hybridfree/eevblog-posts huggingface dataset:
Need help with NPN and unknown load - Page 1
Forum section: electronics / beginners

author: colt
author_rank: Newbie
timestamp: April 10, 2019, 06:05:32 am
content: Hello! I am trying to reuse an old digital camera to make a long duration time-lapse rig. I was able to add some components to the camera so that when power is applied it automatically takes a picture. However, when I try to use an NPN bjt to switch the power the camera does nothing. My circuit is pretty simple but I need help interpreting some unfamiliar waveforms that I'm getting on the scope. Here is my circuit.When sw2 is pressed I expect the camera to turn on as the bjt would now create a path to ground. The camera does not turn on but instead at test point ch2 there is a voltage spike above the npn. I did not take a screenshot, but increasing the value of the gate resistor above 1.1k causes the frequency of the spikes to decrease.sw2 100 OHMZoomed outIf I hold sw1 then I get the following waveformsw1 1.1kI am applying DC voltage where the old lipo connected to the camera. Could it be the charging circuitry that is causing the voltage spike?Do I need to switch the power above the camera with a pnp?Thanks!

author: magic
author_rank: Super Contributor
timestamp: April 10, 2019, 06:45:50 am
content: My guess: the camera turns on, dumps a lot of current on Q1, voltage across Q1 rises, voltage across the camera drops, the camera turns off and tries again.You need a bigger Q1, something like BD433 at least, or more base current, or both.It's not unusual for compact digicams to take up to 1A peak.Even better solution is to use a MOSFET. The ubiquitous IRFZ44N might do if its "typical" performance curves are anything to go by, if not, I'm not sure what popular equivalent "logic level" switching MOSFET might be, maybe somebody else will know.MOSFET has the advantage of much lower voltage drop and no base drive, so higher overall efficiency. You may care about such things if it's battery powered.

author: colt
author_rank: Newbie
timestamp: April 15, 2019, 10:18:21 pm
content: Thanks for the explanation. I had a IRFZ40 laying around and that did the trick.
Need help with opening boardview file(.fz) - Page 1
Forum section: electronics / beginners

author: Dar
author_rank: Newbie
timestamp: April 02, 2021, 10:02:59 am
content: Hi all,Recently I have been attempting to fix an graphics card of mine.I was lucky enough to find a schematic file on the internet,but after many attempts I still cant open it.Here is the error readout by fritzing:Parsing error(1)at line 1,column 1:error occurred while parsing element.And below is the fileThanks in advance!https://drive.google.com/file/d/1njw-wnUQuEbH4k0t7aZy-if4eVxGluCR/view?usp=sharing

author: AlfBaz
author_rank: Super Contributor
timestamp: May 02, 2021, 01:14:32 am
content: Doing a search I came across this post and as it's relatively recent, I thought I'd answer it for future posterityI fell into the same trap by looking for *.fz file extension and the software that opens it.Fritzing was the first piece of software to come up but it's actually a boardview fileA free viewer for these files can be found herehttp://boardviewer.net/index
Need help with RC circut waveform - Page 1
Forum section: electronics / beginners

author: akintos
author_rank: Newbie
timestamp: April 10, 2019, 02:04:11 pm
content: I simulated the circuit described in first image with PSpice and got second image as result, which is expected.(Value of resistor is 0.1k ohm and input signal is 5kHz square wave, -1 ~ 1V)The problem is when I build same circuit in real life and measure input and output voltage(third image), I get almost same waveform.I also attached 5kHz input signal images.When I changed the resistor to 1k or 10k, the input signal was almost square (not perfect)What can cause this?

author: rstofer
author_rank: Super Contributor
timestamp: April 10, 2019, 03:41:51 pm
content: Tau = R * C => 100 usFull charge/discharge occurs at, say, 6 Tau or 600 usMax frequency to see full cycle => 1 / 0.0006 = 1.67 kHz.As you use higher frequencies, you won't get full charge or discharge waveforms.Hit the circuit with 1kHz and change the time/div on the scope to get just one charge and one discharge. The exponential nature will be more apparent when time is spread out.Using 10k will change things, you would want a maximum frequency of just 167 Hz to allow enough time for full charge and discharge cycles.There's nothing magic about 6 Tau, 4 or 5 Tau may be workable. It depends on what you want to see.As to the last trace, I'm not sure what is going on there. What is the yellow trace? Is that the input?

author: rstofer
author_rank: Super Contributor
timestamp: April 10, 2019, 05:58:28 pm
content: In the last figure, it the cyan trace is the input and the yellow trace is the output then it looks like the signal source has fairly high impedance.When you simulate a signal source, you usually assume 0 Ohms output impedance and the only resistance in the circuit is the 1k. But that isn't reality, everything has some kind of impedance. It could be that your source has a pretty high impedance (600 Ohms?) and it is about equivalent to the 1k resistor. Some signal sources have selectable output impedance of 600 Ohms and 50 Ohms.

author: mikerj
author_rank: Super Contributor
timestamp: April 10, 2019, 07:59:31 pm
content: Have you compensated your scope probes correctly?

author: bson
author_rank: Unknown
timestamp: April 11, 2019, 03:44:21 am
content: The linear ramping instead of 1-e^-kt charging indicates the signal source is current limited.
Need help with relays. - Page 1
Forum section: electronics / beginners

author: resistcircuitresist
author_rank: Contributor
timestamp: May 05, 2012, 09:48:47 pm
content: I have two relay boards. One of them is standard 5v dc relay and the other is a solid state. I am trying to trigger several devices, one of them is a small 12v motor.The solid state relay board functions normally by shorting + to input, but latches closed on device side of the relay until load is turned off or is disconnected.Is this normal for solid state relays with inductor type devices?http://www.sainsmart.com/sainsmart-4-channel-5v-solid-state-relay-module-board-omron-ssr-avr-dsp-arduino.htmlThe standard relay works by shorting ground to input and releases on the device side when the input voltage is disconnected. I would have thought that both relays should work by connecting + to input rather than ground to input. Is there a problem with this relay board?http://www.sainsmart.com/module/acceleromete/arduino-pro-mini.html

author: TerminalJack505
author_rank: Super Contributor
timestamp: May 06, 2012, 05:00:19 am
content: First, the SSR has a "zero cross" feature. This implies that the source on the load side must be AC. DC won't work since 0V will never be crossed.Second, if this happens only with inductive loads then be aware that it doesn't look like the PCB maker followed Omron's advice (datasheetpg 386) regarding inductive loads.The datasheet says "No overvoltage absorption element is built in. Therefore, if the G3MB is connected to an inductive load, be sure to connect the overvoltage absorption element."I see a fuse on the load side but that's not the same thing.The PCB maker very likely expects the user to do this since it is very load-specific and would likely interfere with non-inductive loads.If the SSR will shut off for resistive loads but not for inductive loads then you might follow Omron's advise in theSSR Design Considerationsbooklet, pg 831.They advise the use of varistors, zeners, RC snubbers, etc., depending on the various factors.

author: resistcircuitresist
author_rank: Contributor
timestamp: May 12, 2012, 03:35:55 am
content: Thanks for the information. Having trouble finding a 2 channel relay module that i can use with I/O pins, by sending high signal to close relay. Can be powered by 0-12v.

author: dfnr2
author_rank: Regular Contributor
timestamp: May 12, 2012, 03:03:21 pm
content: Assuming you share a common ground, you should be able to drive either with an I/O pin.
Need help with SEPIC converter  - Page 1
Forum section: electronics / beginners

author: Menxiu
author_rank: Contributor
timestamp: February 03, 2018, 04:34:43 pm
content: I'm currently building a SEPIC dc-dc converter. I have laid out the components on LTSpice and I'm having trouble getting the results i want.Requirements :5V input1.245V - 12V outputAlso, how do i manage the current? As i have a prototype built, my LT1370 chip seems to be getting quite hot.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 04, 2018, 02:08:39 am
content: Grounding /SHDN would seem to be a non-starter...Those capacitors in series will generate a singular matrix error. Use a single one, or set RSHUNT = 1e8 or less, or put a resistor across one or both capacitors.Can also add a coupling statement, "K1 L1 L2 0.98" and use a coupled inductor part.Tim

author: Menxiu
author_rank: Contributor
timestamp: February 05, 2018, 10:43:49 am
content: Thanks for the reply. I've managed to get it the SPICE model working by removing the ground to the S/S pin.In my prototype however, i'm not getting any output at all. My inductor L1(Connected to Vin and Vsw) seems to be getting 18V across it. Any idea what could be the issue?
Need help with simulation - Page 1
Forum section: electronics / beginners

author: username
author_rank: Newbie
timestamp: February 16, 2017, 02:25:45 pm
content: Could someone give a detailed guidance on how to simulate the following project inOrCADCapture CIS Litestep by step?Note: This is not homework. I am practicing for exam.Draw a schematics for static analysis of a diode. Simulate the circuit such that static characteristics of forward biased1N4002diode for three temperatures (75 , 25 and 125 degree Celsius) are obtained. On obtained characteristics, indicate what trace corresponds to what temperature, and then determine and display the value of threshold voltage for each trace. For the set point positioned atVd=0.8Vat temperature25 degree Celsiusand for voltage incrementdV=+0.1VordV=-0.1Vdetermine the dynamic resistance of a diode and display it.

author: testian
author_rank: Regular Contributor
timestamp: February 16, 2017, 03:26:24 pm
content: Where exactly is you problem?Creating the circuit, simulating it, changing parameters?
Need help with Simulink for control engineering homework – I'm stuck - Page 1
Forum section: electronics / beginners

author: Xenon_K
author_rank: Contributor
timestamp: June 02, 2025, 11:31:33 am
content: Hey,I have to do a homework assignment for control engineering and need to simulate something in Simulink. Unfortunately, I have no idea how Simulink works. It keeps showing me errors, and no matter what I try, I just can’t get it to work. Is there anyone here who could possibly help me?

author: TizianoHV
author_rank: Regular Contributor
timestamp: June 03, 2025, 06:49:49 am
content: What is the block "input generator"?
Need help with SPI bus between separate 3.3v power rails - Page 1
Forum section: electronics / beginners

author: bfrigon
author_rank: Contributor
timestamp: December 18, 2014, 03:07:05 pm
content: Hi,I am designing a pcb for a touch sensing keypad with a AT42QT1085. The datasheet strongly suggest using a dedicated LDO voltage regulator. So i chose the ADP150AUJZ-3.3 (3.3v output)The system provides two power rails, 3.3v and 5v.My concern is with the SPI communication lines. The MCU is powered by the external 3.3v rail and the pull-ups for the SPI lines are on this rail too.So... Since the MCU and touch IC both runs at the same voltage, even though the touch IC has it's own regulator, i don't think it's gonna be a problem if i connect the SPI lines directly to the MCU.Am i wrong? I just need some advice on that.Also, what special care should i take to make sure i don't mix in noise from the external power rail?here is the schematic for the touch IC :Thank you

author: XFDDesign
author_rank: Frequent Contributor
timestamp: December 18, 2014, 04:53:41 pm
content: As long as they all share a common ground between the SPI source and the MCU, and they maintain the required logic level, there is no problem to be had.

author: bfrigon
author_rank: Contributor
timestamp: December 18, 2014, 08:37:32 pm
content: Thank you

author: suicidaleggroll
author_rank: Super Contributor
timestamp: December 18, 2014, 10:52:32 pm
content: When you're interfacing two ICs, you just need to take two rules into account (at least as far as voltage compatibility goes).1) They share a common ground2) When device A asserts a logic 1, it will be high enough to register a logic 1 on device B (typically Vcc-30%) but not so high that it exceeds device B's "maximum voltage on any pin" threshold (typically Vcc+10%), and vice versa.So two devices running on their own power supplies doesn't matter. It doesn't even need to be the same voltage, as long as #1 and #2 are met. As long as both rails are within 10% of each other you'll be perfectly fine. You'll often even see 3.3v and 5v devices tied directly to each other communicating without a problem, which is just fine as long as 3.3v will register a logic 1 on the 5v device (if the 3.3v device is going to be sending any data to the 5v device), and the 3.3v device's pins are 5v-tolerant (if the 5v device is going to be sending any data to the 3.3v device), which many are for exactly this reason.
Need Help With Stepper Motor Driver TMC5240 LC Filter - Page 1
Forum section: electronics / beginners

author: Ednet1
author_rank: Newbie
timestamp: July 15, 2024, 03:10:56 am
content: Hello everyone,I am using the Analog Devices TMC5240 to drive a Sanyo Denki Sanmotion SM2564C20B41P bipolar stepper motor specs 2A/phase, 2.1 Ω/phase & 11mH/phase. I will be powering the stepper with 24Vdc @ approx. 2A.The data sheet (attached) for the Analog Devices TMC5240 stepper driver suggests that if using a high current that you should use an LC Filter between the driver & the stepper motor similiar to the image Attached.The information they give to select the appropriate components is the wording below."A more elaborate scheme uses LC filters to decouple the driver outputs from the motor connector. Varistors V1 and V2in between of the coil terminals eliminate coil overvoltage caused by live plugging. Optionally protect all outputs by avaristor (V1A, V1B, V2A, V2B) against the ESD voltage. Fit the varistors to the supply voltage rating. The SMDinductivities conduct full motor coil current and need to be selected accordingly."Can anyone please help me in selecting the appropriate Inductors, varistors & capacitors for this LC filter?Also has anyone used the Analog Devices TMC5240 stepper driver, I am hoping to control it with a Raspberry Pi 5 via SPI, I never used one of these drivers before. How do you go about connecting it to the RPI5?

author: m k
author_rank: Super Contributor
timestamp: July 18, 2024, 09:28:10 am
content: So when frequency goes up those components start pulling the motor away from the driver and towards the ground.Calculator(2(pi)fL) is giving a coil value of 80 nH, not very big.Varistor(VDR) is nowadays usually (MOV) an over-voltage protection.Compared to coil and capacitor its operation is fundamentally different.It is supposed to change an extra energy to heat, so wearing while operating.(remember the quality breakfast of pig and chicken)SPI is SPI, nothing special there.What kind of components you've had in mind?

author: Ednet1
author_rank: Newbie
timestamp: July 18, 2024, 12:01:10 pm
content: Thanks M K for getting back to me, after some advice from Harald on the Maker Pro forum I have decided to go with the following components.Varistors: Bussmann/Eaton MLVC08V024C300 clamping 58v 100AFerrite Beads: Murata BLM31PG500SZ1L 50Ohms 100MHz 3.5ACapacitors: Kemet C0603C561J5RACTU 560pF 50V X7RI have attached the data sheets, let me know if I have made any blunders.

author: m k
author_rank: Super Contributor
timestamp: July 19, 2024, 03:19:26 pm
content: Keep driver close to the motor and it should be just fine.

author: Ednet1
author_rank: Newbie
timestamp: July 22, 2024, 01:23:03 am
content: Thanks M K
Need help with the identity of this...... - Page 1
Forum section: electronics / beginners

author: lavo-1
author_rank: Regular Contributor
timestamp: January 09, 2012, 02:09:00 pm
content: Hi chaps, I am hoping that some one will be able to help identify thIs transformer. It is from a MetraPat 4 Pat tester.The primary coil is O/C and thus I am unable to measure what the output from the secondary.I have looked on a few parts catolouges such as Digikey and RS but none of the numbers from the casing seem to match anything.Could this be a bespoke component that I will have to get from Gossen? I can hear my wallet groan as I type!Would love some help or advise on getting a replacement part.The numbers on the case:3.520.057.02M19-092 AGT 07/97Uploaded withImageShack.usShot at 2012-01-09

author: amspire
author_rank: Super Contributor
timestamp: January 09, 2012, 11:45:17 pm
content: The transformer is likely to be one made specially for Gossen. If you can afford a replacement from Gossen, that is the best solution. It may have higher insulation ratings then conventional transformers, or extra shielding.It may be possible to substitute it with an off-the-shelf transformer functionally. If there is room in the case for a second transformer, it may be possible to keep using the original, and feed voltage into one of the secondaries from a second transformer. Any clues to voltages, like voltages marked on the PCB may help. You would need to work out how the windings on the secondary are configured, and then by applying 50.60hz AC to one of the secondary windings, measure all the ratios of the other windings to the first, along with the DC resistance of each winding. That would be a start anyway.It would help if you can get a schematic, but I haven't seen many Gossen service manuals floating around.If you want the meter though to perform to the original safety specs, you probably better go talk to Gossen.Richard.

author: lavo-1
author_rank: Regular Contributor
timestamp: January 10, 2012, 07:56:42 am
content: Many thanks for the reply Richard.It does look like I will have to just get in touch with Gossen and see what they say as I am unable to locate a schematic to try to match a third party transformer.I will post any further developments when I get a reply from Gossen.Thanks again.Jason.
Need help with TTL only termometer and voltmeter and 7 segments display - Page 1
Forum section: electronics / beginners

author: little_carlos
author_rank: Regular Contributor
timestamp: May 10, 2016, 11:37:39 pm
content: Hi, i need to make a voltmeter and a termometer using TTL only chips, and display the info on 7 segment displays, can you tell me which IC's should I use?

author: danadak
author_rank: Super Contributor
timestamp: May 11, 2016, 12:01:51 am
content: http://www.ti.com/lit/ds/symlink/sn7448.pdfhttps://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwjv-s2Z3NDMAhWEJhoKHTosAAQQjRwIBw&url=http%3A%2F%2Fmetrixdriverzo.cf%2F7448-bcd-to-7-segment-display-driver-1550&psig=AFQjCNHQ2MwNUtTiXSicW5DVAYo0fVbcaA&ust=1463011360075478https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwilv8C-3NDMAhWFqxoKHQt_D7UQjRwIBw&url=http%3A%2F%2Ffileindexus.cf%2F7448-bcd-to-7-segment-display-driver-625&psig=AFQjCNHQ2MwNUtTiXSicW5DVAYo0fVbcaA&ust=1463011360075478Regards, Dana.

author: danadak
author_rank: Super Contributor
timestamp: May 11, 2016, 12:05:30 am
content: What are the voltmeter and thermometer chips you are going to use ?Regards, Dana.

author: little_carlos
author_rank: Regular Contributor
timestamp: May 11, 2016, 12:52:38 am
content: Quote from: danadak on May 11, 2016, 12:05:30 amhi, the voltmeter is just a crappy adc reading from 0 to 5V and display the result on a 7 segment displaythe thermometer is a lm35, since accuracy is not required
Need help with Ups/Inverter  - Page 1
Forum section: electronics / beginners

author: sarry86
author_rank: Contributor
timestamp: September 24, 2023, 01:39:28 pm
content: Hello everyone, I have this ups/inverter IGBT 1450VA which was working great until it started showing short circuit on a small lcd screen, I opened it up and started troubleshooting it and indeed I found some fault transistors, I decided to get rid of all of the transistors next to the shorted ones and it worked for some minutes without a problem, but then I heard a relay tripping off, and now it is showing that 2 batteries connected in series have no power at all, and if i disconnect the 24dc in then the battery are showing they are full (28vdc) with another inverter, they are working great no problem, I started to troubleshoot it again starting with the parts I replaced, they are okay, checked other included igbt (GW30NC120HD and G4PH40UD2) they're all fine, I am outta ideas, what else could be the problem here?
need help with variac - Page 1
Forum section: electronics / beginners

author: Raj
author_rank: Frequent Contributor
timestamp: January 26, 2017, 10:16:39 am
content: I was testing nixie using variac and a mastech meter i just recently bought.so i had a 22k resistor to limit current from going above 10ma (the spec of my nixie says current 10ma).The problem is, after i reached the desired voltage on variac, where all digits glow just the right amount ,I went on to measure voltage on variac , I got the result as follows-117v on ac output50v on AC setting of meter (dc output)104v on DC setting (dc output)the problem is ,even after rectification, why is there still 50v ACis one of my diode shot?(which would have definitely lead to magic smoke) (ill check soon after this post)here's a drawing of ithttps://drive.google.com/file/d/0B2ffwyRcquZTYWVkUWJtemZGMmM/view?usp=sharing

author: jeroen79
author_rank: Frequent Contributor
timestamp: January 26, 2017, 10:30:43 am
content: After the rectifier the voltage will still be going up and down, it just won't go below 0.So it will have an AC as well as a DC component.You need a capacitor to smooth out this ripple.

author: Raj
author_rank: Frequent Contributor
timestamp: January 26, 2017, 12:01:30 pm
content: Thanks, with a cap, my meters shown asAlmost same voltage at both side of rectifier.So it was a meter misunderstanding after all(Thought that those 50 volts are under 0)

author: Ian.M
author_rank: Super Contributor
timestamp: January 26, 2017, 12:06:57 pm
content: Its generally a *BAD* idea to use a Variac + bridge rectifier for a DC power supply as nearly all Variacs are autotransformers and provide no isolation from the mains whatsoever. For the sake of your life and sanity, either put a conventional transformer in-between the Variac and the bridge rectifier or run the Variac off an isolation transformer with a fully floating output.

author: Raj
author_rank: Frequent Contributor
timestamp: January 26, 2017, 12:11:50 pm
content: Yes, I do ( forgot it in drawing. Sorry)Thanks

author: Seekonk
author_rank: Super Contributor
timestamp: January 26, 2017, 01:17:52 pm
content: Many meters expect to be reading AC on AC setting. If you do add a capacitor, it still may measure considerable AC which isn't there. Place a .47uf in series with probe to measure actual AC instead of the imposed DC.
Need help with wiring an att-232 transformer into 230v -> 115volt - Page 1
Forum section: electronics / beginners

author: valk
author_rank: Newbie
timestamp: February 24, 2021, 09:03:05 pm
content: Hi!I have a pioneer att-232 transformer, which currently outputs roughly 145volts. I would like to wire it in such a way that its output will roughly be 115V. I have been searching for any datasheet for this transformer, but I could find none. Does anyone here have a clue on how I could approach this?Thanks in advance!

author: Refrigerator
author_rank: Super Contributor
timestamp: February 24, 2021, 10:21:09 pm
content: A transformer can only output fixed voltages that are determined by the number of windings, so if it's not made to output 115V there's no way to make it do so.If you don't have a datasheet you can always probe the pins and write what voltage is where and then see if any combination of them can output close to 115V.Also if there's a winding with multiple taps you cannot mix and match pins because you would end up shorting some windings.Otherwise if there are separate windings you can add them in series to hopefully get the voltage you need, just don't forget to mind the phase, because a winding 180 degrees out of phase will subtract voltage, which you can use to your advantage if the voltage is too high.To test what windings go where you can use resistance mode on your multimeter.
Need help/suggestions for GSM auto-dialer in alarm system - Page 1
Forum section: electronics / beginners

author: Wilsas
author_rank: Newbie
timestamp: August 01, 2013, 09:57:10 pm
content: Hello everyone,I am unsure if this is a noob question/request or something more advanced.So here goes.Basically i need some kind of automatic switch which would work with ~2Hz interval once it gets powered with 12v.I already tried combining a relay with a cap like shown in this video:GSM????.Yet i miserably failed. I have no clue to why the relay just outright refused to go slow enough or change the switching speed at all.After that i started thinking about 555 timer and using only solid state components. But a single simple relay with a cap would be perfect (if it worked like in the video)To sum it up, I need some kind of circuit, which, when powerd by 12v from a motion sensor, would trigger a phone call (press call button twice). #1 priority is reliability #2 priority is price (the lower the better)I am open to suggestions and am willing to learn something new in the progress of making this work!P.S.This would be just an addon to an already working alarm system.

author: G7PSK
author_rank: Super Contributor
timestamp: August 02, 2013, 09:35:42 am
content: What you have in the circuit shown the relay will only switch at the speed that the mechanical parts can move most likely quite fast giving a buzzing sound, the capacitor is only for spark, rf suppression.To change the switch speed you need to do something along the lines of put the relay coil across a capacitor and then connect that to the supply through a resistor and arrange the relay contacts such that when the relay switches it discharges the capacitor.
Need ideas for my first microcontroller based project ? - Page 1
Forum section: electronics / beginners

author: KAI
author_rank: Newbie
timestamp: June 25, 2015, 07:51:41 am
content: I had recently purchased anarduino UNO boardand want to make my first electronic project based on that,so can anyone out there have some ideas so please share it out Ibadly need oneand plzz remember i m just anewbieso suggest simpler ones

author: Kappes Buur
author_rank: Regular Contributor
timestamp: June 25, 2015, 08:35:33 am
content: http://www.instructables.com/id/Arduino-Projects/might give you some idea.

author: picandmix
author_rank: Frequent Contributor
timestamp: June 25, 2015, 08:52:43 am
content: One of the best places to start is the Aduino website, it has everything you need and a very active help forum.Start by looking here for beginner projects -http://playground.arduino.cc/Projects/Ideas

author: daqq
author_rank: Super Contributor
timestamp: June 25, 2015, 11:17:25 am
content: The most traditional way to start with microcontrollers is to blink an LED.For a first bigger project I'd go with a clock of some sorts. Clocks are fun and you will learn a lot - a basic clock is simple, but you can improve tons of different things on it.

author: rcircuit96
author_rank: Newbie
timestamp: July 02, 2015, 06:42:50 am
content: once you've got the blinking LED down, Cylon Eyes is always a good next step.

author: JacquesBBB
author_rank: Frequent Contributor
timestamp: July 02, 2015, 07:09:08 am
content: Try google arduino

author: kolonelkadat
author_rank: Regular Contributor
timestamp: July 02, 2015, 08:04:49 am
content: Just think about what you would want to control in the real world using software.Recently I wanted to add bluetooth to my car stereo, so I got an arduino and got to coding.maybe you would like a laser trip wire in your hallway that will set off an alarm in your room so your parents/roommates/strangers dont catch you "putting on the finishing touches"you could also make an annoying throwie. wire up the microcontroller to make annoying sounds at random intervals and stick it somewhere stealthy.

author: B.B.Bubby
author_rank: Regular Contributor
timestamp: July 02, 2015, 09:51:19 am
content: I'd also recommend diving into something that can be controlled by PWM. Its very useful and fun
Need ideas for small project enclosure for 120V power - Page 1
Forum section: electronics / beginners

author: pussyfoot
author_rank: Newbie
timestamp: April 15, 2013, 01:47:13 pm
content: I'm working on a project that involves mains voltage. I'd like some advice on an enclosure and cabling for it. I suppose the most straightforward way would be to use a 1-Gang PVC Electrical Box with clamps to hold down the wire. It will be ugly as sin, but functional. Any other ideas?In general, how do you handle strain relief of cables in project boxes?

author: KJDS
author_rank: Super Contributor
timestamp: April 15, 2013, 06:55:50 pm
content: The simple way is to put a knot in the cable so it can't be pulled out of the box. I'd back that up with a clamp as knots can slowly be moved over time.

author: Alana
author_rank: Frequent Contributor
timestamp: April 15, 2013, 07:41:08 pm
content: Knot on a cable is mandatory. Sometimes i add hot glue.
Need Identifying some components - Page 1
Forum section: electronics / beginners

author: ARCULA
author_rank: Newbie
timestamp: March 13, 2024, 08:41:31 pm
content: Hello All,I don't know if the "Beginners" section is a good place to ask my questions.I found some old electronic components ;I believe they belonged to TV ; something like High voltage transformers of CRT TVs; but I cannot be sure so, I've decided to post the photos of them here; hopefully someone will recognize them and will give more info about them.Any help identifying these components is appreciated.Edit: Orion CT 451 power transformer (is what looks similar to the components I shared their pictures; Orion CT 451 power transformer was found using Google lens)

author: Terry Bites
author_rank: Super Contributor
timestamp: March 14, 2024, 04:37:15 pm
content: That looks very much like a Plessy parthttps://en.wikipedia.org/wiki/Plessey

author: ARCULA
author_rank: Newbie
timestamp: March 14, 2024, 04:42:01 pm
content: Hi Terry,Thank you for your reply! I think you were able to correctly identify the company behind it! However, I still need to know what that part was! Do you think it was a High voltage transformer? I would also be happy to know how to get it back to operation.best,ARCULA

author: wraper
author_rank: Unknown
timestamp: March 14, 2024, 05:15:22 pm
content: Looks like custom transformer made for Plessy by Siemens.

author: ARCULA
author_rank: Newbie
timestamp: March 14, 2024, 05:23:36 pm
content: Hi Wraper,I think you are right but I want to know what type of Transformer it is? or How it could be brought back to life?

author: wraper
author_rank: Unknown
timestamp: March 14, 2024, 05:38:16 pm
content: Should be from SMPS and having ferrite core. There is no use case for it that would make any practical sense. You could probably design an SMPS around it if measure its specs, but it would make no sense to do from any practical and even educational perspective.

author: ARCULA
author_rank: Newbie
timestamp: March 14, 2024, 06:26:08 pm
content: You know, I thought it could be used as a transformer at least! and I thought it is a high voltage transformer (like a flyback transformer) So, you believe it is not a high voltage transformer?

author: wraper
author_rank: Unknown
timestamp: March 14, 2024, 07:38:21 pm
content: Quote from: ARCULA on March 14, 2024, 06:26:08 pmWhatever it is, it certainly isn't a horizontal line/anode HV supply transformer

author: ARCULA
author_rank: Newbie
timestamp: March 14, 2024, 07:46:17 pm
content: Thank you for sharing your opinion but I still have hopes for knowing what that is and how could it be used! :-) So, I will stay keen for replies here!
Need info on 2SB798DL replacement - Page 1
Forum section: electronics / beginners

author: Crambone
author_rank: Frequent Contributor
timestamp: July 05, 2024, 08:29:34 pm
content: I need a replacement for a 2SB798DLI believe the DL is Hfe 135-270?It in a 28MHz transmitterDrew

author: m k
author_rank: Super Contributor
timestamp: July 14, 2024, 05:37:11 pm
content: https://alltransistors.com/transistor.php?transistor=10915
Need information about K6N27 - Page 1
Forum section: electronics / beginners

author: aug
author_rank: Newbie
timestamp: March 26, 2023, 07:20:12 am
content: Hello.Thanks for reading my topic.I am an novice about eletronics.I have an damaged video card ... that video card was analyzed by an eletronic professional .. only one component was damaged.Is an little component named K6N27 having 6 pins ( 3 in each side ).Doing an search in sites with datasheets was showed that K6N27 is an SOT-363.https://www.diodes.com/assets/Datasheets/ds30088.pdfhttps://www.mccsemi.com/pdf/Products/MMDT3904(SOT-363).PDFhttps://www.21yangjie.com/style/pdf/small-signal-triode/MMDT3904-SOT-363-%E6%B5%B7%E9%B8%A5%E8%84%9A.pdfReading some manufacturers datasheets begin the doubts because different informations.In datasheets have the informations :MMDT3904MMDT3904-7-FSOT-363Collector-Base Voltage 60 VCollector-Emitter Voltage 40 VEmitter-Base Voltage 6 V94 V in an pdf and 40 V in another pdf.Being an video card the voltage is from mainboard ...less of 12 volts ?In datasheets that component K6N27 is 40 and 90 volts.Well ... my questions are :- MMDT3904 e MMDT3904-7-F are exactly the same name for that component K6N27 ? both are compatible ?- SOT-363 , SOT-363-3 e SOT-363-6 are the same type of component ?- K6N27 is an NPN , N-channel or P-channel ?- However the datasheets details are 40 and 94 volts and others high voltages (Collector-Base Voltage 60 V , Collector-Emitter Voltage 40 V and Emitter-Base Voltage 6 V) . Not are exactly used the high voltages values ? Is as being maximum voltage output ?In some forums have replies saying that component is an transistor double N and is generic.Thanks for your reply.Have an nice day.

author: mariush
author_rank: Super Contributor
timestamp: March 26, 2023, 07:37:33 am
content: Video cards work with 12v or less, so it doesn't matter if it's 40v or 60v rated transistors. As long as they can do more than 12v it would be fine.It looks like 2 npn transistors in a single chip, you can double check by looking to see if there's some resistors connected to the base pins of the transistors, usually a resistor is needed on the base of a transistor to limit current.digikey has a bunch of dual npn with those ratings, this 3904 is quite common :https://www.digikey.com/short/v24npprt

author: daisizhou
author_rank: Super Contributor
timestamp: March 26, 2023, 07:41:02 am
content: The component code is K6N, 27 may be the production date or batch number, and the packaging is SOT-363,Please look at the picture
need inputs on my pcb design pwm circuirt - Page 1
Forum section: electronics / beginners

author: noobieguy
author_rank: Newbie
timestamp: January 04, 2013, 02:40:18 am
content: i followed this youtube video:and this circuit without the LEds...i am confused on how to place the leds in the circuitif there are any suggestions or improvements to better up the design please do so...i am just excited about this project.thanks guys.

author: alanb
author_rank: Frequent Contributor
timestamp: January 04, 2013, 08:37:02 am
content: I suggest that as a first step you draw the schematic diagram for this project. Once you see it on paper it should be a lot easier to work out how to connect a led or modify the circuit.

author: noobieguy
author_rank: Newbie
timestamp: January 07, 2013, 04:46:10 am
content: thanks for the reply alanb.i will do what you suggested.
Need interrupt diagram for PIC16F684 - Page 1
Forum section: electronics / beginners

author: khatus
author_rank: Regular Contributor
timestamp: February 16, 2020, 07:43:56 am
content: Hello guys i need INTERRUPT LOGIC diagram for PIC16F684. I can not find it in the datsheet.

author: oPossum
author_rank: Super Contributor
timestamp: February 16, 2020, 07:48:46 am
content: It doesn't have interrupts. Use an 18F series part if you want to write interrupt driven code.

author: khatus
author_rank: Regular Contributor
timestamp: February 16, 2020, 08:20:17 am
content: But it has INTCON,PIE,PIR Registers.

author: jpanhalt
author_rank: Super Contributor
timestamp: February 16, 2020, 08:25:11 am
content: The 16F684 has interrupts:Its logic is pretty standard for Microchip, but it is not all on one page. Search "interrupt". It seems to start at page 35 (IOC) and continues a few pages after that.

author: jpanhalt
author_rank: Super Contributor
timestamp: February 16, 2020, 08:32:34 am
content: I just edited my earlier post. The logic is not all on one page. It starts p 35 with IOC and is continued on subsequent pages. It is pretty standard Microchip interrupt logic with GIE, PIR and so forth.

author: khatus
author_rank: Regular Contributor
timestamp: February 16, 2020, 09:09:40 am
content: Thanks it starts from page 103

author: nali
author_rank: Frequent Contributor
timestamp: February 16, 2020, 09:34:23 am
content: It's on page 107 of the datasheet. Isn't this what you want?http://ww1.microchip.com/downloads/en/DeviceDoc/41202F-print.pdf
Need knowledge about bandwith in DSO - Page 1
Forum section: electronics / beginners

author: Galli
author_rank: Newbie
timestamp: October 26, 2023, 03:45:41 pm
content: Hello, I'm currently doing my technician. I have a question about the following task."What minimum sampling frequency must a DSO have in order to be able to measure the fall time in the pulse voltage shown in Fig. 1.1 up to the 9th harmonic using dot reproduction, vector interpolation and sine interpolation?"The frequenz of this pulse is not essential, i will understand the theory behind this.I know the Nyquist theorem, which says: bandwidth > f*2So far so good. I bought the solution to this task online because I want to check my solution afterwards to get my grade.Unfortunately, I couldn't find anything when I searched online and in my study documents as wellI want to understand the topic and not simply write it off.The solution to the task was as follows:Bandwidth for sine interpolation (si(x)) = f*2.5 (Nyquist okay)but for the bandwidthVector interpolation = f *10and for dot reproduction = f*25I wonder where the other two factors come from and why I can't just use one factor for all 3 functions?And why exactly these factors? And not, for example, *30 or *50. Is there any practical experience here?Thank you for help

author: ataradov
author_rank: Super Contributor
timestamp: October 26, 2023, 04:45:35 pm
content: Apart from Nyquist, those are just arbitrary numbers. I assume they are matching whatever course material was given.There is no Fig 1.1 attached. But you need to keep in mind that "f" here would be the frequency of the highest harmonic you want to reproduce. For a pure sine wave it would be the frequency of that sine wave. For anything that is not sine, you have to take harmonics into account or you will be restoring sine waves.Sampling rate 10x of the signal frequency is an often used rue of thumb when observing digital signals. This is the point where square things still look square.And the only reason for dot reproduction to be higher is to increase the density of the dots. It is no different that vector interpolation and if you can imagine lines between the dots, you don't need 25x sampling.

author: Galli
author_rank: Newbie
timestamp: October 27, 2023, 06:11:55 am
content: Only "random" numbers, okay, and in the practice the factor ten is used normally.Thank you, ataradov.
Need literally everything to start soldering/desoldering. 70 dollar budget USD. - Page 1
Forum section: electronics / beginners

author: husain
author_rank: Newbie
timestamp: December 18, 2014, 11:06:58 am
content: So I think the title explains everything pretty well, I have only 70 bucks to get everything I need to start soldering. I don't mind chinese knockoffs but I want something that feels decent as I doubt I am going to upgrade soldering stations anytime soon. (I don't have very much money and this is a big purchase for me)So my parts list / needs are as follows:Soldering stationDesoldering wickSolderand maybe some better / more useful tips?So far I have been eyeing up the hakko 936 knock off by aoyue as a good starting point. (link:http://www.amazon.com/gp/product/B000VINMRO)But thats as far as I've gotten really.I am mainly buying this to do simple solder work while building my way up to more complicated stuff. Mainly want to get around to soldering a 3ds to do a nand dump but I am not trying that until I am confident I won't be destroying anything. (the pads for a 3ds nand dump are about 0.3mm)So to give you guys a better idea of what I am eventually hoping to do here is a picture of the solder points along with a finger for scale.ignore the blue wire I won't need to use that point, the ones I will be using look like the gold pads

author: Howardlong
author_rank: Super Contributor
timestamp: December 18, 2014, 03:24:03 pm
content: This:http://www.amazon.com/Digital-Rework-Soldering-Station-11-Piece/dp/B0086RA11C/ref=sr_1_3?s=hi&ie=UTF8&qid=1418915983&sr=1-3&keywords=898DI've had one for over four years and use it extensively (lifted circa 1,000 QFN parts with it in that time). It has a 0.2mm tip, I recommend having spares of this tip if you're going to use it a lot, after a while it'll corode.
Need little help to attenuator scematic and does it work? - Page 1
Forum section: electronics / beginners

author: FriedMule
author_rank: Frequent Contributor
timestamp: June 29, 2018, 09:54:35 pm
content: I have designed an attenuator, why so complicated?... Just to learn something and to use it later on:-)My design is as I always do it, serch the net, grap scematics and combine them.I really hope that you will help me with these three questions:1) Am I right by thinking that the double potentometer (1_out) shall on (+) and 2_out shall on lead_to_u4?2) Can it work on only 10 volt or shall some of the values be changed?3) Last question wil it work as an complicated liniar optoisulated attenuator?Kind regards

author: basinstreetdesign
author_rank: Frequent Contributor
timestamp: June 30, 2018, 02:20:31 am
content: What do you want to accomplish with this circuit? I see no input to it.Quote from: FriedMule on June 29, 2018, 09:54:35 pmI don't know what that means. Do you mean "connect (1_out) to +15V, connect (2_out) to lead_to_U4"?Quote from: FriedMule on June 29, 2018, 09:54:35 pmUntil I know what you want to do with this circuit I can't say.Quote from: FriedMule on June 29, 2018, 09:54:35 pmI dont think so as it stands. But if you could make your intentions clearer then I might be able to give you a better answer.It seems that you have an oscillator. If for some reason the output of the op-amp goes high enough to turn on the two opto-isolators U3 and U5 then U5 would pull the non-inverting input of the op-amp low. So its output would then go low, turning off the optos. This allows the non-inverting input to the op-amp to be pulled high by R5 causing the action to repeat. C5 and R13 merely serve to slow the rise and fall of the op-amp down. The pot RV3 may change the duty cycle.That is what I see.

author: FriedMule
author_rank: Frequent Contributor
timestamp: June 30, 2018, 03:33:26 am
content: Thank you for your answer, sorry I did explain it badly .This is an attenuator where the audio signal goes from Filter_+ trough U3 and out to Preamp_Out_+So the U3 act as an electronic pot, managed by the amount of voltage/current that goes trough the LEDSince the H11F3M is not perfect linier, the LM358A do compare U3 and U5 and adjust the U3 so it act much more linier.When the U3 goes down in resistance, the impedance do also go down, to compensate a bit for that, the U4 goes up in value, so that the total impedance value are about constant.Yes I did mean "connect (1_out) to +15V, connect (2_out) to lead_to_U4" :-)Hope that this is a bit better! :-)

author: FriedMule
author_rank: Frequent Contributor
timestamp: June 30, 2018, 06:08:34 pm
content: No one? :-)
Need Micro Switch Solution - Triggered by pressure or impact.  - Page 1
Forum section: electronics / beginners

author: bonifacio
author_rank: Contributor
timestamp: June 18, 2023, 10:02:49 pm
content: Looking for a small switch that can be triggered by either getting hit by a burst of air or by vibration/impact. I've done as much research as I could and wanted to see if there are other solutions. The switch will be momentarily activate a LED. But also has to prevent false activations caused by movement. It would undergo around 90° movements from a horizontal or vertical position.Everything has to be small enough to fit inside a tube rougly around 14mm in diameter.Smaller is better since space is limited.The switch would be powered by a 10180 battery or similar sized battery. Voltage range is 3.7v-5v. Also open to slimmer battery contact ideas. I've just been brainstorming and lack the experience or what solutions are available.The burst of air would be similar to the burst from an eye pressure test at the optometrist.Force wise, maybe 75-100 psi.Also there will be some movement and slight impact that could be used as a activation trigger. Impact would be the 75-100psi burst of air throwing back 9oz of mass.So far I've found Micro Air Pressure Switches and Vibration Switches.Micro Air Pressure Switches are 6mm (Diameter) x 2mm (H) coin shaped. Figured this would be easily accessible and could be harvested from disposable vapes.