hybridfree/eevblog-posts huggingface dataset:
Camera Flash Charging Sound - Page 1
Forum section: electronics / projects

author: CodyW
author_rank: Contributor
timestamp: September 25, 2014, 09:10:45 am
content: Hi everyone,Does anyone know what component or components in camera flashes circuitry are responsible for the high pitch sound when it's charging up?Kind regards,Cody

author: Rerouter
author_rank: Super Contributor
timestamp: September 25, 2014, 09:18:37 am
content: Either The inductor for the flyback or the high voltage capacitor,

author: Richard Head
author_rank: Frequent Contributor
timestamp: September 25, 2014, 11:03:20 am
content: It's the inductor of the flyback converter. The effect is called magnetostriction.

author: Hardcorefs
author_rank: Regular Contributor
timestamp: September 25, 2014, 11:35:54 am
content: It can also be caused by ceramic SMT caps.One of the cap manufacturers (Murata) has a white paper on it, they take a number of manufacturers to task over the incorrect use of Ceramic caps in various Switched designs, they also point out it can lead to mechanical failure of the devices.

author: kiran_shrestha
author_rank: Regular Contributor
timestamp: September 25, 2014, 02:49:38 pm
content: Its because the oscillation running on frequency in audible range. Here's a quick explanation in my blog with circuit U can check it out .Its from my old Achiever camera flash.http://shortedwire.blogspot.com/2014/09/this-is-how-camera-flash-works-19.html

author: Things
author_rank: Regular Contributor
timestamp: September 26, 2014, 11:00:14 am
content: Some camera's can do it purely in software to give you an indication the flash is charging up, but otherwise it's just the small flyback transformer.

author: Niklas
author_rank: Frequent Contributor
timestamp: September 26, 2014, 08:28:41 pm
content: Quote from: Hardcorefs on September 25, 2014, 11:35:54 amYou don't happen to have a link to that white paper? Tried to find it, but without any luck. Would be interesting to read

author: CodyW
author_rank: Contributor
timestamp: September 29, 2014, 07:53:45 am
content: Awesome! Thank you, everyone!Cody

author: Mandelbrot
author_rank: Regular Contributor
timestamp: September 29, 2014, 08:14:34 pm
content: This is why I love this forum so much. I'm a senior in college now and learn about all sorts of cool stuff, but this is the kind of thing that you don't hear about in school.

author: Zero999
author_rank: Super Contributor
timestamp: September 29, 2014, 09:12:57 pm
content: Quote from: Hardcorefs on September 25, 2014, 11:35:54 amIn that case, it's caused by the piezoelectric effect.It also works in reverse: the capacitors will generate a small voltage when vibrated which I imagine could cause acoustic feedback in audio applications.
Camera Stand for doing Reviews - Page 1
Forum section: electronics / projects

author: electronupdate
author_rank: Regular Contributor
timestamp: December 06, 2012, 02:26:12 am
content: This is not an electronics product review, but a video on a camera stand that I am finding useful.Recently I have been doing some reviews which require the camera to be in a macro mode to look at the circuit board on a desk, and then swung upwards to photograph the scope. I have been finding a standard tripod to be somewhat awkward to use.... a hour or so in the workshop has resulted in this crude looking, but surprisingly useful, camera mount that can be quickly swung on two axis. Perhaps this may be useful for others on this board.

author: EEVblog
author_rank: Unknown
timestamp: December 06, 2012, 02:34:11 am
content: Nice and simple.I want something similar that can slide along my entire bench.I'm thinking of an upside down linear rail under the bench (2 benches actually) with some sort fo arm like that that can swing up over the bench and look down vertical. Something like a flexi-ball type arm like the gorilla pods maybe.Then I need to standardise on the camera mount plate, so would need the same mount as my existing Manfrotto Modo, so I can easily move the camera from tripod to one bench and then other without unscrewing the plate.Dave.

author: MikeK
author_rank: Super Contributor
timestamp: December 07, 2012, 01:18:18 am
content: electronupdate,Don't forget about CHDK. If your camera is a Canon you can install CHDK which adds a lot of usefulness, one of which is the ability to take pictures with a simple USB cable instead of having to push the camera button.

author: robrenz
author_rank: Super Contributor
timestamp: December 07, 2012, 01:38:32 am
content: I like the stand, but doesn't your scope have bitmap storage of screenshots?

author: pickle9000
author_rank: Super Contributor
timestamp: December 07, 2012, 02:10:11 am
content: I do the same thing when I document a test procedure. It's faster although it can lack detail. In the old (cro) days it was also to replicate settings.
Camera trigger device using Distance Sensors - Page 1
Forum section: electronics / projects

author: Informatic0re
author_rank: Newbie
timestamp: January 25, 2024, 11:06:42 pm
content: Hello,I'd like to share a project I've been working on for a while now. During my trip to Peru in May 2023 to collaborate with Fauna Forever, an NGO partnered with Wilderness International, I had discussions with scientists about challenges they faced that could be addressed with electronics.One specific issue highlighted was the use of buckets to capture lizards and other small animals for population and variety studies. Unfortunately, this method is invasive, leading to potential harm or death for the animals due to rain or being preyed upon. More details can be found on my project page at Hackaday or on myhttps://www.open-things.de/thing-2.htmlUsing infrared (IR) for cold-blooded animals like lizards proved ineffective due to their size and the limitations of IR sensors. To address this, I developed the RepTraphttps://hackaday.io/project/192032-openthing-2-reptrapThe RepTrap utilizes the VL53L4CD Time of Flight sensor to measure height and trigger a DSLR camera's shutter and focus. While the current MCU is the RP2040 for simplicity, I am considering alternatives due to complexity and sensitivity issues.Here's a brief overview of how the sensor operates:It measures offsets and calibration values for the glass used (similar to black IR glass in remote controls).It calculates a suitable threshold for triggering based on the current height from the sensor to the ground.It calibrates each of the four ToF sensors using this data.It's ready to detect anything passing by that meets the threshold.The RepTrap is already performing well.If you're interested in the project or eager to contribute, feel free to PM me, follow the project, or give it a like.One challenge I'm working on is the power consumption of the sensors, which, despite claiming "very low power consumption," poses difficulties in low-power modes affecting project functionality.Any insights or assistance on this matter would be greatly appreciated.

author: Informatic0re
author_rank: Newbie
timestamp: February 07, 2024, 08:27:24 am
content: I just uploaded a new version using the ESP32 instead of the RP2040.Now I can add BLE support to change the configuration of the sensors
Camera - Page 1
Forum section: electronics / projects

author: Midas
author_rank: Regular Contributor
timestamp: January 16, 2015, 06:48:34 am
content: I need help with this camera it is a bit different from other cameras I have seen and I need help trying to take it apart. I cant seem to get to the shutter area for some odd reason. I tried to take a decent picture but could never get the lighting correct. Under the casing their is a screw lodged between the shutter button and casing and i cant seem to get it out. I did a thread earlier and i just wanted to basically get to where i can control the shutter by using a sensor that detects movement in its surroundings and take a picture. I would have to solder the area where their is zero voltage of course. Any tips as well on how to figure out where to solder and are their any books you guys can direct me to that will help me figure out the insides of a camera.

author: Midas
author_rank: Regular Contributor
timestamp: January 16, 2015, 07:03:41 am
content: It wouldn't allow me to post photos in first post

author: Midas
author_rank: Regular Contributor
timestamp: January 21, 2015, 02:48:32 am
content: I got this camera open eventually I am having such a hard time with the soldering of the shutter areas around cameras and I purchased some paste flux to see if it would be easier but it is not the first camera I attempted to solder was the 2nd photo. The first photo is a better camera and this shutter is a but different can I get some advice
Can a transistor be damaged by limited reverse Vbe current? - Page 1
Forum section: electronics / projects

author: SilverSolder
author_rank: Super Contributor
timestamp: November 25, 2018, 11:53:49 pm
content: Picture a run-of-the-mill small signal NPN transistor, with the emitter tied to ground and collector to a positive supply. The base is connected to -15V via a 10K resistor.This would cause the base-emitter junction to enter into avalanche mode and look like a zener diode, at some constant voltage (6V - 10V or so).Can the transistor conceivably be damaged by this small current constantly, year in and year out, for several decades?

author: langwadt
author_rank: Super Contributor
timestamp: November 26, 2018, 12:18:44 am
content: afaik even if it doesn't immediately damages it, avalanching the base-emitter will make the beta of the transistor drop over time.story goes that it was a common fault with reversed transistors used as low drop switches and that you could recover some of thelost gain by heating the transistor

author: David Hess
author_rank: Super Contributor
timestamp: November 26, 2018, 05:11:20 am
content: Base-emitter breakdown will lower the hfe (beta) resulting in higher noise and higher bias current. This does not matter so much with switching transistors used in circuits with sufficient forced beta, gold doped transistors (RF and fast saturated switching transistors) which have low hfe anyway, and power transistors which operate at high currents where gain drops. But it is fatal for precision and low input bias current circuits like differential pairs.I think the damage mechanism is hot carriers causing dislocations in the crystal structure which lowers minority carrier lifetime. The gold doping used in fast saturated switching and RF transistors also works by lowering minority carrier lifetime explaining why these transistors are less effected. Radiation damage also occurs through this mechanism.The transistor junction can be repaired through annealing but that is hardly feasible with a plastic package.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 26, 2018, 05:40:30 am
content: Incidentally, every so often you see higher voltage diodes advertising similar methods (electron bombardment, transition metal (usually Pt) doping) to control carrier lifetime. At very light doping and over a gently graded junction, this gives reasonable performance (t_rr ~ 30ns) for 600V diodes, at modest expense to Vf (say, Vf = 1-3V at rated current).And it seems to not work so well at higher voltages (~200ns for 1200V, and I think I've seen 2-4us "fast recovery" hockeypucks in the 3-6kV range, which is about as high as Si can possibly go), which makes sense as carrier lifetime depends on doping, and with lighter doping, yeah.Which, by the way, is a good reason why you may find RF or switching or power types stink at low currents -- hFE drops off quickly. Some power transistors this is explicit -- Darlingtons usually, with internal B-E resistors. This doesn't break Ebers-Moll or whatever, so you still get the transconductance you expect, but the base conductance can be higher than you might expect.Tim
Can A4988 Motor Driver Be Used For Brushed DC Motors? - Page 1
Forum section: electronics / projects

author: hal9001
author_rank: Regular Contributor
timestamp: July 07, 2021, 07:55:16 am
content: A4988 is made for driving stepper motors. But can it be used for driving a single brushed DC motor in Full Step Operation if the DC motor is connected between OUT1A and OUT1B? Each OUT group is a full bridge.Can it be driven continuously in one direction until the direction pin is toggled or is there a hardware limitation?Cheers

author: Kjelt
author_rank: Super Contributor
timestamp: July 07, 2021, 08:01:48 am
content: The answer is in the first picture on the left bottom.The first two steps the motor will turn CW the following two steps it will turn CCW.The result is a "hunting" motor response around its start position.So unless you can reprogram the logic, you need a brushed dc motor driver.

author: hal9001
author_rank: Regular Contributor
timestamp: July 07, 2021, 08:25:19 am
content: Quote from: Kjelt on July 07, 2021, 08:01:48 amThanks.The motion for the motor in my application isnt complex. It is going to go in one direction until a sensor is triggered then stopped and returned until the other sensor is triggered.I was thinking I can use the RESET pin to make sure the Phase is always initialized the same when the motor is stopped. Then if I give one STEP the driver will always respond the same way and if I give 2 steps then it will change direction. And the ENABLE pin can be used to turn the motor off between direction changes. Will that work? I might be not understanding the "hunting"described.

author: Kjelt
author_rank: Super Contributor
timestamp: July 07, 2021, 09:55:45 am
content: With hunting I mean the continuous CW and CCW short movements of the axis so it does not stand still, it keeps moving.It is often used in servo applications where there is an encoder feedback path that is used as the current position which is compared to the desired position. If those two can not exactly be matched due to the resolution of the servomotor it keeps doing that same thing.What is driving the stepperdriver, if it is a microcontroller then what I understand of your description you do not really need a motor driver ic. You can do the logic in your microcontroller and drive an H bridge.I would forget about the A4988 unless someone else has a clever idea of using it.If you need repeatability (step) and current protection have a look at the TI DRV8xxx series.

author: hal9001
author_rank: Regular Contributor
timestamp: July 07, 2021, 10:04:12 am
content: Quote from: Kjelt on July 07, 2021, 09:55:45 amYes a microcontroller is driving it. This is a prototype for the customer who hasnt chosen if they are using a stepper motor or bushed DC motor yet. If Im going to include the A4988 for the stepper motor then I was wondering if it will work for testing a DC motor as well by using OUT1. If the A4988 cant work in this way, a separate DC driver will have to go in.
Can ADA4254 be programmed with resistors without digital programming? - Page 1
Forum section: electronics / projects

author: electronx
author_rank: Regular Contributor
timestamp: February 05, 2024, 02:42:03 pm
content: Can ADA4254 be programmed as hardware with resistors without digital programming (GPIO parallel OR spi)?Datasheethttps://www.analog.com/media/en/technical-documentation/data-sheets/ada4254.pdf

author: Terry Bites
author_rank: Super Contributor
timestamp: February 05, 2024, 03:04:06 pm
content: You can't get at the gain set nodes from outside the chip. All of its parameters are programed by writing to the internal registers. Why did you think it migh be possible?

author: electronx
author_rank: Regular Contributor
timestamp: February 05, 2024, 03:09:24 pm
content: It has very low input offset and differential output. 8295 can still be configured as a differential output, but it has a much higher offset. I've never used such an expensive amplifier before or programable .Just wanted to make sure, thanks for your answer.
Can adding MCU Powerdown to Soft-Latch Power Switch be simplifed? - Page 1
Forum section: electronics / projects

author: optoisolated
author_rank: Unknown
timestamp: March 06, 2020, 12:32:13 pm
content: Hi all,I've started working on a project that needed soft-latch power switch, and I thought I'd give Dave's simplified Soft-Latch power switch design a go. One of the changes i've added is to add an additional NPN transistor on the base of the first transistor which allows for the MCU to ground it, which should allow it to power down the unit using software, without impacting the operation of the Soft-Latch switch. The MCU is supposed to leave the pin high-impedance when it's not operating so in theory I should be able connect that pin directly (with a low val resistor) to the base of the first transistor, but I opted to add an additional transistor to allow it be a bit more controlled. (Schematic diagram attached)So my questions are:1. Have I overcomplicated the design by adding the additional transistor, and2. Is there a better way to go about adding the option to allow the MCU to ground the base of the first transistor?Cheers and beersOptoisolated

author: optoisolated
author_rank: Unknown
timestamp: March 06, 2020, 12:48:49 pm
content: Definitely simpler, not sure about cheaper tho; I can buy 100 2N3904's on eBay for a dollar. The PMOS is the most expensive component and even that would run me about 5c/ea on eBay. I like the idea of a single component to manage the power though; might look into that option some more. Defintely want to avoid having to program one if I can, but I'm sure there's plenty of power switch ICs that come programmed with some common logic. Cheers

author: ataradov
author_rank: Super Contributor
timestamp: March 06, 2020, 05:41:51 pm
content: Here is a much simpler version of this switch that also keeps the button available to the MCU during normal operation -https://github.com/ataradov/siggen/blob/master/hw/siggen.pdfSo MCU can use it to just disable the power (may be after a delay or debouncing), or actually use it for normal device operation. In my case I use it for menu navigation and a long press actually disables the power.When the button is pressed, the MCU will be powered and it must set PWR_EN high. If it wants to disable the power, just set PWR_EN low.When MCU is powered, the state of the button is read on BTN_C.

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 06, 2020, 05:44:33 pm
content: You can also refer to this thread:https://www.eevblog.com/forum/projects/soft-switch-latch-help/

author: optoisolated
author_rank: Unknown
timestamp: March 06, 2020, 10:22:35 pm
content: That's definitely simpler.. I like it!
Can anybody ID this Hirose connector? - Page 1
Forum section: electronics / projects

author: mc
author_rank: Regular Contributor
timestamp: August 03, 2018, 09:51:43 pm
content: I've traced it down to being a Hirose connector, but I can't seem to ID the exact connector. It's a 20pin, and the plug side does have a locking sleeve.It's on a late 90's Roland PCNC engraver, and I'm wondering if it's either been discontinued, or was a special.I'm planning on building a new control box, but would prefer to use a new connector and keep the original control box complete, rather than cut the plug of, or change the plug on the engraver.

author: CM800
author_rank: Frequent Contributor
timestamp: August 03, 2018, 10:35:02 pm
content: Looks like the RP13 series to me.https://www.hirose.com/product/en/products/RP13/

author: mc
author_rank: Regular Contributor
timestamp: August 03, 2018, 10:58:28 pm
content: Thanks for that!I went through the RP series, but I must of missed that one.
Can Anyone Convert a Datasheet From Chinese to English? - Page 1
Forum section: electronics / projects

author: bostonman
author_rank: Super Contributor
timestamp: October 25, 2022, 12:20:50 am
content: I have a bunch of these chips and was looking for the datasheet.Unfortunately all I found was this:https://datasheet.lcsc.com/lcsc/1810242111_TM-Shenzhen-Titan-Micro-Elec-TM1629D_C98484.pdfI'm not asking anyone to translate it as in rewriting the whole thing, but can it be converted somehow? I looked on multiple sites and only found the same Chinese version.

author: bdunham7
author_rank: Super Contributor
timestamp: October 25, 2022, 12:35:55 am
content: Sure.

author: bostonman
author_rank: Super Contributor
timestamp: October 25, 2022, 12:54:48 am
content: Oh wow.Does a full version of Adobe convert or you did it some other way?It's not perfect, but, compared to what it was, this is great.Thanks

author: ledtester
author_rank: Super Contributor
timestamp: October 25, 2022, 01:16:01 am
content: I think bdunham7 just used translate.google.com.First save the PDF to your computer.Then on translate.google.com select "Detect Language" and have it translate a Document (not a Website). Provide the PDF you just downloaded and hit Translate.

author: bdunham7
author_rank: Super Contributor
timestamp: October 25, 2022, 01:30:14 am
content: I left clues in the later pages...

author: John B
author_rank: Frequent Contributor
timestamp: October 25, 2022, 06:05:59 am
content: I can recommend google translate. It recreates perfect Chinglish beautifully.
Can anyone describe this mute circuit and how it works for me? - Page 1
Forum section: electronics / projects

author: mkiijam
author_rank: Regular Contributor
timestamp: September 27, 2025, 08:26:40 pm
content: This is an amp I'm working on that seems very quiet. It will only do about 1V RMS before clipping into a 8 Ohm load. I started suspecting the mute circuit may be on, but I can't get my head around how it works.

author: Andy Watson
author_rank: Super Contributor
timestamp: September 27, 2025, 10:21:45 pm
content: Q13 and Q10 perform level-shifting such that Q11 is not conducting when the mute input is low. Or are asking about how Q11 affects the gain of the amplifier?

author: mkiijam
author_rank: Regular Contributor
timestamp: September 27, 2025, 10:38:44 pm
content: Yes, all of it/that. any more thoughts? Thank you!

author: David Hess
author_rank: Super Contributor
timestamp: September 28, 2025, 02:05:39 am
content: The mute function works by disabling the current sources which bias the amplifier circuits.

author: moffy
author_rank: Super Contributor
timestamp: September 28, 2025, 05:34:23 am
content: When 'MUTE' is low Q13 acts as a current source/level shift turning Q10 on, this turns Q11 off, which leaves the current sources Q3 and Q12 active and the amplifier working.When 'MUTE' is high or just open circuit, Q13 is off turning Q10 off which turns Q11 on, disabling the current sources Q3 and Q12 and effectively stopping the amplifier from working.
Can anyone explain the details of what I'm seeing on this pressure sensor die? - Page 1
Forum section: electronics / projects

author: yelneerg
author_rank: Contributor
timestamp: October 12, 2018, 04:13:18 pm
content: This came out of a malfunctioning pressure sensor in a SCUBA diving computer. From the research I've done I'm pretty sure it's a Wheatstone bridge composed of piezoresistive elements. Can anyone give me details on why this is laid out like it is and what the process is for building it up? Does the square bit in the middle constitute the bridge?Album:https://imgur.com/a/fNGvIrs

author: CatalinaWOW
author_rank: Super Contributor
timestamp: October 12, 2018, 04:55:19 pm
content: I am sure the square is not the bridge. The bridge is usually small serpentines that wouldn't show up well compared to the metalizations seen in your picture. The other contacts are consistent with bridge connections in these sensors. Google will give you several hits on ways they can be constructed, though I haven't seen anything specific on SMI's method. My best guess for the square is a shield, or perhaps one electrode of a capacitive sensor for the motion of the diaphram. They would then combine the results with the bridge output for better dynamic range or better accuracy or redundancy or who knows.
Can anyone explain this LED backlight boost circuit to me? - Page 1
Forum section: electronics / projects

author: JGAN
author_rank: Contributor
timestamp: August 23, 2016, 05:49:35 am
content: I'm confused as to why this LED backlight boost circuit has two inductors and two diodes but one output. Normally I would only expect one inductor and one diode. The closest datasheet I could find was for the LM3533, which only has one inductor and diode in the example circuit.What is the reason behind the extra inductor and diode? PP_VCC_MAIN is nominally 4.2v if that helps at all.

author: Siwastaja
author_rank: Super Contributor
timestamp: August 23, 2016, 07:19:39 am
content: Maybe two-phase operation for reduced ripple and better capacitor utilization? This gets more important as the voltage ratio rises. 4.2V to 35V sounds somewhat challenging, so that could be the reason.Edit: Taking a better look, this can't be the reason because the inductors are massively different. Another guess: two different converters for different power levels for maximizing low-load efficiency? The 15uH one would be used by switching at a lot lower frequency when drawing nearly no power, to minimize switching losses.

author: MagicSmoker
author_rank: Super Contributor
timestamp: August 23, 2016, 11:43:04 am
content: As mentioned above, this is probably for two different brightness (ie - backlight power) levels, the 15uH inductor reduces the rms current (though not the average) drawn from the battery at low brightness while the 1.5uH indcutor will, presumably, have lower I²R losses at high brightness/power level.This still wouldn't make much sense (why not wind use a bigger core for the 15uH inductor and wind it with bigger wire) *except* that this schematic claims to be from the iPhone 6S and so one might surmise that the height of any component would be severely constrained, and in this case it probably works out that 2 inductors take up more board area than 1, but at a lot lower height, and the latter was deemed more important than anything else.

author: JGAN
author_rank: Contributor
timestamp: August 24, 2016, 01:19:57 am
content: Thanks for the replies,I was also looking atthis patentand it notes that operation of both switches can be simultaneous. It looks like the intention is to allow for a wider range of input voltages. Is the patent design different from my schematic?
Can anyone explain to this circuit - Page 1
Forum section: electronics / projects

author: sfiber
author_rank: Regular Contributor
timestamp: July 01, 2014, 12:55:57 pm
content: to me.Hi everybody I examine to opt101's datasheet and I understood every circuit in sheets but this circuit.Its not familiar to me and I request to explanation from you what's going on with dc output and signal with timebase output.Thank you

author: Stonent
author_rank: Super Contributor
timestamp: July 01, 2014, 01:05:26 pm
content: It appears to be giving negative feedback?

author: Richard Crowley
author_rank: Super Contributor
timestamp: July 01, 2014, 01:11:55 pm
content: It it simple feedback to stabilize the output of the LED.I don't see any "timebase output". That kind of circuit does not need or use "timebase".

author: sfiber
author_rank: Regular Contributor
timestamp: July 01, 2014, 01:16:51 pm
content: I can see now.This circuit its not about opt101,its about led.

author: rob77
author_rank: Super Contributor
timestamp: July 01, 2014, 01:18:04 pm
content: seems to be a constant light source - the circuit compensates for changes in emitted light due to supply voltage changes , LED intensity fluctuations with temperature...etc..like the linear voltage regulator, but with light

author: sfiber
author_rank: Regular Contributor
timestamp: July 01, 2014, 01:23:41 pm
content: I thought its about opt but I can see for what it is.Thaks to everbody

author: dannyf
author_rank: Super Contributor
timestamp: July 01, 2014, 01:37:52 pm
content: The OPT101 is configured as an I-V converter.In this case, its output is used to regulate the light intensity of the LED: the feedback is to maintain equal potential on pin 2 and pin 3 of OPA627 so that the output out OPT101 is always 10v * 11k / (100k + 11k). As the opt101's output is fixed, the current going over the photodiode must be fixed. which means the light output from the led is fixed.
Can anyone find info on  SXD043B-3  I think it's a music/tune chip. - Page 1
Forum section: electronics / projects

author: Psi
author_rank: Super Contributor
timestamp: January 08, 2025, 07:03:17 am
content: I'm trying to help dad with some mods to a multi-channel motion/doorbell system.I've tired but can't seem to identify 2x ICs. They are probably from the china's local market.The main IC I want to know about is this one SXD043B-3It appears to be a music/tune chip with ~30 selectable tunes programed into it.Maybe with a button input to configure a primary sound and maybe with digital lines to play the other sounds on demand too.The other is NT620M which I'm pretty sure is just a cheap MCU. Not too concerned about this one, it's mainly the one above.

author: Psi
author_rank: Super Contributor
timestamp: January 11, 2025, 04:18:45 am
content: No one could find anything I take it,I kind of expected that, I couldn't find anything either.I was hoping someone might have access to datasheets for china local market IC's.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 11, 2025, 05:01:36 am
content: could be re branded chips, they seems lazer engravedor customs oneswitch does not help muchbut this comes uphttps://www.sodnpoo.com/posts.xml/1_by_one_doorbell_(sxd043)_to_gpio_mod.xml
Can anyone give me an explanation of what this does? - Page 1
Forum section: electronics / projects

author: gerrysweeney
author_rank: Regular Contributor
timestamp: March 28, 2015, 08:23:17 pm
content: Hi All,I am wondering if there is anyone that can give me an explanation as to what this circuit does? what its called etc? Its part of the HP 34401A meter and it looks like some kind of constant current cascode thingy - what I don't understand is the purpose of the cascoding in this design, it does not seem to be high-voltage related. There is bound to be someone who has a good explanation of what this is and I have run out of people to ask. Specifically I mean the part with the orange box around itThanksGerry

author: Andy Watson
author_rank: Super Contributor
timestamp: March 28, 2015, 08:48:08 pm
content: I would have said it was for high voltage protection. The diode, CR202, protects against positive voltage at the terminal. The four transistors combined provide a high voltage stand-off for negative voltages at the terminals. Bear in mind that accidentally measuring the resistance of the mains could put 420 volts across it - that's 105V per transistor.Also, in normal operation, you don't want to have too much resistance between the current source and the terminal. At higher current ranges the voltage burden is going to be little more than 1.2V per stage.Q211 is being used as a low-leakage clamping diode.

author: gerrysweeney
author_rank: Regular Contributor
timestamp: March 28, 2015, 11:14:10 pm
content: Hi Andy,Thanks for the explanation that makes a lot of sense, I never really thought about it from that perspective but now you explained it is sort of obviousThanks againGerry
Can anyone help identify these connectors - Page 1
Forum section: electronics / projects

author: GreyArea
author_rank: Contributor
timestamp: August 21, 2020, 06:33:37 pm
content: Hi, I'm hoping someone may look at these and recognise them off the bat.The large connecter I'm reasonably sure is a JST XH, it measures 10x5.8mm on the outside edges and seems to fit a 2.5/2.54 pitch.The small connector I'm less sure about. The pitch seems closer to 1.5mm and the outside edges are 8x4.5mmThanks

author: coromonadalix
author_rank: Super Contributor
timestamp: August 21, 2020, 07:02:43 pm
content: seems xh series ?? for the 2st pictures

author: OM222O
author_rank: Frequent Contributor
timestamp: August 21, 2020, 08:26:34 pm
content: They're JST connectors, depending on the pitch (spacing between the conductors) it gets a series name like SH or XH. try to measure with a caliper or if that's not an option, take a photo next to a ruler and measure with a software (I personally use fusion 360).

author: GreyArea
author_rank: Contributor
timestamp: August 21, 2020, 11:10:06 pm
content: Thanks, yes I agree the large one does look like an XH 2.54.Still stumped on the smaller one, as I said, the pitch seems closer to 1.5mm but I've looked though this list up to 2.5mm and can't find a match.http://www.jst-mfg.com/product/search_e.php?type=1&id=1&page=1Maybe I should just desolder them and put known ones in.

author: Monkeh
author_rank: Super Contributor
timestamp: August 22, 2020, 12:50:10 am
content: JST XH and PH.

author: GreyArea
author_rank: Contributor
timestamp: August 22, 2020, 11:30:42 am
content: QuotePH! Yes, thank you!!
Can anyone help me compile the source code into a HEX file? About OBD-ii adapter - Page 1
Forum section: electronics / projects

author: daisizhou
author_rank: Super Contributor
timestamp: December 12, 2021, 01:19:41 pm
content: http://www.obddiag.net/allpro.htmlhttps://github.com/abhishekoct18/allpro(Code connection)I found the above OBD-II adapter on the website, and the author published the schematic and source code.But no HEX file was published,I hope to make it in my free time.Hope to help me convert the source code into a HEX file. It is best to convert the schematic into a layout file, which is the file format of the PCB circuit board.I am a beginner in electronics, thank you for your help

author: CJay
author_rank: Super Contributor
timestamp: December 12, 2021, 03:04:59 pm
content: Instructions here:http://www.obddiag.net/allpro_develop.html

author: daisizhou
author_rank: Super Contributor
timestamp: December 13, 2021, 12:17:51 pm
content: I downloaded the code file, but I will not use the compiled software.I do not use MCUXpresso IDE.Can anyone help me compile it? Looking forward to the HEX file I need, thanks

author: daisizhou
author_rank: Super Contributor
timestamp: December 14, 2021, 06:16:25 am
content: Please continue to ask kind people to help me get the HEX file

author: DavidAlfa
author_rank: Super Contributor
timestamp: December 14, 2021, 08:46:06 pm
content: Quote from: daisizhou on December 13, 2021, 12:17:51 pmWhy can't you use it? If the registration is a problem for you, I uploaded MCUXPresso IDE here:https://drive.google.com/file/d/1-zUFTgxUPGZ6hI_S9l-xrlU9UhOOydkB/view?usp=sharingIt's really easy. Install the IDE, click on Import... Existing project... Select the allpro-master folder and it'll find the project.Then just click on build.

author: daisizhou
author_rank: Super Contributor
timestamp: December 15, 2021, 01:34:34 am
content: First of all, thank you all for your help, my country is not accessible by Google, so downloading is very difficult

author: DavidAlfa
author_rank: Super Contributor
timestamp: December 15, 2021, 04:40:19 am
content: Avoiding baidu and other impossible sites to use outside China, what other options are available?MediaFire?Mega.nz? It's owned by chinese company
Can anyone help me find info on this IC? - Page 1
Forum section: electronics / projects

author: Torkrench
author_rank: Newbie
timestamp: December 19, 2016, 09:17:14 am
content: I've got an IC i'm trying to find information about. Has anyone seen this before?

author: NMNeil
author_rank: Contributor
timestamp: December 24, 2016, 02:20:54 pm
content: Without a manufacturers logo it's going to be very difficult. What circuit was it taken from?

author: KhronX
author_rank: Frequent Contributor
timestamp: December 24, 2016, 02:38:06 pm
content: The "8610" part may well be the datecode (1986, 10th week).Best case scenario, it's "only" a custom re-brand of a (more) common part.Worst case, it's fully custom silicon.

author: Gyro
author_rank: Super Contributor
timestamp: December 24, 2016, 03:01:00 pm
content: Yes, knowing what it came out of would help considerably.It looks as if it's been over-printed to me, the plastic package texture has gone. It might possibly be a small PROM or PAL. I wonder if that 16FE is a checksum.
Can anyone help me identify this component? - Page 1
Forum section: electronics / projects

author: tree
author_rank: Regular Contributor
timestamp: November 16, 2013, 12:21:56 am
content: I ordered a sample for a high voltage op amp from TI and I got a bunch of these components instead in the anti-static bag. They are clearly not op amps. They are in a SOT223 package.

author: juani_c
author_rank: Contributor
timestamp: November 16, 2013, 12:38:12 am
content: It could be aTLV1117 LDO

author: tree
author_rank: Regular Contributor
timestamp: November 16, 2013, 01:25:13 am
content: Thank you. And you were absolutely correct. It is the 3.3V (LV) regulator.

author: Monkeh
author_rank: Super Contributor
timestamp: November 16, 2013, 01:45:11 am
content: Quote from: tree on November 16, 2013, 01:25:13 amHey, free regulators.

author: tree
author_rank: Regular Contributor
timestamp: November 16, 2013, 01:47:05 am
content: I suppose. I sampled one 90V op amp but I got 25 3.3V regulators. Two of them I burned out (one on purpose and one by accident) while testing.

author: Monkeh
author_rank: Super Contributor
timestamp: November 16, 2013, 01:53:00 am
content: I imagine they'll send you the right bit if you ask nicely.

author: NiHaoMike
author_rank: Super Contributor
timestamp: November 16, 2013, 10:38:48 pm
content: I once got a bunch of unidentified SOT223 devices instead of some DIP16 PWM controllers. Just sent them an email explaining the problem and got the correct parts in a matter of days.

author: Dave
author_rank: Super Contributor
timestamp: November 16, 2013, 11:10:22 pm
content: On a related note, tree, you might want to clean your Nikon's image sensor.

author: tree
author_rank: Regular Contributor
timestamp: November 17, 2013, 02:59:24 am
content: The sensor is fine. I took that picture through a dirty magnifying lens because I don't have a macro lens.

author: Psi
author_rank: Super Contributor
timestamp: November 17, 2013, 08:47:52 am
content: Quote from: tree on November 17, 2013, 02:59:24 amGet some lens spacers. They have no electronic or optics which makes them cheap.They move the lens spacing outwards so you can focus closer, basically turns any lens into a cheap macro.
Can anyone help me modify the code? Used to make oil reminders - Page 1
Forum section: electronics / projects

author: daisizhou
author_rank: Super Contributor
timestamp: August 24, 2023, 10:46:11 am
content: https://github.com/W-Linus/STM32G030F6P6-GNSSThis is a GNSS locator designed by the author "W_Linus".I want to modify it to be a motorcycle oil reminder,Because my motorcycle does not have a regular oil change reminder,So I plan to make one in my spare time.My plan is to modify the original author's,Add an item for mileage statistics，Since the original author has speed, I want to be able to show the distance,And it has a zero reset function, it is best to have a striking reminder to change the oil when reaching the specified mileage,(I mean there is red background flashing，Press reset to restore)The speed unit only needs to display KM/H,Other units such as m/s, kt, etc. can be canceledhttps://www.bilibili.com/read/cv18153018

author: abeyer
author_rank: Frequent Contributor
timestamp: August 24, 2023, 05:42:28 pm
content: You're already getting a stream of location points: if you want total distance you just need to calculate the distance between each pair in that stream and sum them. What you're probably looking for is the haversine formula:https://en.wikipedia.org/wiki/Haversine_formulahttps://www.movable-type.co.uk/scripts/latlong.html(This is likely to be pretty noisy, and you may want some smoothing or other processing over it, but it would get you started.)

author: daisizhou
author_rank: Super Contributor
timestamp: August 25, 2023, 02:16:47 am
content: Thank you. I am a beginner and I do not know how to program using STM32

author: Jon_S
author_rank: Contributor
timestamp: August 25, 2023, 08:01:38 am
content: Quote from: daisizhou on August 25, 2023, 02:16:47 amST actually have some great resources for training on the STM32. I've had our students go though some and they seemed to think it was good quality. You are expected to already know C for these though:https://www.st.com/content/st_com/en/support/learning/stm32-education.htmlIf you need C as well then Microchip have some decent quality online learning:Basics:https://skills.microchip.com/page/c-programmingMore advanced topics and applications:https://mu.microchip.com
Can anyone help me to fix my car remote starter 791 bypass moduel?  - Page 1
Forum section: electronics / projects

author: Chevy Silverado 1500
author_rank: Newbie
timestamp: November 18, 2013, 04:59:31 pm
content: i installed a remote bulldog car starter model RS82 in my 2000 chevy silverado 1500 5.3 lt automatic a year ago along with a number 791 bypass module which has the pass lock 2.i disconnected my 12volt truck battery. and when i reconnected my battery i went to clear the 791 memory. first i unplugged the 8 pin wire harness connector. then took the number 2 blue wire to ground.then i plugged the 8 pin wire harness back into the 971 module when the red light came on i unplugged the 8 pin wire harness then i waited 10 seconds while the blue number 2 wire still connected toground. after 10 seconds i went to replugged the 8 pin harness back into the 791 module i couldn't get it to seat all the way in. after i removed the 8 wire harness i noticed i bent the number 7 pass lock 2orange - wire onto the number 8 red wire + 12volt constant pin. i straighten the number 7 orange wire pin back. and then replugged the 8 wire harness back into the module. the red light didn't come on so iguess i shorted something in the 791 module.i try ed looking up the numbers 791 and board number CMT - 791A 20: 0060 no luck. can you help me to troubleshoot this and help me to get it working again?

author: Stonent
author_rank: Super Contributor
timestamp: November 19, 2013, 04:44:34 am
content: If nobody here is able to help, you might also try the EricTheCarGuy forums. Somewhat like EEVBlog but for cars.
Can anyone help me verify this amplifier circuit design? Thank you. - Page 1
Forum section: electronics / projects

author: magnumX
author_rank: Newbie
timestamp: December 02, 2017, 06:49:03 am
content: Can anyone simply explain the operation principle of this amplifier design and the graph result of this design. Because I'm wondering that why the Vout and Vin graph result is like that. Furthermore, is it a common source amplifier design ?Thank you. Your help is greatly appreciate.*Attached are the circuit design and graph result.*I'm using the mentor graphic.

author: elal1862
author_rank: Newbie
timestamp: December 02, 2017, 09:08:09 pm
content: This lookssomuch like a homework assignment - and guess what, we're not here to do your homework.

author: Cerebus
author_rank: Super Contributor
timestamp: December 03, 2017, 12:34:39 am
content: Quote from: elal1862 on December 02, 2017, 09:08:09 pmOh look, you've posted a whole 7 messages on here and you're dictating policy?Before you start telling other newcomers what the house rules are I suggest you read them yourself or you're going to make yourself look like an idiot by contradicting them.This question more properly belongs in the "Beginners" topic, the sticky of said topic saying:QuoteSo, yes, if someone's prepared to, wearehere to help you do your homework, if indeed that is what it is.

author: Cerebus
author_rank: Super Contributor
timestamp: December 03, 2017, 12:39:12 am
content: Quote from: magnumX on December 02, 2017, 06:49:03 amYou're going to have to make that graph a lot clearer before anyone can really help. What's the X axis - it's just labelled 'voltage', but voltage of what?

author: magnumX
author_rank: Newbie
timestamp: December 03, 2017, 02:43:21 am
content: Quote from: Cerebus on December 03, 2017, 12:39:12 amI think the X-axis is Vin and Y-axis is Vout because i'm refer to the graph attached below

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 03, 2017, 06:49:28 am
content: You sure that MOSFET is wired up correctly?Mentor Graphics' symbols are the most retarded in the industry...Tim
Can anyone help me with a dual N-P channel MOSFET - Page 1
Forum section: electronics / projects

author: pet_rushi
author_rank: Contributor
timestamp: July 25, 2024, 09:24:35 pm
content: Hello guys,For several years I've been using a low noise discrete mosfet voltage regulator. It works very well for me as the output current does not change much and the noise performance is excellent.The MOSFETs are IRF610/9610.I chose that pair because of the noise performance but not for the high output current.Now I'm thinking of redoing and minimizing the PCB and as I don't need output current more than 100mA I would like to use a N-P channel MOSFET instead of IRF610/9610.I simulated a few dual channel mosfets but the noise performance degrades significantly.I would greatly appreciate it if someone can help me with this.

author: David Hess
author_rank: Super Contributor
timestamp: July 25, 2024, 10:58:04 pm
content: My guess is that the output noise you are seeing depends on the transconductance of the MOSFETs, and the new ones have less transconductance.Why aren't you using a regulator with an error amplifier and feedback? Then the noise would depend only on the zener reference because the output transistor would be within the feedback loop.Below is an old example but could be a starting point. Because the voltage regulator is within the feedback loop, its noise is reduced within the bandwidth of the feedback loop and noise depends only on the reference. Using a regulator has the advantage of adding short circuit and thermal protection, but a transistor could be used instead.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: July 25, 2024, 11:09:36 pm
content: Quote from: pet_rushi on July 25, 2024, 09:24:35 pmDo you mean Spice simulated, or you tested some ?Power MOSFET models are not going to bother too much with noise, so you will need to measure candidates.What noise frequency matters to you ?Spice will give you info on the load regulation,which will be quite poor here, as these are just source followers.Temperature performance will also be poor, as there are no regulation feedback paths.

author: pet_rushi
author_rank: Contributor
timestamp: July 26, 2024, 07:11:28 pm
content: Thanks for the replies!!!Simulation does not work properly.I just tried 2n7000. It works perfectly, the noise performance is better. Have to try the p-channel BS250, which I think is complementary to 2N7000.

author: Peabody
author_rank: Super Contributor
timestamp: July 26, 2024, 09:00:39 pm
content: The two I have run across in the Arduino world are the AO4606 and the Si4599. I don't know anything about their noise characteristics.