hybridfree/eevblog-posts huggingface dataset:
Automatic Integrator Control with time delay IC/oscillator - Page 1
Forum section: electronics / beginners

author: AQUAMAN
author_rank: Regular Contributor
timestamp: June 24, 2014, 11:31:30 am
content: HelloI have a basic opamp integrator circuit. The integrator is quite fast, it integrates over a period of around 300-500nS. I have an SPDT switch that either sets the input to ground or the voltage I want to integrateAt the moment I control it from a DSP through an optical fibre terminals. However I want to somehow remove these terminals and the need for these terminals and the extra control signal from the DSP. So basically I want to make the integration control automated. I wonder if this is possible with some sort of time delay IC like a 555 timer (I dont think a 555 will work though)In the larger circuit I already have a variety of control signals that I could trigger off. You can see the timings I have in the photo I attach. So Vg is turned off, a delay of 200nS occurs, then I integrate for 350nS (or a similar period), then stop.What I would like to do is build a circuit that replaces the IR terminals that I have now with some sort of delay IC that is capable of reproducing the same timings shown. I would somehow trigger it off the falling of Vg.Does anyone have any suggestions?
Automatic phone detection - is this the solution? - Page 1
Forum section: electronics / beginners

author: FriedMule
author_rank: Frequent Contributor
timestamp: August 31, 2022, 05:22:17 am
content: I am trying to get the simplest relay triggers when I am nearby and have found this ESP8266 with a relay on it.It is some Arduino thingy, I have no idea if it demands a separate Arduino board or can run alone?https://www.amazon.de/-/en/gp/product/B07Y8LJG3V/ref=ewc_pr_img_1?smid=A1X7QLRQH87QA3&psc=1Will the solution be able to run this code:https://github.com/skickar/FriendDetectorOr the code in this video:Thank you all:-)

author: rooppoorali
author_rank: Regular Contributor
timestamp: August 31, 2022, 02:28:48 pm
content: For this project, any additional Arduino is not needed. The ESP8266 relay board is enough for handling this project.
Automatic street light | Light sensor | Street light without battery and relay - Page 1
Forum section: electronics / beginners

author: abdulsamaddabu
author_rank: Contributor
timestamp: March 27, 2020, 03:36:21 pm
content: Hey I saw a video few days agoWould someone rectify it, i mean how is his circuit workingi tried it but it was not working as shown in videois this video fake ?

author: SeanB
author_rank: Super Contributor
timestamp: March 27, 2020, 04:28:48 pm
content: Standard triac with a trigger diac, arranged so that the CdS cell is going to short out the gate drive when the ambient light sensed by it is high, and it's resistance is low enough to shunt the gate drive current pulses. Has low sensitivity, and is very sensitive to things like ambient temperature, changes in light level, the particular triac and diac, and has very poor response, so that your load will turn on gradually as it gets dark, as there is a large regime in which it acts like a light dimmer. Best used with resistive lamp loads only, not any sort of LED or discharge lamp, as it will gradually light up the lamp as it gets dark, and dim it as the sun rises.

author: Zero999
author_rank: Super Contributor
timestamp: March 27, 2020, 04:40:03 pm
content: The circuit should work. When it's dark, the LDR will have a high resistance and current will flow through R1 and the DIAC to the TRIAC's gate, causing it to fire, when the mains voltage exceeds the DIAC's breakdown voltage. When the LDR is exposed to light, its resistance drastically drops cutting off the current to the DIAC and TRIAC's gate, so it won't fire.Could you have MT1/A1 and MT2/A2 connected backwards?Were you using an LED or compact fluorescent lamp? You could try connecting a resistor in parallel with the lamp. Try 100k/1W.

author: abdulsamaddabu
author_rank: Contributor
timestamp: March 29, 2020, 04:15:37 am
content: i dont know what will happen when i will connect ac power backward as i was not able to get this circuit workingbut this make me will it work and if yes then why

author: Zero999
author_rank: Super Contributor
timestamp: March 29, 2020, 12:29:36 pm
content: Quote from: abdulsamaddabu on March 29, 2020, 04:15:37 amIt doesn't make any difference which way the mains power is connected, but getting MT1/A1 and MT2/A the right way round is important.
Automatic Voltage Regulator Thoughts  - Page 1
Forum section: electronics / beginners

author: sarakisof
author_rank: Newbie
timestamp: June 04, 2025, 10:18:06 pm
content: Saved a servo motor AVR 500VA from trash. I was ignoring its existence. Dealing with some issues.1.Output AC voltage measures too high. Tried to turn that trimmer pot (red arrow in the pic below) but did nothing.2. AC Voltmeter seems to be stuck or defective (?).3. Based in EU but I own some US gear. 100W max 50/60Hz. Could I use it as a step down transformer for this purpose only?

author: PGPG
author_rank: Frequent Contributor
timestamp: June 05, 2025, 04:59:02 am
content: Quote from: sarakisof on June 04, 2025, 10:18:06 pmI have never had/seen such regulator, but I don't think so.I'd expect from it possibility to regulate output ±10..20% from input voltage.
Automatically switch between supply voltage using a P-channel MOSFET - Page 1
Forum section: electronics / beginners

author: nemail2
author_rank: Regular Contributor
timestamp: April 26, 2021, 09:30:06 pm
content: Hii have a Teensy 3.5 mounted on a PCB of mine where I also feed it 3.3V from, from a LD33V regulator on my PCB.Using a P-channel MOSFET i would like to turn off the PCB-supplied 3.3V rail if the USB port of the Teensy gets connected (e.g. to a PC for programming and debugging).The needed 3.3V would then be generated onboard of the Teensy 3.5.Will this work like intended, even if the 3.3V rail is 0V (e.g. because the PCB is turned off) while the USB port is connected and powered and hence seeing 5V on VUSB?Thanks!

author: mvs
author_rank: Frequent Contributor
timestamp: April 27, 2021, 11:32:21 am
content: P-MOSFET has a parasitic diode inside (shown on your schematic), so your +3.3V rail will get around 2.7V from onboard vreg of the Teensy.

author: nemail2
author_rank: Regular Contributor
timestamp: April 27, 2021, 11:43:04 am
content: well observed, thanks for the hint! is there an elegant way around that or another solution for the issue?i have attached how my 3.3V rail supply looks like. usually I put a reverse diode across Vout and Vin of a linear regulator like the 7805 but I read somewhere that the LD1117V33 doesn't need one...?if the 3.3V rail is up, I guess it wouldn't hurt if it would get around 2,7V from the Teensy VREG, or would it? But also the question is, would it hurt if the 3.3V rail was down, e.g. because the PCB is completely powered off but the Teensy is still powered via USB?

author: mvs
author_rank: Frequent Contributor
timestamp: April 27, 2021, 12:23:54 pm
content: You can swap source and drain of the MOSFET, then switch will work as intended.If you have no other load at +3.3V rail, you can try to connect it directly (most LDOs will survive +3.3V at output with 0V at input).

author: girishv
author_rank: Regular Contributor
timestamp: April 28, 2021, 01:13:40 pm
content: I found the following link very useful when I was researching for Bidirectional control.https://www.ti.com/lit/pdf/slva948?keyMatch=SLVA948&tisearch=search-everything
Automating/Controlling an electric wall heater. - Page 1
Forum section: electronics / beginners

author: paulca
author_rank: Super Contributor
timestamp: September 12, 2019, 07:34:20 pm
content: I have a fancy wall heater. It has a vertical 1 or 2kW fan heater in the back and a glass fronted fake fire effect on the front. I want to take remote control of it from software.The heater is "digital", ie, it's all soft switches. There are two buttons, Flame and Heat. Flame cycles the flame effect through low, mid high, off. Heat cycles through Fan, Low, High. The IR remote also has a "Power off" button.When you power it, it beeps, but defaults to the off state. The press buttons on the side of the fire will accept input but the remote wont until you press the "Power" button the remote.The options open to me are:1.IR Sender to control it. This has the advantage that I don't need to do anything to the fire. It has the downside that in order to get the heater into a known state before I start sending IR codes I have to power cycle it with a relay. It consumes 8A on high and I have a 10A relay.2.Open it up. Tap the push buttons with some wires. Drill a hole, bring the wires out of the metal case and put a Wifi microcontroller and a few mosfets to "press" the buttons. I believe I still need to power cycle the heater to get to a known state. (There is no way to know what state the "Heat" function is in that I can see, so power cycle returns that to a known OFF state).vvvv
Automotive 15 to 3v ideas. - Page 1
Forum section: electronics / beginners

author: chinoy
author_rank: Regular Contributor
timestamp: November 28, 2023, 09:02:06 am
content: My application is automotive. so power in will be between 14.4 and 15v d/c.I need 3.3v or 5v for my my arduino. And display.What is the best way to do this.Space is a constraint. PCB is already made.How I have done it in the past when space was not an issue was Diode to 7812 to AMS1117 3.3v or 5vRight now I have space for one SMD 5 volt regulator 78M05. The data sheet says this can work upto 30v but even at 15V heat is an issue.Idea Im thinking off.1. Just add a resistor on vin. 220 ohms to 470 ohms.2. Double stack two regulators i.e. put the 78M12 then on top of that a 78M033. Use a resistor and 7volt Zener.Any other ideas ?.

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: November 28, 2023, 09:27:26 am
content: A resistor, transorb and a 7805? Resistor + transorb to deal with load dump, regulator to get the final voltage. Whether it works depends on current draw - do you know what that is?

author: Psi
author_rank: Super Contributor
timestamp: November 28, 2023, 09:52:22 am
content: Use a switchmode module that comes in a TO-220 style 7805 package.No more heat issues.https://www.digikey.com/en/products/detail/recom-power/R-78K5-0-0-5/18093025?s=N4IgTCBcDaIEoFoDsAOA0gVgHQAYE6wxAF0BfIAedit: sorry, misread your regulator space as a TO-220

author: Dan123456
author_rank: Regular Contributor
timestamp: November 28, 2023, 10:15:10 am
content: I was gonna say use a regulator, but those things things Psi recommended look really cool!Also, I’m sure you have probably already thought of it but don’t forget to put a little fuse in there! Depending on where you are tapping power from, there could be a 30A fuse for that circuit and I can’t imagine an Aurduino would like 30A very much if something got shorted

author: Psi
author_rank: Super Contributor
timestamp: November 28, 2023, 11:01:22 am
content: They make smaller converters that will do 5V 500mA from up to 36V as switchmode.Here's one that's around 4x3mm PCB module.But its a bit more complicated to use and is intended to solder SMT style to another PCB with some extra caps.https://www.digikey.com/en/products/detail/texas-instruments/LMZM23600V5SILR/9692645?s=N4IgTCBcDaIDIFkBaCwGYBsAGLA1ArAMoCScASiALoC%2BQA

author: BeBuLamar
author_rank: Super Contributor
timestamp: November 28, 2023, 12:20:55 pm
content: I would get one of the Ruideng buck converter. A 5A unit would cost like $30 or so.

author: chinoy
author_rank: Regular Contributor
timestamp: December 02, 2023, 07:21:59 am
content: my current draw is 350 mili amps.Thank you for the ideas.
Automotive Mosfet Driver - Page 1
Forum section: electronics / beginners

author: NotDave
author_rank: Newbie
timestamp: August 09, 2024, 04:42:14 pm
content: Hi,I am building a DIY PDM for an automotive project, I have the following circuit for the outputs, there are 12 of them with the MAIN12V and GND-PWR all connected together. The issue that I am having is the output on indicators for each channel are slightly illuminated all the time and if I PWM an inductive load they flash on all channels with the flyback.Do you have any suggestions on how to better design the output status LED's or better protect the outputs from flyback? I am assuming there is diode leakage or something?

author: TimNJ
author_rank: Super Contributor
timestamp: August 09, 2024, 05:16:19 pm
content: Is the MOSFET really turning off? What is the gate source voltage? Check if it's really pulling down the gate-source completely to 0V. Do you really have the two GND pins disconnected?Schottky leakage is pretty high, yes, but maybe only 10uA @ 25C here, which is probably not enough to turn on the LED noticeably. I can't remember, off hand, how efficient the high efficiency greens are..Just remove the top diode and check.

author: NotDave
author_rank: Newbie
timestamp: August 09, 2024, 06:03:56 pm
content: All the grounds are common through the car, the GND-PWR is just a reference to the large copper pour for the lug to connect grounds.The mosfet is controlled with the high side drive since it is a N channel, here is a table from the datasheet.I will scope the mosfet gate pin and see if it is going to 0V or not

author: Le_Bassiste
author_rank: Frequent Contributor
timestamp: August 11, 2024, 08:35:37 am
content: Quote from: NotDave on August 09, 2024, 04:42:14 pmit's the supply current of your gate driver on PIN6 (and then coming out of PIN2) that's flowing through the LED.

author: PGPG
author_rank: Frequent Contributor
timestamp: August 11, 2024, 02:58:50 pm
content: Add resistor paralel to LED.

author: NotDave
author_rank: Newbie
timestamp: August 11, 2024, 05:19:41 pm
content: Thank you!
Automotive oscilloscope test leads question - Page 1
Forum section: electronics / beginners

author: Chris Wilson
author_rank: Super Contributor
timestamp: November 17, 2019, 01:34:59 pm
content: Can I use 50 Ohm co-ax to make my own (much cheaper) 100MHz scope probe extension leads similar to these please/https://www.picoauto.com/products//test-leads/premium-test-lead-3m-bnc-to-4mm-black-permanent-groundMost of my work is looking at real time signal from things like ABS (wheel speed sensors), both analogue and digital where I need a long lead to reach from within a vehicle to underneath, for a laptop connected USB scope. Thanks.

author: soldar
author_rank: Super Contributor
timestamp: November 17, 2019, 03:04:59 pm
content: I don't know what kind of bandwidth you really need but I have managed fine with coax of any kind or even twisted pair. Heck, I am sending base band video over twisted pair right now with fine results. I think it's when you are up into hundreds of MHz and longer distances that you need to start being more careful. A length of coax or CAT5 should work well, I think.

author: Chris Wilson
author_rank: Super Contributor
timestamp: November 17, 2019, 03:58:02 pm
content: OK, thanks, as my twisted pair stuff (CAT cable) is solid core and as coax seems easier to terminate in BNC I'll try some RG-58, much appreciated.
Automotive PSU Noise - Page 1
Forum section: electronics / beginners

author: NickFearnley
author_rank: Newbie
timestamp: January 24, 2025, 11:46:57 pm
content: Hi all, I've been playing with some automotive electronics and I need a good PSU design for some of my ideas. I have been using cheap amazon PSU boards but wanted something I can integrate onto my own designs. I took inspiration from the schematic from an automotive ECU, so the first part of my design (which includes some protection components, a varistor and a fuse and some protection diodes) is a 5V regulator (LM2940). The second part of the design includes an NCP1117 to provide me 3.3V for an RP2040 IC.I created a small PCB and had it made up. I managed to get the SMD components baked on in my little reflow oven (EZMake oven on Adafruit!).I haven't tested it with any significant circuitry yet but I have loaded it with a 47ohm resistor and measured the output. It's MUCH noisier than I expected. I figured the 3.3V side might not be ideal (as I took that design from the PI Pico reference - not automotive...), but the 5V output is also quite noisy. It has some ripple but minor, the noise is ONLY when the engine is running. It's an old VW, so really it's ignition and alternator noise...I used a handheld scope to measure both outputs. You can see the 5V rail can glitch between 3 and 7 volts, albeit for only around 0.5uS. The 3.3V rail can glitch between 2.4 and 4.8 volts for around the same period. I suspect the same transient causing both. Not sure they're long enough to cause issues but possible, I have SPI (display) and CANbus planned to hang off the rails.I have added a large electrolytic cap on the 12V rail to see if that had an effect but it doesn't.Please see my circuit design, the PCB, and two scope images for the 5V and 3.3V rails.Very much appreciate guidance to improve this (or stop worrying about it.....). Elsewhere, I've had suggestion to just give up and buy a buck converter but for me this is a learning experience.

author: Smokey
author_rank: Super Contributor
timestamp: January 25, 2025, 01:32:45 am
content: 12V automotive systems are nasty environments, especially older cars. Expect all sorts of bad stuff.For your LM2940, look at the "ripple rejection" spec and plots.You will probably want to add an input filter if you can't deal with the noise getting through the regulators.

author: ahsrabrifat
author_rank: Regular Contributor
timestamp: January 25, 2025, 07:21:36 am
content: You can add a TVS diode across the input to clamp transients. You need robust input filtering.

author: NickFearnley
author_rank: Newbie
timestamp: January 25, 2025, 03:25:10 pm
content: Will do and yes better filtering is a good idea. As mentioned the front end (5v) is almost identical to an existing design for an established ECU, so they must have accepted the transients as acceptable for their microcontroller….

author: NickFearnley
author_rank: Newbie
timestamp: January 25, 2025, 03:26:46 pm
content: Thanks for the TVS tip, correct, and if you look at the schematic a TVS is already included as part of the reference I used for the 5V side.
Autorange current measuring with ESP8266 - Page 1
Forum section: electronics / beginners

author: mdijkens
author_rank: Regular Contributor
timestamp: February 28, 2017, 05:56:15 pm
content: I'd like to build a wifi current measuring device based on an ESP-12E and an ADS1115 I have laying around with a range from 1uA to 500mA.I thought of using a 1 ohm 1% resistor for the mA range and a 1K ohm 1% for the uA range.Now I am wondering if I could make it auto-switching by automatically putting the 1 ohm in parallel with a MOS FET Trigger Switch Drive Module from eBay controlled by the ESP when measured voltagedrop over the 1K becomes to high ....This might be a very beginners' approach but is this feasible ?If so, could I extend this approach with more resistors and more mosfet modules to get a better range or better accuracy?

author: fki82
author_rank: Contributor
timestamp: February 28, 2017, 08:07:48 pm
content: I'm not sure what you mena exactly with "MOS FET Trigger Switch Drive Module from eBay", but i assume your curcuit would look a lot like what Dave preseted here:

author: mdijkens
author_rank: Regular Contributor
timestamp: February 28, 2017, 08:37:13 pm
content: No a bit more simplistic. I want to usehttp://www.ebay.com/itm/201662448218to switch a 1 ohm shunt parallel to the 1k shunt.

author: fki82
author_rank: Contributor
timestamp: March 01, 2017, 12:41:57 am
content: The Ebay offer doesn't really say which MOSFETs are used and how the circuit works, so not really sure how well this module would work. But for $1.33 there is not much to lose anyway...What kind of current do you want to measure? (AC/DC)What Voltages are to be expected?Of course, you can do it with parallel shunts.But there are some risks for the connected devices, you need to take care of.If the current/voltage on the shunt resistor rises very quickly, the uC could be too slow to switch the second, low value, resistor and the adc is fried.The same applies if the uC is off.You should protect it via a high value series resistor at the ADC input. You could also add some clamping diodes, just to be sure (The ADC should already have internal ones, I didn't check if they would do the job on their own).The precision also could be an issue.Depending on the leakage current of the MOSFETs, the lower current range could be off for low currents.This may or may not be a problem for your application.

author: mdijkens
author_rank: Regular Contributor
timestamp: March 01, 2017, 09:40:44 am
content: Thank you for your valuable comments.I will measure fluctuating current draw from one 18650 cell in the range of 1uA to 500mA. Main reason for this project is to have it automatically switch the ranges sinces the current draw will fluctuate all the time and without it it is difficult to read the sub mA currents which occur to short to change range manually.The high value resistors, should I put them on all 4 inputs of the ADC? What would be a good value to start with?About the precision, I was hoping to correct that in software but of course I don't know if the correction is linear or more complex (maybe calibration table)...
Autotune PID c code example - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: December 15, 2019, 01:28:04 pm
content: 1. Looking for some autotune PID C code working ones. Which works directly or some minor modifications.2. Application is heater.3.I have tried arduino autotune pid library, but everytime it autotunes different PID values on same settings.4. Tried some from this also:https://github.com/search?q=autotune+pidbut not working properly.

author: jonroger
author_rank: Regular Contributor
timestamp: December 15, 2019, 02:23:42 pm
content: You can often outperform PID with some simple code. For example, heater full on or off when there is a large error and switching to small fixed adjustments per sample period to a duty cycle when error is small.
Autotune PID C code microcontroller start point - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: November 21, 2019, 03:03:11 pm
content: 1. Want to write autotuen PID for heater application. Can you point to some good starting point for c code?2. Any reference library for this?3. tried autotune arduino PID library, but temp is oscillating at set point.

author: Mattjd
author_rank: Regular Contributor
timestamp: November 23, 2019, 10:47:39 pm
content: Id suggest tuning the gain values in say simulink or by hand and then transferring to C.

author: Rerouter
author_rank: Super Contributor
timestamp: November 23, 2019, 11:18:47 pm
content: Split it into 2 parts, the PID control, and the autotuning,Each of these have a number of approaches, but lets say we stick to the normal PID controlSo you now want to auto-tune it, the most common approach is called "step response", where it fixes the output, wait for it to stabilize, change the output by a step of x% wait for it to stabalise, and using the data between those 2 points to work out which values you want (sometimes PI or PD control can behave better than PID)I would begin by putting together the PID or reusing an existing one, you can do auto-tuning with normal PID libraries,

author: Mechatrommer
author_rank: Super Contributor
timestamp: November 24, 2019, 04:49:24 am
content: the academic version is called "adaptive control" or maybe the "robust control", prepare for heavy math belt. the non-academic, or maybe the empiric method isZiegler–Nichols tuning methodbut its heuristic and meant to be done manually by human anyway...trying to do that automatically in code probably resulting in less than ideal time solution, and re-testing, adjustment or recalibration probably will interrupt the working operation of the system, hence the "adaptive" method is developed, i've never tried any of them so this is just a wild guess.
AUX input trough CD player - Page 1
Forum section: electronics / beginners

author: KrisBendix
author_rank: Contributor
timestamp: September 29, 2018, 08:47:30 pm
content: Hi.Just a random tinkering project. I want to use a car radio as an amplifier. Need to get audio in somehow. It has a removable CD player. The connector pins have left and right channels (and s-ground which is for audio input too I guess?). I wonder if there is a way to trick the radio so it stays on CD play mode and lets the audio trough. Ideally to work without the CD player attached. Would free up space for a power supply.Any pins to connect or something like that?

author: jeroen79
author_rank: Frequent Contributor
timestamp: September 29, 2018, 09:49:27 pm
content: An easy way is to keep the CD player attached with a CD in it.Then you switch the audio pins to your Aux.I see that there are two Bus pins. (Bus- is also Gnd)Presumably this is used for the CD player and radio to communicate and let the CD player tell the radio that it is playing a CD.You should investigate what is transmitted over this bus.You can then program a microcontroller to send the same signals.Do you want to keep the radio function?You could also wire the Aux in between the amplifier section and radioreceiver.May be add a switch or relay to keep both functions.

author: KrisBendix
author_rank: Contributor
timestamp: September 29, 2018, 10:59:40 pm
content: No, I don't think I would use the radio. Will have to investigate that option. Thanks for the idea.I think it also has a connector for tape player on the bottom. Maybe it is "less digital". Working with microcontroller would be a bit too complicated for this project tho.

author: robjodicarter
author_rank: Regular Contributor
timestamp: September 30, 2018, 12:57:25 am
content: What car radio is it factory or aftermarket, I made an adapter for the one I have in my garage. Once the radio sees that there is power going to the CD player it will pop up when you turn it on.Quote from: KrisBendix on September 29, 2018, 08:47:30 pmSent from my PH-1 using Tapatalk

author: KrisBendix
author_rank: Contributor
timestamp: September 30, 2018, 10:13:00 am
content: Factory. Model is bl4c 66 9s0 from Mazda 232.

author: Audioguru
author_rank: Super Contributor
timestamp: September 30, 2018, 04:42:00 pm
content: Many people feed audio into a car radio with a little stereo FM transmitter that has a short range.
Avago/Broadcom - PCIe Switch Datasheet??? - Page 1
Forum section: electronics / beginners

author: Tantalum
author_rank: Regular Contributor
timestamp: May 28, 2016, 10:56:53 pm
content: HelloWhy are the datasheets from Avago/Broadcom not available publicly?I actually wanted to determine how difficult it would be to implement a PCIe switch on a PCB. I needed a reference design, a BOM and find out if those chips only needed basic configuration data in an eeprom or if they needed to be programmed from scratch.I can't understand why those information aren't available, there is absolutely no secret or strategic important information about their products in those datasheets.

author: amyk
author_rank: Super Contributor
timestamp: May 29, 2016, 02:48:36 am
content: Short answer: Because they're a bunch of uptight b*stards. You can find datasheets for PCIe switches from IDT here:http://www.idt.com/products/interface-connectivity/pci-express-solutions/pci-express-switchese.g. here's onehttp://www.idt.com/document/dst/89hpes16nt16g2-datasheetIf you search around their site you'll find more information on them. Look for "user manual" or "hardware design guide".

author: Tantalum
author_rank: Regular Contributor
timestamp: May 29, 2016, 07:00:29 am
content: Actually I was looking for a PCIe gen3 switch, 16 lanes 5-6 ports.Only PLX/Broadcom has such ones :/.

author: Kalvin
author_rank: Super Contributor
timestamp: May 29, 2016, 01:20:10 pm
content: Try to find reference designs or open sourced designs that contain the devices you want to use. Maybe that will help you to get started.

author: amyk
author_rank: Super Contributor
timestamp: May 29, 2016, 03:50:57 pm
content: IDT has some, looks like you need to register to download from their site but you can find the datasheets elsewhere too:http://www.datasheetlib.com/datasheet/1428418/89h32h8g3_idt-integrated-device-technology.html

author: Tantalum
author_rank: Regular Contributor
timestamp: May 29, 2016, 07:03:16 pm
content: Quote from: amyk on May 29, 2016, 03:50:57 pmYes I know, they have 3 such switches but:1. They are too huge 32 lanes, those bga chips have between 484 and 1156 balls.2. All 3 are marked as "obsolete"
Avalanche beacon 457Khz transreciever - Page 1
Forum section: electronics / beginners

author: A2
author_rank: Contributor
timestamp: December 21, 2013, 10:25:35 am
content: I am embedded engineer & have to experience of wireless communication sytems. I have to make avalance beacon for 457Khz.I was looking for ready made products but they are very expensive go upto $300.I am looking for some less expensive. I didn't find any circuit for it on internet.Any helpI have to also find position & direction, it includes embedded programming, that I can handle.

author: Zero999
author_rank: Super Contributor
timestamp: December 21, 2013, 01:39:56 pm
content: It's probably expensive because they're safety critical and need to work over a wide temperature range and high humidity. Just buy a good quality one, then at least you can be sure it'll work and comply with the relevant standards.For educational purposes, here's what I found from Google search:https://s3.amazonaws.com/BackcountryAccess/content/papers/457andFuture_000.pdfhttp://arc.lib.montana.edu/snow-science/objects/ISSW-1984-048-053.pdf
Avalanche Transistor - Page 1
Forum section: electronics / beginners

author: kumar
author_rank: Contributor
timestamp: July 15, 2014, 10:55:11 am
content: I want to use an avalanche transistor in my project. It should have a rise time of 1nS and should work at 500 V min. Can any body suggest a suitable transistor ?

author: woodchips
author_rank: Frequent Contributor
timestamp: July 17, 2014, 02:24:19 pm
content: My understanding is that any transistor will avalanche if subjected to a high enough voltage.I had an old scope that used avalanche transistors in the timebase, five of RT3333A across +/-1000V to get a 20V or so sweep voltage at ps/division.Seem to remember an article in Wireless World many decades ago about avalanche transistors.Best bet is to simply experiment with low voltage transistors, to reduce the PSU voltage needed, and see what happens.
how to find low cost pressure sensor - Page 1
Forum section: electronics / beginners

author: avaqsemi
author_rank: Newbie
timestamp: July 05, 2023, 04:19:32 am
content: Any advice to find low-cost pressure sensor? Thanks.

author: xavier60
author_rank: Super Contributor
timestamp: July 05, 2023, 06:18:51 am
content: Quote from: avaqsemi on July 05, 2023, 04:19:32 amI buy the Freescale MPVZ4006GW7U for my washing machine repairs. It's 0 to 6 kPa.I get them for half the standard price on Aliexpress.

author: artag
author_rank: Super Contributor
timestamp: July 05, 2023, 03:09:22 pm
content: I like the BMP280 for atmospheric pressures. The original BMP280 is EOL - there are plenty still available but for new designs you should probably look at one of its successors.

author: Jamesll
author_rank: Newbie
timestamp: July 06, 2023, 06:57:53 am
content: By considering the features, specifications, and calibration requirements, you can select the appropriate low-cost pressure sensor that meets your specific application needs. A further reading ishttps://www.avaq.com/technology/low-cost-pressure-sensorThanks hope it helps!

author: radiolistener
author_rank: Super Contributor
timestamp: July 06, 2023, 07:38:42 am
content: Quote from: avaqsemi on July 05, 2023, 04:19:32 amIt depends on what pressure sensor you're needs exactly. There are a lot of different pressure sensor types, thousands of different types. What do you need exactly?

author: voltsandjolts
author_rank: Unknown
timestamp: July 06, 2023, 07:59:58 am
content: Guys, don't waste your time, this is just trolls from avaq semiconductor. They are really crap BTW.

author: Simon
author_rank: Unknown
timestamp: July 06, 2023, 05:32:28 pm
content: Yep OP and JamesII have a fingerprint match. Both banned. I would never buy products from people who use such stupid tactics.

author: liaifat85
author_rank: Regular Contributor
timestamp: July 07, 2023, 07:33:17 am
content: It's not clear to me what kind of pressure sensor you're looking for. Is it a barometric pressure sensor or the pressure we apply with force? If you're looking for a baromatric pressure sensor, then you can choose BMP 180 or BMP 280https://www.theengineeringprojects.com/2023/06/how-to-interface-bmp180-air-pressure-sensor-with-pi-4.htmlhttps://www.amazon.com/Adafruit-BMP280-Barometric-Pressure-Altitude/dp/B013W0RR6YIf you're trying to sense applied pressure, you can choose an FSR:https://www.sparkfun.com/products/11207

author: Simon
author_rank: Unknown
timestamp: July 07, 2023, 09:21:16 am
content: because they are spammers, one pretends to want to know something then "another account" that is also them replies.
AVdd and DVdd - Page 1
Forum section: electronics / beginners

author: Nikos A.
author_rank: Regular Contributor
timestamp: June 10, 2020, 02:57:47 pm
content: Hi everyone,I design a PCB and I will use some analog components such as Op Amp and Voltage reference (this is my first time of combining analogs and digitals). I want to seperate the voltage lines and for that reason I will use AVdd and DVdd lines.I have a single output buck converter, can I split buck converter's output to create both AVdd and DVdd lines? Of cource I will use AGND and DGND...For example something like thisThanks in advanceNick

author: schmitt trigger
author_rank: Super Contributor
timestamp: June 10, 2020, 03:16:38 pm
content: Yes.However, it is good engineering practice to decouple both with an L-C filter on each leg.

author: Nikos A.
author_rank: Regular Contributor
timestamp: June 10, 2020, 03:21:11 pm
content: Thank you for your prompt responce!!Quote from: schmitt trigger on June 10, 2020, 03:16:38 pmAny advice of calculating the L-C filter?

author: Nikos A.
author_rank: Regular Contributor
timestamp: June 10, 2020, 03:27:14 pm
content: I will use the TPS62740 buck converter and the manufacturer suggests an LC filter as shown belowhttp://www.ti.com/lit/ds/slvsb02b/slvsb02b.pdf?HQS=slvsb02-aaj&ts=1591802713143&ref_url=https://www.google.com/I will use the LOAD pin of the buck converter to supply some of the digital and analog peripherals. Can I use the same LC filter applied on converter's Vout?

author: schmitt trigger
author_rank: Super Contributor
timestamp: June 10, 2020, 07:05:03 pm
content: You need to calculate according to filter any dominant frequencies that you wish to suppress.As a rule of thumb,and it is only a rule of thumb,I use the cutoff frequency at 1/100 to 1/1000 of the clock frequency.

author: Nikos A.
author_rank: Regular Contributor
timestamp: June 11, 2020, 05:45:20 am
content: Could I use just decoupling capacitors on each leg?

author: schmitt trigger
author_rank: Super Contributor
timestamp: June 14, 2020, 10:23:14 pm
content: It all depends on your application.Back when video was still analog, any switching harmonics which fell near the chroma subcarrier frequency, would produce very visible and annoying chroma beats even at 60 db down.Other applications may be more forgiving.
Avoiding Inductor Transients - Page 1
Forum section: electronics / beginners

author: Legion
author_rank: Frequent Contributor
timestamp: March 19, 2014, 08:56:50 pm
content: I'm going to be exploring RL, RLC, LC circuits. Basic stuff, building a filter, looking at output on scope, etc. to ground theory in practice. Only thing I'm concerned about are the potentially large currents/voltages induced when switching the circuit on and off. I don't want to damage any equipment... or myself. If I keep my frequencies below 20kHz and my voltage below 10Vpp, is that enough to keep transients to low levels? Do I need to use inductors below a given inductance value?Maybe I'm being overly cautious but the electronics book I'm reading talks about transient voltages easily exceeding 300V. I'm not sure if a breadboard can handle that.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 19, 2014, 10:15:15 pm
content: If you're doing filters, you're doing (more or less) constant impedance stuff, which won't generate spikes. Rapidly changing impedances, like switches going from closed to open, are what make things dramatic.Tim

author: Legion
author_rank: Frequent Contributor
timestamp: March 19, 2014, 10:20:11 pm
content: Quote from: T3sl4co1l on March 19, 2014, 10:15:15 pmBut there will be switches...

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 19, 2014, 10:43:00 pm
content: Ah, then you'll probably want to put some diodes in to divert the current as needed.Read up on switching circuits, get comfortable with the idea of how an inductor works. Voltage only goes as high as you let it, and current is never more than applied (in the exact same way that a capacitor only delivers as much current as you discharge from it, and never at a higher voltage than it was charged to).Tim

author: Legion
author_rank: Frequent Contributor
timestamp: March 19, 2014, 10:50:44 pm
content: Does shutting off the power have any surge risk to equipment (scopes, FG, components, breadboard)?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 19, 2014, 11:52:57 pm
content: Not usually? Idunno, what power?

author: VK5RC
author_rank: Unknown
timestamp: March 20, 2014, 02:14:57 am
content: Quite a bit depends on the Q of the inductor and any C R after that and before your scope etc, I don't know what equations would help you calculate the peak voltage on collapse of the induction field. I presume you are using AC based around zero volts, a diode won't work for that (unless your working voltage is below its forward conduction and the leakeage doesn't stuff up your l-c calculation - I think it would), I suspect if you are only 10mV or so in the circuit, not too high a Q inductor, and some C R after, and you start on high range with the scope you should be ok. I am sure others can give you a better answer.
AVR atmega32a EEPROM question - Page 1
Forum section: electronics / beginners

author: CalebMcNevin
author_rank: Newbie
timestamp: April 18, 2013, 02:30:56 am
content: Hi,does anyone know if it's possible to accidentally overwrite your program by saving data to EEPROM on an AVR microcontroller? I'm planning on generating random numbers by giving an arbitrary seed on my first power up, then using the last random number generated before power down as the new seed for the following cycles, and I don't want to screw my program up by overwriting part of it. Or am I just completely off? Is the program even in the EEPROM? :pThanksCaleb

author: TerminalJack505
author_rank: Super Contributor
timestamp: April 18, 2013, 02:35:46 am
content: The program is in flash memory not EEPROM so you will be fine.

author: CalebMcNevin
author_rank: Newbie
timestamp: April 18, 2013, 02:59:00 am
content: I guess my noob is showinglol, thanks!

author: Psi
author_rank: Super Contributor
timestamp: April 18, 2013, 12:09:59 pm
content: Don't forget to program the EESAVE fuse bit if you want to preserve EEPROM data between reprograms.(By default the EEPROM data is erased everytime you reprogram the flash)
AVR C  - Page 1
Forum section: electronics / beginners

author: bogdan2013
author_rank: Regular Contributor
timestamp: February 21, 2013, 01:22:03 pm
content: Hello !I want to learn more about AVR C programming language . I understand the basics , but I saw in more complex scripts this words :uint8_tvoilatileTTCRTIMSKTCNTI don't know what are and what are doing .

author: Simon
author_rank: Unknown
timestamp: February 21, 2013, 01:24:25 pm
content: You could start by posting in the microcontroller section of the forum !

author: bogdan2013
author_rank: Regular Contributor
timestamp: February 21, 2013, 01:25:48 pm
content: Ok . Sorry !

author: Kremmen
author_rank: Super Contributor
timestamp: February 21, 2013, 01:34:51 pm
content: Like the man said, there is a better forum for this. Anyway, you have a lot of study in your future. Suggested reading:"uint8_t" - one of the machine architecture independent typedefs in <stdint.h>, a standard toolchain header file. Study AVR-libc runtime library, documented at:http://www.nongnu.org/avr-libc/"volatile" - C keyword; study C language tutorials and guides, available in Interweb and all over the place.TTCR, TIMSK, TCNT - processor peripheral register defines in <avr/io.h>. Study the relevant MCU documentation from Atmel, freely available athttp://www.atmel.com. For example, the popular ATMega328 used in Arduino, can be found here:http://www.atmel.com/Images/Atmel-8271-8-bit-AVR-Microcontroller-ATmega48A-48PA-88A-88PA-168A-168PA-328-328P_datasheet.pdf

author: bogdan2013
author_rank: Regular Contributor
timestamp: February 21, 2013, 01:42:27 pm
content: I started a new topic here :https://www.eevblog.com/forum/microcontrollers/avr-c-14347/.@ Kremmen : Thanks ! I will try to do something with that commands .

author: MikeK
author_rank: Super Contributor
timestamp: February 21, 2013, 07:20:24 pm
content: The guys at AVRFreaks.net can probably provide help.
AVR relays - how do they work? - Page 1
Forum section: electronics / beginners

author: aroby
author_rank: Regular Contributor
timestamp: February 03, 2014, 06:22:43 pm
content: I have an APC UPS which is showing a fault that apparently is due to an "AVR Relay Weld". I opened it up and sure enough there are 4 Omron relays on the board (soldered in, even though these relays can be socketed!). I guess my only option for fixing it is to take the board out and figure out which relays are at fault. I assume from the problem description that they are either shorted or won't activate.But my question is what are they for? As I understand it, AVR is about voltage regulation, so I'm not clear what relays do in that respect. And if they weld together, why would that happen?Thanks for any insight!Anthony

author: krish2487
author_rank: Frequent Contributor
timestamp: February 03, 2014, 06:46:04 pm
content: The way a AVR worksis to switch between different taps on the transformer to boost or buck the incoming AC mains to provide a nearly constant output voltage (gross oversimplification, but for this purpose it should suffice). Quite useful in areas where the line voltage is not constant nor consistent.What I understand from what you posted, it seems two relays have gone bad effectively shorting tap(s). Their going open, generally, should not cause any problem - but it is dependant on the circuit.Checking which relays have gone bad and replacing them should solve the issue.There might yet be another cause, the drive for the relay coil - either the drive transistor or the microcontroller pin (I am assuming there is a microcontroller inside) have gone released the magic smoke and have caused the relay to permanently latch.

author: aroby
author_rank: Regular Contributor
timestamp: February 03, 2014, 10:58:10 pm
content: Thanks for the explanation - I think I get it. I don't see any damaged components so hopefully replacing the relays will get this going. Surprisingly, the only place I have found that has them is in China! Maybe since the boards are made there Omron only sells them there.
AVR/ATTiny48 16-bit PWM Questions - Page 1
Forum section: electronics / beginners

author: meshtron
author_rank: Regular Contributor
timestamp: September 03, 2023, 05:23:25 pm
content: I've got myATTiny48(bare metal, no Arduino platform) working and delivering a nice PWM output on pin PB1 (OC1A/PCINT1) using this code:Code:// PWM outputDDRB |= (1 << PINB1); // (re)set as outputICR1 = 0x18F;// 5kHzOCR1A = (uint16_t)((float)ICR1 * ((float)power / 255.0)); // scale duty cycleTCCR1A = (1 << COM1A1); // non-inverting, OC1A onlyTCCR1B = (1 << WGM13) | (1 << CS11);// set to mode 8, clk/8 timer freqTrouble is I wastryingto get Mode 9 going, but I could never make it work. I thought - based onthis post- that in Mode 9, OCR1A sets the "top" value (so controls frequency) and OCR1B sets the output comparator match value which controls duty cycle. But, I never got correct output on the OC1A pin (even with same COM settings as above). I also felt a bit lost going through the datasheet multiple times, but never getting a clear picture of how - for this 16-bit timer/counter/comparator set - OCR1A and OCR1B interact.So - I guess my question is this: with the pins connected as shown in the attached picture,shouldI be able to use Mode 9 and get output (only) on the OC1A pin? I think - for my purposes - Mode 8 is okay as I don't currently intend to be live-switching frequencies. But, I feel like I'm still missing something fundamental here that many hours and even a glass of good Scotch yesterday were unable to uncover.

author: ledtester
author_rank: Super Contributor
timestamp: September 03, 2023, 08:56:03 pm
content: Quote from: meshtron on September 03, 2023, 05:23:25 pmFrom:https://www.avrfreaks.net/s/topic/a5C3l000000UaD6EAK/t152986?comment=P-1372820Quote

author: meshtron
author_rank: Regular Contributor
timestamp: September 03, 2023, 09:05:00 pm
content: Wow, thanks for that! Matches what I was seeing, but I didn't see anything in the datasheet indicating that was the case - very weird.I have added AVRfreaks to my (long and growing) list of resources. Thanks again!!

author: jfiresto
author_rank: Frequent Contributor
timestamp: September 04, 2023, 07:13:09 am
content: Quote from: meshtron on September 03, 2023, 09:05:00 pmYes, that middle generation of AVR timers can be quirky. I tend to the notion that their design was not exhaustively validated.
Awesome Learning Opportunity free video lectures Black Magic - Page 1
Forum section: electronics / beginners

author: JustMeHere
author_rank: Frequent Contributor
timestamp: October 30, 2019, 02:47:48 am
content: If you go to learning.oreilly.com and search for Howard Johnson, you will find three of his video classes. They are based on his books. Great for learning about how to handle noise. Everyone should know the High Speed Digital Design: Black Magic book.You can get a 10 day subscription for free.
AWG 22 Stranded Wire - Page 1
Forum section: electronics / beginners

author: kfc_n
author_rank: Contributor
timestamp: August 01, 2014, 04:10:08 am
content: Good day!What is the max current rating for AWG 22 stranded wire? Can it go to 3A max? thanks

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 01, 2014, 04:20:57 am
content: Like all good answers, the correct one is "it depends".There are many standards regarding what wire constructions have what ampacity ratings in various environments (free, in conduit, in cable, wound on transformers..).But if you mean for general chassis wiring purposes, yes, it's sufficient. I think most or all standards agree on that, at least the ones that aren't allowing for "direct sunlight in Arizona" conditions.Tim

author: Psi
author_rank: Super Contributor
timestamp: August 01, 2014, 05:23:21 am
content: Google for awg wire current ratings. You wil find a table

author: sleemanj
author_rank: Super Contributor
timestamp: August 01, 2014, 05:29:02 am
content: Quote from: kfc_n on August 01, 2014, 04:10:08 amFor general purposeshttp://www.powerstream.com/Wire_Size.htmI take the chassis wiring and divide completely arbitrarily by 2, which in this case is 3.5A, as a fairly safe area of operation.
awg sizes for solid vs stranded wire - Page 1
Forum section: electronics / beginners

author: ledtester
author_rank: Super Contributor
timestamp: January 11, 2018, 08:52:23 pm
content: This chart:https://www.engineeringtoolbox.com/awg-wire-gauge-d_731.htmllists the diameter and cross sectional area of AWG sizes. Below it also has this caveat:QuoteCouple of questions:1. Is this table for stranded AWG sizes?2. Is there a table somewhere which clearly shows the dimensions for both stranded and solid core wire?Thanks!

author: Paul Price
author_rank: Super Contributor
timestamp: January 11, 2018, 09:07:05 pm
content: Depends on the cable or wire mfg. Different mfg's will specify different real-world wire diameters for AWG standard values. See the data sheet for the wire/cable in question.