hybridfree/eevblog-posts huggingface dataset:
Controller Board for building external monitor from 4k Panel - Page 1
Forum section: electronics / projects

author: wilkems
author_rank: Newbie
timestamp: October 21, 2016, 02:58:53 pm
content: Hey All! First post and I can't find answers anywhere. I found this forum and it looked like the right place!I watched a YouTube video from DIY Perks about building an external monitor from an old laptop panel. I wanted to step it up as I have a dead All-In-One with a 4k screen that I wanted to try it with. The screen is an LTM236FL01, spec sheet here:http://www.panelook.com/LTM236FL01_Samsung_23.6_LCM_parameter_24447.htmlSo here's the ask. Where do I get a controller board for it? I have searched high and low and can't figure this out. Can I get just any board that can run a 4k panel? I'm doing the same thing with a 15.6" 1080p screen from an old laptop and it's a piece of cake. Any insight is welcome!Thanks!

author: senso
author_rank: Frequent Contributor
timestamp: October 21, 2016, 03:31:10 pm
content: Its and eDP interface, so a cable and something akin to this:http://dp2retina.rozsnyo.com/http://abusemark.com/store/index.php?main_page=product_info&products_id=47Basically, its a pwm signal and a couple connectors to go from displayPort/mini display port to the panel connector/cable and its done.

author: ebclr
author_rank: Super Contributor
timestamp: October 23, 2016, 12:03:58 pm
content: This may helpshttps://world.taobao.com/item/39691644618.htm?fromSite=main&ali_refid=a3_430618_1006:1105732177:N:4K%E6%B6%B2%E6%99%B6%E7%94%B5%E8%A7%86%E4%B8%BB%E6%9D%BF:3b0b47a0bd848b976531a944b6405021&ali_trackid=1_3b0b47a0bd848b976531a944b6405021&spm=a312a.7700714.0.0.sNEeXw

author: ebclr
author_rank: Super Contributor
timestamp: October 23, 2016, 12:06:43 pm
content: 2nd optionhttps://world.taobao.com/item/533639210062.htm?spm=a312a.7700714.0.0.POKmPi#detail

author: wilkems
author_rank: Newbie
timestamp: October 25, 2016, 03:40:53 pm
content: Thanks for the responses.Two of the options are all in Chinese, which I'd prefer to not have to deal with if possible.For the other options, they list the supported resolution as 2048x1536. Will they go all the way up to 3840x2160? Or do I have to find specific boards for that? What should I search for? Just a 4k edp controller board?Really looking forward to getting this up and running so thanks for all the help!

author: wilkems
author_rank: Newbie
timestamp: October 25, 2016, 03:56:04 pm
content: Would something like this guy work?http://www.ebay.com/itm/DisplayPort-to-eDP-Converter-LCD-Controller-Driver-Board-Adapter-4K-3840x2160-/152217805617?hash=item2370e36331:g:L1EAAOSwgZ1XvlfZMy biggest concerns are the ribbon cable pinout matching up.

author: ebclr
author_rank: Super Contributor
timestamp: October 26, 2016, 01:20:40 am
content: Here a more Xenophobic friendly optionhttp://www.digitalview.com/Of course is priced acccording
Controller for an Inverse SEPIC (Zeta) Regulator - Page 1
Forum section: electronics / projects

author: Odysseus
author_rank: Regular Contributor
timestamp: November 21, 2019, 07:55:15 am
content: I'm hunting for a switch-mode controller to implement a low-output-ripple inverse-SEPIC (Zeta) regulator, as part of an RF application running on noisy USB power.The best IC I've found so far is theMIC2193, which has the following desired features:- High side P-channel gate driver which enables straight-forward Zeta implementation.- Synchronous N-channel gate driver for high efficiency.- Current-mode control and slope compensation for fast transient response and good stability.- Low pin count- Low costMy second choice at the moment is theLTC1773, which is similar but is a bit more expensive and comes with a couple unnecessary pins/features. Figure 10 in that datasheet is close to what I'm going for.My concern is they are both rather old parts, and stock levels seem low. I'm hoping someone can recommend similar alternatives that aren't as likely to become EOL. Any input is appreciated.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 21, 2019, 06:31:27 pm
content: Haven't looked but going to guess there isn't much out there for integrated P-ch drivers. Do consider bootstrap (or charge pump if necessary) N-ch high side switches!Which, actually... if the output voltage is 6-15V, it should be reasonable to bootstrap power it with a diode from GND... Would still need a bias resistor to charge it up the first time....Too bad no one makes drivers that can go below GND, at least for much time.Anyway, you're not really saving anything by using Zeta over a regular buck or forward converter; that may be easier to solve. Can always put on more filtering or shielding, nothing terrifically hard about this with respect to RF application.Tim

author: SiliconWizard
author_rank: Super Contributor
timestamp: November 21, 2019, 07:22:35 pm
content: The TPS40200 does, and it's usable in a Zeta topology. It's also not expensive.https://www.ti.com/product/TPS40200It doesn't have an additional NMOS driver though, which both ICs the OP suggested have. The NMOS is not strictly required for a Zeta topology AFAIK. Finding regulators with both P and NMOS drivers will be much more challenging...As to the LTC1773, it's pretty expensive, but I don't know where the OP saw it was old and low stock? It's marked active on AD's website, and there's stock everywhere - sure the stock is limited as with pretty much any "specialty" part that has probably not a lot of demand. (Eg: 440 @Digikey)

author: Odysseus
author_rank: Regular Contributor
timestamp: November 22, 2019, 05:50:41 am
content: Yeah, pretty sure I'm guilty of being too picky.Honestly, given that I can easily simulate the LT1773 and guarantee a working solution on the first try, I'm probably going to use it.QuoteI've previously used theLT8471, which has two uncommitted NPN switches with emitters rated to -60V. Asindicated in this app note, it worked nice for generating a clean bipolar supply from USB. I found it rather inefficient, though.
Controlling 80 reed relays - Page 1
Forum section: electronics / projects

author: technix
author_rank: Super Contributor
timestamp: May 07, 2015, 10:52:28 am
content: This is for my DC reference project. I have bought a few used LM399 so now it justifies some 8.5 digit equipment: a DMM be a voltage standard. Obviously I cannot afford any so I am going to make one myself.I don't have those fancy rotary switches and I like to be able to just type in the desired voltage on a keypad, so I have to build the decade switch mechanism using reed relays. This means 10 relays per decade, or 80 relays total. Now how to control those? Will a string of 10 74HC595s work? How to deal with that signal consistency?

author: TiN
author_rank: Super Contributor
timestamp: May 07, 2015, 02:14:12 pm
content: Can you draw a approximate diagram of what you trying to do. As it's difficult to understand meaning, how reed relays can help you make voltage standard.Switchable resistors?

author: bookaboo
author_rank: Frequent Contributor
timestamp: May 07, 2015, 02:19:27 pm
content: I'm not sure of your exact spec but I did something similar for an automated precision variable resistor using a network of relays. I used a binary configuration of resistors, with a little programming I could get any value I wanted, I was able to make it self calibrate so the output was better than a decade box.

author: technix
author_rank: Super Contributor
timestamp: May 07, 2015, 04:07:32 pm
content: Quote from: TiN on May 07, 2015, 02:14:12 pmKelvin-Varley divider, with DPST relays instead of rotary switches.

author: Liv
author_rank: Regular Contributor
timestamp: May 07, 2015, 04:56:00 pm
content: Quote from: technix on May 07, 2015, 10:52:28 amTo control the large number of reed relays I used PCF8574/PCF8574A on I2C bus. The output current of 25 mA allows the direct connection of the relay. Alternatively, you can use a chain of TPIC6C595.

author: SArepairman
author_rank: Frequent Contributor
timestamp: May 07, 2015, 04:57:05 pm
content: this might be expensive if you want low leakage relays.dave jones has a tear down of a calibrator that uses a shit load of relays.http://www.eevblog.com/2013/11/06/eevblog-544-fluke-5450a-resistance-calibrator-teardown/

author: zapta
author_rank: Super Contributor
timestamp: May 07, 2015, 05:03:50 pm
content: You can use binary encoding and save relays, roughly 3.5 relays per decimal digit

author: oPossum
author_rank: Super Contributor
timestamp: May 07, 2015, 05:29:12 pm
content: TPIC6C595 will easily control 8 relays. Cascade as many as you need.http://www.ti.com/lit/ds/symlink/tpic6c595.pdf

author: technix
author_rank: Super Contributor
timestamp: May 07, 2015, 06:08:50 pm
content: Quote from: zapta on May 07, 2015, 05:03:50 pmMore info please? Using binary encoding and the same Kelvin-Varley design? And how to match decimal input to binary?
Controlling a linear CCD  - Page 1
Forum section: electronics / projects

author: electrochem
author_rank: Newbie
timestamp: December 15, 2015, 05:49:58 pm
content: Hi, i am using a linear CCD array for a project (http://oceanoptics.com/wp-content/uploads/Toshiba-TCD1304AP-CCD-array.pdf) i have it working using an Arduino due for the timings, and i am viewing the output on an oscilloscope, i have a very crude data collection system which involves an arduino Leonardo that receives a signal from the due when the CCD is in the Read out cycle however this is highly unreliable and i am looking for a better solution to this problem, i feel that i am hugely over complicating this and i want a simpler system. all help is highly appreciated. this is driving me nuts

author: ajb
author_rank: Super Contributor
timestamp: December 15, 2015, 07:50:28 pm
content: What's your current approach? In what way is it unreliable?I'm no CCD expert, but if you're trying to read out grayscale values I'd guess that the integration time (which I guess is determined by the period of SH?) must be pretty stable to get consistent readings across all of the pixels, so probably best to toggle SH with a timer, and use a timer interrupt to trigger an ADC conversion in sync with it. I don't see a specification for OS setup time in the datasheet, so you may need to delay the start of the conversion to some amount of time after SH is toggled. That would mean using one timer with one compare channel used to toggle SH and another compare channel triggering the ADC. That may be a bit tricky to set up in Arduino, but would give you quite accurate SH and read timings. You'll also have to make sure that the ADC conversion is fast enough to finish in the time allotted by SH. The Due's SAM3X8E can run the ADC at up to 1Msps, but I don't know if the Arduino libs will let you configure it at that speed.

author: electrochem
author_rank: Newbie
timestamp: December 16, 2015, 11:16:52 am
content: thanks, i have something that works really well and reliably now
controlling a phase shift oscillator - Page 1
Forum section: electronics / projects

author: Jan Audio
author_rank: Frequent Contributor
timestamp: February 11, 2021, 04:54:57 pm
content: Hi, i made a single supply phase shift oscillator running at 3,3 volt.Rfb = 470KR1 = 1K5R2 = 10KR3 = 10KC1 = 2U2C2 = 1UC3 = 2U2At R3 i place a 100ohm resistor going into a transistor going to ground.When i control the resistor the sine waveform now is shaping towards some sort of saw waveform.Why is that ?With placing the 100ohm resistor direct to the ground the shape remains good.What can i do to keep the shape a sine wave and still controlling the frequency ?thanks

author: drvtech
author_rank: Regular Contributor
timestamp: February 11, 2021, 06:15:05 pm
content: Think about what the voltage at the top of the resistor would be if the oscillator was not running. Now start the oscillator and what is the voltage going to do? Is it going to stay +ve w.r.t. ground?

author: Jan Audio
author_rank: Frequent Contributor
timestamp: February 12, 2021, 02:48:06 pm
content: It will be nothing when not running because there are capacitors on both sides.I still would like to have a simple 3,3v controlled analog sinewave, for now i use a potentiometer.

author: penfold
author_rank: Frequent Contributor
timestamp: February 12, 2021, 02:58:35 pm
content: Is it only when you have a transistor/resistor combination that you have the sawtooth or do you get the sawtooth shape even if you only have the 100ohm?At your target frequencies, does the opamp have sufficient slew rate for the desired amplitude sine wave?What is the output resistance of the opamp and can it supply the current necessary?

author: Jan Audio
author_rank: Frequent Contributor
timestamp: February 12, 2021, 03:59:13 pm
content: The opamp is a MCP R2R one.Without resistor and direct into the 100 ohm works good.It is the transistor that gives the odd shape.I tryd a FET, it looks good, only i forgot about the 1volt threshold thingie so it is very fast ( always conducting )btw : C2 is also 2U2

author: Terry Bites
author_rank: Super Contributor
timestamp: February 12, 2021, 06:06:07 pm
content: Its not going to be easy. You could go old school and use Vactrols.current controlled resistors eg NSL-32SR3 Optocouplers.Or new school digital pots eghttps://fr.farnell.com/w/c/semiconducteurs-circuits-integres/potentiometres-numeriques/prl/resultats?st=poteniometer%20digital.Good luck!

author: penfold
author_rank: Frequent Contributor
timestamp: February 12, 2021, 06:17:35 pm
content: +1 for digital potsAre you trying to make a voltage controlled oscillator (variable over a range of frequency) or just digitally switch between two frequencies?When you said transistor in the OP, did you mean BJT?

author: Jan Audio
author_rank: Frequent Contributor
timestamp: February 13, 2021, 01:10:47 pm
content: Oh thanks, i have those, very good, how could i forget, havent used them so far, i go try right now.
Controlling a scissor-jack - Page 1
Forum section: electronics / projects

author: Youkai
author_rank: Regular Contributor
timestamp: May 03, 2022, 06:24:50 am
content: I'm working on a project where I want to move a 3d-printed part a few centimeters back and forth. The part will "lay against" the body of the piece normally and then "move away" perpendicular to the surface. The piece will be about the size of your palm and I will have a couple inches of space under it (i.e. inside the main body) for the mechanics. Attached is an illustration of the concept in the open position. The shaded part is the amount it moved away from the body. Someone recommended a scissor-jack as a way to get the piece to move away in a straight line and maintain its orientation.My question is what's the best way to power the jack? My first thought was to use a servo. I could also use a DC motor, which might be smaller, but to do that I would need a motor controller wouldn't I? Can micro-controllers natively run a motor in both directions? I don't need to be able to vary the speed (thought it might be nice) so if necessary I could dial in the voltage with a resistor to get the desired speed and keep that static with only on/off and forward/reverse. This also seems like it would require two switches so I could stop the jack at both ends.Any feedback or other suggestions on how to achieve the desired effect would be appreciated. Thank you.
Controlling a TDK Lambda GEN or GENH PSU with an AR488 GPIB Controller - Page 1
Forum section: electronics / projects

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: November 26, 2021, 01:51:14 am
content: Hi,I am struggling to get the IEEE 488 interface on a TDK Lambda Gen 60-25 Power Supply to work with the AR488 interface.I am issuing the following commands:++eoi 1++eos 3++addr 6 (this is the address of the power supply)*IDN?++read eoiThe power supply seems to accept the commandsI am getting a timeout on the interface it says waiting for DAV.Anybody got any ideas?Thanks!!Jay_Diddy_B
Controlling gate current with a trimmer? - Page 1
Forum section: electronics / projects

author: eTobey
author_rank: Super Contributor
timestamp: January 06, 2025, 08:36:30 am
content: Hi,would it create a big issue, if i use a trimmer resistor to control the gate current of a mosfet in a test circuit?I could imagine, it would create some ringing or some other problems?

author: Andy Chee
author_rank: Super Contributor
timestamp: January 06, 2025, 08:46:47 am
content: As a strict test mockup, I don't see any particular issue.But if your production design is dependent on finely tuned gate current, and this test rig is intended to determine such values for production, then I might suggest you may possibly have a broader design flaw.Is your design a MOSFET linear amplifier of some sort? Please elaborate on the broader purpose for testing.

author: eTobey
author_rank: Super Contributor
timestamp: January 06, 2025, 10:03:24 am
content: Just a BLDC controller.

author: Siwastaja
author_rank: Super Contributor
timestamp: January 06, 2025, 12:45:04 pm
content: With a physically small trimmer, extra inductance probably isn't an issue. However for a BLDC controller are you going to use 6 trimmers and match all of them in value?Really, you would use one value of Rg and then spend possibly an hour taking measurements (ringing, efficiency, etc.), and then choose another value of Rg and redo the measurements.Maybea third value. So it would be simplest by far to just desolder and resolder different values of fixed resistors, this is what I always do. Added benefit is you can commit to as final as possible PCB layout from the start and don't need to waste board area for those trimmers.You can really ballpark-calculate the range of Rg you want to work with (e.g., simple equation matching Qg(tot) = time * gate current), and then fine-tune with measurement. For example, if calculation says 3 ohms, you may want to test with 0, 2.2 and 4.7 ohms.

author: David Hess
author_rank: Super Contributor
timestamp: January 06, 2025, 02:24:49 pm
content: Quote from: eTobey on January 06, 2025, 08:36:30 amIt will work fine. The resistance will dampen any ringing.

author: Terry Bites
author_rank: Super Contributor
timestamp: January 06, 2025, 02:32:17 pm
content: A ferrite bead on the gate also helps reduce ringing.
Controlling modbus TCP/IP slave devices - Page 1
Forum section: electronics / projects

author: Kemme
author_rank: Contributor
timestamp: May 25, 2018, 01:47:42 pm
content: Hello guysI'm planning to create some kind of master device which will control 30 slave devices through modbus TCP/IP. Basically each slave device will be a PLC which will be polled then the master will do some calculations and send commands to all the slaves. This sequence (polling-command) will be performed in a routine once a second. Also some data will be stored in a data base and some data will be displayed on a screen.My idea is to set up an Apache server on Linux and run a PHP script (using some modbus libraries) each second to perform all the controlling tasks. For visualization I would use Javascript so all valid data would be displayed via web browser.What do you think about that solution? Is it a proper way? Do you have any better ideas?

author: janoc
author_rank: Super Contributor
timestamp: May 25, 2018, 10:43:37 pm
content: Well, that's doable - I have done something similar, but only with 3 devices on the network and using Node.js and C# (two different applications) instead of Apache/PHP (Javascript being a slightly more tolerable abomination of a language than PHP).Just don't get tripped up by catastrophically bad implementations of Modbus - almost every single one I have seen has weird bugs and idiosyncrasies that will trip you up. Things such as Modbus working with 16bit words, not 8bit bytes making some operations "fun" to implement, "coils" and "registers" may or may not share the same memory space (both on the PLC and in the library), gems like relying on receiving replies in order (even though the spec explicitly says tonot dothat). Guess what happened when I tried to actually talk to a real PLC (and not just another copy of the library) using one them ...Be prepared for some pretty low level debugging with a lot of bit manipulations and network sniffing. Also do get an actual PLC for development as soon as you can otherwise your code may work perfectly fine with a simulator and blow up spectacularly in random ways when you try to talk to the real hw.Modbus is funConsidering that this stuff is used to control things in nuclear plants and elsewhere is not something that makes one sleep well ...
controlling mosfet biasing directly in the circuit question - Page 1
Forum section: electronics / projects

author: john23
author_rank: Frequent Contributor
timestamp: April 12, 2025, 01:44:28 pm
content: Hello,I have created a circuit shown below in ltspice using tsmc 180nm mosfets.unlike the standart way where we bias the mosfets using the large signal furmulas ,I would like to bias the M3,5,1,2 into saturation while M4,6 needs to be linear using charactersitics plots .How can I make these setting in the circuit below?Photos and Ltspice files are attached.Thanks.https://sites.bu.edu/engcourses/files/2016/08/mosfet-differential-amplifier.pdf

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: April 12, 2025, 05:18:19 pm
content: Hi,The circuit is a differential amplifier. It needs external feedback like this:R1 sets the operating current. I chose 10uA.R2 and R3 provide a feedback divider.This is similar to the op-amp circuit I have added.Regards,Jay_Diddy_B

author: john23
author_rank: Frequent Contributor
timestamp: April 13, 2025, 11:58:49 am
content: Hello J_diddy_B,M3 needs to in saturation,M4 needs to be in linear biased.then based on the biasing we calculating the gain.The is a gm/Id medthod with lots of plots.could you please say what plot I need to use to set the biasing?What plots I need to create to set the gain?Thanks.

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: April 13, 2025, 03:33:48 pm
content: Hi,You need to study the document:https://sites.bu.edu/engcourses/files/2016/08/mosfet-differential-amplifier.pdfthat you provided in the first message.It shows:The author has chosen the set the current in MA at 20uA. I chose 10uA.In the pdf document the author has indicated W/L ratios for the FETs.In the model that you provided, and I edited, all the W/L ratios are the same.Io sets the operating currents. These are mirrored using MA, MB and MC. In the authors example MB is operating at 1/5 of the current of MA. It is 1/5 because of W/L ratio.M3 and M4 are the current mirror load for the differential pair M1 and M2E2 is a voltage-controlled voltage source. This is used to provides feedback. I implemented this as a simple resistive divider, E2 = 0.5 x Vout.Jay_Diddy_B

author: john23
author_rank: Frequent Contributor
timestamp: April 17, 2025, 07:55:17 pm
content: Hello , I am trying to follow the example shown in the manual below.In step 3 they find the proper W/L using mathematical expressions.However I know that these formulas are aproximations ,the realistic way is to usr characteristic plots.What caractestics plots you reccomend me to use in order to get the proper W/L?https://aicdesign.org/wp-content/uploads/2018/08/lecture19-150211.pdfThanks.
Controlling the XR-2206 timing cap with a mosfet - Page 1
Forum section: electronics / projects

author: lk
author_rank: Regular Contributor
timestamp: January 23, 2013, 09:38:25 am
content: Greetings,I have for a long time been playing with the thought of creating my own little Function Generator, I realize it would be optimal to use something like the AD9835, and create it all digitally, and I might go that way. But for now I have thrown my love at the XR-2206cp, mostly because it's apparently 1 year older than myselfWhen poking around and looking at how other users have implemented the chip, generally the output frequency is controlled with jumpers/switches selecting which capacitor is connected between pins 5 and 6 on the XR-2206CP, this made me think if it would be possible to do this switching with N-channel mosfets instead, and that way control of the frequency by selecting the relevant cap for the range you need, i have my eye on the 2n7002 because its cheap and readily available.My main problem is that I don't really know what trouble I will run into when as I both need to charge and discharge the capacitor, through the mosfet, meaning that the current will go both ways through the mosfet, my simulation in LTSpice seems to confirm that it would be possible, but you know how it is with simulations vs reallifeBut just looking at the included ltpsice simulation, I guess it would be in principle possible, and i don't know what bunch of other problems i run into.Any comments are helpful-lkSchematic example from radiohobby storehttp://radiohobbystore.com/diy-xr2206-function-generator-circuit-explane/

author: lowimpedance
author_rank: Super Contributor
timestamp: January 23, 2013, 11:07:45 pm
content: It looks to be possible, plenty of analogue switches out there that are bi-directional and are mosfets basically!.I would say rig up a test circuit and give it a try. Simulation only goes so far as you know, time to roll up the sleaves and have some fun.
Controlling Smart Home Appliances by IFTTT from Arduino using Lithouse Cloud - Page 1
Forum section: electronics / projects

author: lithouse
author_rank: Newbie
timestamp: December 25, 2013, 02:08:23 am
content: Hi All,We are building a portal for Internet-of-Things. With our cloud service (http://lithouse.co/), makers can build connected devices which are integrated with other home-appliances.Here is an instructable for triggering IFTTT from Arduino:http://www.instructables.com/id/Triggering-IFTTT-from-Arduino-using-Lithouse/Please check it out and let us know if you have any question.ThanksTeam @lithousehttps://www.lithouse.co/
controlling stepper motor's in a surveillance camera  - Page 1
Forum section: electronics / projects

author: lolimpol
author_rank: Contributor
timestamp: November 20, 2016, 02:27:25 pm
content: i got myself a 360 degree turnable non ip surveillance camera, now after the teardown, i wanted to drive the stepper motor's inside with the built in driver, because: less cables and arduino's... less messnow i have attached some pictures hoping that one of you smart people can help me with this... thanks. greetings from the Netherlands: Polpictures:(http://imgur.com/a/iqfi4)

author: Ian.M
author_rank: Super Contributor
timestamp: November 20, 2016, 02:49:44 pm
content: So its got a PIC16F76 and a RS485 interface. You've got two choices here - figure out the communications protocol and command it via the RS485 interface, or replace*the PIC16F76 and write your own firmware to handle the steppers. The PIC can be replaced by something like an Arduino without physically removing it as tying its /MCLR pin low will disable it and tristate all its I/O lines so you can safely patch into them.* Although theoretically you could simply reflash the PIC16F76, there's no way back from that as the odds are better than 99% that a commercial product is protected against dumping a copy of its firmware.

author: electr_peter
author_rank: Unknown
timestamp: November 20, 2016, 11:07:14 pm
content: Such PTZ (pan/tilt/zoom) systems are often controlled withPelco-DorPelco-Pprotocol via RS485. I would suggest to implement such protocol before rebuilding motor control from scratch. You can get Pelco-D/P controllers (keyboards/joysticks) as well.

author: Muttley Snickers
author_rank: Unknown
timestamp: November 21, 2016, 12:08:40 am
content: As electr_peter mentioned, most PTZ cameras and housings will incorporate various telemetry protocols such as Pelco P/D, Samsung, Panasonic and numerous others, you will probably find more information and manuals on this unit if you can locate a specific model number or label somewhere on the main board or housing, you may also need to default the unit or configure it via the dip switches as the currently set telemetry protocol and address could be anything and there should also be an on screen menu for setting the location presets, tour groups, speeds, etc. (edited picture below and only a guess).A handy device for testing and configuring these is a PTZ camera tester which again incorporates a number of protocols such as the one pictured below. I couldn’t see the camera module itself in the pictures and it would probably have been a unit with an integrated zoom lens which obviously would have been compatible with the main housing and board.
Controlling USB connection to computer - Page 1
Forum section: electronics / projects

author: tyguy2
author_rank: Unknown
timestamp: May 24, 2017, 04:58:25 pm
content: Hello everyone,I'm working on a project where I need to be able to cut off a USB device (both 2.0 and 3.0) from a computer then reconnect it electronically. Mechanically speaking, it would be the equivalent of unplugging the USB device then plugging it back in later. I was wondering if I needed to use a controller IC to achieve this, or if I could just use BJT's or perhaps relays/ optoisolators to control the connections to the computer. Thanks in advance!

author: Skashkash
author_rank: Regular Contributor
timestamp: May 24, 2017, 05:46:39 pm
content: You'd want a USB switch /mux ic. 3.0 complicates things a bit.But something like this chip.https://www.fairchildsemi.com/datasheets/FU/FUSB340.pdfQuick edit,If this is just for a one off, it might be possible to hack a USB 3.0 hub by interrupting the power to the hub.

author: tyguy2
author_rank: Unknown
timestamp: May 24, 2017, 07:36:33 pm
content: So I think I'll usehttp://ww1.microchip.com/downloads/en/DeviceDoc/00001725D.pdfThis for the USB 2.0 and:https://www.fairchildsemi.com/datasheets/FU/FUSB340.pdfThis for the USB 3.1Will I just be able to attach both chips directly to a USB female connector, or will I need a way to differentiate between 2.0 and 3.1? (picture attached)
Controlling USB KVM Switch using Arduino - Page 1
Forum section: electronics / projects

author: baget
author_rank: Contributor
timestamp: June 01, 2015, 07:29:40 pm
content: HiI would like to control my USB KVM Switch (IOGear GCS1104http://www.iogear.com/product/GCS1104/) using Arduino.I got an Arduino board with ATmega32U4 (Sparkfun Pro Micro 5V) and I'm using code like that:Code:Keyboard.press(key);delay(pressReleaseDelay);Keyboard.releaseAll();to send keys.when I connect it to my computer USB port , the code works great.but when I connect it to my KVM Keyboard Port it does not work. (not even sending a simple keys)what could be the problem?

author: GreyWoolfe
author_rank: Unknown
timestamp: June 02, 2015, 12:09:44 am
content: Baget, forgive the question, but why? It only takes a double tap of the scroll lock key to switch between computers. I have one and it is a simple handy device. Isn't trying to control it by Arduino over complicating things? How will the Arduino know when you want to changes computers? I am just starting to look at Arduinos to dip my toes into microcontrollers so I may be a bit naive here.

author: baget
author_rank: Contributor
timestamp: June 02, 2015, 06:36:40 am
content: it is very simple, I have new Mechanical keyboard that does not work with the KVM Keyboard Port only with the Peripheral USB Port, which mean that I can't switch the KVM using the Scroll lock.so I would like to build a small Keys controller that will be attach to my keyboard, so I Can quickly my computers.

author: SeanB
author_rank: Super Contributor
timestamp: June 02, 2015, 05:30:20 pm
content: Take old keyboard that does work with the KVM ( cheapest one around) and strip the board out of it, and look up the 2 matrix lines for scroll lock, then place in small box with a single button on it. Double tap button to change and all done. Cost is the keyboard ( can be free using an old worn out cheapie), the box and switch. Deluxe model the LED's on the board are visible.

author: baget
author_rank: Contributor
timestamp: June 02, 2015, 06:34:45 pm
content: Quote from: SeanB on June 02, 2015, 05:30:20 pmyes this is also an option,but I'm try see if I can solve the Arduino issue or not...it seem like I need to use HID Boot Protocol, this is the protocol that keyboard use to talk to BIOS.my guess this is what will solve my problems...
Convert PWM solar charge controller to MPTT Charge controller - Page 1
Forum section: electronics / projects

author: inductonator
author_rank: Newbie
timestamp: December 02, 2020, 03:59:28 pm
content: What's the difference PWM solar charge controller and MPTT charge controller apart from Firmware ?Can I write custom firmware for PWM solar charge controller and convert it into MPTT?Is there anything I need to lookout for ?

author: Pineapple Dan
author_rank: Contributor
timestamp: December 09, 2020, 11:38:52 pm
content: The PWM one is likely very cheap and nasty and has no inductor or "real" buck converter. There are loads of designs for ""PWM"" charge controller and MPPT. Also a lot of charge controllers have nothing to do with MPPT but some guy in China figured he'd sell more if he wrote those letters on the casing
Conversion from 24V input to NPN or PNP output - Page 1
Forum section: electronics / projects

author: Yaroooo
author_rank: Regular Contributor
timestamp: July 20, 2021, 08:54:39 am
content: I've made a small circuit to accomplish this function:An input signal of max. 10kHz frequency is applied to RX;Input signal can have a voltage between 5v to 24v, but for first analysis I've assumed 24v;Two functions can be set, NPN output or PNP output based on Jumpers (JP) configuration where JPn is open and !JPn is closed;R3, R4, R5, R6 are voltage dividers to protect Gate;What is my problem:Connecting RX to +24V or GND actually doesn't work either in NPN or PNP configurations. Output is fix to 23,39V.Circuit starts to work removing R4 and R6, but not as expected. In PNP configuration I've:4,76V (RX to GND) and 23,21V (RX to 24V)In NPN configuration I've:23,22V (RX to GND) and 4,66V (RX to 24V)In this two case I don't have a completely working circuit. With voltage dividers, output doesn't work. Without them, gate is not protected and also output never reach 0V (as it should).Can you kindly provide me tips about what is wrong?Unfortunately I've already ordered printed circuits without performing a breadboard test before that (I know, my error). If there's a way to solve the problem using already present pads would be the best, anyway I'd like just to solve the problem.BOM is:Q1, Q2 - 2N7000TAQ3 - VP2106N3-GP.S. As PNP and NPN I'm meaning (maybe wrongly) an inverted and non-inverted output. Not industrial source/sink output.

author: fcb
author_rank: Super Contributor
timestamp: July 20, 2021, 09:51:49 am
content: 24V is above the 2N7002 Vgs(max), it can cope with +/-40V Vgs(max) briefly, but would suggest your application is too much. Could you replace the jumper with a resistor to lower this? Are the jumpers field replaceable?Would suggest that R3/R5 are quite low also. Depending on the quality of the 10KHz you want you can probably increse these values and lower the current. Also, the 2N7002 is failry well turned on by 2.5V to 3V, so you could re-ratio your dividers a bit.Q3 is the biggest issue though. It is a P-channel and in your circuit it always has some voltage between gate and source. Vgs for this part is -1.5V to -3.5V, so it's probably off at 5V rail (gate will be 4.1V, so Vgs=-0.9V), however at 24V rail it will be at 19.7V (Vgs=-5.3v) so very much ON.Vgs(max) is also +/-20V, so you might get away with removing R6 - but not a solution I'd be comfortable with. You are slightly bollox'd if you've done the layout - probably resort to a scalpel to rework it or find a MOSFET that has a bigger Vgs or somesort of protection built in.Quick other thought - you *might* get away with an N-channel as Q3 if you reverse drain and source, and flip your NPN-PNP assignment, but you won't hit 24V out and may have other complications depending on what you are driving.
Conversion of audio amp's AC coupled output to DC coupled output - Page 1
Forum section: electronics / projects

author: ricko_uk
author_rank: Super Contributor
timestamp: July 02, 2020, 03:12:38 pm
content: Hi,I want to modify the output of an audio amplifier I got from Amazon so that it has a DC component (doesn't matter how much, as long as the AC signal says above GND.With reference to the attached picture, it looks like the output is differential. The IC is hidden under the heatsink but in the description it says it uses "TI TPA3116 and NE5532" (here's a link to the datasheet for the power stage one:https://www.ti.com/lit/ds/symlink/tpa3118d2.pdf?ts=1593702988078&ref_url=https%253A%252F%252Fwww.google.com%252F)Would I be able to achieve what mentioned above by just shorting out the two caps?I assume that would work if it was a single ended output but not sure about the differential output.If my suggested solution doesn't work with the differential output configuration, can you offer any quick and simple suggestion to achieve that quickly and simply without having to build a new circuit?(SIDE NOTE: at the back there are a couple of switches which allow to select one of 4 gains for the amplifier)Thank you

author: TheMG
author_rank: Frequent Contributor
timestamp: July 02, 2020, 06:33:37 pm
content: The capacitor is going to be in parallel with the output, not in series with it. It works together with the inductor to form a low pass filter rejecting the high frequency switching of the class D amplifier and only letting the audio pass through.The amplifier output is in effect already DC-coupled, and the differential output makes it possible to avoid DC at the speaker while using a single power supply rail.The TPA3116 also has integral DC protection, which will shut down the amplifier if DC is detected at the output.Unfortunately, this is just the wrong IC for the job. About the only way you're going to do what you want is to float the entire power supply above ground potential (for example, the GND of the amplifier is actually +12V, and the VCC is at +24V, so you have 12V supplying the amplifier but the output always has 12V of DC on it). Such an approach would require of course a more complex power supply setup and will also require the input signal's ground to be DC isolated (by use of a transformer or capacitors), not a very practical approach.

author: NiHaoMike
author_rank: Super Contributor
timestamp: July 03, 2020, 01:18:25 am
content: Check one side of the differential output to ground - it's going to be about half the supply voltage.

author: tooki
author_rank: Super Contributor
timestamp: July 04, 2020, 05:55:19 am
content: Why would you want a DC offset on a speaker amp? (And if you’re not using it to drive speakers, then why did you get a speaker amp?)
Convert a HughesNet from working on AC adaptor to Working on DC Converter !!! - Page 1
Forum section: electronics / projects

author: battery13v
author_rank: Contributor
timestamp: December 17, 2016, 10:24:18 am
content: Hi every one i'm living off the grid ... so i'm using a hughes satellite ISP to connect to internetmy hughes is working in it's own AC Adaptor so i'm forced to turn on the inverter to turn it onthe idea is to make the hughesnet device work on Dc Voltage however in the ac adaptor their is 8 pins that are connected to the hughesi know form the sticker that i have to provide it with 19.5 V and 6.5V but their is 4 return oins that i want to know their role ... are they comunication pins with the ac adaptor?!!!! who knows?-----------------------------------------------------------------------------------------

author: Rerouter
author_rank: Super Contributor
timestamp: December 17, 2016, 10:34:00 am
content: Ok. this looks nice and easy, return means ground,I would attack it by using a 19.5V laptop power brick (they make ones that run from 12/24V), ans some cheap 2A switcher module for the 6.5V
Convert Acceleration into Displacement - Page 1
Forum section: electronics / projects

author: Billo
author_rank: Newbie
timestamp: March 16, 2011, 09:41:13 am
content: Is there an application that I can use to convert non-linear acceleration into displacement?The data is acceleration vs time in CSV format.I then want to view a chart of displacement vs time, either in the suggested application or else save the new data into a CSV file.Thanks for any help you can give me, Bill.

author: allanw
author_rank: Frequent Contributor
timestamp: March 16, 2011, 10:15:39 am
content: Just numerically integrate twice to get displacement. Take a running sum of the acceleration*timestep to get velocity, then running sum of velocity*timestep to get position. Should be doable in Excel. More info here:http://www.google.com/search?sourceid=chrome&ie=UTF-8&q=numerical+integration+excel

author: Unknown
author_rank: Unknown
timestamp: March 16, 2011, 12:57:12 pm
content: Use the trapezoidal integration method using Excel and double integrate.If you interested in the overall integral and not individual points, be careful with the integration results as integrations need a constant to be added to the result.If you are looking at alternating acceleration (eg vibration), make sure your raw data doesnt have a DC offset. If not, force it to have a 0 mean value. Otherwise your displacement will shoot to an unrealistic value over time.Alex.

author: Mechatrommer
author_rank: Super Contributor
timestamp: March 16, 2011, 02:52:25 pm
content: here, the least i can do. assuming you are collecting acceleratormeter data convert into acceleration and time interval are provided/calculated.avst.jpg = the conceptavst.xls = the implementation (rough one)

author: Billo
author_rank: Newbie
timestamp: March 17, 2011, 08:32:12 am
content: WOW !! Super Replies and Super Fast.Thanks very much to you all.Bill
Convert AC/DC regulated power supply to variable (Constant Voltage, Current) - Page 1
Forum section: electronics / projects

author: mastermachetier
author_rank: Newbie
timestamp: August 05, 2019, 08:37:13 pm
content: Hello All,I am new to electronics and have been researching AC/DC power supply circuits.As I understand it a basic power supply works like this.AC power --> Transformer( Takes the AC voltage down to a lower voltage) --> Rectifier( Takes the ac voltage from transformer and makes it no longer go through negative cycle) --> Smoothing Capacitors (evens out fluctuations to create smoother waveform) --> Voltage Regulator ( further smooths signal to a perfectly smooth dc signal)With that all said. I have a power supply at home that is a regulated power supply putting out 27v. I am trying to figure out where I would need to modify in order to convert it to a variable power supply and what steps would be necessary to have it be constant voltage and constant current. The power supply uses LM723CN volage regulator. I am guessing I'd need to someone interface with this IC with a potentiometer to be able to vary the output voltage.Am I on the right track with this project ? Below are pictures of the power supply that I have.https://imgur.com/gallery/JeTFYLH

author: MosherIV
author_rank: Super Contributor
timestamp: August 05, 2019, 08:56:29 pm
content: Hi. Welcome to the forum.What you described is called a linear power supply.Start by looking at the data sheet for the lm723 voltage regulator.It should be relatively easy to get a variable voltage psu.However, bear in mind that the difference between input voltage and output voltage is converted into heat. You will have to make sure you have adequate heat sink and cooling.I would not try to do current limit until you have mastered variable voltage.

author: mastermachetier
author_rank: Newbie
timestamp: August 06, 2019, 12:55:37 am
content: Thanks knowing it’s a linear power supply took my down a good track !
Convert HDMI video to CVBS - Page 1
Forum section: electronics / projects

author: cloidnerux
author_rank: Contributor
timestamp: February 08, 2020, 09:05:45 pm
content: Hello,so I brought myself in some bad situation:The customer wants a solution to convert HDMI from a Camera that only outputs FHD to CVBS/PAL for wireless analog video transmission. Easy enough, shouldn't be a problem. Amazon lists these converters for like 10€. Customer, of course, wants industrial temperature range, somewhat trustworthy components and an isolated CVBS output, in the end it's expensive gear mounted to a drone or crane.So, the initial solution brings up some HDMI receivers and analog video encoders, but after some more digging of course none of them have a scaler, so no CVBS output from this solution.So, quick check what's available as a scaler: Nothing, really, at least not in industrial temperature range.Who would have guessed that interfacing with 57-year-old technology is such a big problem?The ICs used in the cheap converters are of course some "obscure" Chinese parts. All in all, I found one AverLogic, two Chrontel and one Macro Silicon part that is on the converter I have but is not listed on the manufacturer's website.So here I am, some weeks to find some solution that is not prohibitively expensive, can input 1080p@60Hz and is industrial rated.Anyone has any ideas?

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 09, 2020, 02:07:51 am
content: Just get a fairly cheap converter from a somewhat trustworthy brand like Startech, replace any electrolytic caps with high temperature versions from a good brand, add bigger than necessary heatsinks on every chip that gets noticeably warm, and finish off by doing your own temperature validation before sending to customer? (How many units are we talking about?)

author: jonpaul
author_rank: Super Contributor
timestamp: February 09, 2020, 10:20:16 am
content: Any DIY HDMI device will encounter DRM issues, involving medium liscencing.Startech is a good brand and has good supportJon

author: cloidnerux
author_rank: Contributor
timestamp: February 09, 2020, 02:32:27 pm
content: Thanks for the replies.We don't care about DRM, because it is not intended for consumer stuff. The source it will be connected to has no DRM.I will look into the StarTech products.
convert i2s to spdif ? - Page 1
Forum section: electronics / projects

author: kripton2035
author_rank: Super Contributor
timestamp: July 10, 2017, 09:53:31 am
content: Hi ,I have a car radio that cd player outputs digital sound to the amplifier. (phillips RD3-01)I thought the digital audio was i2s as the chips in the radio and cd were made for i2s.so I bought a bluetooth to i2s module based on CSRA64215 chip that works fineexcept that in fact the radio accepts only spdif signal from the cd player ! ...so where can I find a (cheap) module that converts i2s to spdifso that I can hear my phone musics in the car via bluetooththanks for any advice.

author: cat87
author_rank: Regular Contributor
timestamp: July 10, 2017, 01:46:21 pm
content: One way I recently came across of doing this is to get yourself an I2S to AES/EBU converter, then convert the AES to SPDIF. The last one is pretty straight forward.To get the data from I2S to AES/EBU, there are chips that do that. Something like the DIT4192 chips from TI.To get the second part of the conversion, you can try this (from Fig.1):http://www.rane.com/note149.html

author: sokoloff
author_rank: Super Contributor
timestamp: July 10, 2017, 02:22:04 pm
content: Why not just go back to bluetooth and get a BT->SPDIF convertor?Something like:http://amzn.to/2tG6Jn6(I don't own one, but the specs sure look like it would receive audio over BT and output SPDIF on either coax or TosLink.)

author: jaycee
author_rank: Regular Contributor
timestamp: July 16, 2017, 11:03:11 am
content: What you want is an SPDIF transmitter such as Cirrus CS8406 or TI DIT4096