hybridfree/eevblog-posts huggingface dataset:
MAX7456 OSD chip seems unstable at room temp - Page 1
Forum section: electronics / projects

author: Psi
author_rank: Super Contributor
timestamp: June 24, 2013, 07:21:26 am
content: I've been having problems with two minimOSD boards i got from china.They use a ATMega328P and MAX7456 OSD chip on a small pcb (A clone of thishttps://code.google.com/p/arducam-osd/wiki/minimosd)The OSD seem to only work properly once the MAX7456 has got up to temp (ie nice and warm, It's got a metal tab under the chip for heatsinking)When cold it will run for 1-4 seconds then crash repeatably. The time seems to get longer as the chip gets warm until it doesn't crash at all.I've tried running the board off battery to eliminate powersupply noise but they still have this issue.I've eliminated the ATMega as the problem by writing my own code to drive the chip which didn't help either.What's more interesting is that a hardware reset (on the reset pins) doesn't always work to reboot the chip.Where as a full power-cycle always does.I'm starting to wonder if these MAX7456 chips are fake. Perhaps some cheap mcu pretending to be the MAX7456 in software.Has anyone else come across ICs that dont work correctly when at room temp?

author: Psi
author_rank: Super Contributor
timestamp: June 24, 2013, 07:35:15 am
content: UPDATE:Yep, It's has to be fake.I just unsoldered the MAX7456 off one of the PCBs to check if it had the exposed pad underneath, like the chip is supposed to.It does have the metal pad but it's not electrically connected to anything.The official datasheet says it's connected to AGNDI guess connecting the pad was too hard when making the fake.Easier to just slap a die into a dummy package that "looks" the sameIt's probably just a cheap MCU and the reset pin is one of the general inputs.That would explain why the reset pin doesn't fix a crash sometimes.

author: David_AVD
author_rank: Super Contributor
timestamp: June 24, 2013, 09:07:38 am
content: Sneaky bastards!

author: amyk
author_rank: Super Contributor
timestamp: June 24, 2013, 11:26:07 am
content: That is odd, one would expect a regular MCU to not heat up much at all, and probably cost even more. Checking the power consumption might also give some clues.Either way, the simplest fix might just be to put a big power resistor on the chip to keep it warm...

author: Psi
author_rank: Super Contributor
timestamp: June 24, 2013, 12:43:41 pm
content: The max chip cost $24 each and $18 in bulk from digikey or $10 in bulk from maxim themselves.So its a tempting target for fakes.Especially if they can use a $3 mcu.The xtal it uses is 27Mhz so it does run quite fast. mcu wires.Maybe they're overclocking it, that may explain the heat.It doesn't get crazy hot, just nice and warm.Module current draw is 75mA @ 12V (onboard switchmode down to 5V)So around 150mA @ 5V (includes the atmega and 3 leds).Assuming 30mA of that is the leds and the atmega @ 16mhz uses around 8mA.So the max chip is probably using 100mA or so which matches up to the datasheet which says 24mA analog side + 25mA digital side + 58mA output driverhttp://datasheets.maximintegrated.com/en/ds/MAX7456.pdf
MAX811 as debounce? - Page 1
Forum section: electronics / projects

author: technix
author_rank: Super Contributor
timestamp: August 24, 2019, 04:18:29 pm
content: For a button that is not intended to be pressed frequently, is MAX811 (and its clones) a good candidate for a debouncing chip?

author: MosherIV
author_rank: Super Contributor
timestamp: August 24, 2019, 06:13:07 pm
content: A 555 in monstable is just as good

author: Zero999
author_rank: Super Contributor
timestamp: August 24, 2019, 06:20:17 pm
content: Quote from: MosherIV on August 24, 2019, 06:13:07 pmI wouldn't say that. The 555 is more flexible, but it uses much more power, than the MAX811 and requires more external components.The MAX811 seems to be up to the job, but why not do it using software?

author: David Hess
author_rank: Super Contributor
timestamp: August 24, 2019, 06:22:20 pm
content: Quote from: technix on August 24, 2019, 04:18:29 pmSure, I would tend to use a more general solution but the MAX811 is a great choice if the power-on-reset function is acceptable.

author: technix
author_rank: Super Contributor
timestamp: August 25, 2019, 03:35:10 am
content: Quote from: Zero999 on August 24, 2019, 06:20:17 pmSoftware debouncing may not be an option here.
MAX865 charge pump, hard to get working - Page 1
Forum section: electronics / projects

author: ahope
author_rank: Contributor
timestamp: July 27, 2020, 05:16:58 am
content: Hi,I am working on a board where I need +/- supplies to a couple of op-amps.I am trying to use the MAX865 dual-output charge pump. It will nicely double the 3.3V supply and provide positive and negative supplies of double the input, i.e. +/- 6.6v.I can make it work - some of the time. It will successfully run on some board, while on other boards it will not work properly and outputs +2.7 and -1.4 while being fed with 3.3v.Everything else on these boards runs fine, STM32L4´s, digital pots, input mux, all I2C devices etc.Does anyone have experience with the MAX865 and can share some advice on how to make it work reliably?I have attached a snapshot from the relevant area of my board.
MAX8815A Output Maximum Current based on Input Voltage Level - Page 1
Forum section: electronics / projects

author: joersam24
author_rank: Contributor
timestamp: May 11, 2012, 03:59:28 am
content: Hi to all,I'm planning to use MAX8815A DC-DC Step-up converter in our project. It is stated in its datasheet that at 5V output it can output 500mA from 1.8V input and 1A from 2.5V input... My question is does it capable to output more than 1A of current if the input voltage is 4.5V~5V? Its switch current limit is 2.5A.Does anyone knows the basic formula to compute maximum output current of DC-DC Converter?

author: mariush
author_rank: Super Contributor
timestamp: May 11, 2012, 05:19:39 am
content: Page 4 answers your questions.Maximum load current vs input voltage...vout = 5v ... follow the line... 2.2v for about 0.8A , 2.7v for about 1.05A, 3.2v for > 1.3A

author: joersam24
author_rank: Contributor
timestamp: May 11, 2012, 05:48:35 am
content: Thanks for the info mariush, but I want to know its maximum current at Vin=4.5V~5V... Does anyone knows the formula on how to compute? thanks...
Max9611 high internal temperature - Page 1
Forum section: electronics / projects

author: prudencio
author_rank: Newbie
timestamp: March 18, 2019, 11:31:39 pm
content: Hi EverybodyDoes anyone have been using MAX 9611 CURRENT SENSE?The internal temperature has increasing up to 122 degrees celsius when I increase the input voltage to device with 0 current.see below the measurements:As I increased the input voltage, the internal temperature rose.input voltage RS+ pin2------4,067v current =0 intrenal device temperature 39,30 celsiusinput voltage RS+ pin2------5,048v current =0 intrenal device temperature 46,08 celsiusinput voltage RS+ pin2------6,044v current =0 intrenal device temperature 55,20 celsiusTkanks a lot, best regards
MAX98357 addition bulk capacitance sizing? - Page 1
Forum section: electronics / projects

author: cprosser
author_rank: Contributor
timestamp: November 15, 2021, 06:04:21 pm
content: Hi folks,I've been working my way through the MAX98357 datasheet (https://datasheets.maximintegrated.com/en/ds/MAX98357A-MAX98357B.pdf) and it has the following comment:Power-Supply InputVDD, which ranges from 2.5V to 5.5V, powers the IC, including the speaker amplifier. Bypass VDD with a 0.1μF and 10μF capacitor to GND. Some applications might require only the 10μF bypass capacitor, making it possible to operate with a single external component.Apply additional bulk capacitance at the ICs if long input traces between VDD and the power source are used.I'm thinking a switching type electrolytic capacitor is the right component for the job. But I have zero intuition as to what capacity it should be.Any suggestions?thanks,Chris

author: cprosser
author_rank: Contributor
timestamp: November 16, 2021, 04:44:01 pm
content: Did some more research on this and something I wasn't aware of is the USB inrush current limitations that state no more than 10uF should be seen at device connection. (https://electronics.stackexchange.com/questions/38361/usb-powered-device-with-multiple-decoupling-capacitors?utm_source=pocket_mylist). This device is going to be powered by USB, using a Lolin D32 Pro, but tapping the USB 5V directly.The datasheet for the MAX98357 already specifies 0.1uF and 10uF. Which is just a little over that limit. I'm not going to bother with an additional bulk capacitor to avoid all that extra complexity to avoid the current limitations that connection.--chris

author: mariush
author_rank: Super Contributor
timestamp: November 16, 2021, 05:42:52 pm
content: 0.1uF ceramic for decoupling.some capacitor for bulk energy ... yeah, 10uF is a reasonable value, but it's only the maximum allowed when the device is inserted (so that you don't have those big spikes)See the answers athttps://electronics.stackexchange.com/questions/38361/usb-powered-device-with-multiple-decoupling-capacitorsIf you use ceramic capacitors, maybe use a 10uF 25-50v rated.If you use polymer/solid capacitors, i'd use 10uF 15-25v rated.For electrolytic... I'd use higher voltage rating just so you get a lower esr.Like the answer above says, you could also have a bigger bulk capacitor in parallel with a resistor, so that when you insert your device the big capacitor doesn't cause a spike and limits the current.You could use a rc circuit (or a microcontroller) to enable a p-channel mosfet and basically short out that resistor a few seconds after the device is inserted.
MAX98357A KiCad Schematic Help - Page 1
Forum section: electronics / projects

author: UncookedCorn
author_rank: Contributor
timestamp: November 16, 2023, 12:20:26 am
content: I have been looking around at several schematics for this speaker amplifier and it looks like there are various ways to set this up. I am just wondering if my schematic is done properly, as I already have the PCB for this design and no sounds are playing. Any idea what I could be doing wrong? Thank you!(The first picture is mine and the others are different schematics I came across).

author: SiliconWizard
author_rank: Super Contributor
timestamp: November 16, 2023, 04:05:15 am
content: As you have it configured, it's set up for a 12 dB gain (GAIN_SLOT to GND).If you are sure about the I2S signals you are generating, I would check two things:- That you have set the "SD MODE" GPIO to 1. If it's 0, the amplifier will be in shutdown.- That the value of R5 is correct. Check the datasheet. What is the logic high level of your GPIOs? 370k would be the "small" value for 5V logic, selecting the right audio channel. If your logic is 3.3V, it doesn't correspond to the recommended values and so I wouldn't be sure of the behavior in this case.
Max9926 Mode B experience? - Page 1
Forum section: electronics / projects

author: Tom18991
author_rank: Contributor
timestamp: March 09, 2019, 05:46:05 am
content: Anyone here have experience with the MAX9926 VR sensor chip? I'm trying to get it into Mode B, and set my own external trigger threshold voltage to 2.5v, and have followed the data sheets to the letter, but the chip seems to ignore my external threshold voltage and instead outputs a nice 0-5v pulse even when the VR sensor input (simulated by function generator) is down to 50mV. Has anyone here successfully used Mode B to set their own trigger voltage?
MAX9926 VR Conditioning question - Page 1
Forum section: electronics / projects

author: mtechmatt
author_rank: Regular Contributor
timestamp: September 20, 2017, 09:01:25 am
content: Hi guys,I am having some issues conditioning a crank/cam signal from a Honda S2000 for one of our ECUs.The Crank is a 24 tooth wheel (evenly spaced), the cam is a 3 tooth wheel (spaced like an even 4 tooth wheel with one of the teeth removed. The Honda sensors are normal VR type sensors that produce an AC waveform as the teeth pass itWe use the MAX9926 VR zero-crossing point detector chip in our ECU for triggering the MCU interrupts. The circuit we use for the chip is as below (1),Yes, we have tied the -VE channels of the input (+ve on the device) to GND as that is what the factory ECU seems to do, although the + & - lines from the sensor do have their own pins into the ECU, so this could be changed. We did try it just running direct the -/+ from each sensor to the MAX9926 and received very strange interrupts from the chip - non sensible visually.We get perfect signals which look like (2) (LOGIC PLOTS ARE FROM THE INT ROUTINE OF THE MCU AND JUST SHOW A SPIKE WHEN THE FALLING EDGE OF THE MAX9926 OUTPUTS ARE RECIEVED) up to around 6,000rpm then we lose sync (would be around 2400hz of signal on the crank line), and the logic analyser outputs show (3) (extra and missing teeth).I plan to scope it today pre, and post MAX9926 to see what is happening and I welcome your input at solving this!(1) INPUT CIRCUIT(2) NORMAL TEETH SUB 6,000RPM(3) SYNC LOSS AT/OVER 6K RPM

author: kosmos
author_rank: Contributor
timestamp: January 12, 2024, 08:48:13 pm
content: Hello, your post is already very old, but I would still be interested to know if you have found a solution. I have the same problem that from around 2500 Hz the output only shows high. Despite the fact that I give the signal generator a clean sine wave with 20V peak to peak to the MX9926.
Maxim MAX414CPD or alternative - Page 1
Forum section: electronics / projects

author: 0culus
author_rank: Super Contributor
timestamp: January 02, 2020, 05:33:19 am
content: I'm looking at building a project where I'm going to need a quad op-amp. The original BOM calls for a MAX414CPD, which appears to be obsolete and the only way to get it is through Dave's favorite "one hung low" sellers from China. I'm a little apprehensive about counterfeits, for obvious reasons. Is there a pin-for-pin replacement for this part that's still in production and can be had from reputable suppliers?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 02, 2020, 06:22:26 am
content: OPA4228, LT1127, LT1214?Tim

author: viperidae
author_rank: Frequent Contributor
timestamp: January 02, 2020, 06:25:04 am
content: Looks like a pretty standard pinout. What's the application? You may not need the exact same bandwidth, offset, voltage range, etc.

author: 0culus
author_rank: Super Contributor
timestamp: January 02, 2020, 05:24:54 pm
content: Application is building the original MIT Coffee Can FM-CW radar project. I intend to build the original one, then modify it to work on higher bands + eventually design a PCB for the low frequency electronics.
maximum and minimum common mode logic in diff pair - Page 1
Forum section: electronics / projects

author: john23
author_rank: Frequent Contributor
timestamp: April 21, 2025, 01:32:45 pm
content: Hello,in the photo below taken from the manual we have the conditions for ICMR.Why the biasing condition for M5 which ensures saturation for M5 dictates the minimum of input common mode voltage range?https://aicdesign.org/wp-content/uploads/2018/08/lecture19-150211.pdfThanks.

author: mtwieg
author_rank: Frequent Contributor
timestamp: April 21, 2025, 01:38:28 pm
content: ICMR is defined by when "one of the transistors leaves saturation". Certainly this includes M5 as well, since changes in IS5 will affect Iout.So obviously "the biasing condition for M5which ensures saturationfor M5" would be relevant.
Maximum NiMH voltage vs. Maximum NiCd voltage... - Page 1
Forum section: electronics / projects

author: alank2
author_rank: Super Contributor
timestamp: July 13, 2019, 02:14:43 am
content: I'm looking to make a battery pack for a vintage computer (Epson PX-8) and it looks like after checking out the schematic, they don't seem to have any sort of voltage regulator on the battery, but seem to count on 4 cells of NiCD to give a valid range. Feeding 5.4V from my bench supply into the battery connector and I checked the voltage on a port on the back and it was coming up 4.95V, so I think they have something that is reducing it a bit. If I drop the 5.4V to 5.3, 5.2, the VCC goes down in .1V steps too, so it is following the battery voltage. So my concern is could the higher maximum or fully charged voltage of the NiMH be too much for it? How much higher is it than NiCD?Here i the technical manual for it:http://www.vintagecomputer.net/fjkraan/comp/px8/doc/px8-tech-manual.ch2.pdfPage 2-4 starts the power area, but 2-13 says when fully charged "5.4V" and low voltage 4.5V to 4.8V.I've got some NiMH batteries - should I try to make a pack out of them? Or should I stick to NiCD?

author: MosherIV
author_rank: Super Contributor
timestamp: July 13, 2019, 06:20:05 pm
content: Hi. As far as I know NiCAD and NiMH have near identicle max and min voltages.Main differences between them:NiMH has higher energy density.NiCAD has better high current output characteristics.

author: alank2
author_rank: Super Contributor
timestamp: July 14, 2019, 01:14:19 pm
content: I always that that NiMH had a higher charged voltage. I ended up getting some NiCd's at a local place that had the machine to spot weld them together and I got them to join them for me at no charge. All I had to do was use some hot glue on the pack.

author: magic
author_rank: Super Contributor
timestamp: July 14, 2019, 01:21:42 pm
content: NiMH can go up to 1.45V or so when freshly charged to their full capacity.But this site says NiCd are similar:https://batteryuniversity.com/learn/article/charging_nickel_based_batteriesPossibly the built-in charger limits voltage to 1.35V per cell so using NiMH would have been safe too.

author: tggzzz
author_rank: Super Contributor
timestamp: July 14, 2019, 04:13:00 pm
content: Beware of the different maximum trickle charge rates, and of the capacity specs claimed on fleabay.

author: alank2
author_rank: Super Contributor
timestamp: July 15, 2019, 03:05:52 pm
content: Thanks for the info everyone; I ended up going to interstate and they had both types I needed (4/5 sub c and 1/3 aa) in NiCd and didn't charge me to spot weld them together so I've got the original type working.
Maximum power point  in solar converters - Page 1
Forum section: electronics / projects

author: ocset
author_rank: Super Contributor
timestamp: July 14, 2018, 09:14:48 pm
content: In solar converters , the maximum power point is simply referring to the current drawn from a solar panel, above which there is no more delivered power from the solar panel (to the load, eg battery) if the current is increased from that level.Do you agree?

author: CopperCone
author_rank: Super Contributor
timestamp: July 14, 2018, 09:26:28 pm
content: It's a favorable impedance point. I think about it like a specific input impedance to voltage converter.Or maybe a better way to think about it is that you want to transform your load to mimic a specific impedance.

author: ejeffrey
author_rank: Super Contributor
timestamp: July 14, 2018, 09:35:06 pm
content: Yes it is the operation point on the I/V curve that has maximum power. If you try to draw more current the voltage drops enough to lower the power. If you draw less current, the voltage does not increase enough and you end up with less power.

author: ocset
author_rank: Super Contributor
timestamp: July 14, 2018, 10:02:57 pm
content: Thanks, in that case, what we need to be able to do, is calculate the amount of power dissipated (wasted) in the solar panel itself by the current drawn from it...So, power = V*I…….Well, we can measure the current…but how do we assess what the voltage is?....presumably the voltage is the nominal open circuit panel voltage minus the input voltage to the switching converter that’s downstream of it. Is this correct?What is the open circuit panel voltage when the panel is under full sunlight?Is this figure very different from the open circuit panel voltage when the panel is in dull daylight?

author: CopperCone
author_rank: Super Contributor
timestamp: July 14, 2018, 10:31:46 pm
content: Wikipedia explains how well each tracking method works in terms of efficiency pretty good

author: ocset
author_rank: Super Contributor
timestamp: July 14, 2018, 10:38:32 pm
content: Thanks,In fact, all we would need to do, is simply regulate the input current to the switching converter which charges the battery...and then every now and then incrementing it , whilst monitoring the output voltage and current....as V*I at the output starts going down, then back off the input current. Do you agree?

author: CopperCone
author_rank: Super Contributor
timestamp: July 14, 2018, 10:46:26 pm
content: thats one way, wikipedia really does have several different scenarios, solutions and evaluations though.
Maximum speed of pmsm motor from Kv - Page 1
Forum section: electronics / projects

author: swatHuman
author_rank: Newbie
timestamp: August 14, 2024, 12:33:07 am
content: Hello Everyone!I was wondering if it is possible to find the maximum achievable speed of a brushless motor by looking at the Velocity constant Kv?Looking at a few definition of Kv here:https://en.wikipedia.org/wiki/Motor_constantsKv = W(no-load) / VpCould you please explain what is Vp here? is it the peak voltage measured across one phase to another phase of the motor? OR is this phase to neutral(midpoint of the star connected motor load)?Also I found this thread that has a different formula:https://e2e.ti.com/support/motor-drivers-group/motor-drivers/f/motor-drivers-forum/1271711/mcf8315a-speed-control-issueElectrical Speed = (DC/sqrt(3)/(Back Emf in mV/Hz))*1000Could you please explain if they are the same?
Signal integrity (max stub length) for MIPI-DSI differential pair  - Page 1
Forum section: electronics / projects

author: ricko_uk
author_rank: Super Contributor
timestamp: April 03, 2025, 05:52:53 am
content: Hi,On a PCB, there are 6 MIPI-DSI lanes (3 differential pairs) and they operate at 500 MHz. They have 1.5 mm-long stubs. I am pretty sure at this frequency that stubs length is safe, but could someone please confirm that is so?Thank you
may programer projekt. - Page 1
Forum section: electronics / projects

author: Aigars
author_rank: Regular Contributor
timestamp: April 17, 2014, 02:31:51 pm
content: its stil not finishet. i wayting for parts from ebay.its a universal programer.

author: at2marty
author_rank: Regular Contributor
timestamp: April 17, 2014, 07:27:19 pm
content: Pretty cool. Did you write the code for it? If so are you willing to share it?

author: Skimask
author_rank: Super Contributor
timestamp: April 18, 2014, 10:07:55 am
content: Looks almost exactly like a copy of the old Warp13a PIC programmer from back in the late '90's, modified and updated just a little bit...And not very universal at that...

author: Aigars
author_rank: Regular Contributor
timestamp: April 18, 2014, 10:11:12 am
content: i dont know jet, its mising sam parts. parts be coming next weak from ebay.
Maybe you guys can help? - Page 1
Forum section: electronics / projects

author: Kilroywashere
author_rank: Regular Contributor
timestamp: August 08, 2021, 11:27:12 pm
content: So a buddy of mine asked me if I could build him a fake bomb for his airsoft buds.... I am fully able to follow schematics and to build such device ... I was thinking some sort of timer like 25 min and at the end of that time it would sound an alarm... in order to shut it off you have to put a code (using dip switches maybe? )i started to think its beyond my engineering skills ... I want the password to be able to be changed ( i guess i have to use a micro controller and some sort of code to set them via the dip switches on the fly. Like i dont want to keep the same password for the next gameIs there a better way to do this? how would you guys go about it?It would be nice if i could even have some motor that sprays air soft pellets , or like a bad smell? but i would think just a beep on a speaker will work just fine ...I have all sorts of cool things i can use on it 8 seg Led stuff and the chips to back them up i have some micro controllers and 555 timers ...I just dont know how to put all the bits together for this one ... I could make something beep and maybe use a 555 timer to count down... but how would i stop the count down and how can i change the password on the fly after the game is over?any help would be awesome ...

author: Kilroywashere
author_rank: Regular Contributor
timestamp: August 09, 2021, 03:40:04 am
content: I did not see this beforehttps://www.instructables.com/Arduino-defuseable-bomb-perfect-for-airsoft-games-/this helps me

author: james_s
author_rank: Super Contributor
timestamp: August 09, 2021, 06:25:44 am
content: I was going to suggest, this seems like a perfect Arduino project. You can get the little Nano clones for just a few dollars that are great for putting together projects like this where you connect together a some premade modules. You can get all sorts of displays, buttons, keypads, blinky lights, whatever you want it to look like.

author: Gyro
author_rank: Super Contributor
timestamp: August 09, 2021, 09:04:18 am
content: QuoteNot until you change the meaningless clickbait title.
MB1260 XL-MaxSonar-EZL0 Teardown - Page 1
Forum section: electronics / projects

author: Charles Creations
author_rank: Contributor
timestamp: February 20, 2015, 06:18:19 am
content: Hi Everyone,I did a teardown of a MB1260 XL-MaxSonar-EZL0 made by MaxBotix, and despite their pictures on the website, the top of the board is encased in a cured silicone compound. This made the teardown very destructive, so I thought I would share my results to prevent others from having to do the messy task of removing the silicone.Quick Specs:-10Hz Update-5V or 3V3 Supply-Max Range of 10m-42KHz Ultrasonic Frequency-1cm Resolution-4 layer board with power and ground plain internal (all signals on outside)-46Vpp transmit pulse with 500us pulse length at 42KHzThe unit looks like this:Explanation of Attachments:"Capacitor Map"This shows the location and value of all capacitors. Some were too small to be measured with my meter, so they have a question mark."Resistor Map"This shows the location and value of all resistors. They were measured in circuit, so may have errors."ICMap"This shows the main ICs. Notably, there is a L324A quad opamp, a PIC16F690 microcontroller, and what I believe is a BJT package being used as a diode."50%OverlayFlat"This is an image of each side of the board overlayed with transparency, so you can see where vias connect on the far side."Schematic"This is a crude schematic of the circuit I put together. It is not complete, but it gives the general gist of it. Of note, the sense line for the amplifiers is not switched on after the transmit pulse, so the design relies on the high impedance of the resistor and op amp input to protect it from overvoltage. I measured almost 46Vpp on the output with my oscilloscope. The labels "A#" refer to the pins of the the PIC, so the PIC's pin 1 is A1.
MBUS (Meter Bus) Master Analog Circuit - Page 1
Forum section: electronics / projects

author: FxDev
author_rank: Regular Contributor
timestamp: May 27, 2018, 01:20:09 pm
content: Hello everyone.I will work on MBUS master project in nowadays. I want to read 50 slave mbus calorimeters. Every meter has own battery.So can you suggest me working master circuit about that?Thanks!

author: FxDev
author_rank: Regular Contributor
timestamp: May 31, 2018, 12:20:08 pm
content: Any ideas?

author: rstofer
author_rank: Super Contributor
timestamp: May 31, 2018, 04:29:50 pm
content: And you expect us to go searching for reference material on MBUS? Why don't you link something.Got any specs on the calorimeters? How can we even search when we don't know what to look for?MBUS can refer to a lot of things including the flip up rear sight for a rifle.Google for 'mbus driver circuit', there might be something useful.This MBUS idea seems pretty clever if a circuit is limited to 2 wires to provide both power and signal. If I was choosing a transfer scheme and I wasn't constrained to 2 wires, this isn't the one I would choose.

author: FxDev
author_rank: Regular Contributor
timestamp: June 02, 2018, 02:53:03 pm
content: After all searching i choose to not to make it.Thanks everybody.
MBus-Master schematic  - Page 1
Forum section: electronics / projects

author: rokspy
author_rank: Contributor
timestamp: August 04, 2025, 08:25:26 pm
content: Hi.Found this image of the M-Bus Master schematic that I'm interested in. However, I have trouble understanding some parts of the circuit - emphasis on the part labelled "6. quiescent current source". A little bit about M-Bus: master-slave protocol, where the master communicates by varying voltage on the bus, and the slave responds by changing current consumption on the bus. Unit consumption of a slave is 1.5mA, aka the consumption when it is not communicating. There can be many slaves connected to the bus, and their total quiescent current can exceed the "space" event of a single slave during communication, when it increases the current cons. to ~20mA.So far, I believe the circuit works as follows:* The 2. part should create the "Space" event with ZD1 zener and emitter-follower circuit (T2); the PNP (T1) can bypass the zener and feed emitter-follower with 37V, making the "Mark" event. T3 discharges the bus when T2 base < bus voltage.* The 3. part seems a lot like a differential amp. circuit (except the R7 and R12) and would amplify the R9 voltage drop that's proportional to the slave consumption.* The 4. part, to my understanding, would keep track of the overall slave consumption by charging C3 through R17 and D3. The voltage on C3 would practically not react to quick current changes during slave communication.* The 5.part compares the voltage from 4. and the amplified voltage from R9 and can differentiate communication current from overall quiescent current.I also might be completely wrong about the explanation.About part 6. I believe that T5 should counter the voltage drop across R9, so that the whole bus voltage would not drop when there are many slaves connected. But I have trouble exactly seeing how it plays into the circuit as a whole.
MC12 lost CD: spectrum-soft site no longer exists. - Page 1
Forum section: electronics / projects

author: Terry Bites
author_rank: Super Contributor
timestamp: April 12, 2023, 11:18:21 am
content: I had to upgrade to Win11 (a degrading experience) and I needed to install MC12 on my shiny new workstation.I cant find MC12 out there any more all links end up on the now defunct MC site.Any ideas of where there is real copy of the CD or zip- not the demo version??Prseumably all the library upgrade will be missing from the soon to be abolished interweb as well.

author: jonpaul
author_rank: Super Contributor
timestamp: April 12, 2023, 09:00:21 pm
content: http://www.intusoft.com/

author: Messtechniker
author_rank: Frequent Contributor
timestamp: April 12, 2023, 09:38:24 pm
content: You might want to look here:https://www.eevblog.com/forum/projects/microcap-12-is-free-(as-in-beer)-now/msg4794392/#msg4794392

author: Terry Bites
author_rank: Super Contributor
timestamp: April 12, 2023, 09:41:02 pm
content: You pointing me to a completley different product n'est-ce pas?

author: Terry Bites
author_rank: Super Contributor
timestamp: April 12, 2023, 09:42:00 pm
content: Diamond geezer!

author: jonpaul
author_rank: Super Contributor
timestamp: April 13, 2023, 01:31:52 am
content: https://en.wikipedia.org/wiki/Micro-Caphttps://micro-cap.informer.com/download/

author: Terry Bites
author_rank: Super Contributor
timestamp: April 13, 2023, 11:02:28 am
content: cheers guys. Sadly it wont update its librarary.Anyone got an up to date library to share?

author: JugglingElectrons
author_rank: Contributor
timestamp: December 25, 2023, 07:13:26 pm
content: A bit late to the party, but the Wayback Machine has several captures that have the Micro-Cap 12 Download link on the left side of the page.v12.2.0.4 is available here and I've got it working with the full CD 58MB download even on Steam Deck!Download Page:https://web.archive.org/web/20210429030323/http://www.spectrum-soft.com/download/download.shtmDirect to v12.2.0.4 Zip:https://web.archive.org/web/20210429030323/http://www.spectrum-soft.com/download/mc12cd.zip
MC12095 Prescaler Equivalent - Page 1
Forum section: electronics / projects

author: simon christo
author_rank: Regular Contributor
timestamp: July 17, 2021, 12:03:03 am
content: Hi there! I'm finding it hard to find the part MC12095.Is there an equivalent, that is easier to source? Thanks Simon.

author: Benta
author_rank: Super Contributor
timestamp: July 17, 2021, 11:12:43 am
content: Lansdale Semiconductor perhaps? They second source obsolete Motorola parts.
MC14500 system - Page 1
Forum section: electronics / projects

author: Simon123
author_rank: Regular Contributor
timestamp: January 21, 2014, 10:11:11 pm
content: Hello!I have built this system, but now, when i finaly have time to start working on it again i have found a little(big) problem.To start doing anything usefoul with cpu, i need to load IEN and OEN registers.Now i have already built it on pcb, aand i dont want to change anything to much.I just need to get logic 1 or 0 on the input.(of the cpu)Any suggestions?https://sites.google.com/site/elektronikasimon/mc14500-microprocessor-and-computer
MC33035 BLDC motor controller - Page 1
Forum section: electronics / projects

author: GbR
author_rank: Contributor
timestamp: July 13, 2023, 04:12:50 pm
content: Does anyone here have experience with the MC33035 BLDC controller chip? I managed to get the motor working, but initially, the motor doesn't start as soon as I turn the speed potentiometer. I need to press the brake button first to start the chip. After that, I have to quickly turn the potentiometer within 3 seconds; otherwise,it goes to sleep again and i need to press the brake button again. Basically, the chip goes into sleep mode after 3 seconds of the motor stopping, and need to press the brake button each time to wake it up. Is there any way to stop that? I want the motor to rotate without pressing the brake button everytime.

author: MarkS
author_rank: Unknown
timestamp: July 14, 2023, 01:25:07 am
content: Can you show your circuit? I'm far from an expert, but none of us can help if we don't have the ability to see what may be wrong.
mc33907 CAN Transceiver  - Page 1
Forum section: electronics / projects

author: sanwal209
author_rank: Regular Contributor
timestamp: October 04, 2017, 06:30:18 pm
content: Hi Folks,I have designed a recent project which includes mc33907(System basis chip) and mc33907 microcontroller. There are three CAN on board two uses external transcievers and one is included mc33907. Rest of two are working perfectly but CAN transceiver in mc33907 doesn't work. I have check the signals and signals from MCU reaching to the pins of mc33907.mc33907 is also generating all the required voltages, only CAN transceiver is not working.Is there anybody who worked with this chip before?
mc34063 question  - Page 1
Forum section: electronics / projects

author: hedley
author_rank: Contributor
timestamp: January 02, 2025, 02:35:06 pm
content: I recently hooked up an electronic load - and am not sure if I am doing something wrong , as in circuit for the past 20 years we have had this device delivering 600mA @ 5V without a problem . I have the setup as per the attached spreadsheet , but as soon as I set ma MA on the load , after a few minutes the DUT shuts down ( no output ) , with a 250ma load as the input voltage reduces then the DUT seems to forget about the 5V output and track the input voltage with a +- 0.8V difference .Just seems strange and I am sure I am missing something really basic

author: rteodor
author_rank: Frequent Contributor
timestamp: January 02, 2025, 03:53:06 pm
content: As far as I know this converter has a (very discretely documented) limit on duty cycle of 84%. That would be 5.95 V at the input in 3mA test.In the 250mA test case it could be the over-current protection resistor. Limiting should occur at 0.3V. Hard to say without a schematic or a at least a value for that resistor.No idea for for the 400mA test case.

author: hedley
author_rank: Contributor
timestamp: January 03, 2025, 08:10:36 am
content: Thanks for reply - I did some more measurements , looking specifically at duty cycle ( as measured on an oscilloscope vs the calculation ) .The resistors ( over current protection ) I have 4 * 1 Ohm in parallel = 0.25 ohm and I also tried with three in parallel to get 0.33 ohm .If the input voltage is raised to 16 Volts , I can get +- 600ma on the 5V output - which is what is needed for the circuit that is powered . BUT ->I took an IR photo and the device MC34063, and the inductor ( PE 53606 [114uH, 940ma max )] ) outer case is +- 65 Degrees C .Ideally I could find a more robust device that could accept input range of 12 VDC -> 17VDC and output 5VDC at up to 1.2 Amps - clearly the worst case 12V drop across the device @ 1.2 Amps would require dissipation of 14 .4 watts of heat ,

author: PGPG
author_rank: Frequent Contributor
timestamp: January 03, 2025, 09:15:54 am
content: Quote from: hedley on January 03, 2025, 08:10:36 amMC34063 is very, very old construction. When I was looking at DCDC for the first time in 80s I got uA78S40 datasheet (it is practically the same as MC34063).Distributors like Digikey or Mouser have good selection tools.After selecting by parameters sort elements by price and then look at stock (if huge than element is popular) and read datasheet.10 years ago I was selecting DCDC IC to be used and I have big table of ICs I made those time, but it is 10 years old and I was searching for up to 1A ICs.I've selected LM5017 (direct step down to 3V3 from 7.5V-100V). I like COT (with Ton being f(Vi)) controller mode.

author: mikerj
author_rank: Super Contributor
timestamp: January 03, 2025, 12:55:34 pm
content: Quote from: hedley on January 03, 2025, 08:10:36 amRegardless of anything else the inductor does not have sufficient current rating for your 5v, 600mA requirement. In buck configuration the peak switch current is twice the load current, so 1.2A in your case.
MC34063 Question about converting positive voltage to negative voltage - Page 1
Forum section: electronics / projects

author: YOSHIZAKI
author_rank: Newbie
timestamp: March 21, 2024, 11:53:42 am
content: This is a 5V to -12V circuit, the IC used is MC34063.I don't know why the output is -12V, but the Ref voltage divider is divided into positive 1.25V

author: selcuk
author_rank: Frequent Contributor
timestamp: March 21, 2024, 12:03:27 pm
content: Vout measurement is referenced to circuit ground. Feedback measurement is referenced to GND pin of the IC. And GND pin is not connected to the circuit ground but to the Vout. You can connect feedback voltmeter reference to circuit ground.

author: YOSHIZAKI
author_rank: Newbie
timestamp: March 21, 2024, 01:25:06 pm
content: I can first see that the output is a negative voltage, and then think that the negative voltage becomes positive because the GND of the IC is not connected to the circuit ground. But is there any more intuitive way for me to judge the positive and negative voltages? Or how you imagined it?

author: selcuk
author_rank: Frequent Contributor
timestamp: March 21, 2024, 03:03:33 pm
content: I didn't comment about the IC. I'm just saying that you have two voltmeters. You need to connect their references (negative probes) to the same potential to compare them. The output voltage is -12V and the feedback net is at -10.75V. There is a 1.25V difference between them.

author: Miti
author_rank: Super Contributor
timestamp: March 21, 2024, 03:50:29 pm
content: Print the schematic on paper and write all the voltages relative to the circuit GND. See what you get.

author: Terry Bites
author_rank: Super Contributor
timestamp: March 21, 2024, 04:59:47 pm
content: Vo=-Vref(1+R1/R2) so for a -12V output R1/R2 =8.6 . No mystery there.See fig 13 of attached. Their R1 is your R2 and vice versa.

author: TimFox
author_rank: Super Contributor
timestamp: March 21, 2024, 05:36:16 pm
content: I wish manufacturers of flexible ICs such as this one would avoid naming a pin "ground" if there is a good reason to connect that pin to something else than the ground plane.I once designed a circuit using a shunt regulator chip (precision version of the common TL431) where the PCAD model had a "GND" pin for the negative terminal, but I was using it as a two-terminal device to make a negative reference voltage with respect to the ground plane.The PCB layout guy connected that pin to ground, instead of how I drew it on the schematic as a Zener diode (with pin numbers).(Incidentally: why are there zero precision three-terminal reference chips for a negative reference voltage?)

author: YOSHIZAKI
author_rank: Newbie
timestamp: March 22, 2024, 07:07:17 am
content: Thank you for your reply. I followed your suggestion and wrote down the positive and negative voltages, now it's clear.
MC34063 , US1M vs schottky diode - Page 1
Forum section: electronics / projects

author: Drirr
author_rank: Regular Contributor
timestamp: August 23, 2025, 10:54:30 am
content: Hi,I have a simple, cheap side project where I wanted to use my old trusty MC34063.Input voltage: 24V, output: 5V @ 300mA… what could possibly go wrong?I bought an MC34063 at a local store and put everything together. And… a problem occurred. At just 100mA the MC34063 overheated and died.So I thought maybe I had bought a fake IC. I switched to a TI MC34063, but the same thing happened.I tried different capacitors (ceramic, electrolytic), different inductors… nothing helped. The only difference was that instead of a Schottky diode I used a US1M fast diode (from mouser.com). Efficiency wasn’t important to me.When I replaced it with a Schottky, everything worked fine. But why??? 🤦

author: gamalot
author_rank: Super Contributor
timestamp: August 23, 2025, 11:17:55 am
content: I've been playing around with a 34063 boost circuit lately. While its efficiency and ripple aren't ideal, it's cheap, simple, and reliable.I've always used Schottky diodes and never had any problems. The reverse recovery time of the US1M diode you're using is 50ns, and as far as I know, the reverse recovery time of Schottky diodes can be considered zero.

author: Drirr
author_rank: Regular Contributor
timestamp: August 23, 2025, 11:25:51 am
content: I've always used Schottkys too, but I have no idea why using a standard diode is a problem. 50ns still seems pretty fast. Or maybe there’s something fishy about the US1M...
MC34063 with external N-mosfet - Page 1
Forum section: electronics / projects

author: Emil
author_rank: Regular Contributor
timestamp: May 05, 2015, 01:16:33 pm
content: Hi,I'm trying to make a circuit using an MC34063 switching regulator and an external N-channel mosfet. The input is 36V regulated DC and my requirement for the output is 4A at 12V with <200mV ripple.The datasheet has an example circuit using an NPN transistor, but no examples using mosfets, so I based my design on the external NPN example. I have added a resistor (R1) between pin 2 of the MC34063 and gate on the mosfet to keep Vgs below 20V. Other than I have only changed some component values.Does this look like workable design? Any problems or suggestions for improvements?Emil

author: c4757p
author_rank: Super Contributor
timestamp: May 05, 2015, 01:26:56 pm
content: You'll lose way too much power in the FET because you're not saturating it. It'll drop VGSwhen "switched on", translating to huge power loss at 4A.Try a PMOS, and with an active driver:You'll have to adapt it to clamp VGS.Better yet, just don't use MC34063. It's horrid enough for low-power applications...

author: Emil
author_rank: Regular Contributor
timestamp: May 05, 2015, 03:36:31 pm
content: Quote from: c4757p on May 05, 2015, 01:26:56 pmI used an N-MOSFET on the high side.. Obvious when you point it out, but I missed that. Thank you.I'm curious what makes the MC34063 horrid?Emil

author: rob77
author_rank: Super Contributor
timestamp: May 05, 2015, 03:54:39 pm
content: 34063 is my favorite switchmode regulator - but i wouldn't use it with external transistor (not even thinking about external mosfet)it's a simple and CHEAP - therefore ideal for small converters in hobby designs... but it's OLD and inefficient compared to modern chips.for 12V 4A i would look after a more modern chip capable of synchronous operation (driving 2 mosftes - top one is the switcher and the bottom one is replacing the shottky diode)

author: c4757p
author_rank: Super Contributor
timestamp: May 05, 2015, 03:57:55 pm
content: It's slow. The hysteretic control makes it unpredictable in terms of frequency, hard to filter, and in some cases quite noisy. The current-limiting behavior is overly simplistic for many applications and wasteful with its huge 1V threshold. Current-limiting is slow, meaning it doesn't do much against things like core saturation, and the output transistors are fragile.The cheapness is a benefit, of course, and I'm not above using one where its many drawbacks aren't a detriment.

author: Emil
author_rank: Regular Contributor
timestamp: May 06, 2015, 03:17:41 pm
content: I might go with an LM2678 instead. Anything horrid about that one?

author: rob77
author_rank: Super Contributor
timestamp: May 06, 2015, 05:35:53 pm
content: Quote from: Emil on May 06, 2015, 03:17:41 pmthose should be OK. - simple circuit and high enough frequency (smaller inductor and caps)
MC34063 with Very Bad eff. ?? !! - Page 1
Forum section: electronics / projects

author: fastpay
author_rank: Newbie
timestamp: November 23, 2010, 07:11:59 pm
content: i am trying to make a dc-dc converter and saw a video here in this nice blog about using MC34063 and i though life is easyanywayit is from 9-12 Volt to 18 volt 4 ampmy first trial was using a discerect comp. using 300 Khz but without feedback just constant load ( i was about to begin to make the feedback cir. )the mosfet peak curr was about 10A and coil peak curr was about :10Anow i said to use MC34063 since desing the feedback maybe it will so diff. , i faced a problem that the IC could only support switch curr less than 1.5A and using MC34063 datasheet design equ. my peak will reach 16 Amp. so i have to use an ext. transistor and on freq, 50Khzbut i shocked i foundthe mosfet peak curr became 48A and coil peak curr was about :48A !!!!!!!!!i used the same mosfet & the same diode in both design so i guess changing them will not solve the problemso any tips to improve the eff.please check the attachment imagesthanksbye

author: NiHaoMike
author_rank: Super Contributor
timestamp: November 23, 2010, 07:25:34 pm
content: Use a better controller.
MC68SEC000? - Page 1
Forum section: electronics / projects

author: technix
author_rank: Super Contributor
timestamp: November 09, 2017, 08:03:29 am
content: Does anyone have any experience with MC68SEC000? How much difference is there between this chip and MC68HC000? How to program the chip? Will GCC work or do I need to use something exotic like SDCC? Is there some kind of memory conventions? How to hook up standard parallel NOR Flash ROM and SRAM to the thing? What about the dreaded DTACK line? Can I mix 8-bit and 16-bit peripherals?

author: Benta
author_rank: Super Contributor
timestamp: November 09, 2017, 10:06:57 am
content: The 68SEC000 can be used in place of 68HC000 with no problems. The difference is the option to build a system with 8-bit bus. Software/firmware is the same.
MCON 1.2 crimp tool? - Page 1
Forum section: electronics / projects

author: mayor
author_rank: Regular Contributor
timestamp: August 30, 2024, 11:31:34 am
content: Hi, I've Googled quite a bit and can't find an affordable alternative crimp tool for MCON 1.2 sealed connections. I need a tool that can handle the seal, not jsut the wire crimp.Any suggestions?Thanks!

author: mayor
author_rank: Regular Contributor
timestamp: October 01, 2024, 10:25:10 am
content: Answering my own question, should someone find themselves in the same situation! The Sargent Tools CT26 works for 20AWG (and probably also a size up and down from that)