA input / firmware - Page 1
Forum section: electronics / projects

author: kyndal
author_rank: Regular Contributor
timestamp: November 06, 2019, 09:27:40 pm
content: Hi Guys,i have a 7" LCD with a board using the MST703-LF (Datasheet posted elsewhere. but i'm attaching here for the next guy)the MST703 allows for VGA input, but on my board is not populated. and I'm hoping to get that workingi haves seen a couple of similar but not quite layouts for other chips. or low res pictures where i just cant quite make it out.handful of 75ohm resistors, capacitors etc but not exactdo any of you guys have the same / similar board. that could post high resolution picture / capacitor / resistor valueshave a schematic for the MST703 VGA input ?I'm also not sure if a different firmware is required to enable this, or if its automatic ? can be set over i2c??Rune

author: Tantratron
author_rank: Frequent Contributor
timestamp: November 01, 2024, 08:03:08 am
content: Hello, I've been working on both MST703 and the RTD2660 but have you done any progress, is your project still under going ?Albert
[SOLVED] MT3608 boost circuit issues.  - Page 1
Forum section: electronics / projects

author: gmc
author_rank: Regular Contributor
timestamp: September 29, 2020, 02:50:28 pm
content: I've trying to get a project working where I need to provide 12V from 5V (USB)I am using the MT3608 and have seen a bunch of circuits where this is possible. Not for me thoughhttps://www.olimex.com/Products/Breadboarding/BB-PWR-3608/resources/MT3608.pdfCircuit I have is attached.The issue I have is if I provide 5.2V from my PSU it works as expected. Get a nice stable 12V out.If however I power from USB, or drop the voltage to 5.1V the output drops to 5V.Pulling my hair out. Swapped out the MT3608, same issue.Does anyone have any experience with these chips and has had similar issues?

author: gmc
author_rank: Regular Contributor
timestamp: September 29, 2020, 03:25:32 pm
content: Solved.The 22uF input cap was dead - open circuit. Replaced and now its working even down to 4V. Very odd, didn't think the input cap would make much difference but obviously it does.
MT561-B LVDS Controller - Modes Question? - Page 1
Forum section: electronics / projects

author: killingtime
author_rank: Regular Contributor
timestamp: May 23, 2017, 02:37:52 pm
content: Hello,I have an LCD panel (Optronics M170XW01) that takes an LVDS input, and I'm looking for a controller to drive it (from a VGA source).The LCD panel has a native 1280 x 768 resolution, and from the pin assignment on the datasheet has a 1 channel 8 bit input (4 data pairs + 2 clock wires).The controller board I'd like to use is MT561-B and it has the resolution modes listed on the pcb reverse:What I'm unclear on is the data following the resolution, for example:Mode 24: 1280x768 -6 -2What does the -6 and -2 mean?I found a pdf for the above board wich lists the resolution modes in a table with the footnote '1 ?-2 screen parameters IT model, not single dual LVDS' but that statement doesn't mean anything to me.Any pointers appreciated.Thanks.

author: bktemp
author_rank: Super Contributor
timestamp: May 23, 2017, 02:52:23 pm
content: -1 and -2 means it is singe and dual channel LVDS output-6 and -8 refers to the bit arrangement in the LVDS stream, more often named VESA (8bit) and JEIDA (6bit) mode.Your panel uses single channel VESA mode, so 1280x768-1-8 should be the correct one.But this mode doesn't seem to exist.I found the listed modes often wrong on those cheap VGA/DVI display controller boards.You can try all modes with 1280x768 or slightly higher resolutions to see if one of them produces a useable image.If you get the -1/-2 modes wrong the display shows only every second pixel, -6/-8 modes should show strange colours if the wrong mode is selected.

author: killingtime
author_rank: Regular Contributor
timestamp: May 23, 2017, 05:01:40 pm
content: Hi bktemp,Thanks for the reply. I might give it a go.There are many people selling these LVDS boards (various types) but I've found hardly any info published on them (modes and bit arrangements).

author: necromago
author_rank: Newbie
timestamp: June 09, 2017, 09:26:52 am
content: Quote from: bktemp on May 23, 2017, 02:52:23 pmHelloI also recently bought one of this MT561-b to drive my 14.1inch LG LCD, however I am having hard time to make it work properly. The lcd is one LP141X13-C2K2. I was able to have the board menu on the screen, but the resolution does not seem to be correct because it shows 6256x9168@ 5Hz!!!Does anyone could help sort this issue out, please?Can it be the LVDS cable?If I want to wire a new LVDS I will need to have the correct lcd datasheet and I was only able to find to the LP141X13-C2....I have already gone through all the resolution options on the board using the jumpers and also none, getting the same issue all the time...Thanks in advance.BRM
MT561-B universal driver board LCD - Page 1
Forum section: electronics / projects

author: necromago
author_rank: Newbie
timestamp: June 09, 2017, 12:12:50 pm
content: HelloI also recently bought one of this MT561-b to drive my 14.1inch LG LCD, however I am having hard time to make it work properly. The lcd is one LP141X13-C2K2. I was able to have the board menu on the screen, but the resolution does not seem to be correct because it shows 6256x9168@ 5Hz!!!Does anyone could help sort this issue out, please?Can it be the LVDS cable?If I want to wire a new LVDS I will need to have the correct lcd datasheet and I was only able to find to the LP141X13-C2....I have already gone through all the resolution options on the board using the jumpers and also none, getting the same issue all the time...Thanks in advance.BRM

author: bktemp
author_rank: Super Contributor
timestamp: June 09, 2017, 12:57:00 pm
content: The controller board does not know which or even if a LCD is connected, because LVDS is only an output. You need to set the resolution manually using the jumper settings.Does your PC detect the correct resolution set by the jumpers?

author: necromago
author_rank: Newbie
timestamp: June 09, 2017, 01:48:56 pm
content: Unfortunately the PC does not recognize the board yet... I think I will need to buy a new hdmi to vga converter as I suspect that the cable HDMI to VGA that I am using does not do the job properly...Any recommendations for the converter to buy (on cheap!)Thanks

author: bktemp
author_rank: Super Contributor
timestamp: June 09, 2017, 03:31:34 pm
content: Why are you using a HDMI to VGA converter + VGA to LCD converter instead of a DVI/HDMI to LCD converter?They are slightly more expensive, but have a better image quality because there is no digital -> analogue + analogue -> digital conversion.

author: necromago
author_rank: Newbie
timestamp: June 13, 2017, 07:30:53 am
content: Well the thing is that on the MT561-B board the only input in the VGA port. My notebook only has HDMI output video port and also my raspberry pi uses the HDMI output.So this is why I need to convert source video from HDMI to VGA input on the MTY561 board!Thanks

author: stevelup
author_rank: Regular Contributor
timestamp: June 13, 2017, 07:33:16 am
content: I think the point bktemp was making is that you would be better off with a different board - one with HDMI or DVI input.

author: necromago
author_rank: Newbie
timestamp: June 13, 2017, 12:08:34 pm
content: I agree with that, however I have this board now and I would not want to scrap it...Any recommendations on the cheapest one with HDMI input incorporated?V56 Universal LCD TV Controller Driver Board?Thanks

author: paulcav
author_rank: Contributor
timestamp: October 07, 2017, 01:58:28 pm
content: you are better off getting a HDMI to LVDS board like thishereyou just need to contact the seller with you LCD part number and they configure the boart and provide the LVDS cable.
MT6820-B controller board display quality - Page 1
Forum section: electronics / projects

author: omer987
author_rank: Newbie
timestamp: January 12, 2022, 09:16:14 pm
content: Has anyone experimented with MT6820-B display controller board ?If I connect the board to a laptop with the laptop panel,is the image sharpness will stay the same ?Is it will stay the same after a week of continuous use ?Thanks in advance

author: thm_w
author_rank: Super Contributor
timestamp: January 12, 2022, 11:39:41 pm
content: Why would it change after a week? Or do you mean it might not be reliable, maybe, its not exactly a high quality design.https://hackaday.io/project/179868-all-about-laptop-display-reuse/log/193115-wip-mt6820-b-board-informationhttps://www.aliexpress.com/item/32806988374.html

author: omer987
author_rank: Newbie
timestamp: January 13, 2022, 02:03:20 pm
content: Quote from: thm_w on January 12, 2022, 11:39:41 pmThe question refers to sharpness.The display can become blurry after some usage time with problematic boards.
mu45 meter. Need to change scale from 1mA to 5A - Page 1
Forum section: electronics / projects

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: December 04, 2020, 05:59:49 am
content: Can you print out new meter scales for the mu45? I had a 1mA meter laying around and made up a quick and dirty shunt for it so the needle shows 0-5A. I'd like to drop in a new backing with the correct scale.Or do I just by a new meter with the shunt and correct scale built in?
Multi Channel DC Motor Control with RS485 - Design - Page 1
Forum section: electronics / projects

author: Factotum
author_rank: Contributor
timestamp: November 07, 2023, 07:45:24 am
content: Hey everyone.I'm considering building a controller for a new piece of installed kinetic art.I need to drive 12 lots of linear actuators (24v, 3A continunous, brushed DC motors).There's no braking, position sensing, freewheeling or other issues associated with motors. Run times are few second each in various sequences but fairly continuous. Controls for each actuator are : run, direction, speed (can be combined e.g. PWM)The reason for RS485 is the control unit has limited output options - RS485 is one of them.At this point I'm not sure if just buying 12 generic units off the interwebs or building a custom 12 way board (based on something likehttps://www.pcbway.com/blog/technology/Powerful_H_Bridge_DC_Motor_Driver.html) is the way to go.Either way I need to control them - figured some sort of MPU (Arduino, ESP) taking commands (maybe MODBUS) over RS485, driving something like a PCA9685 multiple PWM output device...Or just bite the bullet and buy the gorgeous stuffhttps://electromen.com/en/products/item/motor-controllers/dc-motor/EM-348C/Also interesting solutions (in frustrating breakout modules that will make heat sinking a pain with frustrating prices)https://www.pololu.com/category/11/brushed-dc-motor-driversAnyhow, thought the gallery might have some ideas / thoughts...Thanks!
Multi channel low cost low side driver  - Page 1
Forum section: electronics / projects

author: MadScientist
author_rank: Frequent Contributor
timestamp: February 02, 2021, 10:19:37 am
content: Can anyone recommend a multi channel ( 4+) low side driver 500mA per channel, that has short circuit protection, I’m looking for a solution to replace the venerable ULN driver , but it’s cost sensitive but I need something with integrated over current protection ( or at least detection ) the on semi NCV7240 is ideal but expensive

author: gnuarm
author_rank: Super Contributor
timestamp: February 02, 2021, 10:56:01 am
content: I see the NCV7240 for $1 at a several disties in qty. What do you consider cheap? At $1 for 8 channels, a transistor isn't much cheaper.

author: MadScientist
author_rank: Frequent Contributor
timestamp: February 02, 2021, 11:56:56 am
content: 200 -500 annual qty

author: gnuarm
author_rank: Super Contributor
timestamp: February 03, 2021, 09:30:37 am
content: Quote from: MadScientist on February 02, 2021, 11:56:56 amSo even a $2 part is cheap enough? How much time do you spend to save $200 to $500???

author: MadScientist
author_rank: Frequent Contributor
timestamp: February 03, 2021, 11:40:18 am
content: Thanks , but I’m simply asking about possible alternative not debate my dollars and cents perspectives

author: Zero999
author_rank: Super Contributor
timestamp: February 03, 2021, 04:03:20 pm
content: It's worth spending a reasonable amout of time to save that much annually, because it will pay off in a few years.The NCV7240 looks like a bargain though. I came up with an idea for implemening an electronic fuse with discrete components, but even with the cheapest parts, it'll probably still work out more expensive.Here it is for educational purposes.
Multi-function panel mount meter for new power supply. - Page 1
Forum section: electronics / projects

author: electronics-whiz
author_rank: Regular Contributor
timestamp: February 16, 2017, 01:06:37 am
content: I built a new power supply from a couple of variacs I was given, rectifier, switches, etc.It has 2 different outputs one for DC another for AC. What I would like to do is find a panel mount meter preferably digital and ideally run off of 110-120VAC, battery would be okay too though although less preferred.I would like this meter to have the following specs:2 different input sections one for AC, one for DC(may actually need 2 different meters for this I don't know yet.)My power supply will do 0-280V AC, and probably 405V DC factoring in that is 1.44 times the AC voltage.The variacs are rated 3.5 amp but I think I can overdrive them okay to 5 amps and what I have a breaker rated for. So needs to measure 0-5 amps, preferably maybe 10 A.I almost think this may need 2 meters as I assume I would need one input for the amperage, another for the voltage for each meter to measure. So this meter would need 4 separate input pairs. I don't have issue if the only meters like this need some kind of switch, etc to change their settings, etc.Any ideas? Or would I be better off using external DMMs, etc.?

author: james_s
author_rank: Super Contributor
timestamp: February 16, 2017, 01:16:34 am
content: I think I would use four separate panel meters, one for ACV, one for DCV, one for ACA and one for DCA. I've been fairly impressed with the inexpensive LED panel meters from China that are all over ebay and such, you could have a look at those. For the AC meters it might be worth adding an external true RMS converter, there at least used to be some single IC solutions for that. You'll need an isolated power source for each of the meters, small isolated DC-DC converters will work, or you could use an additional small power transformer. A single meter with a selector switch could be done, but meters are so cheap now it makes more sense to me to have one dedicated to each parameter you want to monitor.

author: john61ct
author_rank: Regular Contributor
timestamp: February 16, 2017, 01:35:20 am
content: these guys do good work make it pretty for youhttp://www.frontpanelexpress.comAlso Blue Sea's
multi pin PCB connector - Page 1
Forum section: electronics / projects

author: sdouble
author_rank: Frequent Contributor
timestamp: June 22, 2015, 09:50:54 pm
content: Hi everybody,I'm working on the next release of a low noise charge integrator.The circuit is pretty simple, I don't want to discuss it here.THe point is that I have to cope with the High voltage biasing of the sensor. In other term, I have 1kV on the pcb.The pcb itself is not really a problem. But, I need a 6 or 7 pin pcb connectors which could sustain 1kV between neighboring pins.I need both male and females parts.I guess that the standard 1/10" pitch connectors won't do the job : too small insulation distance to sustain 1kV.If you guys know some good supplier, I'm very very much interested.Cheersjulien

author: Richard Crowley
author_rank: Super Contributor
timestamp: June 22, 2015, 10:46:39 pm
content: So how many pins actually have high voltage on them? Only one? All of them? Some of them?Where are you? (Please complete your user profile to include your country.)

author: jmole
author_rank: Regular Contributor
timestamp: June 22, 2015, 11:06:26 pm
content: It's VERY common for manufacturers to leave out pins on "standard" connectors to enable them for higher voltages.e.g.,this power supplyuses a very standard Molex 396 connector with the center pin removed for the AC inputs.
Multi pin resistance / continuity - Page 1
Forum section: electronics / projects

author: horle
author_rank: Newbie
timestamp: November 23, 2017, 04:01:19 pm
content: Hey guys!I'd like to check if any of 24 pins in a connector are shorted. I thought of implementing some switch matrix to route any pin combination to 2 wires and then measure resistance.I can think of several ways to attack this problem but I'm not sure if any of them might be superior.Surely I can solve this with a lot of relays, maybe even transistors? I also know there are switch matrix ICs but I'm not sure if I can measure resistances through such a device properly.So maybe you guys think: poor electronics noob, everyone knows that you use the famous XY to solve this.Any advice that would spare me costly failures are highly appreciated. My hobby budget is quite limited at the moment

author: duak
author_rank: Super Contributor
timestamp: November 23, 2017, 06:15:30 pm
content: I had to do a similar test with about 1000 lines on a complex flex circuit. I used some FPGAs (Field Programmable Logic Arrays) that implemented a 1000 stage shift register. The shift register implemented a rotating bit (1 on, 999 off) that started at one end and stepped bit by bit to the other end. Each shift register stage drove an FPGA I/O pin that could be set to provide a weak pull up to Vdd. Each pin could read or sense the actual output signal and logically compare it to the orginal rotating bit pattern. If there was an difference, the controller would stop and then determine if there was a short circuit to circuit common or to another output by examining the states of the I/O pins. This scheme didn't determine actual resistance as the faults essentially short circuits.I didn't have access to the both ends of the flex but in your case you could implement a checker that drives one end of the cable and reads the other. In the simplest case the receiver could be 24 LEDs and the driver a hardwired shift register, a rotary switch or even some test points that could be scanned manually. Note that this scheme requires that the driver provide a connection to either a test voltage or circuit common.Hope this makes sense,Cheers,

author: Brutte
author_rank: Frequent Contributor
timestamp: November 23, 2017, 08:21:35 pm
content: I had similar problem for bed-of-nails tester.I have used an eval uC with USB interface, 32 pins used. Each pin could be driven in one of four states:- output high- pullup- pulldown- output low32 IOs total.So essentially through USB I was:- sending some IO drive sequence,- 1ms delay- sensing IO pins.All that mess of bits was controlled and analyzed by host application.
Multi-plexer-plexer for 16.3 Kbps communication - Page 1
Forum section: electronics / projects

author: Rora
author_rank: Newbie
timestamp: August 30, 2019, 12:48:22 am
content: I'm designing an array of reader contacts for 1-wire ID buttons. I'll be using the new T.I. TMUX1108 8:1 multiplexers due to its excellent RON, leakage, and off/crosstalk isolation--it meets or exceeds the performance of the 1-Wire OEM chips designed for the same purpose.I'd like to follow a pattern of using 8 of these with the A0, A1, A2 inputs in parallel across all 8. The enable pin would then be multiplexed by a 9th. This would allow, say, 011 to select S3 on all 8 multiplexers, then cycle through the enables for each with the 9th multiplexer to read all the S3s in order.The communication through the multiplexer will be 16.3 Kbps 1-Wire TTL with a bus master that has advanced slew control and A/D filtering, so I expect it should work pretty reliably... that's why I need someone to tell me why this is a bad idea.

author: Kleinstein
author_rank: Super Contributor
timestamp: August 30, 2019, 06:22:37 am
content: The principle idea to combine 8 MUX chips is OK. For just logic signals, one may not need so low an R_on and very low leakage. Just normal 74HC(t)4051 (74LV4051 for less capacitance) should be sufficient.The more critical parameter than R_on may be the capacitance (some 60 pF at the common pin of the TMUX1108, 24 pF for the LV4051).8 of these chips would add up quite a bit.However for the control of the enable pins, I would not use an analog MUX chip, but a logic gate decoder.The function is similar, but no extra pull down / pull up needed. One has to check polarity - something like 74HC138 should work.Alternatively one could keep the enable pins all active and use a 9th MUX as a second stage, choosing one of the outputs from the 8 chips of the 1 st. stage. This would reduce the capacitance, as only 2 chips would contribute.

author: Rora
author_rank: Newbie
timestamp: August 30, 2019, 10:48:55 am
content: Quote from: Kleinstein on August 30, 2019, 06:22:37 amThis idea makes the most sense, this way all signal lines are not sharing any contacts. Would also allow me to place the pull-ups on the 8 individual signal commons which would keep the downstream 1-wire device charged until it is switched onto the main common, instead of on all 64 signal lines. Would just need to program in a short wait when switching the 8 muxes to a new set of sources.
Multi-sourced RJ45 ethernet jack? - Page 1
Forum section: electronics / projects

author: globoy
author_rank: Frequent Contributor
timestamp: June 27, 2022, 05:48:57 pm
content: I'm designing my first POE device and looking at parts selection. Lots and lots of different RJ45 connectors. I'm hoping to tap some of your collective experience to find out if there is a part or parts that are essentially multi-sourced (same footprint). My application is a bit cost sensitive so I'm looking for a basic single-port type. Ideally it would have the yellow/green LEDs and shielding (but open to other possibilities). Doesn't have to have magnetics. Can be top or bottom entry for the connector tab. Right angle, PCB mount (either SMT or TH is ok). POE power is < 5 W.What are your go-to part numbers?

author: thm_w
author_rank: Super Contributor
timestamp: June 27, 2022, 10:51:14 pm
content: Discussed a bit herehttps://www.eevblog.com/forum/microcontrollers/rj45-with-integrated-magnetics-different-configurations/

author: globoy
author_rank: Frequent Contributor
timestamp: June 28, 2022, 02:21:10 pm
content: Thank you thm_w.
Multi-tap Transformer in LTSpice - Page 1
Forum section: electronics / projects

author: Filter_head
author_rank: Contributor
timestamp: October 19, 2014, 10:54:41 am
content: The LTSPICE model for a transformer is attached. Primary is two windings in parallel with three windings on the secondary side.The SPICE directive for the mutual coupling between the windings is also shown (assumes ideal coupling).Q: Is what's shown the proper way to mutually couple the windings for a transformer of this type?It "appears" to work in the simulation (i.e. produces the voltages expected in the entire amplifier circuit) when inductor values are selected to produce the required voltage drops.That said, it was easy to do and therefore must be wrong. Can those of you skilled in modeling transformers in SPICE take a peek and chime in (why it's right, wrong or how it should be revised). Will add to this information if more is needed.
Multi-turn pot - Page 1
Forum section: electronics / projects

author: mojoe
author_rank: Frequent Contributor
timestamp: October 07, 2025, 05:33:21 am
content: Is a multi-turn pot like what's in the picture available? I've looked on Mouser, but didn't find anything in the same form factor. I measured about 9.6 mm across the width (top to bottom in the picture). A 5 or 10 turn would be ideal.

author: Uunoctium
author_rank: Frequent Contributor
timestamp: October 07, 2025, 06:14:47 am
content: According to their announcement, Megatron has the smallest multiturn pot of the world, series SMT. Diam is 10,5mmØ, but length is 19,2mm min for 5-turnDatasheet:https://www.megatron.de/fileadmin/user_upload/Datenblaetter/Winkelsensoren/Potentiometer/DS_SMT_en.pdf

author: Nominal Animal
author_rank: Super Contributor
timestamp: October 07, 2025, 11:51:29 am
content: Your best bet in such confined space is to use an O-ring (or even a rubber band) to the actual multiturn pot, and just have a mechanical shaft holder in place of the current pot. This used to be a common solution a few decades ago with radios and large adjustable air-gap capacitors.

author: MarkF
author_rank: Super Contributor
timestamp: October 07, 2025, 11:53:44 am
content: Mouser has theBourns 3856 Series 3 3/4 turn pots.The body is 19mm diameter though and the pin pitch is 0.25 in. with a 0.25 in. shaft.About the smallest I could find on a quick search.

author: Fraser
author_rank: Super Contributor
timestamp: October 07, 2025, 12:08:15 pm
content: I know of no ‘COTS’ multi turn potentiometer in that small form factor. In my experience such would normally be a custom part, likely based upon a miniature multi turn trimpot topology.In situations where a miniature multi turn potentiometer is required, I have seen multi turn trim pots used. A small brass shaft is attached to the brass trimpot adjuster. This is not something I would wish to do as it seems like a “hack” but I have seen it used on commercial equipment to good effect. I have no idea of the trimpot life expectancy if regularly adjusted.There is a temperature calibrator that I own that uses this “adapted trimpot” approach and it has been reliable. Picture attached.I think the trimpots used in this ‘hack’ are the version with a finger grip adjuster. Picture attached.Fraser

author: Fraser
author_rank: Super Contributor
timestamp: October 07, 2025, 12:32:21 pm
content: Others have faced this same challenge and I found a 3D printable adapter to add a knob shaft to a standard multi turn trimpot.https://www.printables.com/model/1085661-multiturn-trimpot-knob

author: mikerj
author_rank: Super Contributor
timestamp: October 07, 2025, 02:31:46 pm
content: Quote from: Fraser on October 07, 2025, 12:08:15 pmThe Bourns ten turn trimmers are only rated for a life of 200 cycles.