hybridfree/eevblog-posts huggingface dataset:
Nvidia GTX 690 10 Phase Power Supply - Page 1
Forum section: electronics / projects

author: Lance
author_rank: Frequent Contributor
timestamp: May 01, 2013, 06:59:38 am
content: I was just browsing around the nvidia site looking at specs for the current set of cards, and apparently the GTX 690s have a 10 phase power supply:Here's the page it's listed on, go to the internals tab:http://www.geforce.com/hardware/desktop-gpus/geforce-gtx-690/product-demoWhat I can't figure out is why they're doing that. It would give you a very low ripple power supply, but would it not be simpler to use traditional filtering techniques?I also imagine having all that extra switching gear on board would generate a bit of EMI.Does anyone have any insight into this? I thus far haven't been able to find anything on google.

author: Rerouter
author_rank: Super Contributor
timestamp: May 01, 2013, 08:00:49 am
content: i believe it is primarily to keep to cheap lower current DC-DC converters as opposed to 1 big one, that or it could well be as you say to get the output ripple and response much better than a single chip solution is capable,or another spin, it could tie in with the power savings modes, that the efficiency is higher over the full range by only enabling phases as needed,

author: SeanB
author_rank: Super Contributor
timestamp: May 01, 2013, 10:24:39 am
content: Multiphase supplies also have a much reduced ripple, as well as allowing a faster loop response, as they tend to use much lower values of output capacitance. Very good in a GPU which can go from low power ( 20W) to 200W in a single 100MHz clock period, and which have a supply voltage that needs to be maintained within a very tight tolerance as well, as well as varying according to load.

author: Fsck
author_rank: Super Contributor
timestamp: May 01, 2013, 11:23:04 am
content: It also spreads the power loss across (should be) more surface area, which should improve efficiency.

author: metalphreak
author_rank: Frequent Contributor
timestamp: May 01, 2013, 01:02:20 pm
content: The GTX 690 is also a dual GPU core card. There is probably 5 phases for each one.

author: free_electron
author_rank: Super Contributor
timestamp: May 01, 2013, 01:49:56 pm
content: Smaller inductors and smaller caps as each only handles 1/10 the total current.That, and low ripple.Modern cpu moderboards use 6 to 8 phases. Even tablets like the ipad use 4 to 5 phases for the core.

author: Lance
author_rank: Frequent Contributor
timestamp: May 06, 2013, 01:32:07 am
content: Very interesting. Does anyone know of any good books about power supply design? I want to learn more about this subject.
NVM problem - SLG47105 - Page 1
Forum section: electronics / projects

author: amintegia
author_rank: Contributor
timestamp: June 12, 2024, 01:24:19 pm
content: Hello,I am trying to use an SLG47105 integrated circuit through its module, SLG47105V GreenPAK DIP Adapter. The objective of this project is to have an operation similar to the example of use provided by the manufacturer, that of an electric screwdriver.Datasheet SLG47105:https://www.renesas.com/us/en/document/dst/slg47105-datasheet?r=1563736Example document for electric screwdriver:https://www.renesas.com/us/en/document/apn/cm-364-rechargeable-electric-screwdriver?r=1563736To apply this example of operation, I am downloading the NVM file of the example of the electric screwdriver from the GreenPAK software to program the registers of the SLG47105 through I2C using an ESP32.I have been able to apply this example in the module but I have encountered the problem that when I cut the power and restart the module, it loses the configuration that had previously loaded. I have been able to see that perhaps the influence has some register that directly influences the operation of the NVM, such as the address register F5. I have made tests touching this register but I have not seen any positive change. In addition, when setting the 1960 register, I2C reset bit with reloading NVM into Data, register (soft reset), to value 1 the module restarts after a certain time of operation, (15 seconds approximately).I would appreciate any help to try to solve this problem.Thanks in advance.
NX-305 Alarm Fob Repair - Page 1
Forum section: electronics / projects

author: ludzinc
author_rank: Unknown
timestamp: July 28, 2015, 12:39:14 am
content: http://ludzinc.blogspot.com.au/2015/07/alarm-fob-replacement.htmlTLDR;I swapped chips to make a cheap replacement home alarm fob

author: SeanB
author_rank: Super Contributor
timestamp: July 28, 2015, 07:45:30 pm
content: Centurion remotes are the same chip, and would work in your application. Cost $10, and you also can get the add on "beauty pack" which gives a selection of case colours and new silicone rubber keyboard button assemblies. I have done a chip swap on some to fix ones which had gone swimming, and the traces corroded off.Tip for longer battery life is to add a small tantalum capacitor across the battery connections. I generally use a small 4u7 to 22uf 16-25V tantalum cap, depending on whatever will fit the space, and which I can grab off a scrap PCB in the pile. Means a battery still will work even though it has really high internal resistance. Downside is the low battery warning period ( flashing led on button press) drops down a lot, so you do not get the usual month of flashing for low battery till no workie, more like 2 days a year later.
NXP Kinetis K60 MCU - Terrible Documentation [SOLVED] - Page 1
Forum section: electronics / projects

author: eecook
author_rank: Regular Contributor
timestamp: December 21, 2016, 09:12:12 pm
content: Hi All,I just got my FRDM-K64F Freedom devkit, I'm playing with Keil uV and getting acquainted with this MCU but the datasheet is just horrrible. In particular, the MCU is a MK64FN1M0VLL12. There is no well documented data on the clock operation and modes, for example. I have been googling like crazy and nothing.Does anybody out there can point to some useful documentation for this micro or the K64F family in general? Otherwise, I'll end up doing reverse engineering from the header files which I am trying to avoid.**UPDATE 1**Aparently this MCU used to be marketed by freescale (now NXP), and behold, the old datasheet looks way better. I'll leave the link in case somedoby else has this problem.Datasheet:http://www.nxp.com/assets/documents/data/en/reference-manuals/K64P144M120SF5RM.pdfNow, why the hell would NXP strip away valuable data and leave the user with a shitty incomplete datasheet? ArgggCheers,Simon.
NXP PCF-series I2C I/O expanders and repeated-start - Page 1
Forum section: electronics / projects

author: HwAoRrDk
author_rank: Super Contributor
timestamp: February 11, 2021, 10:01:35 am
content: I'm thinking of an application for the ESP32's ULP co-processor that will involve interfacing with an I2C I/O expander. The I2C support of the ULP isverylimited, but I think it will meet my needs. Basically, it has two dedicated processor instructions:I2C_RDandI2C_WR, which can only read/write 8-bits of data at a time, and make certain assumptions about the I2C slave it's talking to.One of the assumptions is in how it talks to the slave device. According to the ESP32 Technical Reference (section 31.6.2), the RD/WR instructions both generate a repeated-start after sending the slave address and register address.I'm wondering if this is compatible with NXP's PCF series of I2C I/O expanders. Looking at the datasheet of, for example, the PCA6408A shows (in fig. 8) that write commands don't appear to support the aforementioned transaction sequence. Reads do, however.Can anyone confirm that the PCF series definitely do not work with a repeated-start between register address and data? Or maybe they might?I know that the Microchip MCP23008 does support such operation, but I would be disappointed to be limited to that particular part.(BTW, what is up with NXP's I2C I/O expanders? Why do they have a zillion different parts that mostly all seem to do the same thing?)

author: Berni
author_rank: Super Contributor
timestamp: February 11, 2021, 11:53:01 am
content: That I2C repeated start is a messy subject.Some drivers use it, some don't. Some chips say in the datasheet they need it and actually don't care about it, some chips say they need it and actually do need it...etc some chips are implementing SMBus, or '2 wire bus' or something rather than the actual trademarked I2CIn my experience 90% of I2C chips don't care if you use a proper repeated start or a stop followed by start in its place, they work either way. But there are some rare chips that do care and will for example read back garbage if you don't use a restart.There usually are (sometimes difficult) ways of making your I2C peripheral use the right one. So id say just try it and see if it works, if not then try to manhandle the I2C driver into doing the right thing, or worst case take manual control and bitbang the I2C bus, its so slow anyway that you need to actually slow down bitbanging code with a bunch of delay to run slow enough for I2C spec.

author: HwAoRrDk
author_rank: Super Contributor
timestamp: February 12, 2021, 01:10:27 am
content: Quote from: Berni on February 11, 2021, 11:53:01 amHmm, I guess it will be a case of 'suck it and see'.Quote from: Berni on February 11, 2021, 11:53:01 amThe thing is with the ESP32 ULP I2C is that it's so fixed in what it does that you either take it or leave it. There seem to be very few ways of altering its behaviour.I have seen that some people have written bit-bang code for the ULP, mostly it seems to be able to use I2C devices that want to spit out 16 or more bits of data.
NXP pressure sensor range confusion - Page 1
Forum section: electronics / projects

author: Circlotron
author_rank: Super Contributor
timestamp: November 09, 2021, 08:38:38 am
content: Looking for an NXP absolute pressure sensor, 0 to 1 bar absolute, that is to say, vacuum to normal atmospheric. Trouble is, one is described as15 to 115 kPa, Absolute,and the other-115 to 0 kPa, Gauge, and AbsoluteDisregarding the slight difference in span, do they both cover basically the same pressure range?Does the slope of volts vs pressure go the same direction?The one I want should have ~5V output at normal atmospheric and decreasing voltage as the pressure is reduced / vacuum increased.https://www.farnell.com/datasheets/2291657.pdfhttps://www.farnell.com/datasheets/2291544.pdfI want to find a SMD replacement for this through-hole one. MPX4100APhttps://www.nxp.com/docs/en/data-sheet/MPX4100A.pdf

author: CaptDon
author_rank: Super Contributor
timestamp: November 09, 2021, 02:04:41 pm
content: Can't speak for your exact parts, but years ago I used several different Motorola produced sensors and it was interesting to note that their 'two port' sensors (the ones with a hose barb on each side could be used to sense pressure or vacuum depending on how the hoses were connected to your project. Typically the two port sensors were used as differential detectors to sense restrictions such as a dirty air filter. We replaced a lot of VERY expensive 'Magnehelics' with very cheap Motorola MXP sensors. If I remember, with no differential you got an output voltage that was half the excitation voltage and I had to go through an opamp with adjustable offset and adjustable negative feedback to set 'scale'. So I ended up with a 'Zero' adjust and a 'Gain' adjust. We also had experience with some 4-20ma. sensors. I designed a system with PSI metering for a company and calibrated the current loop. They wanted to sense 0-100,000 psi for a hydraulic system. Sadly the sensor they purchased was 0-150,000 psi and they put the cylinder retaining rods right through the corrugated steel roof and out into a field. I got a call-back on that one!!!
NXP RT1020 VCOM USB @ 26MBytes/s - Page 1
Forum section: electronics / projects

author: moffy
author_rank: Super Contributor
timestamp: November 30, 2019, 01:10:06 am
content: Speed Tests USB NXP RT1020 using CDC_VCOM_LITE and custom Windows program LogDue (30/11/2019)I have modified the NXP example (usb_device_cdc_vcom_lite) for the RT1020 to test the USB throughput available using a virtual serial port (cdc_vcom). No driver is required under Windows 10 as the device enumerates as a serial port. The RT1020 transmits varying buffer sizes, using a bulk endpoint send routine. On the Windows side The program LogDue (excuse the name) opens the serial port and reads the transmitted data, displaying the throughput in bytes/s. You need to compile the program with the correct com port for your device in the main routine. Adjust to suit.I varied the DATA_BUFF_SIZE in Virtual_Com.h for the RT1020 and recorded the results below. I didn't realise that getting such througput for an embedded microprocessor USB could be that easy. The only modifications I made to the code are in the included: Virtual_Com.c and Virtual_Com.h. I hope you find this useful.DATA_BUFF_SIZE is in Virtual_Com.h of the RT1020 program1. DATA_BUFF_SIZE = 256, 5MBytes/s2. DATA_BUFF_SIZE = 512, 10MBytes/s3. DATA_BUFF_SIZE = 1024,16MBytes/s4. DATA_BUFF_SIZE = 2048,26MBytes/sin ChristMark O'Farrell
Nylon Cable Grip from Mains Plug - Page 1
Forum section: electronics / projects

author: veryevil
author_rank: Unknown
timestamp: October 25, 2012, 08:48:00 am
content: Hey, I'm desperately trying to find a supplier of nylon cable clamps to hold down a mains cable. Exactly like you find in a mains plug. Just a small strip of nylon with a bump in the middle and two screw holes in!Help!Thanks everyone.Steven

author: Thor-Arne
author_rank: Unknown
timestamp: October 25, 2012, 01:01:46 pm
content: Quote from: veryevil on October 25, 2012, 08:48:00 amRS has those, search for "cable clips" or "cable clamps".Like these:http://no.rs-online.com/web/p/cable-clips-clamps/1361407/
NZH4V7B not 4.7V but 4.1V - Page 1
Forum section: electronics / projects

author: Simon
author_rank: Unknown
timestamp: June 10, 2018, 10:25:16 am
content: http://www.farnell.com/datasheets/1508365.pdf?_ga=2.37418980.599149318.1528625668-87911620.1528625668I got these zeners and was running 20mA through them but I only ever got 4.1V. I have just tested some as I am about to make more prototypes up and discover that using the 121GW they are indeed not 4.7V, 4.1V seems to be the lower end of 4.3 standards

author: PA0PBZ
author_rank: Super Contributor
timestamp: June 10, 2018, 11:32:25 am
content: So what is the marking on them?

author: Zero999
author_rank: Super Contributor
timestamp: June 10, 2018, 01:25:33 pm
content: That is on the low side.Are you sure they've not given you a 4.3V part?Is it hot? Low voltage zener diodes have a negative temperature coefficient.

author: Simon
author_rank: Unknown
timestamp: June 10, 2018, 05:17:54 pm
content: Quote from: Hero999 on June 10, 2018, 01:25:33 pmYes, it is in fact a lowest 4.3V part at best, no it was room temperature when I measured the part right off a tape and brand new with a 4mA test current. when in use I think i got 4.2V with 20mA going through.
OBD-II and J1939 connector adaptors for DB9 - Page 1
Forum section: electronics / projects

author: Martin F
author_rank: Regular Contributor
timestamp: October 30, 2016, 01:05:01 pm
content: Hi there, I am looking for a stable quality supplier of adaptors for DB9/J1939 and DB9/OBD-II connectors.What I'm looking for is similar to this product:https://www.aliexpress.com/item/Cable-Truck-J1939-9pin-to-DB9-Female-Cable-1-5m/1930396004.html?spm=2114.40010308.4.59.BjgVcqHowever, I would like to be sure of the quality and secure a stable supply.Anyone who know of potential suppliers for this type of connectors?Thank you,Martin
Objects' identifier - scanner - Page 1
Forum section: electronics / projects

author: panoss
author_rank: Frequent Contributor
timestamp: February 06, 2020, 07:46:56 pm
content: I want to make an objects' identifier. Let me explain:Let 's say I have a shop, I 'm selling tools.A customer brings a screwdriver and says 'I want a screwdriver like this one'.I put it under my super scannerand it recognizes the screwdriver 's bit among tens of others very similar.Is there a sensor that can do this?
Observed trace Z for JLCPCB 4-layer boards - Page 1
Forum section: electronics / projects

author: KE5FX
author_rank: Super Contributor
timestamp: February 28, 2023, 06:11:40 am
content: Thanks to DK4XP for sending some PCBs for his downconverter project,as mentioned in this thread. I hadn't had any prior experience with JLCPCB, so I took the liberty of TDR'ing a couple of test coupons on one of Gerhard's boards:The 12-mil trace is a solid match, with a reflection coefficient corresponding to about 1.05:1 VSWR. The 6-mil trace is clearly much too narrow.In both cases there is some mismatch at the ends due to capacitance between the SMA center pads and the the ground plane underneath. It's worse at the end with the actual SMA jack than it is at the end with the resistive load (2x 100-ohm 0603 in parallel), likely because the SMA center pin adds some capacitance to ground. Clearing the ground plane underneath the center pad would help.

author: Gerhard_dk4xp
author_rank: Frequent Contributor
timestamp: February 28, 2023, 08:13:49 am
content: My results are about the same.HP54750A + Agilent 54754A 18 GHz differential TDR plug in.With Rosenberger precision SMA, smaller Pad and GND cutouts on layer 2 and 3,the trace is essentially flat, maybe a tiny inductive location. Next I'll try more vias inthe SMA decal, since the SMA contacts L1 and L4, but the effective ground planeon the board is L2.The funny bends don't do any harm.The 6 mil trace was to test escaping BGAs.This is the cheap 4 layer process, 5 boards for €5 or so. No impedance control option.

author: KE5FX
author_rank: Super Contributor
timestamp: February 28, 2023, 07:20:06 pm
content: Looks good. Do you have a trace for the Rosenberger version? Curious if the fiber weave shows up.
Obstacle Avoiding Vehicle - Page 1
Forum section: electronics / projects

author: Siddhat
author_rank: Regular Contributor
timestamp: June 05, 2019, 02:33:39 pm
content: I've successfully built a vehicle using logic circuits that can avoid obstacles in its path. I started the project taking the objective of just making an obstacle avoiding vehicle. But I am thinking to use it in something practical and helpful. Thinking that adding an application to the concept of obstacle avoidance to some practical and helpful cases would make the project more strong and attractive. So, what would be the application of this vehicle in real world scenarios?

author: NiHaoMike
author_rank: Super Contributor
timestamp: June 05, 2019, 03:25:43 pm
content: How about a vacuum cleaner robot?

author: ejeffrey
author_rank: Super Contributor
timestamp: June 05, 2019, 08:29:52 pm
content: Or a beer delivery robot.

author: Audioguru
author_rank: Super Contributor
timestamp: June 05, 2019, 08:43:43 pm
content: Why did you use antique 74xx series TTL logic ICs that were used more than 40 years ago?Cars are made today that drive by themselves and avoid obstacles.
Obtain High Drain 18650 Cells - Page 1
Forum section: electronics / projects

author: MrAl
author_rank: Super Contributor
timestamp: March 09, 2018, 02:51:22 pm
content: Hello,Anyone know where to get high drain Li-ion cells 18650?They must have:Button topRating "Max discharge current" of 20 amps or moreNote i can not use flat top, and can not use less than 20 amps max discharge rating.Thanks.

author: drussell
author_rank: Super Contributor
timestamp: March 09, 2018, 04:27:49 pm
content: If you`re trying to find some locally, you might try the e-cigarete / vape shops as they will have high-discharge cells for replacement in the e-cigarette battery pack units.A friend of mine just replaced the ones in his unit, "IMR 18650" by AWT (Awieite Technology) and are rated 3000 mAH, 40A discharge. His old set lasted him a couple years and he's a very heavy "vaper"... sucks on the thing constantly, set at something like 60W.Just a thought.
OCTAL BUS TRANSCEIVER PIN VOLTAGE DIFFERENCE!! - Page 1
Forum section: electronics / projects

author: kfc_n
author_rank: Contributor
timestamp: May 21, 2014, 08:49:44 am
content: Dear friends, does anyone know here why is this happening? upon checking all the voltage to the input, all must read 5v(normal state) but there are two input pins that are not the same with the others, thanks.... attached is an image of octal bus transceiver with voltage reading in each pin

author: Dago
author_rank: Frequent Contributor
timestamp: May 21, 2014, 09:56:26 am
content: Sounds like those channels are either shorted to ground or broken or both.Measure with a multimeter to see if they are indeed grounded (or low impedance).

author: nitro2k01
author_rank: Frequent Contributor
timestamp: May 21, 2014, 10:06:36 am
content: What does the rest of the schematic look like? How are the dir and /oe lines driven?

author: kfc_n
author_rank: Contributor
timestamp: May 21, 2014, 10:32:56 am
content: OE is connected to micro controller, while DIR is also connected to VCC. I will try to replace it..then let you know the result.. thanks, how could I test wether it is shorted?

author: kfc_n
author_rank: Contributor
timestamp: May 21, 2014, 10:39:23 am
content: I tried testing whether or not it is shorted, I tapped the multimeter probe 1(GND) to ground of IC while probe 2(+) to pin 6 and pin 9, it went to - voltage... but I tried tapping probe 2 to working pins, it read 5v. Does it mean it is indeed shorted?

author: nitro2k01
author_rank: Frequent Contributor
timestamp: May 21, 2014, 05:20:42 pm
content: If DIR is connected to Vcc, port A is acting as an input and port B is acting as an output. Ie, port B is driven by the chip, and it follow whatever is on port A. Where is port A connected? What drives port A?

author: kfc_n
author_rank: Contributor
timestamp: May 22, 2014, 03:30:03 am
content: I found the culprit, the octal bus transceiver inputs are the one causing the inputs to drop... thanks
octopuss curve tracer changes,help needed - Page 1
Forum section: electronics / projects

author: m3vuv
author_rank: Super Contributor
timestamp: November 09, 2021, 11:09:42 pm
content: Hi all,im trying to cobble this together,the issue is the only available transformer i have to hand is too big,i measure 16v on the output,what value component changes do i need to make this work with what i have? tia

author: m3vuv
author_rank: Super Contributor
timestamp: November 10, 2021, 12:37:46 am
content: am i right in thinking if i swap the 22r for a 2.7k and the 100r for a 950r ,also swapping the 1k 1w for a 1120 ohm resistor that will give a test current of 14ma @ 4.1v on the test probes?,tia.

author: m3vuv
author_rank: Super Contributor
timestamp: November 10, 2021, 01:53:17 am
content: well ive built this,with the values i proposed i get about 4 ish volts on the test leads,that is untill i connect any grounds,then shoots up to the full 16v,can anyone shed light on this,needless to say it doesent work,this has me totaly baffeled,could the transfo have a leak to the mains ground and cause this?,tia .

author: m3vuv
author_rank: Super Contributor
timestamp: November 10, 2021, 02:40:39 am
content: well finaly sorted it,it must of been a leaky transfo,changed it for a 12volt 1va small pcb mounted one and its now working a treat!.
octopuss issue - Page 1
Forum section: electronics / projects

author: m3vuv
author_rank: Super Contributor
timestamp: August 22, 2018, 01:07:53 pm
content: hi all ive just built this :http://www.electronics-lab.com/diy-generic-curve-tracer/ ,it sort of works,however when i look at a diode junction it only gives a display with the diode hooked up in one direction,in the other direction the display shows a horizontal line ie open circuit,on my old huntron it used to invert the display,also when i try to test a cap it shows a verticle line ie short,it seems to measure resistance ok,ie the trace rotates with a variable pot across the probes,any ideas?.

author: Wolfgang
author_rank: Super Contributor
timestamp: August 23, 2018, 04:17:45 pm
content: Hi,your tracer is a very limited thing in many aspects.For something more useful, may I suggest the following sites:https://www.changpuak.ch/electronics/Curve_Tracer_advanced.php(really usable)https://www.changpuak.ch/electronics/Curve_Tracer.php(basic, just to show the principle)Still, have fun !
Odd (unstable) behavior in xtal CMOS oscillator - Page 1
Forum section: electronics / projects

author: ChristofferB
author_rank: Frequent Contributor
timestamp: March 11, 2018, 11:45:53 pm
content: Hi!I'm building a little 455KHz square wave oscillator to use as a BFO, using this fairly standard layout:with another inverter after as buffer, and whatever I do, I can't get it to put out the XTAL frequency!I didn't have the 100p trim cap so i had 68p over each leg and then a 40p trim cap paralleled across one of them, and it puts out a VERY high frequency (compared to 455KHz) - 5-15 MHz! on a few rare occasions i've managed to get the desired freq out by tweaking the trim cap, but with a terrible waveform, and so unstable that if i cycle power, it returns to the 5-15 MHz output..the 455 xtal is really one of those plastic packed ceramic resonators used in radios.Any clue as to what's going on? I kinda thought xtal oscillators should either resonate at their freq. or not at all.thanks!

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 11, 2018, 11:57:50 pm
content: Try putting a parallel resonant tank on the inverter input. Also, it's an unbuffered type (CD4069UB or 74HCU04), right?Tim

author: BrianHG
author_rank: Super Contributor
timestamp: March 11, 2018, 11:57:59 pm
content: Quote from: ChristofferB on March 11, 2018, 11:45:53 pmWith a 450Khz ceramic resonator, you should be thinking capacitive loads at 220pf to 470pf at the input side of the inverter, if not ever higher. You should even add a 100 to 470 ohm series resistor at the output of the inverter before it reaches the resonator & 1 meg resistor. Note that to drive a digital clock, you still use the direct square wave output from the inverter.Don't forget a 0.1uf decoupling cap for the inverter IC!!!Also make sure your inverter is a Schmidt for such a low frequency. Regular inverters may have their input float around the switch threshold and oscillate like mad ignoring the resonator.

author: ChristofferB
author_rank: Frequent Contributor
timestamp: March 12, 2018, 12:32:19 am
content: Thanks! I'll try out with a schmitt trigger, more capacitance and a small-ish series resistance tomorrow!

author: w2aew
author_rank: Super Contributor
timestamp: March 12, 2018, 02:08:43 am
content: And be SURE to add a power supply decoupling cap at each IC as BrianHG suggested - very important.

author: BrianHG
author_rank: Super Contributor
timestamp: March 12, 2018, 02:28:56 am
content: Quote from: w2aew on March 12, 2018, 02:08:43 amI also forgot to say that you need to GND the inputs of unused gates. Otherwise, they also may oscillate randomly. Especially in a breadboard environment.Also, the GND side of the caps should go straight to the GND pin row on a bread-board, not the GND rail. This also removes additional signal bounce introduced by jumper that 1 jumper-wire to the GND rail.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 12, 2018, 03:35:46 am
content: If it's CD4000 family, it can be powered with wet string. Bypass is inconsequential. 74HC is fine if it's within a few inches. Don't use AC or LVC.Tim
SOLVED: Odd backcurrent from glow plug  - Page 1
Forum section: electronics / projects

author: DanEdwards
author_rank: Contributor
timestamp: March 02, 2022, 06:11:52 pm
content: Quote from: Daned33 on March 02, 2022, 08:15:59 pmHiI'm trying to drive a glow plug with a P channel mosfet.With the test setup I have, I was switching 12V at 1Hz with a duty cycle of around 40% which allowed the glow plug not to heat up too fast or out of control.Is anyone able to please explain what I'm seeing on the scope?On initial switching, the current peaks at 20A and drops down to 0A in around 60ms.After switching off it jumps to -16A and curves to 0A in again 60ms.It looks like the glowplug is acting as a capacitor and inductor at the same time.I attached a screencap of the scope.Thanks in advance.

author: Benta
author_rank: Super Contributor
timestamp: March 02, 2022, 07:22:30 pm
content: As we don't see your test setup, hard to say. How are you measuring the current?There seems to be an AC coupling in that circuit.

author: Wolfram
author_rank: Frequent Contributor
timestamp: March 02, 2022, 07:22:43 pm
content: Is your current measurement channel AC coupled in some way? It could either be the transducer itself, or the input configuration on the oscilloscope channel.

author: Benta
author_rank: Super Contributor
timestamp: March 02, 2022, 08:05:54 pm
content: I don't think it's 'scope AC coupling, that usually also works well at very low frequencies.Perhaps the OP is using a current transformer for measurement?We just don't know, this is all pure guesswork.I hope that some day the OP can post a question with ALL necessary information.

author: DanEdwards
author_rank: Contributor
timestamp: March 02, 2022, 08:15:59 pm
content: Quote from: Wolfram on March 02, 2022, 07:22:43 pmSolved!Do'h! Must have accidentally put the channel in AC decoupling. I blame no indentations on the entry rotary encoder of KS scopes.Thanks for the help Benta and Wolfram. Yeah, could have been a bit clearer that I was using a AC/DC current scope clamp.Quote from: Benta on March 02, 2022, 08:05:54 pmSorry, not often I ask for help on forums. I thought it would have been something obvious, thus slight lack of all the information.

author: Benta
author_rank: Super Contributor
timestamp: March 02, 2022, 08:33:50 pm
content: Glad you solved it
Odd flat flex cable pitch - Page 1
Forum section: electronics / projects

author: HSPalm
author_rank: Regular Contributor
timestamp: February 13, 2014, 12:56:41 pm
content: Hi,just salvaged maybe 20 character LCDs from the e-waste here at work, some old ericsson office telephones. The connector cable is a flat flex cable with 12 pins. The two outer most pins measure 11mm center to center (or left side to left side, in the picture). So the pitch is 0.916mm, or 0.036 inches. Can't seem to find a matching cable or connector anywhere. Have you seen this dimension before?

author: TerraHertz
author_rank: Super Contributor
timestamp: February 13, 2014, 02:10:07 pm
content: Are you trolling? Or just off by one?12 pins, means 11 intervals between them. You're measuring 10.99, which should be 11.0The inter-pin spacing is 1.0 mm

author: HSPalm
author_rank: Regular Contributor
timestamp: February 14, 2014, 01:30:13 pm
content: Of course it was something obvious like this! Thanks for noticing, feeling a bit stupid now

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: February 14, 2014, 01:42:51 pm
content: SeeFencepost error

author: HSPalm
author_rank: Regular Contributor
timestamp: February 17, 2014, 07:28:50 am
content: Quote from: mikeselectricstuff on February 14, 2014, 01:42:51 pmQuoteI feel much better now, thanks.
Odd Order Active Filter Calculator - Page 1
Forum section: electronics / projects

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 02, 2016, 11:46:57 am
content: Most calculators only show 1st and 2nd order stages. This is a waste: in a synthesized filter (Bessel/Butterworth/etc.), odd order filters always have one real pole, which means you can simply throw in an RC pole somewhere. So if you find that you need, say, a 4th or 6th order filter, you can sweeten it to a 5th or 7th with no problem whatsoever.Of course, the RC values for the 3rd order stage aren't simply R and C, so you need a calculator to figure that out.http://beis.de/Elektronik/Filter/Act3PoleLP.htmlTim

author: moffy
author_rank: Super Contributor
timestamp: March 02, 2016, 10:49:07 pm
content: Nice! Thanks for the info, it is always handy to have a means of calculating the filter component values.Also the first input RC reduces the BW that the opamp sees, nice if you have a high BW input signal.
Odd WS2812 LED failure - seeking help on why/how this happend: - Page 1
Forum section: electronics / projects

author: Odd
author_rank: Regular Contributor
timestamp: February 09, 2023, 06:48:25 pm
content: On three sides of my garage under the roof ridge, I have about 1800LED's (waterproof)for every 200 or thereabout, they are fed by power from a 5v power rail.This has been working fine for years, with themes for "Halloween, advent, Christmas, new year", etc.The photo below is underexposed low, warm-white/orange-ish light.Recently - FIVE leds failed in a strange way - they can be switched on/off, but are on something that resembles full power, and two of them are pink-ishhow is it possible that five behave like this, yet have the ability to switch on/off ? (I mean... they apparently can co 0...100% - but not 11% brightness - like the rest )What could cause such failure? - if I believed the WS2812 were more advanced, I would even guess some calibration data got written/overwritten.

author: Odd
author_rank: Regular Contributor
timestamp: February 09, 2023, 07:39:32 pm
content: solution: .. power cycling the strip fixed it!
ODrive: High performance motor controller - Page 1
Forum section: electronics / projects

author: madcowswe
author_rank: Newbie
timestamp: December 26, 2016, 05:38:01 am
content: Hey,I thought you guys might be interested in my project called ODrive. It is an open source 2-axis brushless servomotor controller, meant to be used with cheap but high power hobby motors.You can read theproject blog here.Click gif for full video:As this is an open source project, here are links to theHardwareandSoftwaresources.Any and all suggestions, comments, and especially participation is warmly welcome.Cheers,Oskar

author: madcowswe
author_rank: Newbie
timestamp: January 20, 2017, 06:03:30 pm
content: Hey guys, the v3.1 boards have come back from the factory, check it out!I asked CircuitHub to take a video of the manufacturing, Hopefully ODrive will enable inexpensive machines that go this fastClick for video.I also have some more pictures here:link
Odyssey V1 DEV BOARD.  - Page 1
Forum section: electronics / projects

author: rickey1990
author_rank: Regular Contributor
timestamp: December 05, 2015, 11:38:55 pm
content: Okay!!! First my apologies for my Microsoft paint sketch, being a one man band its cheap and it gets the job done. Also I like to show things to different people who arnt necessary electronics enthusiasts, like a parent wanting do teach electronics with there kids. That was one of my main goal's producing something cheap, universal and was a good learning tool. Started off being for prototyping retro computers, but there was afew things I didn't like with other boards. I also think electronics should be taught at a younger age. As soon as you get the board you need to work out your resistor values for your voltage regulator.Do you use a AA battery pack, a 9v battery, 12v adapter. Theres some basic soldering, Also the main tracers will be silk screened on, so you can understand how the circuit works.Spacing suitable for 4 x 6 protoboards, however boards need edge cutting or sanding.Boards should be ready before Christmas. Planning on selling on ebay Mini version 10cm x 6 - 3 boards for £9.99, $16USA, $21AUD. And this one 12 x 6 cm for £9.99
PF correction  - Page 1
Forum section: electronics / projects

author: grifftech
author_rank: Frequent Contributor
timestamp: February 03, 2016, 08:32:29 pm
content: I have a shaded pole motor and want to add pf correction. It is 16 ohms. What size capacitor do I need?120V60hz

author: oldway
author_rank: Super Contributor
timestamp: February 03, 2016, 09:34:05 pm
content: Not enough informations to answer to your question.We need the value of the current and of the PF under load or the value of the current and lag angle between current and voltage
Off the shelf available multiconductor DC power cables? - Page 1
Forum section: electronics / projects

author: ezalys
author_rank: Frequent Contributor
timestamp: September 17, 2020, 03:14:28 am
content: I'm building a collection of 1 U rackmount pieces of instrumentation which have a separate DC power supply which will be in a separate box. I need to cable them together, but I don't particularly feel like making the cables myself. I need five pins (more is ok!) plus shield. If it was just three, I'd almost surely just buy XLR cables. The conductors will carry a maximum of maybe 1 amp of current at 15 volts. DB-9 serial cables would be great but I don't think they can take much current.Do such cables exist that are mass produced? Would be nice to just buy 10 of them in various lengths.

author: TimNJ
author_rank: Super Contributor
timestamp: September 17, 2020, 04:03:41 am
content: Depends on how much you want to pay, but for one-off, maybe cost isn’t a big problem.I’d consider shielded M12 cable like this one:https://www.digikey.com/product-detail/en/te-connectivity-amp-connectors/T4162223005-002/A142335-ND/9919801Not sure if you’re planning on using the shell as a power supply common? Not sure the type of shielding these cables use, i.e. foil or braid, so don’t know if it can really pass a current or not.

author: ezalys
author_rank: Frequent Contributor
timestamp: September 17, 2020, 04:05:51 am
content: The shield will just be a shield. There will be a ground line.
off the shelf  industrial 5W AC/DC  module - Page 1
Forum section: electronics / projects

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: June 18, 2019, 12:13:27 pm
content: Hi,I want a 220V AC range input, 5W 12V output -40 ~ 85c operating miniature AC/DC module, digikey has some parts, but they are a bit pricey and on the low stock, Do you recommend something?

author: BravoV
author_rank: Super Contributor
timestamp: June 18, 2019, 12:15:08 pm
content: Aliexpress

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 18, 2019, 01:10:07 pm
content: "Cheap", "industrial". Pickone.Tim

author: SiliconWizard
author_rank: Super Contributor
timestamp: June 18, 2019, 01:28:33 pm
content: What would be your target price per 100? Per 1000?The RECOM RAC05-12SK is relatively cheap, it's dependable and there is reasonable stock at Digikey:https://www.digikey.com/product-detail/en/recom-power/RAC05-12SK/945-3117-5-ND/7603370(there's never going to be thousands of pieces of stock for this kind of parts, if you need more, you'll have to ask). Were you expecting to spend less than a few dollars on such a module?Edit: just realized it's rated up to 70°C only, whereas you're targetting up to 85°C. Is this requirement mandatory? If so, I can suggest the Meanwell MPM-05-12, which is even cheaper. Meanwell may not be as good as RECOM, but that's still decent.

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: June 18, 2019, 01:33:01 pm
content: QuoteIndustrial then!LS10-13B12SS from mornsun seems nice,https://www.mornsun-power.com/uploads/pdf/LS10-13BxxSS.pdfDo you recommend them? are they reliable?

author: XaviPacheco
author_rank: Regular Contributor
timestamp: June 18, 2019, 02:17:09 pm
content: Quote from: ali_asadzadeh on June 18, 2019, 01:33:01 pmWhere would you buy them? What's the price? I couldn't find it. I have used RECOM modules, and I recommend them.
OFF THE SHELF Inverter Board, 100-250V DC at ~100-200 mA or More - Page 1
Forum section: electronics / projects

author: LaserSteve
author_rank: Super Contributor
timestamp: January 27, 2025, 09:32:22 pm
content: Building new test stations at work for solid state relays.Does anyone know of stock inverters other than Amazon, made by a repeatable source with controllable 100-300 or 100-250 VDC at 100-300 mA.I need eight of them plus spares.Rolling my own is not something my boss will tolerate.Thanks,Steve
Off the shelf packaged battery packs? - Page 1
Forum section: electronics / projects

author: ajb
author_rank: Super Contributor
timestamp: July 02, 2018, 05:01:20 pm
content: I've been asked to build a device that will require a ~12V, ~2Ah battery. It's a one off, so I don't want to go to the trouble of designing charging/protection circuitry, but I do want something that will be easy for the end user to deal with and have a reasonably low chance of blowing up.TalentCell 12V packsare inexpensive and well-reviewed and pretty much a perfect form factor for what I want, so I got one to check out.The good:- inexpensive- they claim over/undercharge and short circuit protection- there's no switching converter on the output, so no worries about the pack shutting down when idle (a big concern for my application)The bad:- there's no charging, balancing, or protection circuitry evident, so at best they're relying on per-cell protection devices to protect the pack.[EDIT: turns out there is a protection board, it's on the side of the cell pack that's stuck down with foam tape, so it's not visible unless you peel the cell pack out]- they require a specific 12.6V charging adapter, but use a generic 5.5mm barrel jack.I'm tempted to go with the TalentCell pack and retrofit a 3S protection/balance board (there's some space in the pack), but I wonder if anyone has any other recommendations for a better ready-made solution. In an ideal world I'd love to find a pack that has a buck-boost charger built in that can charge from a standard 12V supply and a protected direct output, but I would settle for an external charger that uses a less common connector, as long as it's something user-friendly. I'd like to keep the pack separable from the device, but I'd rather NOT go with an RC-style shrinkwrapped pack, since those don't offer much physical protection to the cells and the connectors tend to not be user friendly. I could go to a 4S or 5S pack if that opens up my options.Any suggestions?

author: JS
author_rank: Frequent Contributor
timestamp: July 02, 2018, 05:12:02 pm
content: Charging time?If you can live with slow charge a cheap unreg 12V adaptor can do the job, you only need the 12V+ at the end of the charging cicle with low current and the nominal 12V unreg have a higher output at low loads...JS

author: timpattinson
author_rank: Contributor
timestamp: July 03, 2018, 05:27:54 am
content: Not cheap, and the connector isn't great but they are absolutely bulletproof and self-balance.12v LiFe batteries, mostly designed for small vehicle starting but LiFe doesn't have the cranking/deep cycle tradeoff you'd see in a lead acid battery.https://earthxbatteries.com/shop/etx12aJust keep in mind they specify the capacity in lead-equivalent - the actual Ah is approx 3x less.

author: nctnico
author_rank: Super Contributor
timestamp: July 03, 2018, 11:05:49 am
content: Always use a battery pack which has a UN38.3 certification. It may cost a bit more but you have some guarantee it won't crash and burn. Think about your liability!There are standard battery packs available which have protection circuitry etc built in. Check Digikey, Element14, etc.
Off-the-shelf panel mounted scrollwheel rotary encoder? - Page 1
Forum section: electronics / projects

author: igendel
author_rank: Frequent Contributor
timestamp: June 19, 2017, 11:18:42 pm
content: Hi all,A client came up with a request that's beyond my experience. basically the product needs a scrollwheel, similar in form and function to that of a PC mouse, but is has to be set in a 1.4mm metal panel. To make matters worse, the wheel needs to be perpendicular to the internal PCB (like an "L" from the user's perspective), although I could connect them with wires if needed. It also has to be off-the-shelf because it's a small production and there's no way to get a custom part.I looked at rotary encoders but so far couldn't find a kind with a scrollwheel (only thumbwheels), or one that can be mounted to a panel easily the way I need it.Any ideas? thanks!

author: fcb
author_rank: Super Contributor
timestamp: June 20, 2017, 12:27:42 pm
content: The synth community often use something similar for MODULATION or MOD (often paired up with PITCHBEND) - they'll be loads of examples of homemade ones and perhaps a few OEM types.PITCHBEND usually has a spring centre return - beware.

author: Fungus
author_rank: Super Contributor
timestamp: June 20, 2017, 12:49:54 pm
content: Quote from: fcb on June 20, 2017, 12:27:42 pmAnd MODULATION has a limited range of movement - doesn't turn infinitely like a scroll wheel.I think the search term the OP wants is "optical thumbwheel encoder"

author: CM800
author_rank: Frequent Contributor
timestamp: June 20, 2017, 12:51:29 pm
content: http://uk.farnell.com/alps/ec10e1220505/encoder-horiz-10mm-24det-12ppr/dp/2064974This is what is usually used, you may be able to buy the wheel itself from aliexpress or similarProblem is, most mouses use part of the injection moulding to hold the wheel in position you will likely need some machined parts or 3d print....

author: igendel
author_rank: Frequent Contributor
timestamp: June 20, 2017, 02:46:34 pm
content: Thanks for the suggestions, the MOD wheels I found so far look ideal in terms of mounting, but that they are indeed limited range. In the optical encoder domain I have my eye on the F-16 Fighter variant - a single unit will probably cost more than my client's entire budgethttps://www.consolite.co.uk/air/control-potentiometers-and-encoders/The EC10E1220505 needs the wheel and extra mechanical setup for both, again not my domain. If you have any other ideas I'll be happy to hear!

author: CM800
author_rank: Frequent Contributor
timestamp: June 20, 2017, 07:17:58 pm
content: I'd imagine, the reality is, unless you can find a company in china that makes the assemblies for another company who makes mouses and are willing to fob some off to you...you're gonna need to get mechanical. Sorry!

author: igendel
author_rank: Frequent Contributor
timestamp: June 20, 2017, 08:13:59 pm
content: Quote from: CM800 on June 20, 2017, 07:17:58 pmYes. Well, at this stage it'll probably be much easier for me to convince the client to use an alternative interface deviceThanks again,
Off-the-shelf variable dual lab power supply up to +/- 100 V, +/- 100 mA or so - Page 1
Forum section: electronics / projects

author: Messtechniker
author_rank: Frequent Contributor
timestamp: February 21, 2025, 09:42:10 am
content: Since the car/auto market demands more and more high voltage opamps, I’d like to test a few. To this end I need a variable dual +/-100 V, +/- 100 mA lab power supply preferably off-the-shelf. These animals do exist (R&S NGA 142, for example), but cost an arm and a leg (> 2k EUR). Haunting the internet for several days now did not reveal anything suitable off-the-shelf.Anyone out there with an idea?Already thinking about a DIY stacked 783 circuit with current limiting foldback.

author: mikerj
author_rank: Super Contributor
timestamp: February 21, 2025, 10:31:46 am
content: TheCSI 5003EIIImeets/exceeds your specs, though it is a typical generic import PSU so don't be expecting R&S quality.

author: Messtechniker
author_rank: Frequent Contributor
timestamp: February 21, 2025, 11:02:24 am
content: Not quite. Does only +/- 50 V in dual mode. I definitely need +/-100 V.Downloading the CSI 5003EIII manual is slow as molasses.Price is right and of course I am not expecting R&S quality here.

author: Roehrenonkel
author_rank: Frequent Contributor
timestamp: February 21, 2025, 12:20:45 pm
content: Hi Messtechniker,if you can get your hands on a HP6627-A it would fit your requirements.It's a 4-channel 50V 800mA (20V 2A) PSU with GPIB.Good luck

author: BennoG
author_rank: Frequent Contributor
timestamp: February 23, 2025, 06:58:58 pm
content: Found one in Ireland.https://www.ebay.nl/itm/305339812757?_skw=HP6627Depending on how hard you need it it is a nice unit.I have it's 1 channel 120V 1.5A cousin.Benno