hybridfree/eevblog-posts huggingface dataset:
Does Proteus has a active I2C LCD library? - Page 1
Forum section: electronics / projects

author: laoadam
author_rank: Newbie
timestamp: July 14, 2021, 04:11:18 pm
content: Hi,I am testing an Arduino+JHD-2X16-I2C LCD as picture, it doesn't show, whats wrong need help please.ThanksAdamhttps://ibb.co/pw1fJX7Code:#include <Wire.h>#include <LiquidCrystal_I2C.h>// Set the LCD address to 0x27 for a 16 chars and 2 line displayLiquidCrystal_I2C lcd(0x27, 16, 2);void setup(){// Robojax code for LCD with I2C// initialize the LCD,lcd.begin();// Turn on the blacklight and print a message.lcd.backlight();// Robojax code for LCD with I2C}void loop(){//start of loop Robojax code for LCD with I2Clcd.clear();lcd.print("Robojax");lcd.setCursor (0,1); // go to start of 2nd linelcd.print("Hello World!");//lcd.print(millis() / 1000);delay(500);//end of loopcode Robojax code for LCD with I2C}
Does running multiple CAN buses in the same cat5 cable sound like a bad idea? - Page 1
Forum section: electronics / projects

author: e100
author_rank: Frequent Contributor
timestamp: June 19, 2018, 07:15:45 am
content: Currently I have a CAN bus running at 20k baud that collects data from multiple sensors. Would adding adding a second CAN bus to talk to another bunch of sensors at a faster rate (using another 3 wires) be likely to cause problems?. The two busses would have their own ground return wires, and they would only be connected together at the power supply.

author: capt bullshot
author_rank: Super Contributor
timestamp: June 19, 2018, 07:26:43 am
content: should work

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 19, 2018, 01:53:09 pm
content: Ground return? Presumably, on the other remaining pairs?Just mind that you'll get a little noise / impedance between those. That is, between the different pairs in the cable. Nothing CAN can't handle, by a long shot, if it's wired up in the usual way.The pairs themselves should be quite good: the twist rates are different just for this sort of reason. Other CAN buses will be jealous of the red carpet you're putting it on here.Tim

author: schmitt trigger
author_rank: Super Contributor
timestamp: June 19, 2018, 04:12:26 pm
content: Theory says it should work but I would still perform a simple experiment:Run data thru one of the CAN lines, while monitoring the other in recessive state.With a dual channel scope you should trigger from the active channel. That way, any noise that is synchronized to it you'll know is the crosstalk.

author: max_torque
author_rank: Super Contributor
timestamp: June 19, 2018, 04:54:49 pm
content: As long as you run each bus through the correct pair of cables (ie the ones twisted together) then i'm sure oyu won't have an issue, especially down at just 20kbaud.CAN gets bundled up, un shielded in much worse conditions than those existing in a Cat5 cable with CAN running on the other cables!I guess you can't just up the baud rate, because that's the easiest option to get a higher throughput?

author: linux-works
author_rank: Super Contributor
timestamp: July 04, 2018, 03:00:09 pm
content: 20k baud does not sound very fast (cars often are at 500kb).it should work. I'd run a test to see if any checksum errors are seen or if you get any NAKs. try various traffic patterns using a traffic generator to see if crosstalk becomes a real issue.but 20k is quite slow, so that's not very hard to do.for fun, I'd try various combos of can-h and can-L on the pairs of wires; perhaps running some 'out of phase' (so to speak) may be beneficial. testing will show.
Does Sharp panel support Vesa DSC? - Page 1
Forum section: electronics / projects

author: junsu
author_rank: Newbie
timestamp: January 23, 2018, 07:23:19 am
content: Hi,I study MIPI interface and try to run LS055D1SX05.MIPI Tx Board support Vesa DSC 3:1.However, if see LS055D1SX05 datasheet, it is said that only Qualcomm FBC support it.But, Panel with same NT35950 Driver IC supports Vesa DSC.Does LS055D1SX05 support Vesa DSC?Or are there other 4K panels that support Vesa DSC 3:1?LS055D1SX04 supports Vesa DSC, but it is not 4K.(1440x3840, i want 2160x3840)

author: daveshah
author_rank: Unknown
timestamp: January 23, 2018, 11:30:09 pm
content: The example configuration in the datasheet for the LS055D1SX05 is FBC, but there's no reason it should support DSC also, the driver chip certainly supports DSC. Try using the compression configuration from the 04 on the 05.BTW both the LS055D1SX05 and LS055D1SX04 are the same resolution. Both are 2160*3840 but only use 2 subpixels per pixel. The arrangement is just described differently in the different datasheets.
Does this 4-lane MIPI DSI LCD display controller support 2 lane mode? - Page 1
Forum section: electronics / projects

author: Cory Parsnipson
author_rank: Contributor
timestamp: February 10, 2023, 11:06:14 am
content: Hello! I've been shopping around for LCD screens that have a DSI interface so I can use it with a raspberry pi 3. One of the screens I'm looking at is this (https://aquamarine-mead-34.tiiny.site/), which is a 5" IPS display with 4-lane MIPI DSI interface and 1280x720 resolution. I've been looking at datasheets trying to figure out if this is compatible with my RPi and was wondering if someone with more knowledge could help me out.Unfortunately, it looks like a raspberry pi 3's DSI interface only has 2 lanes. So I was looking at the datasheet trying to see the screen's driver IC has a 2-lane mode. The screen apparently uses a driver IC with the part number ST7703D. I found a datasheet here (http://files.pine64.org/doc/datasheet/pinephone/ST7703_DS_v01_20160128.pdf), but I am not familiar enough with all this stuff to be certain if I can use this with a 2-lane host.I found a section that talks about LANSEL, but all configurations appear to use 4 lanes.If I'm inferring from what I learned about dsi lanes from this article I found (https://pcbartists.com/design/embedded/using-4-lane-mipi-dsi-display-with-stm32-2-lane-dsi-host), it looks like this controller doesn't have any 2-lane configurations?I just wanted to be sure before I pass on this display. Everything else about it is really good...
Does this battery charging IC (TI BQ25713) support “pass-through” charging? - Page 1
Forum section: electronics / projects

author: ItsumiMario
author_rank: Newbie
timestamp: September 07, 2020, 11:33:57 pm
content: Hey guys, first post!My question is regarding the Texas Instruments BQ25713 buck-boost battery charger IC, data sheet herehttps://www.ti.com/product/BQ25713What I am trying to achieve is this: I am building a device that needs to be portable, is about the size of a lunchbox, has components that have power requirements of 5V @150 mA and 12V @ 350mA (both need to be powered simultaneously), and can be powered in either a “plugged into the wall” mode and “unplugged from the wall” mode. When in unplugged mode, it’ll be powered by battery, and when in plugged mode, it needs to both power the device and charge the battery. I’ve seen this feature be called “pass-through charging” in the context of commercial battery power banks. Basically, the charging aspect needs to function exactly how most regular people use their phones and tablets: it runs on batteries, and when I plug in my ac adapter cable the battery charges and the device continues operating without any hiccups.For smaller projects with less voltage requirements, I’d use the Adafruit PowerBoost 1000C, which elegantly combines a boost to 5V and has a load sharing charger circuit that lets you charge the battery and power the device simultaneously. But after tons of searching, I can’t find any equivalent board that does the same thing but for 12V.So I’m thinking about making my own battery management board, and am looking for an appropriate IC that supports “pass-through charging” of lithium batteries and also boosts to 12V plus has all the battery safety features someone would need. (Also a nice bonus would be simultaneous dual output voltages of 5V and 12V, but not an absolute requirement since I could just split the 12V output into two branches and buck one of the branches down to 5V) Does the BQ25713 fit the bill? I’ve read the data sheets, and I think that it does, but I’m a noob EE hobbyist and wanted to see what you guys thought, or if you have any alternative ideas.Thanks!

author: thm_w
author_rank: Super Contributor
timestamp: September 09, 2020, 08:52:12 pm
content: That is quite a complicated charger IC.You can power the device from the battery, then whether it is charging or not it doesn't really matter, battery power will always be available.Some features they mention: Two-Level Adapter Current Limit and Processor Hot IndicationBut these are only relevant when pulling large amounts of power from the charger + battery.

author: richard88
author_rank: Newbie
timestamp: April 13, 2024, 09:42:11 pm
content: Hi,I'm also trying to figure out how to use this Pass-Through-mode to do battery charging. Were you successful ?I got the board but it's quite unstable, not sure if I did it right.Thanks.
Does this circuit look correct to connect DA-15 (Gameport/MIDI) to RPi (MT32Pi)? - Page 1
Forum section: electronics / projects

author: sofakng
author_rank: Regular Contributor
timestamp: December 31, 2021, 02:29:57 am
content: I'm trying to connect an older PC with a DA-15 (Gameport/MIDI) to a Raspberry Pi using MT32Pi.The Gameport/MIDI is +5v and the RPi is +3.3v so I'm using an optocoupler and voltage divider. I can't use the +3.3V on the RPi because it's not exposed on the device I'm using.Does this look correct or could it even be simplified?Ignore the MIDI CONN FEMALE in the center. It's only there to visualizer the MIDI wires.Thanks so much for any help!
Does this IGBT bridge meaningless ? - Page 1
Forum section: electronics / projects

author: Md Mubdiul Hasan
author_rank: Regular Contributor
timestamp: December 16, 2019, 04:30:08 am
content: Hello My Dear Friends!Hope this post finds you well.I am trying to develop a AC to DC rectifier 110V/50 A range.Feeling that I am doing wrong on making the full bridge or half bridge portion.The IGBT module I am using is FF75R12RT4,https://www.infineon.com/dgdl/Infine...2805fd8fd76151One module contains 2 IGBT that makes me confusing!I need to understand my switching topologies firstTake a look my diagram, how the current flows back from primary winding of TR for a full cycle?[ Specified attachment is not available ]1. When point A is positive then Q2 conducts, Q1 is OFF?2. When point A is negative then Q1 conducts Q2 is OFF?3. When point B is positive then Q4 conducts, Q3 is OFF?4. When point B is negative then Q3 conducts Q4 is OFF?Freewheeling built on doides are available, whats 2uF high voltage is doing here?

author: Berni
author_rank: Super Contributor
timestamp: December 16, 2019, 06:53:16 am
content: Umm... The schematic looks like AC/AC 3 phase to single phase converter, and the 2uF is simply across the supply rails.You sure you know what you are doing here? Mains voltages at these powers are very dangerous, don't mess with it if you are not sure of how it works.

author: Md Mubdiul Hasan
author_rank: Regular Contributor
timestamp: December 16, 2019, 10:15:59 am
content: Quote from: Berni on December 16, 2019, 06:53:16 amA is DC+, B is DC- bus node. They don't change polarity. It's a regular full bridge, sketched in a rather nondescriptive way. 2uF are DC bus bypass capacitors, strongly suggested to avoid IGBT overvoltage caused by large di/dt.Whats in your mind to be " correct " for " current' flow directions?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 16, 2019, 02:41:59 pm
content: A and B are swapped. Follow the diodes, it's shorted as shown.Tim
Does this input requires additional ESD protection or is it good as is? - Page 1
Forum section: electronics / projects

author: zapta
author_rank: Super Contributor
timestamp: November 26, 2023, 12:55:29 am
content: I am designing a board that has this frontend to measure low end current. Does the opamp input requires ESD protection or is it sufficient to use the 'almost short' shunt resistor as protection.

author: Konkedout
author_rank: Frequent Contributor
timestamp: November 26, 2023, 06:22:45 am
content: There is a lot I do not know about what you are doing there. But this op amp has high input bias current and an ABS Max differential input of 1V. The inverting input is fed by a DC resistance = 10K||1K = 909 ohms, and I would limit current into the non-inverting input by placing a resistor value close to that in series between pin 3 and R3. Then maybe add a pair of 1N4148 diodes (1 in each orientation) between the op amp inputs to clamp the voltage there. If you are using SMT then you could also do that with a BAV99. In normal operation the differential voltage between those inputs ought to be < a few mV so the diodes would not do anything except during some abnormal stress event.

author: zapta
author_rank: Super Contributor
timestamp: November 26, 2023, 07:02:40 am
content: @Konkedout, the full schematic is herehttps://github.com/zapta/daq/blob/main/heater/kicad/heater.pdf. This board measures RMS voltage and RMS current on a resistive load that is fed with PWM. A typical PWM source is a 24VDC supply switched with a series MOSFET at 1Khz. The circuit should handle measurements of up 28V and 4A peak. The circuit has floating ground and +/- 2.5V for the opamps. The circuit need to be agnostic to the polarity of the PWM signal on J1 (that is, swapping the wires connected to J1 should not change the readings).1. I gather from your answer that the choice of op amp may be sub optimal ('high bias current'). I did notice slight asymmetry, having different absolute reading at TP4 if I flip the polarity of the PWM at J1. Is this related to the bias current you mentioned? Do you have a better op amp in mind? It needs to be a fast enough to track the fast changes of the PWM.What do you think about the TLV3541IDBVR?2. Regarding the 1V limitation, my thinking is that the voltage at pin 4 is +/-250mv relative to ground due to the voltage divider and the voltage on pin 3 is even smaller due to the small shunt in parallel. Does this make sense or do diodes between pins 3,4 will still help?(This approach to measure the PWM power is discussed herehttps://www.eevblog.com/forum/projects/how-to-measure-on-a-pwm-load/new/#newand it works well except for a slight asymmetry I mentioned above).
Does this means short to ground in Chinese? - Page 1
Forum section: electronics / projects

author: Kokoriantz
author_rank: Frequent Contributor
timestamp: March 12, 2023, 06:25:16 am
content: I have a DS of CS8683 but only in Chinese. It is in PDF but idiograms are images cannot be translated by Google. Luckily they wrote in English (Float) that I can guess the lower the resistor to the ground, lower is the frequency, after which I suppose shorting it, is 300Khz. Before I plug it can someone confirm my guess? Thanks

author: ataradov
author_rank: Super Contributor
timestamp: March 12, 2023, 06:51:53 am
content: Yes, it is "direct to ground".Google translate on the phone translates this picture fine though the camera.
Does this motor have a datasheet?  - Page 1
Forum section: electronics / projects

author: Dmeads
author_rank: Regular Contributor
timestamp: November 13, 2019, 12:50:53 am
content: Hi all! I have this single phase induction motor from a fan.It says lakewood 101A 120v/60hz 0.68Amp INS CL APAT. 6, 227,822;6,439,862 AND PAT. PENDINGTHERMALLY PROTECTED L. CAPACITOR:4. OMFDCOM-WHITE HI-BLK MED-BLUE LOW-RED.I'm trying to find the datasheet to get the peak current value needed for start up.Thanks.

author: floobydust
author_rank: Super Contributor
timestamp: November 13, 2019, 01:42:03 am
content: No - It's a specialty four-pole permanent-split capacitor motor, discussed in the patents. Allows cheaper laminations yet slim construction.For Lasko fans, by Lakewood Engineering and Manufacturing Co. their stuff is made in china. It won't have a datasheet.I would just lock the rotor and quickly measure the current. Fan motors are high-slip so it should not be too much, it seems to need around 120VA steady.Note older 2011 Lasko fans had recalls in the USA:"An electrical failure in the fan's motor poses a fire hazard to consumers.Remedy: RepairRecall date: March 24, 2011Units: About 4.8 million units"US 6,227,822US 6,439,862

author: andy3055
author_rank: Super Contributor
timestamp: November 14, 2019, 11:50:36 am
content: Quote from: Dmeads on November 13, 2019, 12:50:53 amInduction motors usually have a starting current that is about 3 times the running current.
does this power buss look right - Page 1
Forum section: electronics / projects

author: nus
author_rank: Contributor
timestamp: November 24, 2017, 06:46:43 pm
content: sorry, my understanding of electronics is a bit shady. but I want to make this power buss for a +12 -12 +5 linear power supply

author: Gyro
author_rank: Super Contributor
timestamp: November 24, 2017, 06:59:51 pm
content: Yes, it looks correct in terms of polarities, but it is a bad idea to use transistor symbols for voltage regulators. Check the datasheets carefully - 78xx and 79xx have different pinouts!

author: jbb
author_rank: Super Contributor
timestamp: November 24, 2017, 08:20:09 pm
content: Thanks for providing pictures.The diode rectifier is a little concerning. It looks like you've got two half-wave rectifiers. If the currents on the +12 and -12 rail are fairly equal, that should be OK. If the currents are unequal, you will end up with a DC current in the transformer winding, which can be very bad news.DC current in a transformer secondary causes DC flux in the transformer core. A little bit is OK, but if you have too much, the core can enter saturation. During saturation the primary inductance drops away, then the primary current can spike really high and cause damage. So I would say that you definitely need a fuse in series with the primary.A good way around this is to use a centre tapped transformer:

author: nus
author_rank: Contributor
timestamp: November 25, 2017, 09:03:08 am
content: So was more asking about just the buss board and the polarity of the caps. not sure what sort of chaps i should use, was just going to go overkill and do 1000uf. cheers for the heads up on the voltage regulators, just about to start making that board. also, chees for the heads up on the transformer i'll have a look around for some

author: nus
author_rank: Contributor
timestamp: November 25, 2017, 09:06:21 am
content: do you think i will get much loss at the end plug, this board is like 310mm long. main traces are like 100 thou
Does This Schematic Look Right? - Page 1
Forum section: electronics / projects

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: November 06, 2017, 12:56:21 pm
content: It's a high voltage power supply, ignore the diode at the bottom. The numbers on the flyback transformer are the number of turns.This is the transformer and zvs driver:http://highvoltageshop.com/epages/b73088c0-9f9a-4230-9ffc-4fd5c619abc4.sf/de_DE/?ObjectPath=/Shops/b73088c0-9f9a-4230-9ffc-4fd5c619abc4/Products/ZVS_Driver_kit_ACMy question: Should the earth ground be in place on the bottom half of the cascade? Or should it not be grounded?

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: November 06, 2017, 09:52:50 pm
content: bump

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: November 07, 2017, 12:32:41 pm
content: pls

author: prasimix
author_rank: Unknown
timestamp: November 07, 2017, 03:15:48 pm
content: Yes, you can connect to ground any of secondary output, to have ground referenced output (output positive or negative to ground). But, I'm doubting that is enough for driving X-ray tube. Perhaps some sort of output current and voltage control should be necessary for prolonged tube lifetime. Maybe you should consult tube datasheet/manufacturer to see at least what is min. voltage (different anode needs different voltage, e.g. tungsten usually needs 60 kV, some other works starting with just 15-20 kV, etc.). There you can also get some idea about grounding.

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: November 07, 2017, 05:58:09 pm
content: I'm not using a real x ray tube, just an old soviet rectifier. There is some online documentation on how to produce x-rays with it:http://4hv.org/e107_plugins/forum/forum_viewtopic.php?106277

author: floobydust
author_rank: Super Contributor
timestamp: November 07, 2017, 06:12:50 pm
content: They're running over 0.1mA at 50kV through the 2X2 tube (5W good to 15 seconds but very hot).2.2MEG 25W ballast resistor?I'd consider smallish voltage-multiplier capacitors to give current-limiting instead. Ripple should get averaged out over the long exposure times.
Does Windows XP have problems with ”modern” LANs? - Page 1
Forum section: electronics / projects

author: AndersJ
author_rank: Frequent Contributor
timestamp: April 27, 2020, 04:45:29 pm
content: My local network has mostly Windows 10 computers, and a Synology DS713+ NAS as a fileserver.The NAS is a bit slow at times but it works well, and needs no keyboard and monitor.All is well, but not lightning fast.I also have a XP machine, for some legacy projects, and that is where I have problems.It seems there is a timing issue between the XP and the NAS.The XP is very slow to select files on right clicks.File selection takes many seconds, and sometimes it fails totally to select files.It seems like there is a long timeout before it fails.30 seconds perhaps, or 60, irritatingly long anyway.File handling is generally slow, but works,except för the occasional right click issues.Does XP have networking issues, that were not present a few years ago?Any remedies?

author: Wilksey
author_rank: Super Contributor
timestamp: April 27, 2020, 05:48:53 pm
content: Not that I have noticed, I have a Netgear ReadyNAS and that runs the same speed from XP to 10, I run through GB switches, pfSense firewall and a set of 1200Mbps home plugs (TP-LINK), the drives are mapped through Samba 4 DC controller on Ubuntu 20.04 and I have the pfSense virtualised on ESXi, as well as the DC, so there are multiple network routes to go through and it gives me the speed I expect.

author: tunk
author_rank: Super Contributor
timestamp: April 27, 2020, 06:00:34 pm
content: Look like XP uses SMBv1 and there might be some incompatibilities.Maybe there's some settings on the NAS you can change.

author: David Hess
author_rank: Super Contributor
timestamp: April 27, 2020, 09:03:38 pm
content: Other than XP being limited to SMB version 1, there should be no issues. You might check that your switches and network cards have flow control enabled.NFS can be installed on XP if you think it might work better than SMB.

author: Mr. Scram
author_rank: Super Contributor
timestamp: April 27, 2020, 09:07:03 pm
content: It's worth mentioning SMBv1 has been disabled by default on modern systems after it turned out to contain a significant vulnerability.

author: duak
author_rank: Super Contributor
timestamp: April 27, 2020, 09:09:53 pm
content: Have you checked into IPV4 and IPV6 settings? Our home internet provider gave us a new router/firewall that defaulted to IPV6. An older iMac running Mint Linux couldn't reliably access some IPV4 hosts through WiFi.
Does x2 14 DIP ribbon cable to x1 IDE Type Connector Exist - Page 1
Forum section: electronics / projects

author: bostonman
author_rank: Super Contributor
timestamp: August 02, 2024, 01:28:57 pm
content: I'm repairing a counter and it has a flaky ribbon cable connection.It's (what I believe) a x2 14-pin DIP (two separate 14-pin DIPs) to what I'm calling a 28-pin IDE type female plug (the typical rectangular plug that has a key in the middle and plugs into the main board). I've found ribbon cable with a 14-pin DIP to DIP and 14-pin DIP to just the end of the cable cut.Due to not finding this configuration, my thought is to buy the 14-pin DIP to cut end, cut the IDE (?) end, and solder all twenty-eight wires together.Most likely I can buy the plug and and crimp it myself, but believe it takes a press to make the connections tight.Before taking such an approach, does anyone know whether this configuration exists and/or the name of it so I can find it myself?

author: ajb
author_rank: Super Contributor
timestamp: August 02, 2024, 04:03:50 pm
content: The regular IDE type connectors as you call them can be applied using a vise. I usually use a small panavise, but a bench vise will work too (just use some bits of PCB or something to protect the connector if the vise jaws are serrated). Parallel-jaw pliers are also good for smaller connectors, like 50mil pitch connectors on 25mil ribbon. Knipex pliers wrench or similar is great with their high leverage.The DIP connectors will need some sort of supporting die to install. It may be feasible to improvise something, perhaps even 3D printed, for the job, but it may be just buying the ribbon cables with those already installed and saving the trouble

author: ledtester
author_rank: Super Contributor
timestamp: August 02, 2024, 04:07:22 pm
content: Quote from: bostonman on August 02, 2024, 01:28:57 pmYou can use a vise like in this video:https://youtu.be/40oXq8tCrBA?t=2m15sor get this hand tool:https://www.amazon.com/Accessories-Crimp-Ribbon-Cable-Connectors/dp/B007R2JEM4

author: bostonman
author_rank: Super Contributor
timestamp: August 02, 2024, 04:37:19 pm
content: I assume the cables don’t come ore-made then?What is the name of those “IDE” type connectors so I can buy them to attach?

author: ledtester
author_rank: Super Contributor
timestamp: August 02, 2024, 05:02:15 pm
content: They are called "IDC" - insulation displacement connectors.Here is the Digikey product page that has them:https://www.digikey.com/en/products/filter/board-in-direct-wire-to-board/317At Mouser use this page:https://www.mouser.com/c/connectors/headers-wire-housings/and select "IDC" for Termination Style.
Doing opamp educational stuff - suggestions wanted - Page 1
Forum section: electronics / projects

author: DrGonzoDK
author_rank: Regular Contributor
timestamp: August 01, 2017, 06:50:27 am
content: So, I've been contributing some time to a project that teaches high school-age (15-18) kids about electronics - mostly analog with a bit of boolean logic thrown in for good measure.And, one thing that is always a focus of interest is amplification, so I've been working on a "how does an opamp work" thing, and for this thing, I'd really like to sort of build up something basic that works and elaborate that a bit.Now, I've done some basic material on a very basic, three-transistor opamp with about ~15x gain top closed-loop gain, with a reasonably nice bandwidth (at least 1MHz G*BW). I've attached a simple photo (I've translated the annotations to English so you guys can actually understand it) of the first iteration design they're gonna construct...So, to my question, what would be a good next step? Introduce current sources, current mirrors? Or would adding a buffer stage to the output be a better thing to explain?EDIT: Oh, and before I get a lot of "why the f**k is there a germanium transistor in there", we happened to get our hands across a large lot of PNP Ge's for almost no money, so that's why.

author: danadak
author_rank: Super Contributor
timestamp: August 01, 2017, 11:33:14 pm
content: The OpAmp with buffer / output driving stage much more useful.But so are current sources and mirrors, although most of the timethey come with a part internally, one does not need to design themexternal.Regards, Dana.

author: Ian.M
author_rank: Super Contributor
timestamp: August 02, 2017, 12:40:14 am
content: Maybe take a look at the GAP/R P65 OPAMP schematic. Its a very early solid state silicon six transistor OPAMP module. SeeOp Amp History - Analog Devicespage 33 (H.31). Also seehttp://www.philbrickarchive.org/pp65a.htmfor specs and how to trim it (as the PP65A potted module used external trim components).

author: DrGonzoDK
author_rank: Regular Contributor
timestamp: August 02, 2017, 09:14:08 am
content: Quote from: Ian.M on August 02, 2017, 12:40:14 amYeah, I've read that before, it's an excellent piece of writing! And thanks for reminding me of it. Good idea! Obviously one thing that has to be discussed from this is, well, supply voltage. These discrete opamp designs are really for one set of supply voltages - you have to design your desired supply voltage into the value of the resistors to the rails and from the output transistor.I'll check out the fabled Section H document again!!
Domestic induction heater - presentation  - Page 1
Forum section: electronics / projects

author: analityk
author_rank: Regular Contributor
timestamp: February 20, 2025, 10:13:20 am
content: Good morning,I’d like to show you what I’m working on. Maybe you’re familiar with this and have some interesting insights to share.This is an induction furnace. The inductor is connected in series with a resonant capacitor. Thanks to this, at the resonant frequency, the circuit has minimal impedance (theoretically equal to the circuit’s resistance), which makes control significantly easier.To track the phase of the signal, I used a current transformer on the primary winding of the transformer. The transformer is powered by a full-bridge circuit, and instead of using PWM, I control it via phase shift (essentially like two half-bridges, but with a changing "overlap" time).The core of the system is an Infineon (Cypress) PSoC4 CY8C4245AXI-483 microcontroller. To precisely match the operating frequency of the microcontroller and the resonant circuit, the clock for the MCU is generated by an Si5351A chip.Feel free to check out the photo gallery at (Buy Me a Coffee page):https://buymeacoffee.com/romanowski2/galleryI greatly appreciate any technical and material support.(gpt translated ofc)Best regards,Analityk

author: analityk
author_rank: Regular Contributor
timestamp: April 02, 2025, 03:44:26 pm
content: Hi, this time i will show you progress that i did in my induction heater project.Now my stove is able to melt aluminium with only 350 W drawing from psu.More comments about this device you can find in description to this video.https://www.youtube.com/shorts/GSl343ljduA
Don't do this with your BG7TBL distribution amplifier - Page 1
Forum section: electronics / projects

author: erikka
author_rank: Regular Contributor
timestamp: November 20, 2022, 01:49:34 pm
content: Some time ago I purchased a BG7TBL distribution amplifier. It has been working well.But as it mentioned on the front panel it could also be a 10 MHz frequency standard so I opened it up and was happy to see you only needed to add an OCXO to have an standalone 10MHz standard and distribution amp.The external input was still operational and after connecting to an external clock the device switches over to the external clock, this is nice behavior when you want to run everything from one better reference.But something weird showed up.When ever you connect an external reference some phase shifts started to happen. To investigate I used an external source at 10.000001 MHz, 1 Hz offset and recorded the output phase versus the external source using Timelab.As you can see in attached picture the output phase shifts with the same period as the difference in frequency. This suggests that the internal OCXO leaks into the external input signal and causes a phase shift depending on the phase of the internal OCXO versus the external inputSomething to be aware of and maybe avoid this distribution amplifier with an internal OCXO if you ever need to connect it to an external reference.

author: NiHaoMike
author_rank: Super Contributor
timestamp: November 20, 2022, 03:38:23 pm
content: Wouldn't an easy fix be to add a circuit to disable the internal OCXO when external input is connected? Or if the failsafe behavior is wanted, have the OCXO be phase locked to the input.

author: erikka
author_rank: Regular Contributor
timestamp: November 20, 2022, 03:39:47 pm
content: Yes,Depending on your phase accuracy requirements sometimes you have to do a bit more work.
Doorbell extender project - Page 1
Forum section: electronics / projects

author: Peabody
author_rank: Super Contributor
timestamp: May 24, 2018, 10:25:02 pm
content: I have a standard wired doorbell which is powered by 16VAC, but I need to add some kind of extender so if I'm outside on the back patio I can hear if someone is at the front door. There are official doorbell wireless extenders at Home Despot for about $45 or so, which wire into the existing chime unit and broadcast to the new chime, which plugs into mains. But I wonder if there's a cheaper and cooler solution.I already have one of these wireless remote things:https://www.ebay.com/itm/321546878529but it's not clear if I could use it for this. The transmitter is battery powered, but it seems I would need an AC relay at the chime that would short a transmitter key and make it transmit. Then I would need a 5V power supply for the receiver, plus a buzzer of some kind.Has anyone here already gone down this road? Is there a solution that's better than just buying an HD unit?

author: Gibson486
author_rank: Frequent Contributor
timestamp: May 25, 2018, 01:16:13 am
content: Something i learned....if there is something that already does it, just buy it. You could make your own, but then you buy the parts, then you have to put it together, then you realize, dam....I forgot something. Then you have this brick that sits on your desk for the next two weeks. Then you have your wife ask about the project....then you finally get around to finishing it....but you see it is 2 months later and your wife already had her brother install the new thing behind your back.
Doorbell Solenoid: To AC or to DC? - Page 1
Forum section: electronics / projects

author: NivagSwerdna
author_rank: Super Contributor
timestamp: December 01, 2020, 08:44:56 pm
content: I bought an old door chime which has 4 solenoids each of which causes a hammer to strike a chime bar.The chime is intended to be driven by 16VAC with the sequencing of notes performed by an electromechanical device inside the chime (Basically a set of contacts and a motor driven rotor)I would like to replace the sequencer with an ESP32 or similar and activate the bell via MQTT.I could continue to power the device with 16VAC in which case I would need 4x Triacs and associated Optos, or instead drive the solenoids with DC (say 12V?) in which case I would just need some NChannel logic level MOSFETs..Which way do you think I should jump?

author: james_s
author_rank: Super Contributor
timestamp: December 01, 2020, 08:46:53 pm
content: I would start by checking the performance of the solenoids on DC, if they work ok then that's probably the easiest thing to do.I quite like the idea of the motor driven sequencer though, that sort of mechanical contraption isn't seen much anymore.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: December 01, 2020, 08:48:35 pm
content: Oh my god, I just flashed back to my childhood. We had that thing too right next to the door.

author: Zero999
author_rank: Super Contributor
timestamp: December 01, 2020, 09:55:42 pm
content: Please keep the original mechanical timer and make your modifications reversible. It might be worth some money in the future.Another option if it needs AC is to use two MOSFETs connected back-to-back and photovoltaic opto-coupler such the VO3120, APV2111 etc. Does it need to be isolated though? It's not mains, so you could simply drive the TRIACs directly from the MCU. The ESP32 does seem a bit overkill though. You could do this more cheaply with an old 8-bit micro.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: December 02, 2020, 12:01:40 am
content: Quote from: Zero999 on December 01, 2020, 09:55:42 pmWill do.Quote from: Zero999 on December 01, 2020, 09:55:42 pmI need connectivity to my network, as I plan to use this for functions other than just being a door bell. ESP8266 or ESP32 seems the cheapest way to get WiFi and some programmability.

author: amyk
author_rank: Super Contributor
timestamp: December 02, 2020, 03:48:51 am
content: I guess you want to change the notes it plays? Otherwise the easiest option to make it remote would be a relay.
Dot and Tape Supplies ? - Page 1
Forum section: electronics / projects

author: B J
author_rank: Contributor
timestamp: January 04, 2021, 03:59:51 pm
content: I'm looking for a source of the material that we used to use for the "Dot and Tape" method of making a circuit board. --The last supplier I can find is the Bishop Graphics Co., however they apparently no longer exist. -- I want to make quick and cheap, one up boards, and looking for a method to do this. -- Ideas and/or suggestions ? ---Thanks

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 04, 2021, 04:14:11 pm
content: I'd be highly surprised if anyone has made these for years. For quick homemade PCBs, laser transfer or photoetch is the way to go

author: retiredfeline
author_rank: Frequent Contributor
timestamp: January 04, 2021, 04:22:10 pm
content: You got me curious about what they are called. It seems the search term you need is "etch resist transfer". There some hits on shops but the websites were so old you wonder if they really still have stock.Every now and then I see howtos for homemade boards, but I'd rather pay more for shipping or wait, than mess with chemicals, been there done that, and give up soldermask and silkscreen.

author: RoGeorge
author_rank: Super Contributor
timestamp: January 04, 2021, 04:23:34 pm
content: - PCB houses can make them for you pretty cheap now, some for less than $10.- photo method, CNC milling, inkjet printing to copper clad or Laser printer + ironing (heat transfer) the print to the clad, hand drawing with resist ink, etc.Many of the other hand made prototyping techniques are shown here:Eventually you can experiment with various self adhesive tape + Exacto knife.

author: pardo-bsso
author_rank: Frequent Contributor
timestamp: January 04, 2021, 05:11:33 pm
content: Do you mean something like Rubylith?Perhaps sending the patterns you need to a vinyl plotting shop would do. Most of that stuff resists a bath in acid.

author: octillion
author_rank: Contributor
timestamp: January 05, 2021, 01:24:00 am
content: I bought these dry transfer resist patterns from Datak probably late 90's, never used them, but still feel like I'll use them one day. Pictures attached. I also have a scan of their PCB processing instructions, but need to process it a bit to get it to post.I found this website (copyright 2007, different parent company than the last page of the PCB instructions):https://www.industrialelectronics.biz/philmore/datak.htmAnd some residual stock on Digi-Key (marked obsolete):https://www.digikey.com/en/products/detail/datak/DE-51/27709

author: octillion
author_rank: Contributor
timestamp: January 05, 2021, 01:38:46 am
content: Datak Printed Circuit Processes & Instructions
Dot matrix LCD touch screen? - Page 1
Forum section: electronics / projects

author: rf-fil
author_rank: Regular Contributor
timestamp: January 30, 2023, 10:34:44 pm
content: Displays are the bane of my existence.. It's always impossible to source what I need. I would like to design in a dot matrix LCD with a touch screen into my project. About 3 inch diagonal size. Why dot matrix? Low power and visible in sunlight. Both OLED and TFT are common enough, but both are power hungry and aren't visible in direct sunlight. Is it very expensive to get a resistive panel custom designed for a 3rd party LCD? How does everyone go about this, for small quantity prototypes? I like the Sharp memory LCD in particular because of their nice resolution and low power.I would consider e-ink too, but they are too slow to update for my application.

author: Benta
author_rank: Super Contributor
timestamp: January 30, 2023, 11:27:27 pm
content: Which resolution are you looking for?

author: rf-fil
author_rank: Regular Contributor
timestamp: January 31, 2023, 01:54:09 am
content: Resolution is not that critical - anything from 128 x 64 might already work.

author: fchk
author_rank: Frequent Contributor
timestamp: January 31, 2023, 08:28:43 am
content: These displays are quite popular and rather easy to buy - at least in Europe.https://www.lcd-module.com/fileadmin/eng/pdf/grafik/dogl128-6e.pdfhttps://www.lcd-module.com/fileadmin/eng/pdf/grafik/dogxl160-7e.pdfThere are different versions of each display, transmissive, transflective, and reflective - which would be your choice.Touch: For small quantities custom solutions are way too expensive, especially capacitive touch, which needs optical bonding. Resistive touch degrades readability, plus you need a suitable panel.I'd suggest going with PCB based touch with an extra touch controller like this:https://www.microchip.com/en-us/products/touch-and-gesture/capacitive-touch-solutions-for-buttons-sliders-wheels-and-proximityThis boils down to simple PCB design and is well suited for small quantities.fchk

author: Ian.M
author_rank: Super Contributor
timestamp: January 31, 2023, 08:58:38 am
content: Maybe this resistive touch sensor could help?Intelligent Display Solutions TP-CI064-4021-01 2.7in 4-wire Resistive Touch Screen Overlayhttps://export.rsdelivers.com/product/intelligent-display-solutions/tp-ci064-4021-01/intelligent-display-solutions-tp-ci064-4021-01-4/1250235
Double buffering in STM32 with HT and TC interrupts - Page 1
Forum section: electronics / projects

author: Red_Micro
author_rank: Regular Contributor
timestamp: November 18, 2020, 08:38:25 pm
content: I'm trying to build a double buffer (or ping pong buffer) using the HT (Half transfer) and TC (Transfer complete) interrupts from STM32. Also, I'm using DMA with circular array. I have the algorithm below. I know I'm doing something wrong so I appreciate any guidance. The problem I'm facing is kind of like a race condition. When checkingCode:if (half_complete == 1 && transfer_complete == 0)both flags are already active so this condition is not going happen. It seems both interrupts happen too quick so both flags are like fighting. The ADC sampling frequency is 6 kHz.Code:#define ADC_BUF_SIZE 216volatile uint16_t ADC_buffer;volatile int16_t transfer_complete = 0;volatile int16_t half_complete = 0;volatile int32_t array_average = 0;HAL_ADC_Start_DMA(&hadc1, (uint32_t*)ADC_buffer, ADC_BUF_SIZE);while (1){if (half_complete == 1 && transfer_complete == 0){array_average = array_avg (ADC_buffer, 108);half_complete = 0;}else if (transfer_complete == 1 && half_complete == 0){array_average = array_avg (ADC_buffer, 216);transfer_complete = 0;}}/*Conversion DMA half-transfer callback in non-blocking mode.*/void HAL_ADC_ConvHalfCpltCallback(ADC_HandleTypeDef* hadc){half_complete = 1;}/*Conversion complete callback in non-blocking mode.*/void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef* hadc){transfer_complete = 1;}/*Average function */uint32_t array_avg (volatile uint16_t buffer[], uint16_t size){uint32_t sum = 0;if (half_complete == 1) {for (int x = 0; x < size; x++) {sum += buffer ;}}if (transfer_complete == 1){for (int x = 108; x < size; x++) {sum += buffer ;}}return sum/(int32_t)size;}
Double-checking address decoding - Page 1
Forum section: electronics / projects

author: metertech58761
author_rank: Frequent Contributor
timestamp: October 27, 2021, 02:09:57 am
content: So I ended up choosing a replacement MPU for my tester project, and along the way, I had to redo the address decoding for the I/O ranges.Can anyone take a look and see if I did it correctly?

author: MegaVolt
author_rank: Frequent Contributor
timestamp: October 28, 2021, 08:28:10 am
content: Code:A15 A14 A13 A3 A21 U40 0 1 1 U20 0 1 0 U3If I understand correctly, the choice of chips is correct.The polarity of signals A00 and BCS is not very clear? Active 0 or 1?

author: metertech58761
author_rank: Frequent Contributor
timestamp: October 28, 2021, 11:37:05 am
content: The 8CS line is the active-low chip select line for the 8279 IC on the display board, and disregarding shadow copies, should correspond to 0x2008-0x200B.A00 is the mode select line for the 8279; when address 0x2008 is selected, this line should be low, putting the 8279 in data mode. When 0x2009 is selected, this line should be high, putting the 8279 in command mode.

author: MegaVolt
author_rank: Frequent Contributor
timestamp: October 28, 2021, 12:08:22 pm
content: Here is the project in the simplest simulator. You can call the truth table and check if it works correctly.I see the simultaneous selection of BCS and A00 simultaneously with the selection of chips U2...U4. I don't really understand if this should be the case.123.dig.txt rename to 123.digSimulatorhttps://github.com/hneemann/Digital

author: metertech58761
author_rank: Frequent Contributor
timestamp: October 29, 2021, 10:31:11 am
content: I guess I was a bit too optimistic to squeeze the 8279 in like that.I may have to rearrange the coding to move the 8279 down to 0x2800 / 0x2801 instead.

author: metertech58761
author_rank: Frequent Contributor
timestamp: November 01, 2021, 11:40:26 pm
content: OK, so I ended having to kick the 8279's 8CS and A00 lines further down to 0x4000 / 0x4001 (and swap the two addresses in firmware).

author: MegaVolt
author_rank: Frequent Contributor
timestamp: November 02, 2021, 07:44:23 am
content: Glad to hear that the issue is resolved))What program was used to draw the schematic?

author: metertech58761
author_rank: Frequent Contributor
timestamp: November 02, 2021, 12:29:55 pm
content: KiCad.Now that it seems the design of this board has finally settled into place and I have the HC11 chip on hand, I can begin layout of this PCB.Next up - the redesign of the display / keyboard PCB (want to replace the 8279 with something more modern).
Double-even reads from HM628128ALP EEPROMs - Page 1
Forum section: electronics / projects

author: Aggressive_Doughnut
author_rank: Contributor
timestamp: March 23, 2019, 03:14:21 pm
content: I arbitrarily grabbed a tube of HM628128ALP EEPROMs from the shelf, slapped one in my little arduino-based programmer, and gave it a quick test and... oddly... I get no odd values read from the ROM in my little displayContents table, instead I get the data from address 0 showing for both address 0 and address 1, the data from address 2 for both 2 and 3, and so on:000: 2a 2a 0d 0d 2f 2f 34 34 39 39 1a 1a 14 14 0c 0c...When I read the odd values outside of a loop, they all read fine. After a while of fooling around I split the ROM-reading loop into an even loop and an odd loop and everything works great.Has anyone ever seen this before? I don't see it as a "feature" in the datasheet anywhere. I get this for all of my HM628128ALPs but not other EEPROMS.

author: Deni
author_rank: Regular Contributor
timestamp: March 23, 2019, 03:42:25 pm
content: HM628128ALP is SRAM, not EEPROM isn't it? Although that should not affect reading...

author: newbrain
author_rank: Super Contributor
timestamp: March 24, 2019, 03:05:09 pm
content: Yes, it's a 16kB CMOS static ram (neither ROM nor EEPROM).As the programmer is self built, and I presume coded: is it complying with the needed setup and hold times (i.e. CSx, OEn or address to data read)?Is the A0 connection good and low resistance?Can you check signal integrity with a scope?Which speed grade are those RAMs?

author: amyk
author_rank: Super Contributor
timestamp: March 24, 2019, 05:57:09 pm
content: Check the configuration of the A0 pin. If it is set to open-drain (maybe with only the internal pullup enabled) then this behaviour is possible.
Double motor driver with CANFD and EtherCAT - Page 1
Forum section: electronics / projects

author: mkschreder
author_rank: Contributor
timestamp: March 27, 2019, 04:42:24 pm
content: This is a project that I have been developing while streaming my work live on youtube. This is a versatile motor drive circuit with flexibility in mind designed in KiCad on linux.All work (except for the most repetetive and boring stuff) has been reclrded on many hours of video allowing you to follow the design from the ground up.Currently I am working on the firmware for this board continuing in the same live streamed fashion.Link to playlist: KiCad Motor Drive Design:https://www.youtube.com/playlist?list=PLOqygfz5v1haqbrFWuP6PPZdeAk7FletdLink to most viewed video:https://youtu.be/5-GwQi7LG-AEnjoy.And feel free to give me feedback.Sent from my SM-G960F using Tapatalk