hybridfree/eevblog-posts huggingface dataset:
Instability in power supply duty cycle and ripple - Page 1
Forum section: electronics / projects

author: jmw
author_rank: Frequent Contributor
timestamp: December 17, 2018, 01:37:55 am
content: I've been working on a 5 V -> 150 V power supply for Nixie tubes. Basic specs are 100 kHz DCM boost operation in peak current mode using a LM3478 as the controller. So far it's working as expected, and can supply 15 mA of current at 150 V. However, I found the 200k frequency adjust resistor picked by the datasheet's formula yielded a frequency of 92 kHz, so I tried replacing it with a 180k resistor, and it's now just over 100 kHz. However, there's now an instability in the duty cycle on my constant test load, and the output voltage looks unstable.Things I've noticed: increasing the power stage output capacitor gets rid of the instability, as does (of course) decreasing switching frequency. Is the most likely culprit:1) bad loop compensation - the LM 3478 doesn't appear to have a good way to for me to measure the loop bandwidth with voltage injection, so I've compensated the controller based on a model of the error amplifier from the datasheet and an accompanying application note.2) current mode ramp instability - seems unlikely since DCM is supposedly stable without any artificial ramp? Changing the resistor that allows additional slope compensation doesn't appear to fix it.3) something else?Before (Rfa = 200k, fs = 92 kHz):Gate waveformOutput rippleAfter (Rfa = 180k, fs = 103 kHz):(I've seen it much worse - appears like it's wandering up and down with some very short and long periods)

author: prasimix
author_rank: Unknown
timestamp: December 17, 2018, 06:36:25 am
content: Quote from: jmw on December 17, 2018, 01:37:55 amDon't see a reason why you shouldn't try to inject test signal into FB voltage divider as I donehereand try to tweak compensation network connected on COMP pin.
Instable digital control loop around triangle wave generator - Page 1
Forum section: electronics / projects

author: nano
author_rank: Contributor
timestamp: March 13, 2016, 05:13:45 pm
content: Hey there!I’m trying to generate a triangular wave with my STM32F3DISCOVERY demo board.The Idea is to toggle a IO pin with 100kHz and integrate that the signal to get a triangle.Because the MCU can only switch between 0V and 3V I create virtual refence point at half the supply voltage with PWM (also 100kHz) and a low pass filter.I tried to sketch the idea:I use the build in op amps of the STM32 to build this circuit:The next picture shows the toggled IO pin (1 yellow) and the output (2 blue).To move the triangle to the midpoint I had the Idea add another filter at the output and control the DC voltage by measuring this point with the ADC (5).I created a digital PI control loop (1kHz sampling frequency) around the following circuit which seems to work well.If I now readd the integrator from the first circuit it all starts to oscillate at around 140Hz.Next pictures are taken at (3) at different timebases.The triangle is generated but unfortunately there is this huge 140Hz component.Why does it start to oscillate? How can I fix that?Thanks!

author: Fulcrum
author_rank: Regular Contributor
timestamp: March 13, 2016, 08:59:17 pm
content: So if I understand you correctly, (3) is connected to (4)? Your circuit diagrams is a little hard to follow. Have you tried to simulate the whole thing? You can use LT spice or TINA-TI. I feel that often simulations sheds light on strange effects you had not anticipated. Good luck!

author: nano
author_rank: Contributor
timestamp: March 14, 2016, 07:01:32 am
content: I have to apologize for not actually drawing the whole thing.I followed your advice and fired up LTspice and drew the complete scematic (see atachments).Similar to the real world behaviour the circuit starts to oscillate with a low frequency.

author: Berni
author_rank: Super Contributor
timestamp: March 14, 2016, 02:09:41 pm
content: Problem is with the AC only feedback path on the opamp as there is only a capacitor in there. Due to that there is nothing to define the DC output level so it drifts off in to one of the rails where weird stuff happens as its forced to clip.

author: moffy
author_rank: Super Contributor
timestamp: March 16, 2016, 12:26:44 am
content: Just put a large value resistor across the 100pf capacitor, 1M to 10M to compensate for your DC offsets. Don't worry about other feedback schemes.

author: nano
author_rank: Contributor
timestamp: March 17, 2016, 06:20:17 am
content: Thanks moffy and Berni!A large resistor indeed fixed the problem.

author: moffy
author_rank: Super Contributor
timestamp: March 18, 2016, 10:22:34 pm
content: Glad to hear. Thanks for letting us know.
Install Inverter in my Car (12VDC - 230VAC) - Page 1
Forum section: electronics / projects

author: dupreezarmand
author_rank: Unknown
timestamp: April 01, 2016, 05:50:42 pm
content: Hi Guys,As you can guess already from the subject, I want to install an "over the counter" 300W to 500W inverter in my car.Input: 11VDC to 15VDCOutput: 230VAC (let's say 300W inverter for now)My question is regarding the hookup, with the 3 important goals:1. Do not set the car or myself in the car on fire2. Do not cause harm to the cars electrical systems3. It must work as expectedHere comes the questions:1. I could hook this up through the cigarette lighter port, but this seems a bit cheap and I would be able to have a max 150W Inverter?2. Do I hookup directly on the battery or on a spare fuse?3. Grounding requirements?4. Voltage spikes (maybe the inverter should have such protection built in)?5. Ignition-on operation, and how that is achieved (generally, it will vary from vehicle to vehicle)I could simply just hookup Red and Black to the battery, or cigarette lighter and it will work, but for a permanently installed unit, this makes me uncomfortable.I would appreciate if you guys could answer a question.Thanks,Armand du Preez

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: April 01, 2016, 06:04:38 pm
content: Have you watched?

author: SeanB
author_rank: Super Contributor
timestamp: April 02, 2016, 06:15:06 pm
content: First you want to use a thicker cable than they supply you with, typically i will use 4mm or 6mm copper stranded wire for the leads for that, and go directly from the battery positive itself, with a fuse within 10cm of that cable ( preferably a 30A fuse, and with an extra sleeve on the unfused cable to the battery), then a short negative lead either to the battery itself, or to a proper ground connection made to the vehicle chassis metalwork, preferably a good nut and bolt with the bare metal exposed both sides, and protected with a liberal coating of Tectyl after tightening ( going to be messy, so make sure it is hidden), and with the cables routed to the device using either sleeving or a tape sleeve and with anti chafing protection where it goes through metal parts.Mount inverter where it is not exposed to dusty air, and if you want remote operation use a properly rated 30A Hella relay ( beware of the fakes that claim 30A, but melt at 5A, mostly from a certain outlet with a M in the name), use an old Toyota branded headlight relay ( common in the used parts trade, and nice in that you get a whole assortment of types) and a switch to turn it on and off. If you use an ignition switched line to power the relay there is less risk of you running the battery down by accident, and if you do not then it will drop out at around 6V leaving you with a flat battery that will be much reduced in life.If you want to run separately use a separate battery and a split charger controller ( CI has them at a price for caravanning, but easy enough to DIY your own) so the inverter battery only will be damaged instead of the main battery.
Install urJTAG in Mac - Page 1
Forum section: electronics / projects

author: DavidDLC
author_rank: Frequent Contributor
timestamp: February 18, 2022, 06:56:49 am
content: I have googled how to install it, and the only result I found was to install MacPorts first.Is there another way to do it without MacPorts ?I'm not very familiar with the Mac system yetDavid

author: tooki
author_rank: Super Contributor
timestamp: February 18, 2022, 07:57:43 am
content: I’m not familiar with the urJTAG package, but as a general rule, if MacPorts instructions are available, there’s not likely to be an easier way. (The whole point of MacPorts is that someone else has already done the work to figure out what it takes to get the package running on the Mac, so you don’t have to. People rarely create a MacPorts package (or whatever it’s called) if the software has a native Mac port.)

author: DavidDLC
author_rank: Frequent Contributor
timestamp: February 18, 2022, 06:28:40 pm
content: TookiThank you very much for your answer. I will follow your advice and install MacPorts.
installing TPM into a laptop - Page 1
Forum section: electronics / projects

author: carbon dude oxide
author_rank: Frequent Contributor
timestamp: August 27, 2013, 01:01:06 pm
content: hello, i have a P170em laptop from clevo and i would like to make use of the TPM functionality. now i know the computer is able to have this option as the service manual has the schematic for itGo to page 59 for the schematic. I have also verified and found the footprint for this IC chip and support circuitry on the motherboard. Would it work if i bought all the components required of this and then soldered them into the empty footprints? or is it likely that the computer would not allow it?
Help USB Thermal Printer - Page 1
Forum section: electronics / projects

author: djluck
author_rank: Newbie
timestamp: November 15, 2014, 08:19:07 pm
content: Hello,Am am trying to install on my mini pc (Intel Celeron 1037u Dual Core Mini PC) a 80mm Thermal Receipt Printer .My mini pc is running on debian operating system. As I read on the internet you must first instal "cups", but unfortunately I am unable to accomplish this.I've been trying the process described here (but as I said without luck ):https://wiki.debian.org/SystemPrintingThe error that I get is this:apt-get install cupsReading package lists... DoneBuilding dependency treeReading state information... DoneSome packages could not be installed. This may mean that you haverequested an impossible situation or if you are using the unstabledistribution that some required packages have not yet been createdor been moved out of Incoming.The following information may help to resolve the situation:The following packages have unmet dependencies:cups : Depends: libslp1 but it is not installableDepends: poppler-utils (>= 0.12) but it is not installableDepends: ghostscript (>= 9.02~) but it is not installableDepends: ssl-cert (>= 1.0.11) but it is not installableDepends: cups-filters but it is not going to be installedRecommends: foomatic-filters (>= 4.0) but it is not installableRecommends: printer-driver-gutenprint but it is not installableRecommends: ghostscript-cups (>= 9.02~) but it is not installableE: Unable to correct problems, you have held broken packages.Can somebody help me with my problem or propose an alternative??Thank you in advance, cheers,Djluck
Instek GDS-2000A scope front end - Page 1
Forum section: electronics / projects

author: uMinded
author_rank: Newbie
timestamp: June 03, 2013, 02:37:48 am
content: Anybody interested in doing a reverse-engineering project of the GW Instek GDS-2000A Oscilloscope front end?Front End, Big PictureI am a fan of front end analog work and most of the released schematics are for DIY and 1-2MHz models and the leap of engineering between a 10MHz and 300MHz pathway are quite drastic. My own designs peak out around 7MHz...Anybody interested?
Instek PS3030 no schematic - Page 1
Forum section: electronics / projects

author: jeeves47
author_rank: Newbie
timestamp: July 11, 2017, 09:52:59 am
content: I recently bought an Instek PS3030 Power Supply as spares or repair. I thought that as long as the transformer was o.k. repairing the circuitry would be fairly straightforward. I tried to get a circuit diagram online, but could only find a block diagram. There was nothing at the output and the controls had no effect. There was 18volts across the 4700uF 63v smoothing capacitor, and at the collectors of the pair of 2N3055’s. There was nothing at their bases. I replaced the D213 - I used a TIP41C - and its associated transistor with no effect. The +15v, -15v and 2.5v reference voltages were all present. I resoldered a couple of suspect joints (someone had been there before me), checked the print for cracks, and started to meter individual component with the power off. I know that this can be misleading, but it is a very useful tool anyway. I found nothing until I got to the front sub-panel which carries the four control pots. The middle lug on the coarse current pot was o/c to the two ends. I unsoldered it and took it apart. There was indeed a break on the carbon track between the lug and the slider. I replaced it, turned it on and got that satisfying sound of relays clicking. It’s now fine. I’m sure that I could have spent hours studying the schematic if I had had one and never have arrived at the correct diagnosis. The old-fashioned ways can still yield results

author: Cliff Matthews
author_rank: Unknown
timestamp: July 11, 2017, 11:58:07 am
content: Good thread here:https://www.eevblog.com/forum/testgear/quick-look-gw-instek-gps-3303-power-supply/
Instrument Amplifier gets Warm - Page 1
Forum section: electronics / projects

author: PStevenson
author_rank: Regular Contributor
timestamp: October 26, 2011, 09:15:12 pm
content: I made a microphone preamp using a INA217 Instrument Amplifier IC at the heart of it and to power the overall circuit I used an LT1054 switch cap voltage converter to give me upto -15/+15 voltage, the whole circuit works fine however I am very new to using Instrument amplifier IC's and when this circuit is running it gets warm - not too hot to touch or anything just noticeably warm I just want to know if this is normal really.

author: amspire
author_rank: Super Contributor
timestamp: October 26, 2011, 10:32:45 pm
content: You are running at +-15V with a 10mA quiescent current, so that is 300mW in the amp - you should feel it as a little warm.Richard

author: PStevenson
author_rank: Regular Contributor
timestamp: October 26, 2011, 11:01:40 pm
content: thankyou, so it won't damage the IC or shorten its life at all?

author: amspire
author_rank: Super Contributor
timestamp: October 27, 2011, 12:27:04 am
content: No. It is exactly the way that that particular IC works.You can get much lower power IC's, but that is probably a pretty nice chip, if you don't mind the 300mW.Richard.

author: PStevenson
author_rank: Regular Contributor
timestamp: October 27, 2011, 09:58:57 am
content: no, I don't mind the 300mW - I should have probably read the datasheet a bit more closely I was shocked when I plugged in the old DMM and saw the power usage but it's not a problem - it'll be mains poweredthanks so much for the info
Instrumentation Amplifier gain accuracy problem - Page 1
Forum section: electronics / projects

author: filssavi
author_rank: Frequent Contributor
timestamp: May 23, 2016, 09:15:59 pm
content: As a part of a larger project I'm developing a load cell front-end, the first circuit I've prototyped is the one attached where I have the ADC connected to I2C to an arduino uno taking the measurements, the signal from the load cell is at 10mV and has to be amplified to meet the ADC's (ADS1115) full scale input range, so I used an istrumentation amplifier (AD8236) with suitably selected precision gain setting resistor.The problem I'm having is a gross gain error, so basically the amplifier gain is only 7 instead of 25 as it should be; the theories i'm coming up with are as follows:1) even though the in-amp is marked on the datasheet as Rail-to-Rail input and output has some limitation in input and output so it cant gain so much with reference voltage grounded2) since the prototype board is through hole (Inamp and ADC are SMD on breakout-boards) wired point to point with 30 AWG wire wrapping wire and the wire (not more than 10 cm) between sensor ground and inamp reference-ground (which are soldered toghether really close) is enough to cause gain accuracy issues as stated in the datasheet3)something else I haven't thought offso what do you think is the issue here?UPDATE 1: I need a gain of 25 to get from the 10 mV FS of the load cell to the 256 mV FS off the ADCIf the first is the likely culprit my solution to that would be lift the reference pin to mid supply and use the ADC as differential bethween vref and vout of In-amp, can it work or i need a fully differential amp and have a real differential front-end

author: StillTrying
author_rank: Super Contributor
timestamp: May 23, 2016, 09:32:07 pm
content: Quote from: filssavi on May 23, 2016, 09:15:59 pmG = 5 + 420 k?/RGI make the gain with 21K 25. Are you sure the 21K is not 210K that would give a gain of ... 7.

author: filssavi
author_rank: Frequent Contributor
timestamp: May 23, 2016, 09:36:27 pm
content: That is exactly the point (i could have been clearer now that I think about it, i'm sorry)the gain i need is 25 (10mV cell output, 256 mV ADC input range) instead i get only 7, i already measured the gain setting resistor and it is the correct value (i'll double check tomorrow but the RS catalog number is correct the value stamped on the resistor is the correct one)

author: tszaboo
author_rank: Super Contributor
timestamp: May 24, 2016, 12:24:22 pm
content: How much is the VREF? What generates it?

author: filssavi
author_rank: Frequent Contributor
timestamp: May 24, 2016, 12:44:19 pm
content: Right now i have it directly connected to the In-amp ground and this is connected throug a 30awg wire to the load Cell groundIn the proposed solution i will set it to mid supply (2.5 V) by using a buffered (to get low impedance) eesistive divider from power supply

author: tszaboo
author_rank: Super Contributor
timestamp: May 24, 2016, 02:16:59 pm
content: Well both of them should work. I suggest to measure R1 again just to be sure.
Instrumentation amplifier temperature drift problem AD8422 - Page 1
Forum section: electronics / projects

author: qat
author_rank: Contributor
timestamp: July 25, 2024, 02:36:05 pm
content: Hi,I have a circuit to precicely measure temperature, but I've stumbeled upon a stange issue.The idea is that the system can use the analog multiplexer to measure across a known resistance to get an idea of the momentary offset of the measurement compared to the theoretically ideal voltage (to compensate for things such as temperature drift), then immediately proceed to measure across the thermistor and compensate using the offset. I've assembeled my board, and to test things out I've soldered on a precision resistor in the thermistors place, and almost everything is working fine.The problem I have is that my tempearure drift is a lot higher than expected, but not always. When measuring across the "thermistor" (replaced by a precision resisotr) the voltage is bang on, and the temperature drift across a few degrees is almost not measurable, however, when measuring across the "resistor" (also precision resistor) the tempeature drift resulting from the AD8422 is almost 1mV/K! To simulate tempearure changes I've got a thin straw to blow air through to precicely target only the AD8422.The two measurements are almost identical! The only exception is that the common mode voltage of one measurement is higher (around 7.1V vs. 4.1V), but that would only result in a greater offset voltage at the output defined by the CMRR?Does anyone have any ideas why this might be? Should I increase R6 to decrease the CM voltage?See my circuit attached to this post.

author: David Hess
author_rank: Super Contributor
timestamp: July 25, 2024, 06:42:24 pm
content: You are exceeding the input common mode range of the instrumentation amplifier. Both inputs have to be 1.2 volts above the negative supply voltage, and 1.5 volts below the positive supply voltage.When measuring the resistor, the positive input is only 0.4 volts below the +10 volt positive supply which is too high. Th 2 kilohm resistor needs to be at least 7.5 kilohms.

author: qat
author_rank: Contributor
timestamp: July 26, 2024, 07:39:50 am
content: Quote from: David Hess on July 25, 2024, 06:42:24 pmThis is correct, thanks for the response. I tried swapping the 2k for a 10k, and had to increase the overall supply voltage and now it works as expected! It's strange how the issue manifested itself in the temperature drift
instrumentation amplifier what's the real upside? - Page 1
Forum section: electronics / projects

author: BiOzZ
author_rank: Regular Contributor
timestamp: July 13, 2013, 03:41:04 am
content: i sat thru 5 hours of the live show and i totally forgot to ask the question ...i have picked up and used instrumentation amplifiers when dealing with high precision differential stuff (like shunts) simply because someone suggested it to me years ago and they worked wonders for the application without much calibration or tinkering if any ... i have read the wiki and they seem simple enough but i have gotten amazing performance out of some of the AD ones i have used and they seem to have very low offset and noise and all sorts of plusses ... and i have seen some so called differential amps with the same voltage followers usedwhat are some other common uses for an instrumentation amp? what are the real advantages? there rather expensive so i avoid them where i can but if they're just amazing for a few useful tasks than that might save me quite a bit of time and hardware!thanks yall!

author: ddavidebor
author_rank: Super Contributor
timestamp: July 13, 2013, 06:14:55 am
content: Maybe linearity? I don't know

author: ejeffrey
author_rank: Super Contributor
timestamp: July 13, 2013, 06:43:33 am
content: High precision differential measurements are what instrumentation amplifiers do. What more do you want? Measuring things like bridge circuits and current shunts are their bread and butter. Cases where the common mode voltage is 100s of times higher than the differential signal. You can save a few cents by making one with a few opamps, but it isn't usually worth it. By the time you get high precision resistors and good opamps the price difference isn't that much, and you still won't have as good a resistor matching as a laser trimmed IC. For low precision applications and if the common mode voltage is relatively low then just build one from a few cheap opamps.

author: Marco
author_rank: Super Contributor
timestamp: July 13, 2013, 11:40:57 am
content: AFAICS the triple opamp setup of an instrumentation amplifier provides symmetry of input impedances and using an integrated one gives you laser trimmed resistors which are all in very close proximity (and thus the same temperature) providing better common mode rejection than you could achieve with a discrete setup.

author: Mechatrommer
author_rank: Super Contributor
timestamp: July 13, 2013, 04:42:22 pm
content: Quote from: BiOzZ on July 13, 2013, 03:41:04 amOffline SMPS.Quote from: BiOzZ on July 13, 2013, 03:41:04 ambetter CMRR, better spec, better CMRR.Quote from: BiOzZ on July 13, 2013, 03:41:04 amthe expensive one you saw, is either speced for higher common mode range, usually mains rated, and better CMRR. if you can get away without external passive components, go ahead build your own single chip diff.amp. there is another type, low rated CM range, TTL or CMOS or something, even a single chip can do, built by Agilent, Tektronix et al, but the price and CMRR are beyond imaginable.
Instrument/Project cases with heatsink/fan provisions? - Page 1
Forum section: electronics / projects

author: bitbanger
author_rank: Regular Contributor
timestamp: March 26, 2016, 05:52:20 pm
content: Hi Folks -Anyone know of any bench instrument cases roughly the size of a bench multi-meter (or smaller) that has integrated provisions for sizable heatsink and fan? Thinking something with the entire backside dedicated to such.I've kicked around the idea of just designing a one-off and making it myself, perhaps with two off-the-shelf CPU cooler combos, but at this point I'm feeling lazy and wouldn't mind spending a little money and not have to hack it. I can design around the case (this is just a side project, and form and fit are more important than final spec's). Need to mount a few TO220's or TO247's, likely dissipating 120-150W total. I can isolate with mica, so no worries there. I don't mind having to machine a bit, I'd just prefer to avoid making it all from scratch.Anything come to mind?Thanks!
Insufficient Power on my Load - Page 1
Forum section: electronics / projects

author: DarkArrow29
author_rank: Newbie
timestamp: September 22, 2018, 06:20:29 pm
content: Hi! I have this simple circuit that activates a load, whenever the switch is pressed (shorted). When the switch is released from being pressed, the load will power down slowly. I have already put this up on a breadboard. When the load is an LED, it works! But the actual load that I will use is a 2W MP3 Decoder. The load only receives 17.4 mW (based on my schematic diagram below) but before reaching the LM317, the power is 4.11 W. How can I make the load receive at least 2W. Please help! Thank you!

author: HB9EVI
author_rank: Frequent Contributor
timestamp: September 22, 2018, 06:36:16 pm
content: this circuit is not working like that. The switch activated transistors are a mess; either, what i recommend, switch the LM317 directly with a hardware switch, or you use a single pnp transistor switching the base with a resistor to ground, emitter to the plus terminal of the supply - but that has to be a higher power model than a BC558; e.g. a BD140 - but that's all pretty silly for the purpose - use a switch - that's it.

author: Benta
author_rank: Super Contributor
timestamp: September 22, 2018, 07:53:56 pm
content: And use 120 ohms for R5 and change R2 accordingly.

author: DarkArrow29
author_rank: Newbie
timestamp: September 23, 2018, 03:54:02 am
content: Just made a big change, sorry. So my new simulation makes the LED light up at 4.17V. If I will replace the LED with an MP3 Decoder Module with 2W and 3.7 to 5V requirement, how can this circuit activate the said module?

author: HB9EVI
author_rank: Frequent Contributor
timestamp: September 23, 2018, 08:44:58 am
content: Why do you use the same silly setup again now? I told you, it's not correct like that.The pnp transistor has to be with the emitter on the plus rail; the load on the collector, the base with a resistor and switch to ground; the npn transistor is obsolete
Insulating electrodes - Page 1
Forum section: electronics / projects

author: akis
author_rank: Frequent Contributor
timestamp: January 26, 2015, 04:37:52 pm
content: I have some electrodes they are disks of 2mm thickness and approx 20mm diameter. One side is electroded (silvered) the other is not. I typically put a blob of solder right in the middle of the silvered side connecting a wire to it. I would like to insulate the rest of the disk's silvered side.I was thinking of :1) nail varnish.2) super glue3) polyurethane varnish as used for woodNail varnish comes with a nice applicator brush but I have tried it and it flakes off quite easily.Super glue will definitely not flake off, but it is harder to apply smoothly and uniformly as I do not have a brush for it (the brush would most likely get glued in place).Polyurethane is also an idea as I have used it many years ago on furniture except I am not sure if it will be thin enough to apply to those small disks.Do you have other ideas?

author: qwaarjet
author_rank: Regular Contributor
timestamp: January 26, 2015, 05:12:09 pm
content: I have used boron nitride spray to make a thin insulating layer on electrodes beforeand hot glue applied with a hot air gun works surprising well at high voltage also various epoxy potting compounds
insulating the back of a tft lcd / 2s2p 18650 charger question - Page 1
Forum section: electronics / projects

author: franksterb92
author_rank: Contributor
timestamp: August 02, 2021, 08:54:25 pm
content: ok so I'm building this handheld rpi3a+ I'm using the adafruit 5inch tft that's being drove through the dpi interface on the gpio but i need to electrically isolate the back of the screen as it is metal and wanted some advice what to use to do so and the second part of my question is I'm designing a 2s2p 18650 battery charger and I'm confused on if i can use 2 2 cell charger ic's safely to charge the 2s2p pack

author: thm_w
author_rank: Super Contributor
timestamp: August 04, 2021, 11:59:58 pm
content: Kapton tape or 3D print a cover.You can't use 2 chargers you will either need a charger with balancing built in, or just charge to the ~8V total of the pack and use matched cells or BMS.https://www.eevblog.com/forum/projects/2s-18650-chargebalanceoverdischarge-pcb-required-which-supports-a-vin-of-10-8v/https://www.eevblog.com/forum/beginners/2s-life-charger/
Insulation material in T962 reflow oven - Page 1
Forum section: electronics / projects

author: Miti
author_rank: Super Contributor
timestamp: March 03, 2021, 02:44:03 am
content: Does anyone know what is the white insulation material in the T962 oven? Could it be asbestos?Cheers,Miti

author: james_s
author_rank: Super Contributor
timestamp: March 03, 2021, 03:06:11 am
content: It's probably mineral wool, you can get that for insulating around fireplace flues and such. Extremely unlikely to be asbestos.

author: Miti
author_rank: Super Contributor
timestamp: March 03, 2021, 04:02:24 am
content: I found something in German, Chrome can translate into English.https://www.mikrocontroller.net/topic/218615
inteasting bluettoth speaker chip RDA5856, where is the stereo output?! - Page 1
Forum section: electronics / projects

author: helmy
author_rank: Contributor
timestamp: April 01, 2018, 08:42:07 pm
content: I got this very cheap bluetooth speaker for under $2 , took it apart to see what is inside and found this chip RDA5856TEthe datasheet for it can be found herehttps://github.com/RDA5981/RDA5856/blob/master/Datasheet/RDA5856TE_Datasheet_V0.03.pdfsome other variations of it can be found on the same githubit has its own MCU and DSP core, and some nice features like USB OTG, UART, 12C , i2S ADC, DAC, the list goes on, and apparently according to some posts on twitter the ic goes for 0.60$ from china, however i didn't find it on alibaba,there is also some sort of free eclips based IDE for it!I was wondering if anyone else in here have came across it and have some more details like a basic application circuit, where to find that IDE (I am still looking)it says it has stereo DAC output in the datasheet, but i can only see one DAC output pin, am i missing something? or is that a mistake in the datasheet!

author: kissste
author_rank: Newbie
timestamp: April 10, 2018, 08:09:12 pm
content: I agree, it's an interesting chip, especially together with RDA5981 (ARM Cortex-M4).
Integrate LED in projector - Page 1
Forum section: electronics / projects

author: Schlonz
author_rank: Newbie
timestamp: January 21, 2015, 10:16:26 pm
content: HiI got an old projector with a broken lamp. I bought a 100W LED and a lens to replace the old lamp, so that I can enjoy a movie and save a little of energy and money.The ballast has two power rails, a 380V and a 15V (measured 300V and 10V) it has two optocoplers (input and output). It should drive a mercury gas lamp (Osram P-VIP 150/1,3). The brand and serial number of the ballast is fub 3104ML 94V0, but I cant find something useful on the web...I also messured the data coming out of the projector (I read here it could be a UART signal (bit time 1ms)) but it doesnt fit to a UART speed.If I bypass the two data lines coming from the ballast with a wire the projector starts working but has some creapy interruptions.thanks a lot and Im sorry for my englishLeonPS: If somebody need more informations or some pictures then write a short message
Integrated EMI Filters don't commute in correct way - Page 1
Forum section: electronics / projects

author: Apix
author_rank: Newbie
timestamp: September 06, 2022, 07:41:52 am
content: Hi thereI'm working on a board that I developed by myself. I've a problem with some integrated EMI Filters. I have an STM32 MCU connected to a micro sd. I've placed some emi filters between the STM32 and the uSD card connector.In the first relese of the board I've used some ST EMIF06 and everything was ok. Due to IC shortage I had to change the EMI Filters and I'm currently using some Nexperia IP4254CZ8-4.The problem is that I'm not able to mount the uSD card from the STM32. I've changed my FW to just use a single data signal instead of the whole 4 bits bus and what I've seen is that placing a flying wire on the bus lines let the uSD Card be mounted.I'm not able to understand if it's a capacitance problem or something else. It seems also that putting a little capacitance to ground doesn't affect anything. Putting the same capacitance to vcc everything works fine.I've also attached part of the schematic.What you think it might be which causes this failure?Thank you very much for your time!
Integrated Magnetics and Isolation - Page 1
Forum section: electronics / projects

author: veryevil
author_rank: Unknown
timestamp: March 23, 2018, 09:30:49 am
content: I'm looking to use this integrated RJ45 connector in a PoE design I'm working on and want to be clear about the 1.5kV isolation.https://www.belfuse.com/product/part-details?partn=0813-1X1T-57-FDo I need to keep 4mm distance between the power outputs 5,6,10 & 11 and the data pins 1,2,7,8 & 9?Do I connect the shield to a ground plane on the non-isolated side of the flyback converter?Does anyone have a layout using integrated magnetics that I can see a screenshot of?

author: veryevil
author_rank: Unknown
timestamp: March 23, 2018, 11:25:33 am
content: Found this link which makes sense to mehttp://pcb1001.blogspot.co.uk/2009/07/gigabit-ethernet-controller-design_11.htmlCan anyone confirm?

author: ovnr
author_rank: Frequent Contributor
timestamp: March 23, 2018, 06:45:30 pm
content: Power outputs are at the same potential as the data pins on the connector side; therefore, they must be routed away from the local data pins (left side of the schematic) with your normal clearance - which in your case may be 4 mm.Shield gets connected as per the image you linked.
Integrating a 2.7" LCD with Raspi? - Page 1
Forum section: electronics / projects

author: kaiserhaz
author_rank: Newbie
timestamp: May 18, 2016, 05:43:48 am
content: Hello,I got a 2.7" LCD (230k dots) from a digital camera, and I kinda wanted to use it with a Raspi. Don't know, however, if this is possible or not.If it is somehow possible, then I plan to make, if necessary, an adaptor.I tried looking at the original board for any signs of an LCD driver, which I would definitely need.There is this one IC that I can't identify though. The number on it is 30219 (+ some date code).It has an M logo on it, as per attachment. I suspect it to be the driver, since it's soldered at the back side of the board, just behind the LCD connectors.FYI the LCD looks like this:https://www.amazon.co.uk/BestDealUK-Screen-Display-Panasonic-DMC-FZ28/dp/B00AQSV0VY?ie=UTF8&*Version*=1&*entries*=0

author: macboy
author_rank: Super Contributor
timestamp: May 18, 2016, 03:43:28 pm
content: If you didn't find a complete spec within 15 minutes, stop looking. Little color LCD modules are too cheap these days to bother trying to salvage one. For less than $8 you can buy a 320x240 color LCD with touchscreen (which you can ignore if you don't need it). It has full specs and 0.1" headers for easy connection. This is a random example from a quick ebay search:http://www.ebay.com/itm/NEW-2-8-Inch-TFT-LCD-Display-Touch-Screen-Module-with-For-Arduino-UNO-GJ-/262398763375Pick up some "Dupont" wires for connecting to the Pi while you are at it. You should be able to get three 40-pin cables (Male-Male, Male-Female, and Female-Female) for less than $3. e.g.http://www.ebay.com/sch/i.html?_nkw=dupont+F-F+%28120x%2C120pcs%29
Integrating a Yamaha PSR-E413 Keyboard into a homemade synth - Page 1
Forum section: electronics / projects

author: krismate
author_rank: Newbie
timestamp: January 24, 2020, 04:38:05 pm
content: Hi guys,I have almost no prior experience with CPU's so I would like help with my project (: .I dissected the and intend to use it for my synth by translating the logic to voltage per octave.https://www.manualslib.com/manual/1528785/Yamaha-Psr-E413.html?page=58#manualAny help from more experienced people would be grand, be it a plan or some tips.Cheers!
Integrating ASK 433MHz module into the PCB - Page 1
Forum section: electronics / projects

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: June 24, 2017, 09:14:29 am
content: Hi,We know that these modules are dirt cheap, but for compactness, I want to integrate the whole module into the main PCB, do we have a schematic for them? what about the single chip solution versions? also can we integrate the PCB antenna, say a 17CM trace that wraps around itself,Some modules like Lr45b seems to use a very simple circuit ,what about the transmitter, do we have a similar case?

author: stj
author_rank: Super Contributor
timestamp: June 24, 2017, 11:30:58 am
content: just design your pcb with a cutout to fit a module into
Integration constant ruins BW problem - Page 1
Forum section: electronics / projects

author: john23
author_rank: Frequent Contributor
timestamp: June 07, 2025, 06:26:30 pm
content: Hello ,I have built a good PID controller ,The main issue is PI controller.In the time domain I get good responce where I see the integration in action.However because of C1 50n I get BW of 1K.When I lower the C1 to 100p i get a square output on time domain instad of rectangular shape which means there is no integration.So there is no way to have 1Mhz BW and a triangular shape integrator?Thanks.LTspice files are attached.

author: Andree Henkel
author_rank: Regular Contributor
timestamp: June 10, 2025, 01:45:18 pm
content: What is the time constant / dead time of the controlled system the PID controller is intended for?Basically there is no point in making your I part of your PID faster than that.
Integrator with the signal connected on the positive input - Page 1
Forum section: electronics / projects

author: nihial
author_rank: Regular Contributor
timestamp: January 31, 2025, 12:42:24 pm
content: Hello,Is it ok to connect in the integrator configuration the signal on the + input on the AOP ?If yes, is there subtleties one should know ?Best regards,

author: jwet
author_rank: Frequent Contributor
timestamp: January 31, 2025, 01:41:15 pm
content: Almost but not quite.For this to work, the input to the non inverting input should be fed with an RC that is equivalent to the RC on inverting side. This creates sort of an non linear RC integrator on the non inverting input. The other integrator on the inverting side but fed with with the NI input is non linear but with the error in the opposite direction- the overall combined response is a an integrator. The configuration looks a bit like an op-amp subtractor and you can do a cursory analysis by thinking this way.There is another non inverting integrator called the DeBoo integrator. Google it. Its a different topology but makes it possible to make single supply integrators that work pretty well.Overall, the standard inverting integrator is the most flexible and precise circuit and should be used primarily. Inverting amps with the "virtual ground" feature and the reflection of the load to this point solve a lot of problems.

author: nihial
author_rank: Regular Contributor
timestamp: February 02, 2025, 07:40:03 pm
content: Thank you for your answer I didn't know about the DeBoo integrator always good to learn new topologies. i'd need to find out how to have a non zero reference for the integrationWhen you say "the input to the non inverting input should be fed with an RC that is equivalent to the RC on inverting side". You mean that the impedance viewed from + and - inputs should be the same right ?When you say "For this to work", did you meant working at all or be the least non linear as possible ?I tried some simulations without matching the RCs and it seems to integrate (well enough for my application at least I don't need a pure mathematical integrator)

author: jwet
author_rank: Frequent Contributor
timestamp: February 04, 2025, 01:26:13 am
content: The circuit would be an op-amp with a C for negative feedback and a r feeding the - input which gets grounded. On the plus input, you'd have a cap to ground and a series R that feeds in the voltage. The two RC's are the same. You can google around for this circuit and an analysis, it must be an assignment by some devilish professor.When you say "for this to work", I mean to 1% kind of linearity versus an RC circuit with an exponential response. If you're very unpicky this is sort of integrator.A good integrator as used in fancy DMMS (mulit-slope converters- HP34401, etc) have linearities in the 0.1 part per million range (7 digits). This takes a lot of attention to detail.
Intel Atom processors E3845 1.91 GHz - Where can these be purchased? - Page 1
Forum section: electronics / projects

author: AndersJ
author_rank: Frequent Contributor
timestamp: July 01, 2021, 01:49:12 pm
content: It seems traditional suppliers are out stock.Any suggestions to where Intel Atom cpu’s can be found?

author: coromonadalix
author_rank: Super Contributor
timestamp: July 01, 2021, 04:00:56 pm
content: With the chip shortage going on around the world, the best is to wait ?
Intel Atom Z8000 Reference Design - Page 1
Forum section: electronics / projects

author: sanwal209
author_rank: Regular Contributor
timestamp: August 17, 2017, 05:48:54 pm
content: Hi Folks,I am going to start building a SBC based on Intel Atom Z8000. I am looking for the reference designs for the processor and couldnt find anywhere. If any one you have it please do share.Thanks, looking forward
Intel Hex file - Page 1
Forum section: electronics / projects

author: sandeepkumar
author_rank: Newbie
timestamp: December 15, 2020, 01:31:50 pm
content: Hi,I am working on a project to make an assembler for 8051 series microcontrollers.Here's a question I have: (This question may sound dumb to you)What defines the amount of bytes to be stored in a record?Example file for reference::0F00000075800075A000801478FA0000D8FC22EB:0F000F00D2A21108110811081108C2A222C2A022:0E001E00C2A175800F110F758001110FD2A0C5:0F002C00758048110F758065110F75806C110F6D:0F003B0075806C110F75806F110F75802C110F70:0F004A00758020110F758057110F75806F110F82:0F005900758072110F75806C110F758064110F17:0F006800758021110FE5B0B4F7FBE5B0B4FFFBD5:0200770080A364:00000001FFHere the first two records has F bytes of data; but can we combine them in one record which has 1E bytes of data?Will the file be the same if it was this?:1E00000075800075A000801478FA0000D8FC22D2A21108110811081108C2A222C2A0XX // XX is the checksum:0E001E00C2A175800F110F758001110FD2A0C5:0F002C00758048110F758065110F75806C110F6D:0F003B0075806C110F75806F110F75802C110F70:0F004A00758020110F758057110F75806F110F82:0F005900758072110F75806C110F758064110F17:0F006800758021110FE5B0B4F7FBE5B0B4FFFBD5:0200770080A364:00000001FF

author: Ian.M
author_rank: Super Contributor
timestamp: December 15, 2020, 02:02:46 pm
content: See Intel'sHexadecimal Object File Format Specification.The record length in theory can be up to 255 bytes, however its unwise to make records that long. Anything much over 70 characters per line is pushing your luck as some older tools may have limited length line buffers. Also some hardware tools have record length limits as low as 16 bytes and some poorly written ones may barf if, within blocks of contiguous data, the record length isn't a power of two, and isn't aligned to an address that's a multiple of the record length!

author: sandeepkumar
author_rank: Newbie
timestamp: December 15, 2020, 02:13:42 pm
content: So 16 Bytes is the unwritten limit? Thank you for response.

author: Peabody
author_rank: Super Contributor
timestamp: December 15, 2020, 09:51:44 pm
content: Yes, you can combine the first two lines as you've shown.The hex files I see are universally either 0x10 data length or 0x20, and of course the last line of a block can be a partial. Those are convenient lengths when examining a file. And 0x20 is good because the 32 bytes take up 64 characters, and with the overhead you are still under 80 columns.HxD, my hex editor, offers a choice of 16, 20 and 32 byte lines when exporting in IntelHex format.
Intel intelligent power note I2C communication - Page 1
Forum section: electronics / projects

author: npelov
author_rank: Frequent Contributor
timestamp: August 15, 2019, 06:15:38 pm
content: Background: I have a server board Intel S1200V3RP (S1200V3RPL) and I'm powering it from a 12V pico power supply. The power consumption varies between 15W and 50W. I want to make battery backup power - I'll put buck-boost to provide the stable 12V for the board and then I'll power it from 15 to 19V AC adapter. I'll have switch to provide power from a battery - I'll probably use two diodes as a start.To the point: The board has I2C/SMBus connector for the power supply. Does someone know if the protocol is described somewhere? I don't know much about SMBus - Is it any different than standard I2C? Can I get SMBus commands from IPMI specification documents?Most of this is just for fun. The system is working without the I2C connected, but there is a blinking LED for power redundancy lost and the BMC is reporting "reports redundancy has been lost", which is kinda annoying.I also want to connect my solar panel to the power sully to reduce power consumption during the day. If I can report the power via I2C it would be nice for logging.

author: langwadt
author_rank: Super Contributor
timestamp: August 15, 2019, 06:28:23 pm
content: afaiu I2C and SMbus is virtually the same as long as you stay below 100kHz but not so slow you hit the SMbus timeout