hybridfree/eevblog-posts huggingface dataset:
FT232RL .NET library being shady - Page 1
Forum section: electronics / projects

author: osmosis321
author_rank: Regular Contributor
timestamp: March 19, 2011, 05:05:25 pm
content: I use PuTTY: bytes received correctly.I use the .NET wrapper: everything appears to work, Write() returns with FT_OK and the right amount of bytes showing as written, but the PIC receives a single 0x00 byte. Subsequent Writes are identical except the PIC receives 0x01 from then on.What the ..?! Either I'm doing something terribly wrong or there's a bug in the driver, or something.Has this happened to anyone else?

author: osmosis321
author_rank: Regular Contributor
timestamp: March 19, 2011, 07:07:51 pm
content: it turns out the problem is with the particular overload of the Write() method I'm using. The overload that accepts a String parameter fails, likely because of some Unicode encoding/decoding issue.I've neither the time nor inclination to solve the String encoding problem. I'm thinking the best way to get past this is to just use the other overload, which accepts a char array, and which actually works.The only annoyance there is I'll have to change my interfaces as well.

author: red_mamba
author_rank: Contributor
timestamp: March 19, 2011, 07:14:27 pm
content: Never had problems in C#Quote
FTDI FT2232H IO voltage - Page 1
Forum section: electronics / projects

author: Aiy
author_rank: Regular Contributor
timestamp: January 07, 2022, 09:42:26 am
content: Hello All,I am designing a board with an FTDI FT2232H as USB interface.According to the datasheet VCC and VCCIO to the device is specified as 3.3V.I am wondering if anybody have experience with running the VCCIO at different levels, i.e. 1.8V or 2.5V ?Best regardsAIY

author: tszaboo
author_rank: Super Contributor
timestamp: January 07, 2022, 09:46:37 am
content: VCCIO Operating Supply VoltageMin: 2.97 VTyp: 3.30 VMax: 3.63 VPlease read the friendly manual.
It is "safe" to have a serial port connected to an unpowered TTL shifter? - Page 1
Forum section: electronics / projects

author: mcinque
author_rank: Unknown
timestamp: May 01, 2019, 07:40:14 pm
content: Hello all,let's assume we have a CHIPI-X USB to serial adapter... do you see any potential issue for the serial port if the chip is leaved unpowered but connected to an active RS232 serial port (loops, shadow voltages or currents or any other issue)?There is a level shifter between the serial and the serial bridge, should it be totally passive if unpowered, do you agree?

author: mcinque
author_rank: Unknown
timestamp: May 01, 2019, 07:43:39 pm
content: Level shifter diagram. It is powered by the VCCIO generated by the FT231X.Shouldbe totally passive if unpowered, do you agree?
FTDI FT232H SPI - Page 1
Forum section: electronics / projects

author: ice111
author_rank: Newbie
timestamp: October 14, 2014, 09:31:41 am
content: I am currently using FT232H interfacing using SPI with my STM32F2xxand I am developing the firmware and the PC application. I am using D2xx .dll library for the USB communication.I have problem to get >1 Mbps of data!My current architecture is, I create a thread that runs a while loop to read for data avaialble and call FT_Read!and the data size that I am sending for each transfer is 128 bytes,while(true) {dataCommand = 0x20;dataCommand = 0x7F;dataCommand = 0x00;ftStatus = ftDevice.Write(dataCommand, 3, ref dataWritten);do{ftStatus = ftDevice.GetRxBytesAvailable(ref dataRead);} while ((dataRead == 0) && (ftStatus == FTDI.FT_STATUS.FT_OK));ftStatus = ftDevice.Read(resultCommand, dataRead, ref dataWritten);but i am only able to get about 500kbps! this is very low... may i know how can i increase the speed/??i am desperate....

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: October 14, 2014, 10:13:11 am
content: QuoteThat may be your problem. I believe USB2 high speed uses 512 byte frames

author: ice111
author_rank: Newbie
timestamp: October 15, 2014, 02:15:53 am
content: When I tried to send 512 bytes, from my firmware and I read it back in my PC, i couldnt get any data!I get all the data with value of 0...What went wrong...

author: Psi
author_rank: Super Contributor
timestamp: October 15, 2014, 04:50:41 am
content: Check what the stm32 spi clock is running at. Your never going to get more than what the spi port can clock out

author: ice111
author_rank: Newbie
timestamp: October 15, 2014, 05:16:04 am
content: I managed to solve the 512 bytes transfer!I am clocking my SPI with my STM at 2MHz(I am using C# .NEt application suing D2xx library from FTDI)Is there anyway to speed up my data receive???I am using a thread to read FT_Read continuously with 1ms timer, i should be reading data for 1000 times, but when I add a counter in FT_READ thread i am only able to get 500 times..If I add a delegate to process the data, my receive counter will drop to 300 times...May i know how can I speed up the process??

author: Psi
author_rank: Super Contributor
timestamp: October 15, 2014, 07:09:08 am
content: A quick look at the signal with a scope should tell you why its slower than it should be.
FTDI Programming Issues - Page 1
Forum section: electronics / projects

author: physiii
author_rank: Newbie
timestamp: June 28, 2016, 01:49:31 pm
content: I am having trouble programming through USB. I can read data from the port fine, problem is, I can not write to the microcontroller unless an external programmer is also attached to TX and RX (see attached pictures). With that attached I can read and write through the USB.I would like to fix this in the next revision, can someone help me out?Thank youphysiii
FTDI website shop - where usable? - Page 1
Forum section: electronics / projects

author: peter-h
author_rank: Super Contributor
timestamp: December 12, 2022, 05:30:32 pm
content: They have an online shophttps://ftdichip.com/products/ft230xq/which gives reasonable pricing!But no way to use it, apparently, from the UK. Has anyone tried it?There is no way to contact FTDI, although I do have an email from separate comms, and they tell me to contact distis.

author: Karel
author_rank: Super Contributor
timestamp: December 12, 2022, 05:56:30 pm
content: Quotehttps://ftdichip.com/corporate-profile/

author: peter-h
author_rank: Super Contributor
timestamp: December 12, 2022, 08:34:55 pm
content: and...?

author: Buriedcode
author_rank: Super Contributor
timestamp: December 12, 2022, 11:00:54 pm
content: Seems to be working fine for me - you have to register to add things to your basket, but the website looks like pretty much every other one.What browser are you using?

author: peter-h
author_rank: Super Contributor
timestamp: December 13, 2022, 02:08:39 pm
content: I suspect the shop is not for EuropeAnyway, mouser.com has stock at the same prices as this FTDI "shop", and the franchised disti price is also the same. I bet the FTDI distis are really pleasedBut they had a great run last 2 years, extorting an extra £1 per FT232 chip.
FT232H GPIO access using VCP driver - Page 1
Forum section: electronics / projects

author: brumbarchris
author_rank: Regular Contributor
timestamp: February 20, 2024, 10:27:31 am
content: Hello all,I am using one of the FTDI C232HD USB 2.0 HI-SPEED TO UART CABLE.The schematic of this cable indicates the Q1 P-FET on the VCC line, which can be used to cut off the supply to whatever device is supplied from this cable. This transistor is controlled by the ACBUS9 pin of the FT232H IC on which this cable is based.I would like to control this pin so that I can programatically cut off power to the device I use. Do you know if this can be doneusing the VCP driversand UART operating mode? (I do not control the software on the PC side, which is done by another "entity"; so using the D2XX drivers is not an option).I know that with a one-time use of FT_PROG I can configure the ACBUS9 pin to operate as a GPIO and the following statement exists in the FT232H datasheet:QuoteHowever, this statement is not clear whether operating this pins as GPIO mode while the UART interface is being used is possible using the D2XX drivers only, or if it can be done using VCP too (anything I write to the COM port would be transparently transmitted further by the FTDI chip, I do not know how to send commands to the FTDI chip itself using the VCP driver only).Regards,Cristian

author: PCB.Wiz
author_rank: Super Contributor
timestamp: February 20, 2024, 04:14:00 pm
content: I think the normal usage is to operate as PWREN# which is low when the port is open() and high when closed()Is that enough control for you?

author: brumbarchris
author_rank: Regular Contributor
timestamp: February 21, 2024, 07:40:27 am
content: Thanks for the reply. This helped a lot!I found out the pin was already configured as PWREN#, but I had to enable the selective suspend feature in the option drivers, in order to get any reaction from it.Regards,Cristian
Fuel injection the old school way (but not too old) - Page 1
Forum section: electronics / projects

author: poptones
author_rank: Frequent Contributor
timestamp: November 20, 2012, 11:04:45 pm
content: This last weekend we had the first Formula One event in the states in many years. They even built a shiny new track for the event outside Austin Texas. I guess because car racing was on my mind, and a little because it seemed fun, I thought I'd share the basics of a fuel injection system I designed many moons ago.

author: Baliszoft
author_rank: Frequent Contributor
timestamp: November 20, 2012, 11:22:39 pm
content: Wow! Cool!

author: jeroen74
author_rank: Frequent Contributor
timestamp: November 21, 2012, 07:44:46 am
content: This is how electronic fuel injection controllers were implemented in the early 70s/80s, like some versions of L-Jetronic.
Fujitsu FMM5515ZET - Page 1
Forum section: electronics / projects

author: HalfSpace
author_rank: Regular Contributor
timestamp: November 29, 2014, 01:17:55 am
content: Hi Guys,I have some Fujitsu FMM5515ZET ICs and looking for a datasheet on them. I think it’s a LNA (Low Noise Amp) for RF work. Tried the web with no luck, any information or datasheet would be much appreciated.HalfSpace
full bridge Class-D amplifier idle losses - Page 1
Forum section: electronics / projects

author: poorchava
author_rank: Super Contributor
timestamp: August 13, 2018, 07:52:13 am
content: Hey,I'm designing a class-D amplifier, although not for audio, rather for generating specific signals with high power (~1.5kW) for measurement purposes. I have a simple question, to which I was not able to find answer.Does the power loss associated with reverse recovery occur when there is no load? I have taken into account stuff like tr/tf losses under load, Coss losses regardless of load, conduction losses under loas and so on, but calculations don't seem to match the reality or spice simulations.On the side note, for the sake of calculations can I assume that a single branch of a full bridge in class-d operates like a normal buck converter?
Full bridge converter rectifier - Page 1
Forum section: electronics / projects

author: Drirr
author_rank: Regular Contributor
timestamp: May 14, 2022, 02:46:59 pm
content: Hi,I am working on DC-DC full bridge converter from 48V to approx 300V/1A . I would like to avoid two secondary windings because of capacitance. Is there any reason to avoid full bridge rectifier and one inductor? Is 2x diode drop only reason?ThanksDavid

author: Benta
author_rank: Super Contributor
timestamp: May 14, 2022, 04:08:20 pm
content: Quote from: Drirr on May 14, 2022, 02:46:59 pmBasically yes. At 1 A power dissipation isn't an issue. You'll need snubbers on the four rectifiers.
Full-bridge motor/coil driver recommendations with external sense resistor - Page 1
Forum section: electronics / projects

author: uer166
author_rank: Super Contributor
timestamp: December 31, 2019, 12:59:49 am
content: Does anyone have any good single or (ideally) dual full-bridge driver recommendations? Requirements are:200mA drive at 3.3V-9V voltage input rangeCan support external current sense resistor (important)Does NOT do any constant-frequency (e.g. TI DRV8833), or constant-off time (e.g. DRV8833C) current regulation from external resistorEither does cycle-by-cycle current regulation, basically re-setting output at current limit and re-enabling at new PWM input rising edge, OR:Does not do any current regulation, but still supports external current sense resistorThe issues with these requirements that I found:Plenty of ICs do current regulation with the external sense resistor which I don't wantPlenty of ICs don't do any current regulation, but they don't support shunt resistor explicitly. I'd be scared of putting a shunt resistor in GND reference path since that would shift the control voltages into negativesWhat I'm trying to do is bipolar excitation of an inductor into saturation at around 5KHz, that external resistor is there to detect the saturation and also as sensor feedback. Are the above requirements mutually exclusive? Sounds like I really want a simple (low) power stage instead of a fully integrated motor driver. Don't want to go discrete either since the current solution is a mess of FETs/BJTs.

author: langwadt
author_rank: Super Contributor
timestamp: December 31, 2019, 01:44:31 am
content: the ancient L298? hough the voltages are a bit lowas for putting a shunt resistor in GND reference path, if you keep the sense voltage less than a diode voltage you might stay within spec of most ICs

author: uer166
author_rank: Super Contributor
timestamp: December 31, 2019, 01:49:49 am
content: Quote from: langwadt on December 31, 2019, 01:44:31 amI need something like 0.5V of range, outside of diode voltage. I think it may still work with current limiting resistors in the signal paths but still sketchy.
full schematic for modern dual function generator (siglent, rigol, etc) - Page 1
Forum section: electronics / projects

author: SArepairman
author_rank: Frequent Contributor
timestamp: April 23, 2015, 12:35:02 am
content: I am looking for a recommendation on a full dual function generator that is sold as reasonable lab equipment to plagiarize the analog front end of.I need a function generator that can go up to 5-15MHz and has dual outputs.I basically need a lab tool that can phase shift two sine/triangle waveforms (and have all the FG adjustments). But this lab tool would be used infrequently. I figure so long I don't want to pay for the bells and whistles I can make the analog front end fairly cheap (for a machine that normally costs 2000$+) and then program a micro controller to configure the DDS chip, I just need to test a few patterns.I assume that rigol uses one of those AD dds chips, I just want a tried and true build around them with no guess work. I don't want to design a function gen, but I need this capability to test another project and determine if its needed in another project.

author: nctnico
author_rank: Super Contributor
timestamp: April 23, 2015, 01:01:23 am
content: Someone beat you to it:www.ebay.com/itm/121478483178There are cheaper versions with a lower maximum frequency.

author: SArepairman
author_rank: Frequent Contributor
timestamp: April 23, 2015, 01:39:55 am
content: oh yea, I would like 0.1 degree or better phase shift resolution. i sent the guy on ebay a PM to find out what the resolution of that unit is.1 degree wont cut the mcustard here.
full wave rectification with mosfets (LT new part) - Page 1
Forum section: electronics / projects

author: M. András
author_rank: Super Contributor
timestamp: September 25, 2013, 08:34:51 pm
content: http://www.linear.com/product/LT4320#overviewjust bumped into this. are there any other similar solutions to save power on diode bridges when you want to use higher currents from a transformer etc? or anyone succesfully made a fullwave rectifier with fets?the control chip and 4 fair priced fets are way more then lets say a 50A diode bridge but the difference in power dissipation is amazing which means no need for a big ass heatsink just for a rectifier

author: JeanF
author_rank: Regular Contributor
timestamp: September 25, 2013, 09:08:48 pm
content: Hello !There is a recent thread about this chip :https://www.eevblog.com/forum/beginners/a-niche-chip-for-mains-powered-ac-gt-dc-'linear'-based-psu/hope this helps,all the best

author: M. András
author_rank: Super Contributor
timestamp: September 26, 2013, 03:07:08 pm
content: hehh thanks totally missed that thread
Fume extractor - Page 1
Forum section: electronics / projects

author: Charlie86
author_rank: Regular Contributor
timestamp: December 02, 2017, 03:00:08 am
content: Hi,Does anybody here hava made decent fume extractor. Not just fan with some small filter, but something like Weller zero smog. If someone have good DIY please share it. I found this one, which is good but I am looking for something more professional,..Thx
Fume extractor automatization - Page 1
Forum section: electronics / projects

author: dodo911
author_rank: Newbie
timestamp: July 12, 2025, 12:52:01 am
content: Hi, I'm trying to automate a fume extractor using a relay controlled by an Arduino. I have a JBC soldering station clone, and I want the fume extractor to turn on only when I'm using the soldering iron.In the soldering iron holder, the metal part is connected to a 2.5V weak pull-up resistor, and the C245 tip is connected to protective earth (PE).Can I simply connect PE to the Arduino's GND and then read the 2.5V signal? Or is there something potentially dangerous about this approach?

author: macboy
author_rank: Super Contributor
timestamp: July 13, 2025, 07:31:22 pm
content: I solved this using one of those "green" power bars. My soldering iron goes to the master/control AC socket and my fume extractor and a couple task lights go to the switched sockets. It is a low cost, off the shelf solution that doesn't involve connecting an Arduino or whatever anywhere near mains. The power bar has an adjustable threshold and can be set to turn off when the iron is in the stand and idling (Metcal auto sleep stand), but I choose to have it run continuously when the iron is powered.

author: thm_w
author_rank: Super Contributor
timestamp: July 16, 2025, 09:54:08 pm
content: I would also recommend green power saving power bar, can be bought for $10-15. This way you will never leave the soldering iron on.But if you did want to use the arduino, you can connect to PE and read the signal. I would use some series resistor and capacitor for filtering, maybe diode or TVS for esd protection.
fun looking trace on PCB - Page 1
Forum section: electronics / projects

author: JBeale
author_rank: Frequent Contributor
timestamp: March 23, 2021, 10:05:46 pm
content: I guess the squiggly traces may be a pair of "meander line" antennas. This is a wifi module from an Epson inkjet printer model WF-3620. Anyway, just thought it was a fun design!

author: Anders Petersson
author_rank: Regular Contributor
timestamp: March 24, 2021, 10:39:16 am
content: Very funny-looking indeed! Must be developed by simulated evolution or something...?Also interesting to see how they made a uFL connector optional without affecting the RF path much, with two presumably zero-ohm resistors as jumpers.

author: ch_scr
author_rank: Frequent Contributor
timestamp: March 24, 2021, 11:07:24 am
content: Even more funny is that these modules are connected over usb - only difference is they have to be supplied with 3.3V, not the usual usb 5V. A smd linear reg works nice.The module in question even has drivers for windows!Pinout from center to edge of the pcb is: 3.3V, USB D+, USB D-, Gnd, Gnd

author: tszaboo
author_rank: Super Contributor
timestamp: March 24, 2021, 12:02:05 pm
content: This is a so-called Gosper fractal antenna.It looks to me a very silly design choice, as it should be used if you want a high bandwidth antenna. The fact that they used a second one for antenna diversity tells me that it also doesn't work as expected.

author: ThomasDK
author_rank: Regular Contributor
timestamp: March 24, 2021, 12:57:02 pm
content: They even decided to patent it:https://patents.google.com/patent/US20080084352

author: Anders Petersson
author_rank: Regular Contributor
timestamp: March 31, 2021, 10:02:00 am
content: Quote from: Anders Petersson on March 24, 2021, 10:39:16 amOff-topic: I've since read that zero-ohm resistors still exhibit inductance and capacitance, so they might still affect the RF path.

author: temperance
author_rank: Super Contributor
timestamp: April 01, 2021, 12:40:42 am
content: Some interesting reading about SMD resistors:Source:https://www.vishay.com/docs/60107/freqresp.pdf
Fun: RGB LEDs for my bathroom - Page 1
Forum section: electronics / projects

author: El_Zog
author_rank: Newbie
timestamp: September 25, 2011, 05:36:55 pm
content: Hi,I had for a couple of years, an old IKEA lamp in my bathroom. There is also another light on a wall, so this one was not really usefull. When i found on ebay and other sites some chineese vendors that propose cheap power RGB leds.. I thought, well, why not ?I like the big polished glass diffuser on the lamp, perfect for enhencing rgb color mixing and making diffusing light.First I wanted to do custom electronics, but when i found this:http://www.goodluckbuy.com/30w-rgb-ip67-waterproof-led-light-driver-ac85v-265v.htmlWell.. It's supplied with a remote, not expensive... I have a lot of other project's, so, well, this one toke about 15 minutes to be ready.I waw planing to use 3x10W RGB LEDs, but one was defect, so it's actually working with two. A third will come, even if the actual power is more than enoughPhotos:The old lamp:The parts:The result:Quite easy, but fun ! It cost me about 25€ and just take a few minutes to assemble ^^

author: Psi
author_rank: Super Contributor
timestamp: September 25, 2011, 11:56:52 pm
content: If RGB led lighting is the only light source you have in the room try this, its quite trippy.Put 3 coloured objects on a bench in the room red,green,blue. Or you can just locate objects of these colours on shelves in the room. (Try to get/find objects as pure to their colour as you can, red object that looks like a pure red in normal light etc).Now look at the objects and change your led lighting colour between red, green and blue.You will notice that the objects turn from brightly coloured to completely black when you change the lighting colour away from their colour.

author: Zero999
author_rank: Super Contributor
timestamp: September 26, 2011, 04:16:20 pm
content: Is it bright enough to light the whole room when all the LEDs are on?Do you have any other lighting in the room?Have you considered adding a couple of extra white LEDs?Even if it's bright enough, the colour rendering will be poorer from an RGB LED than a broad spectrum white LEDs.

author: IanB
author_rank: Super Contributor
timestamp: September 26, 2011, 05:37:51 pm
content: Quote from: Hero999 on September 26, 2011, 04:16:20 pmCheck the first post:Quote from: El_Zog on September 25, 2011, 05:36:55 pmThe LED light is not the main light, it is just for decoration.

author: El_Zog
author_rank: Newbie
timestamp: September 26, 2011, 07:02:08 pm
content: Yes, and the 6W of each color is plenty enough to light the whole room. The white is quite cold, but not bad at hall, can be used for normal lighting.
Fun with Jaycar's Dalek voice modulator kit - Page 1
Forum section: electronics / projects

author: vk3yedotcom
author_rank: Frequent Contributor
timestamp: November 13, 2020, 11:07:00 am
content: A couple of videos describing my mods to this kit for other applications.The first video is a speech inverter. That could have been used to decode simple types of voice scrambling.The second is a frequency shifter.There are potentially other uses not discussed, eg maybe a bat detector with the frequency shifter.
Fun with Linear datasheet decoding.... - Page 1
Forum section: electronics / projects

author: rx8pilot
author_rank: Super Contributor
timestamp: December 15, 2017, 05:15:50 am
content: I am hoping someone can help me understand what I am missing on this datasheet for a Linear LT3652 charger.Trying to layout a test circuit with this chip and the method to calculate the inductor does not appear to match the examples given.The formula to determine the inductor given in IMG-A.PNGValues used in the sample schematicRsense= .05 (50mOhm) Current senseICHG(max)= 2amps charge currentVbat(flt)= 8.3v Float voltageVIN(MAX)= 12v Max input voltageIMG-B.PNG is the sample schematic where the inductor is 8.2uHIt also shows the rather miraculous setup where 12 watts goes in and 16.6 watts comes out - it makes power I guess. Convenient for sureI did not get a number even in the ballpark of 8.2uH - closer to 1. This looks simple, but clearly, I am messing it up.http://cds.linear.com/docs/en/datasheet/3652fe.pdf

author: rx8pilot
author_rank: Super Contributor
timestamp: December 15, 2017, 06:24:01 am
content: Quote from: edavid on December 15, 2017, 06:09:07 amAs I sit here staring at the data sheet....I see this. IMG-C20v max - ripple at 30% = 8.1uHDamn sneaky details. Thanks for taking a look. Still trying to figure out the 120% efficiency, lol.

author: ConKbot
author_rank: Super Contributor
timestamp: December 15, 2017, 02:33:03 pm
content: "Vin_reg loop servos maximum charge current to prevent AC adapter outlet from drooping lower than 12v"The charger will just thrash on the adapter for all it's worth while keeping it pulled down to 12v. Given that it will be power limited at 3v/cell (less after efficiency takes it's toll) calling that 2A output with that adapter is a tad dubious. But its peak output current will indeed be 2A for a small bit of the charge, and they aren't making the final product, just showing off one of its capabilities of that IC. The circuit will still run fine when the beancounters "value engineer" the wallwart from a nice 1.5A unit down to a 1A unit.
Fun with PWM filters, voltage dividers and LED drivers - Page 1
Forum section: electronics / projects

author: philpem
author_rank: Frequent Contributor
timestamp: April 21, 2014, 09:18:48 pm
content: Here's a fun one...I'm putting together a two-output LED driver using the On Semiconductor NCP5007 boost converter:http://www.onsemi.com/pub/Collateral/NCP5007-D.PDFPower supply is 5V, and there's a PIC driving the enable pins (individual) and a common PWM signal. The application circuit is identical to Figure 29 in the datasheet (page 16); I've attached a schematic from my LTSPICE modelling attempts.What I'm having trouble with is figuring out how they came up with the resistor divider values (R2 and R3 in my schematic) and figured out the requirement for 95% duty cycle to fully dim the LED with a 3V 5kHz PWM signal on the "PWM" line. I need to check that the resistor values still hold for a 5V supply, and if not, recalculate them for a similar PWM range.The voltage at FB is held constant at 200mV by the current regulation loop. What changes is how much the PWM contributes to this 200mV, and by extension how the LED current changes.So far I've tried modelling the circuit as a potential divider (R1 as the "resistor to Vin", R2+R3+R4 as "resistor to GND") and ignored the 100n capacitor, but my results don't match up with LTSPICE. In fact, they're not even close... What am I missing?Thanks,Phil.

author: dannyf
author_rank: Super Contributor
timestamp: April 21, 2014, 09:47:03 pm
content: R1/C1 form a low pass filter that, with the pwm signal, generates an analog output which is summed, through r3/r2, with the voltage drop over that 10ohm resistor.effective, for a given duty cycle, the controller adjusts its output voltage so that the voltage at the fb pin remains 200mc.

author: philpem
author_rank: Frequent Contributor
timestamp: April 21, 2014, 10:21:21 pm
content: Quote from: dannyf on April 21, 2014, 09:47:03 pmI figured out that much -- the problem is the summing junction and sense resistor also seem to load down the filter, which means my calculations mean precisely bunk.In that example, V1 is set to 100% duty, or a theoretical 3V at the "AV" (average) node. In actual fact, there's 374.79mV there.If I assume R1 forms a voltage divider with R2+R3+R4, I get:V(AV) = 3.0 * ((R2+R3+R4) / (R1+R2+R3+R4)) = 282.7mV (an error of about 25%!)Looking at it again as a divider formed by R1 and R2, with the low end of R2 held at 200mV:V(AV) = 200mV + ((3V - 200mV) * (10k / (150k+10k))) = 375mV (ah ha!)Which now leaves me to solve for V(R4). SPICE says that's 102.02mV... which I think means I need to invert the solution for the resistor divider based on the fact that I want the ground offset but know the value of the "input" and "output" voltages (top and midpoint)... I'll have to look at the maths for this.
Function Gen Project - Page 1
Forum section: electronics / projects

author: flano
author_rank: Contributor
timestamp: September 22, 2012, 12:55:27 am
content: Hi,I have been working on this project for while and would be interested to get the opinions of some of the more experienced forum members on the analogue part of the circuit and the layout as I'm very much a beginner in this area.The design has 2 boards, a front panel with LCD and touch controls, and the function gen board which will plug into the front panel. I have not yet ordered the PCBs.Please let me know what you think. All of the design is open source.Thanks Mike

author: notsob
author_rank: Frequent Contributor
timestamp: September 22, 2012, 01:21:06 pm
content: AS a reference, here is how someone else made onehttp://www.electronics-lab.com/projects/test/013/index.html
Function generator - inductor WTF - Page 1
Forum section: electronics / projects

author: c4757p
author_rank: Super Contributor
timestamp: September 27, 2013, 01:53:15 am
content: This is a pretty bad copy of a schematic (3312A), so at first glance, I saw this inductor, and my first thought was "0.47 uH? Well, that's a bit small, I guess, but it kinda makes sense..."But then I found it in the parts listing...Yes, that says 0.0000004 uH. As in 400femtohenrys. And yeah, that kinda looks like a "p", as in 0.47 picohenry.Huh? Is this a misprint that somehow carried through to both schematic and listing?A 470 fH inductor would be a 9 micrometer long piece of 16 gauge wire...

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: September 27, 2013, 02:19:01 am
content: Hi,I am sure the schematic is correct and the parts list is wrong.I found the same part 9100-3548 is used 85662A spectrum analyzer display.In that part list it is described as 470nH.Jay_Diddy_B

author: c4757p
author_rank: Super Contributor
timestamp: September 27, 2013, 02:20:09 am
content: Ha, yeah, I eventually found it by searching for the part number. I knew it wasn't 470fH! But it still threw tired and stupid me for a loop

author: amyk
author_rank: Super Contributor
timestamp: September 27, 2013, 10:37:57 am
content: I'm guessing the U should be a 7; 0.00000047H is right.
Function of this diode....image included - Page 1
Forum section: electronics / projects

author: xwarp
author_rank: Frequent Contributor
timestamp: December 23, 2019, 04:09:09 pm
content: I'm drawing a blank on the function of the diode, but I'm going to guess it's suppose to help turn the transistor off?So the open end of R3 has a either a low input, or, +5 via a pullup. VDD is +24 vdcWhen the circuit it "on", it provides +24 vdc from VDD through the collector to another circuit.Help me remember what I've forgotten, or, what I never knew.....lolThanks!

author: GromBeestje
author_rank: Frequent Contributor
timestamp: December 23, 2019, 04:44:24 pm
content: What kind of load is this circuit supposed to drive?If it is some inductive load, it might be a flyback diode. If you remove the power from an inductive load it will generate a voltage in the opposite direction. A flyback diode will allow that surge to be dissipated. Otherwise it will blow up your transistor.

author: Nusa
author_rank: Super Contributor
timestamp: December 23, 2019, 04:50:10 pm
content: Generally it's there to protect the transistor from feedback. In some transistors, it's integrated in the transistor package.

author: graybeard
author_rank: Frequent Contributor
timestamp: December 23, 2019, 05:36:22 pm
content: If the base-collector junction becomes forward biased by a difference in the collector voltage and vid the diode will turn on preferentially since it has no external series resistance and prevent and significant current flow in the base-collector junction. However since the entire circuit is not show it may be there for other reasons.

author: xwarp
author_rank: Frequent Contributor
timestamp: December 23, 2019, 10:16:56 pm
content: I unfortunately do not have the schematic for the circuit this output supplies.The input of the circuit that the VDD output goes to begins with several resistors. I believe to be essentially voltage dividers, so essentially a resistive load.
Function of zener diode on inverter input? - Page 1
Forum section: electronics / projects

author: drummerdimitri
author_rank: Frequent Contributor
timestamp: August 20, 2021, 08:28:58 pm
content: I took apart my Meanwell TS-400 true sinewave inverter out of curiosity and found a small zener diode connected in parallel to the 12V DC input.What could be the purpose of this diode in such a configuration? Is it to provide a voltage drop across the input for the low voltage cut-off of the inverter?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 21, 2021, 04:28:06 am
content: Transients. Hopefully it's big enough that it doesn't blow out before the fuse does, under extreme conditions (reverse battery, high voltage jumpstart, load dump).Tim

author: drummerdimitri
author_rank: Frequent Contributor
timestamp: August 21, 2021, 07:51:38 am
content: Quote from: T3sl4co1l on August 21, 2021, 04:28:06 amUpon closer inspection, it seems that the glass surrounding it has cracked for some reason.What should I replace it with? I've never worked with zener diodes and not sure what specs I should look for.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 21, 2021, 08:32:31 am
content: I'd just remove it, and inspect other things for overvoltage.What, does it still work? So it blew open indeed? Well, there you have it?...I see in the product spec, no particular automotive immunity standards, certainly not ISO 7637-2 or the like anyway. Indeed without any spec, it's hard to see why they bothered to put anything there at all...For a recommended replacement, a nice beefy 1.5KE15A is probably an alright start. It won't withstand surges much better, but has a better chance of clearing the fuse when it does fail. There are much bigger TVSs rated for automotive load dump, but they are rather pricey, and you might not ever really need that level of protection, so, eh. A modest sized TVS like this, should be alright against stuff like inrush surge, and motor and ignition transients.I might also simply recommend operating it off a battery+charger directly, without sharing it with any automotive systems, if this is indeed an automotive context. It's simply not rated for the voltages present in most vehicles.Tim

author: drummerdimitri
author_rank: Frequent Contributor
timestamp: August 24, 2021, 04:35:23 pm
content: Quote from: T3sl4co1l on August 21, 2021, 08:32:31 amI tested the Zener diode and it was indeed damaged so replaced it with a 1.5KE15A TVS diode as you suggested and the unit still works perfectlyDon't have the intention of using it on anything except battery power so I could have easily done without it but as I had a couple laying in my parts bin, I decided to install it anyway.
FunJa Weather Station - use screen with own PCB? - Page 1
Forum section: electronics / projects

author: LC333
author_rank: Newbie
timestamp: January 02, 2023, 09:46:03 am
content: I've recently got a FanJu made weather station with colour LCD, these can be had quite cheaply and come in various brands. The screens and case are particularly good with room inside but they don't come with the most accurate sensors and some don't allow setting relative pressure. So I'm thinking for a little project and learning exercise to get rid of their internals but use the LCD using my own design/software with a microcontroller. I'm pretty experienced with microcontrollers and have done PCB designs before including wireless sensors, but never driven an LCD directly. So no problems designing a PCB to fit and interface with the zebra strip to the LCD, but I just need some confirmation I'm along the right lines with some design decisions.As can be seen from the picture of the internal PCB with CoB there are around 84 connections to the LCD and a rough count up shows the LCD has approx 160-170 segments (including the icons). I'm assuming this means it works with two back planes. I found some LCD driver chips NXP PCF8576C which interface to a microcontroller via I2C, these drive up to 4 back planes and 40 segments per plane if I understand correctly, so I would need two of these chips (they can chain together) to support addressing 80 segments over 2 back planes.Does this sound suitable, am I along the right lines?

author: LC333
author_rank: Newbie
timestamp: January 04, 2023, 09:34:30 am
content: Okay after doing a bit more research I think PCF8576C chip will do the job and I've seen a few examples where these chips have been used to drive LCD displays. I've got a couple of the chips on order and just need to design and order a PCB with the pads correctly spaced to interface with the LCD panel and with the chips on. As I have no idea of the pinout on the LCD panel and which connection drives which segment and which are the back plane pads, I will build a test board that will allow me to wire up each pad to each pin breadboard style using jumpers. Once I know it works and what goes where I can design a PCB.Will be a few weeks until I have the test board so will feed back then if it works or not.
Funny Robotic Project I've Been Working On - Page 1
Forum section: electronics / projects

author: DonEduardo
author_rank: Newbie
timestamp: December 06, 2014, 09:15:26 pm
content: Here's a funny little robot I built with Roomba wheels and various miscellaneous parts. It started as just a challenge for myself but now I've grown fond of the little guy. Can't decide if he's male or female though. I refer to it as "he", my wife calls her "she" and puts bows in her hair. Hope you enjoy:http://youtu.be/O-tMkmGyhYA

author: IO390
author_rank: Regular Contributor
timestamp: December 06, 2014, 09:36:38 pm
content: That's cute. Reminds me of the robot from "Short Circuit".

author: Tinkerer
author_rank: Frequent Contributor
timestamp: December 07, 2014, 06:51:16 pm
content: That is a funny little robot. Something is so amusing about how the head is moving around. Dont think I have seen anything quite like that for the head movement on any commercial toy robot. Would make a great toy though.

author: DonEduardo
author_rank: Newbie
timestamp: December 07, 2014, 07:16:18 pm
content: Thanks for the comments! I did spend some time trying to get the head movements to flow. Just a tad faster or slower and everything seemed to change. How fast he looks up compared to how fast it moves back down all seemed to make a difference.That head jerk when I first turn him/her on though is not mine. I think it's the Propeller booting up. Perhaps I need to not power the servos until everything is up and running.I want to get him to self dock like the Roomba's do. I've been reading up on how the infrared signals work on them.
Fuse 1500VAC 4A to 9A - Page 1
Forum section: electronics / projects

author: geggi1
author_rank: Frequent Contributor
timestamp: April 10, 2024, 01:08:05 pm
content: HiI got a project working with 1500VAC and 4,5A to 9A.For this project I'm looking for some fuses capable of 1500VAC but the only thing i can find is 1500VDC photovoltaic.Fuses designed for distribution transformer protection is not suitable because they are to large and to slow.I'm looking for something that is 10 to 15mm thick and 85mm to 150mm long. Also fuse holders.It is going to be panel mounted and personnel will not have access to the fuses when energized.Please come with reccomandations.

author: mag_therm
author_rank: Frequent Contributor
timestamp: April 10, 2024, 07:05:23 pm
content: From my experience this will be difficult.If in EU search for 'GS Semiconductor fuses' ' IEC269 -IV'If in USA try 'Norberg~IES 4237 South 74th East Avenue Tulsa, Oklahoma 74145'But I did not see any small fuses above 1000/1200 Vac.You might put RFQ to one of these, or similar providers.Provide the the fault level and type of bus protection upstream.

author: Terry Bites
author_rank: Super Contributor
timestamp: April 15, 2024, 03:41:24 pm
content: I'd check out SIBAhttps://siba.de/en/products/fuse-detector/fuse-detector.html?fdf=Sem.Cond.Prot.+Fuse-LinkThe product selector page lists by part number. You have to work hard to find their product pages in amongst a forest of PR wankery.Crap Site SIBA!!

author: Zero999
author_rank: Super Contributor
timestamp: April 17, 2024, 09:28:39 am
content: Quote from: geggi1 on April 10, 2024, 01:08:05 pmUse photovoltaic fuses. If the fuse can break 1500VDC, then breaking 1500VAC won't be a problem. It's much more difficult to break DC, than AC.What breaking capacity do you require?

author: Gyro
author_rank: Super Contributor
timestamp: April 17, 2024, 10:51:06 am
content: Quote from: Zero999 on April 17, 2024, 09:28:39 amYes, the breaking capacity (prospective fault current of the source) is an extremely important parameter.

author: jonpaul
author_rank: Super Contributor
timestamp: April 17, 2024, 11:01:04 am
content: Get catalog and site for old USA fuse firls:littlefusebussmanj
Fuse box for testing? - Page 1
Forum section: electronics / projects

author: mkiijam
author_rank: Regular Contributor
timestamp: December 22, 2023, 10:21:18 pm
content: Has anybody come up with a "FUSE" meter / dummy load but with the idea that you clip it into an existing fuse holder and then can set it to whatever current you want. Some sort of "Smart Fuse"?
Fuse corrosion - Page 1
Forum section: electronics / projects

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: November 07, 2024, 01:44:30 am
content: I found a ~1960s-era Grundig TK79U reel to reel tape machine while thrifting. Inside is a bit of a mystery, why is only one fuse corroded?Like really just the fuse, the holder seems uninterested in whatever the fuse is doing.And the other fuse is fine.The machine is clean and dry, not even a musty smell.

author: coppercone2
author_rank: Super Contributor
timestamp: November 07, 2024, 02:55:03 am
content: I think that green is nickel. Maybe the fuse holder is tinned and the fuse is nickel plated.That is just my guess, because the fuse holder is bendy, they don't like putting nickel on stuff that flexes alot, its stiff. Fuse holders deform alot when you insert a fuse compared to alot of other contact things.But they do have nickel plated fuse blocks, so i don't know. You can get nickel plated brass or tin coated copper alloy commonly for fuse holders

author: ebastler
author_rank: Super Contributor
timestamp: November 07, 2024, 07:22:16 am
content: Where are those fuses in the circuit? Could it be the case that one of them sees AC, the other DC (or rectified AC)?

author: factory
author_rank: Super Contributor
timestamp: November 07, 2024, 01:51:26 pm
content: This is a common issue with Grundig equipment of a certain age and some other makes from Europe, the corroded fuses & holders appear frequently on the UK vintage radio forum.Dissimilar metal corrosion is a thing.David

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: November 07, 2024, 02:37:17 pm
content: Yeah, must be different metal in the other fuse. Maybe consistency wasn't much of a thing back then.The unit still runs, that's the funny part.I guess I'll be joining a vintage radio forum soon!
fuse for primary or secondary? Is  mains breaker will be ok for LOW voltage app? - Page 1
Forum section: electronics / projects

author: 001
author_rank: Super Contributor
timestamp: November 22, 2018, 04:03:15 am
content: Hi!I use 2x24vac@20a transformerWhat the best way to add fuses? Primary or secondary windings?Can I use automatic mains breaker like this in LOW voltage secondary?

author: Ian.M
author_rank: Super Contributor
timestamp: November 22, 2018, 05:28:22 am
content: As long as its before a full wave rectifier so it only 'sees' AC it will work safely, but if its a thermal or thermal-magnetic breaker, the voltage drop across its series heater element at full load current may be excessive - what's acceptable as a percentage drop from a 240V supply, is probably *NOT* going to please you when the same voltage drop is a ten times higher percentage of a 24V supply.*NEVER* use an AC mains breaker for DC!Rare Exception: Unless it actually has a DC rating and type approval.

author: 001
author_rank: Super Contributor
timestamp: November 22, 2018, 05:37:39 am
content: Quote from: Ian.M on November 22, 2018, 05:28:22 amYeaI`m understand itThe main question is minimal breaker coil voltage drop at rated current and timeAnd breakers off not at rated currents but at x2 x3 overloadHow to select right nominal range?

author: Ian.M
author_rank: Super Contributor
timestamp: November 22, 2018, 05:53:11 am
content: Consult its datasheet!

author: David Hess
author_rank: Super Contributor
timestamp: November 23, 2018, 03:26:15 am
content: There should always be a fuse on the primary side to handle transformer shorts which can otherwise be very bad news.A fuse on the secondary side is optional. The only time I commonly see this included is *after* the big input filter capacitors when used in combination with a crowbar circuit.

author: Siwastaja
author_rank: Super Contributor
timestamp: November 23, 2018, 06:55:22 am
content: Many transformers have internally fused primary, and they don't absolutely require an input fuse - consult the datasheet. If it says nothing about this, an external fuse is a very good idea. Estimating the inrush current may be difficult if not specified; a slow-blow fuse should be used, and you can try finding the lowest value which doesn't blow.
fuse help - Page 1
Forum section: electronics / projects

author: grifftech
author_rank: Frequent Contributor
timestamp: May 22, 2015, 01:38:24 am
content: I need a .8-.9 amp fuse for a project but only have .7 A and .4 A fuses can I just bodge 2 .4 A fuses in parallel I intend to draw about 750 ma continuous

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: May 22, 2015, 01:43:45 am
content: No, they wont share current evenly.Fuses aren't that accurate anyway. They are also temperature dependent.with current at 1.1 times the rating it might take minutes to blow.They are only really to protect the pcb tracks, wires and prevent fire.If you need such a high level of discrimination then some sort of current sense or even reed relay.Otherwise try the 0.7 or then go to 1 amp, or buy online.

author: grifftech
author_rank: Frequent Contributor
timestamp: May 22, 2015, 02:48:20 am
content: my fuse bodge is working

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: May 22, 2015, 07:47:16 am
content: good luck.Here are some others you may like to try.

author: OC71
author_rank: Contributor
timestamp: May 22, 2015, 08:02:08 am
content: @ Hacked FridgeMagnet,Do you have a chart for wrench size versus amps?

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: May 22, 2015, 08:55:24 am
content: No need for more detail than this.If you want 2600 amps just a nail in parallel with an 11mm wrench.