hybridfree/eevblog-posts huggingface dataset:
Headphone preamp confusion - Page 1
Forum section: electronics / beginners

author: Honda Rider 271
author_rank: Contributor
timestamp: March 19, 2017, 03:14:14 am
content: OK so I just assembled this thing and a couple questions since none of this is explicitly stated in the sparsely prepared assembly document.Uhh, I did make a stereo preamp right? If so wtf do I have two 2 terminal hookups and then one 3 terminal thing for the power?http://imgur.com/a/iLOWWHere is the design document for whatever it's worth:https://www.scribd.com/document/342342736/Electrons

author: Audioguru
author_rank: Super Contributor
timestamp: March 19, 2017, 04:05:23 am
content: The imgur link shows an error in the document number. Please copy the schematic and post it HERE with your reply (not over at imgur).You also linked to a document full of things and we do not know which thing you are talking about. Please copy it and post it HERE.

author: Honda Rider 271
author_rank: Contributor
timestamp: March 19, 2017, 04:25:19 am
content: Oops derped out on the link. Here is the correct one:http://imgur.com/a/iLOWWI can't attach the PDF here because it's too big. I'm not really talking about any one thing in the design document, this is a question on the overall build. For example, the kit included two boards, but only discusses one board. However, it has enough components to complete two full boards EXCEPT for the opamps (LME). The document is strangely written, going into absolute novice detail about soldering, but then assuming a fairly advanced understanding of electronics for the actual implementation.So my question is basically, is that one board sufficient for stereo amplification? If so, how do I wire up the audio signals in and out for stereo, with only the Vin/0V and Vout/0V. And if not, how does the second board come into play?Really appreciate any help!

author: DimitriP
author_rank: Super Contributor
timestamp: March 19, 2017, 04:51:38 am
content: QuoteA picture is worth a thousand words .....Each board is one channel.You need both boards for two channels.It also uses a dual power supply which is why you have three connections for power -,0,+It's all in the picture

author: Honda Rider 271
author_rank: Contributor
timestamp: March 19, 2017, 05:41:06 am
content: OK so they literally sent me two of the exact same board and that pic just shows one board.The second one isn't finished cuz they sent included only a partial copy of the components...lol.http://imgur.com/a/yLMAD
headphone repair - lower volume on left side - Page 1
Forum section: electronics / beginners

author: soulboy
author_rank: Newbie
timestamp: July 01, 2018, 09:09:52 am
content: Hi,new to forum, total newb as far as electronics goes although I've always liked fixing and repairing things.I've got some Sennheiser headphones. They work but the volume is lower on the left side. I've opened up the earpieces and they seen fine inside and are securely soldered. I can't find any definitive answer on Google or Youtube as to what is at fault. I've run my finger down the length of the cord, bending it to try to test for signs of a break, cut in sound etc but there is none.I recently bought a basic multimeter as I am interested in learning a bit more about how to fix and test things. The readings from the jack plug are when on the 200 resistance setting are:tip to ring 37.2tip to sleeve 34.8ring to sleeve 3.3I don't know how to decipher this.As the left side headphone driver still works, but is at a lower volume, do these readings indicate that the driver is faulty or do they indicate that the cable is broken, maybe very near or inside the jack plug and that replacing it would fix the issue.Appreciate any adviceThanks

author: bson
author_rank: Unknown
timestamp: July 01, 2018, 12:00:43 pm
content: Tip and ring are the two channels, L and R, and the sleeve is a common ground. Remember in audio R stands for: Right, Ring, Red. Did it use to work or did you just get them? If the latter, then the wiring is probably non-standard and tip might be ground. If you can I'd start by sounding them out to make sure it's the headphones and not the jack they're plugged into by having a signal generator produce a 10mV rms 1kHz tone and use that to probe the plug and literally sound out the wiring.
Heat Dissipation Aluminum Core PCB & LEDs - Page 1
Forum section: electronics / beginners

author: made2hack
author_rank: Frequent Contributor
timestamp: July 01, 2016, 08:10:11 am
content: Hello all,I'm not sure how to calculate the following. I want to SMD solder either 3 LEDs or 6 LEDs to an aluminium core PCB. The LEDs in question arePK2N (datasheet)and, according to the datasheet, the Thermal resistance of Junction to Slug is 8 deg C / W.So, if I want to run these at around 2.2W (600mA * 3.6V typical), does that mean that they generate approx 18 deg C each? So, if I place 3 of them, do they raise the temperature by 54 deg C? For 6 of them, 108 deg C? Also, the resistors will dissipate approx 2W or 4W (if I use 3 or 6 leds).The total area of the AL PCB will be approx 9.1 cm2 (17 mm radius, 34 mm diameter) and 1mm thick. It is 35um Copper (1oz) but I don't have the datasheet for thermal conductivity figures.How would you go about trying to work this problem out? Do I need extra fins on the PCB? Or should I limit myself to just 3 LEDs?
Heat gun modification with SSR controller  - Page 1
Forum section: electronics / beginners

author: ec911
author_rank: Newbie
timestamp: November 19, 2014, 11:10:55 pm
content: Hi,This is my first post on the forums, and I have a question for you concerning a SSR. I am modifying a heat gun to control the temperature precisely with a rex C100 controller and a SSR. The thermocouple is installed inside the nozzle just past the element. Everything is working good except when I tried to install a power diode that I salvaged from the heatgun to reduce the voltage to the element since I don't need it to work at full power.After I installed the diode, when I turn on the heat gun and the controller, it gets up to the set value but then as soon as it reach the temp and the SSR turns the power off, it won't turn back on. I'd like to know if it's because I have a zero-cross SSR that it doesn't work.Thanks

author: macboy
author_rank: Super Contributor
timestamp: November 20, 2014, 02:43:52 pm
content: Yes, almost certainly.Try putting a capacitor across the diode, around 0.22 to 1 uF. This will allow a little bit of current in the reverse direction too, maybe enough to make it work. You can't use just any capacitor, it should be an X2 rated AC safety capacitor. If you have ever salvaged parts from a switching power supply (old ATX computer supply, most consumer electronics supplies) then you have definitely come across these.They are always rectangular and have "X2" among the markings.

author: ec911
author_rank: Newbie
timestamp: November 20, 2014, 07:24:33 pm
content: Ok I will try that thanks!Do you think a random turn-on SSR would also work without a capacitor across the diode?

author: cybertronicify
author_rank: Regular Contributor
timestamp: December 04, 2014, 10:37:43 pm
content: This might be a bit late, but have you tried to replace the SSR with a TRIAC?
Heat gun PWM control for SMD soldering - Page 1
Forum section: electronics / beginners

author: Gala
author_rank: Newbie
timestamp: August 17, 2015, 10:32:22 am
content: So i plan on buying a cheap automotive heat gun and hacking it up to PWM the heater and the fan to control them, along with a LCD with a thermocouple sensor to show temperature. I've designed this simple circuit:And i just wanted some feedback. Is it ok? Can it be improved? The ACX and GATEX to go STMicroelectronics 600V 40A TRIAC's.

author: singapol
author_rank: Frequent Contributor
timestamp: August 17, 2015, 10:47:52 am
content: Why go to all this trouble when you can buy a cheap hotair station like 858 but make sure the voltage is compatible to your country. Please don't say you want to experiment and learn.http://www.amazon.com/Kohree%C2%AE-Digital-Rework-Station-Solder/dp/B00ITMPQS2/ref=pd_sim_sbs_469_2/175-3140822-1778067?ie=UTF8&refRID=1FKYDS3W6S77RYQFCXV7Dave has a video on it.

author: Gala
author_rank: Newbie
timestamp: August 17, 2015, 10:53:05 am
content: Cost. The heat gun is 20 bucks and i have all the parts at my school, free

author: GreyWoolfe
author_rank: Unknown
timestamp: August 17, 2015, 11:32:35 am
content: What is truly the fascination about lowest cost. You may very well end up with something almost but not quite good enough and that will be frustrating. Look here:http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1312.R1.TR7.TRC2.A0.H0.Xyihua.TRS1&_nkw=yihua+858&_sacat=0and it works quite well. I have one and am happy with it. And, as a side note, it is actually designed to do what you want it to.

author: singapol
author_rank: Frequent Contributor
timestamp: August 17, 2015, 04:54:51 pm
content: Quote from: Gala on August 17, 2015, 10:53:05 amCan you imagine holding a heat gun and trying to desolder a sot23 transistor or a smd resistor or cap? The nozzle is too big and more of surrounding components get heated up. 858 comes with 3different sized nozzles for better heat distribution.It also has a magnetic switch which cuts off power when it is rested on it's cradle. Right tool for the right job as they say.And you look more pro using it...

author: xenocide702
author_rank: Contributor
timestamp: August 17, 2015, 05:55:02 pm
content: Ordinarily I'd agree with the OP and say screw it, roll your own. You'll definitely learn a lot, regardless of how the project turns out. Even if it doesn't end up in a hot air station, that board could be very useful in other projects.That said, I'd strongly encourage you to just buy a hot air station, if only for the nozzle adapters. Even the cheap knock offs are usually pretty decent. We're only talking 20 bucks difference, and your heat gun wouldn't come close to the fit and finish of even the worst knock off.

author: wraper
author_rank: Unknown
timestamp: August 17, 2015, 06:05:26 pm
content: You will blow off most of the parts from PCB with that thing. Also, without temperature control it will be pretty useless anyway. You'll end up burning the parts and PCBs.
Heat-Gun Temperature  - Page 1
Forum section: electronics / beginners

author: PerPC
author_rank: Contributor
timestamp: May 09, 2012, 12:56:38 am
content: Before i disassemble this iphone i need to know whats a safe temperature to use on my heat gun to melt the glue that encases the phone just good enough to cut through it around the sides. So once again, here i am EEV. A little word of advice goes a long way. Thank you for your time.

author: saturation
author_rank: Super Contributor
timestamp: May 09, 2012, 12:52:13 pm
content: General info. Most hot glue usually melts under 200C. Most electronics tolerate >=250C for 10 seconds, of sustained heat. Ordinary hot glue will melt in < 100C, way within the safe range of parts.In the case of the iPhone, any plastic is the shell will not take hot air without some some change. You can open most iPhones, at least 3G and under, with just a suction cup and screwdriver, no hot glue there. Youtube has so many how-tos on this.
Heat shunts/clips for soldering, and soldering sensitive components - Page 1
Forum section: electronics / beginners

author: IdahoMan
author_rank: Regular Contributor
timestamp: April 23, 2018, 04:55:37 pm
content: I don't like having heat or margnetic fields around electriclal devices, but you have to solder things. So, what are the best methods for protecting components (or anything) from the heat of soldering when you have to solder them? (or heatgun, flame, whatever even)What about the use of heat/thermal-shunts (clips, alligator clips, needle-nose)*? What are the rules there, and has anyone ever done an experiment/video (using probes or FLIR) on where the heat actually goes, over a length(s) of time at certain applied temperatuers?*Example:"A small piece of beeswax may be placed between the protected unit and the heat shunt.When the beeswax begins to melt, the temperature limit has been reached. The heatsource should be removed immediately, but the shunt should be left in place."

author: oldway
author_rank: Super Contributor
timestamp: April 23, 2018, 05:58:56 pm
content: You can't safely solder or desolder a germanium transistor without it.But it does not need to be a copper jaw, a long nose or a universal pliers do the job very well.

author: jmelson
author_rank: Super Contributor
timestamp: April 23, 2018, 06:07:38 pm
content: Quote from: IdahoMan on April 23, 2018, 04:55:37 pmYes, as Oldway says, for germanium, you need it. But, look at modern SMT components. The whole board is heated to 250 C for several minutes, and 100% of components are expected to survive for the full life of the equipment after that!I haven't used a heat sink clip when soldering since about 1965.Jon

author: Cerebus
author_rank: Super Contributor
timestamp: April 23, 2018, 06:09:43 pm
content: Something with copper or aluminium jaws would be ideal, but in practice steel usually does the trick. My favourite tool for this is the humble surgical hæmostat, aka forceps, available very cheaply on fleaBay or you favourite alternative online vendor.

author: Gregg
author_rank: Super Contributor
timestamp: April 23, 2018, 11:36:17 pm
content: Here are some steel ready made tiny spring clips that work well. They can be ground to finer points.https://www.amazon.com/gp/product/B06XCFPLVZ
Heat sink fan - Page 1
Forum section: electronics / beginners

author: bootloader9800
author_rank: Contributor
timestamp: January 26, 2021, 08:00:01 pm
content: Hello All!Can someone please, recommend a goodfanto suck out heat that is being dissipated by the MOSFETS in my RC plane ESC?The board gets relatively hot during operation and I don't want heat to be a reason why the ESC dies on me.Thank you

author: Benta
author_rank: Super Contributor
timestamp: January 26, 2021, 08:19:51 pm
content: If it's a plane, you normally have a pretty big fan out front, or?But define "warm". If you burn your fingers, it's too warm. If it's just uncomfortable, it's OK.

author: bootloader9800
author_rank: Contributor
timestamp: January 26, 2021, 08:21:49 pm
content: It is finger burning hot. The airflow is definelty not enough, during flight.

author: Benta
author_rank: Super Contributor
timestamp: January 26, 2021, 08:36:20 pm
content: Well, with no further details, I'd say the ESC is underrated for the motor you're using.

author: bootloader9800
author_rank: Contributor
timestamp: January 26, 2021, 08:43:17 pm
content: Ok. Thanks for your reply.
Heat sinking desgin choice question for power devices in general - Page 1
Forum section: electronics / beginners

author: lk
author_rank: Regular Contributor
timestamp: September 02, 2013, 06:33:29 am
content: Greetings,I got an update from microchip for one of their power mosfetshttp://ww1.microchip.com/downloads/en/DeviceDoc/20005159B.pdf, the low Rds ON made me curious. And then i noticed something, the the bottom pad is connected to the drain of the device, and this is a puzzle to me, I realize there is a perfect good explanation for it, it just escapes me.In my little limited world i would have been made more sense to connect the pad to the source, as usually the N-channel mosfets are connected after a load. And it would therefore be able to dissipate to a large ground plane, rather to what you would need to create for it on the drain side.The only thing i can come up with is to protect other "random" devices on the board from the changes in temperature. If i look at a device like the lm7805 in TO-220, ground is on the tap, so it could in principle dissipate to the ground plane, perhaps there has been a change in best practices between the creation of the two devicesAnyway im just curiousAnd to bad that the MCP87130 is only available in one of those no lead packages, it would have been nice in a S08 or something, i have seen Daves mess after trying to solder one of these small leadless packages-lk

author: kizzap
author_rank: Unknown
timestamp: September 02, 2013, 07:28:18 am
content: The tab connection depends on the way the silicon is doped. The bottom of the silicon is bonded to the output tab, and then bond wires are used to wire to other parts of the device as needed. it all comes down to pricing, and if it is cheaper to make the tab the input then so be it.-kizzap

author: Andy Watson
author_rank: Super Contributor
timestamp: September 02, 2013, 07:58:39 am
content: Consider where the voltage drop occurs when the device is passing a current. For bi-polar transistors this is obviously the collector junction, for MOSFETs it's less obvious but presumably it will be on the drain side of the channel. V * I = power dissipation. Makes sense to make the collector/drain from the largest part of the silicon structure with the best heatsinking capability.

author: lk
author_rank: Regular Contributor
timestamp: September 02, 2013, 08:54:09 am
content: Hi Andy and Kizzap,Thank you both for your answers, and im trying to come up with a clever thing to say in response, but the only thing that comes up in my head is a busy tone-lk
Heater circuit question - Page 1
Forum section: electronics / beginners

author: ec911
author_rank: Newbie
timestamp: May 29, 2015, 11:04:12 pm
content: Hi,I've drawn a heating element circuit from a hot air station and I'm trying to learn from it to get better at understanding electronics.It is a heating element driven by a BTA12-600B triac which is controlled by microcontroller via a MOC3021 optoisolator.Here's the schematic (sorry if it's badly drawn)Could somebody explain me what the green path with the capacitor C6 and R14 is for?

author: Paul Moir
author_rank: Frequent Contributor
timestamp: May 30, 2015, 01:56:44 am
content: I think it's an RC snubber, which is designed to protect the triac by shunting the inductive kick that occurs when you turn off an inductive load. It's the same idea as using a reverse biased diode on a relay to protect the transistor that turns it on and off in a DC circuit, but the RC snubber works with AC.The thing is a heater usually has very little inductance, so I don't think it's very necessary?

author: ec911
author_rank: Newbie
timestamp: May 30, 2015, 02:09:59 am
content: Thanks for the reply! I was to post the answer I just found while searching on google, it is indeed a RC snubber.I don't know about the necessity.. ??This is from an Aoyue 852a++ hot air station.

author: ec911
author_rank: Newbie
timestamp: May 30, 2015, 03:20:39 am
content: Also, what would be the purpose of the big ceramic resistance R10? Is it some kind of choke for the heating element?

author: Tomorokoshi
author_rank: Super Contributor
timestamp: May 30, 2015, 03:55:42 am
content: Are there any other parts like fuses or thermal switches in the circuit? Anything thermally connected to that 1/2 ohm resistor?

author: ec911
author_rank: Newbie
timestamp: May 30, 2015, 04:12:21 am
content: No, I've double checked and it's in serie with the M1 terminal and the heating element.This is the big 5w resistor

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: May 30, 2015, 04:29:26 am
content: QuoteMaybe to limit the current before the heating element is hot.

author: SeanB
author_rank: Super Contributor
timestamp: May 30, 2015, 07:32:21 am
content: Resistor limits current to the heater when it is cold, and also is supposed to be a fusible resistor if the heater goes short circuit, though there with that white ceramic resistor it is not likely to do so. The snubber across the triac limits the rate of change of voltage across the device, so that spikes on the incoming mains do not trigger it by accident.

author: ec911
author_rank: Newbie
timestamp: May 30, 2015, 09:23:10 am
content: Ok got it, thanks for the clarification!
Heathkit Analog Tube Oscilloscope Model HO-10 - Page 1
Forum section: electronics / beginners

author: zker666
author_rank: Contributor
timestamp: July 18, 2010, 07:53:29 pm
content: I have an ancient Heathkit HO-10 oscilloscope, and i have no idea what the hell to do with it!!! I cannot find any useful info on the internet about it, and i was wondering about the specs of this certain scope. It has to be as well back as the mid 40's and it is a dual trace o-scope, 10mHz bandwidth, and it wont work, but thats an easy fix. The 1V2 tube is busted and im ordering a new one, but in the mean time i want to know some information on it. PLEASE HELP!!!

author: DJPhil
author_rank: Frequent Contributor
timestamp: July 18, 2010, 08:00:42 pm
content: Here's a start:http://www.vintage-radio.info/heathkit/It's a monitor scope, compact and designed to be part of a permanent installation.Hope that helps.

author: slburris
author_rank: Frequent Contributor
timestamp: July 18, 2010, 08:11:44 pm
content: You can find the operation manual, parts list, and schematic at:http://www.mods.dk/manual.php?brand=heathkitScott

author: zker666
author_rank: Contributor
timestamp: July 19, 2010, 12:14:56 am
content: Thank you both so much helped alotZachary

author: Unknown
author_rank: Unknown
timestamp: July 19, 2010, 09:41:50 am
content: If it's from the 40s, it's probably not triggered or calibrated, which makes it of limited utility compared to the 'modern' scopes like Tektronix made since 1960 or so.

author: zker666
author_rank: Contributor
timestamp: July 19, 2010, 06:59:43 pm
content: Yeah, it has a quite high calibration, within ±6%, which is a pretty accurate scope for the 40's! But, it isnt triggered, so repetitive signals have to be adjusted on the frequency range just right so you can see the changing waveform, but, it doesn't matter about the accuracy, i just really need it to see changes in frequency, like for a pwm circuit, oscillator, 555, etc.

author: Unknown
author_rank: Unknown
timestamp: July 19, 2010, 07:24:54 pm
content: Calibrated means that there's a graticule (grid), and the vertical and horizontal settings are marked with X V/div or Y us/div. This allows you to do simple measurements (with 3% tolerance or so). I believe calibrated oscilloscopes were introduced in the 40s, but I'd expect Heathkit to be a bit behind the 'big boys' like Tektronix.

author: zker666
author_rank: Contributor
timestamp: July 20, 2010, 01:50:09 am
content: Yeah, it is one of the smaller models, but with ALOT more quality, and, plus, heathkit back then was a big name in the early 40's, because Tektronix was founded in 1946 i beleive, but it does have simple calibrations, but i really just need it to measure signals

author: zker666
author_rank: Contributor
timestamp: July 20, 2010, 01:57:59 am
content: Check out my youtube channel, zker666, and my latest videos will be there reviewing the Scope.
Heathkit AR-29 Stereo Amp Kit from 1971 - which capacitors to discard / replace? - Page 1
Forum section: electronics / beginners

author: Miguel Angelo
author_rank: Contributor
timestamp: July 02, 2013, 03:52:54 pm
content: I have bought an "unbuilt" Heathkit AR-29 Stereo Amplifier from 1971 (http://smg.photobucket.com/user/mhardy6647/media/AR-29.jpg.html) on eBay. The previous owner probably opened back then and took the manual out to plan the build and never returned to the box to build or put the manual back. I have not really looked into the box yet other than to confirm that the original manual was there. I have managed to get an used but complete manual on Ebay. The wood box that sold as a separate kit AE-19 (and was also probably purchased at that time) has not been found yet, but they are looking for it.My question is considering that the kit is more than 50 years old, some of the capacitors may have not aged well and though they may not fail at the outset, their useful life may be affected. My limited knowledge would say that electrolytic capacitors would be more vulnerable and that the low capacity ceramics would be basically impervious to time.Should I replace the capacitors preemptively and if so which types? Any other concerns with such vintage kits?

author: Lightages
author_rank: Unknown
timestamp: July 02, 2013, 05:56:33 pm
content: Replace every capacitor that is an electrolytic, tantalum, or any can type caps. Any film and ceramic types should be ok.
Heathkit IT-11 Capacitor Checker - Page 1
Forum section: electronics / beginners

author: SgtRock
author_rank: Unknown
timestamp: May 10, 2011, 12:08:54 am
content: Dear EEVBees:--As Gomer Pyle USMC used to say; " Heyelp, Heyelp, Heyelp."--I am getting -0.16VDC at pin 8 of the 6BN8 instead of -0.22VDC as per the schematic. I have checked all voltages, cleaned all switches, checked or replaced, all components, verified wiring, substituted tubes and am tearing out my remaining hair. See link to schematic below.http://www.heathkit.nu/IT-11_schematic_1600.png--(1) Why would I get -0.16VDC and not -0.22VDC?--(2) What alteration could I make to get -0.22VDC?Your suggestions are humbly solicited.Clear Either

author: vk6zgo
author_rank: Super Contributor
timestamp: May 10, 2011, 01:10:12 am
content: The voltage is a very low one in Vacuum tube terms,& depending on what they used to read it,may be really eithernearer or closer away from your reading.Does the tester work with this voltage? If so,ignore it & say that it is just due to component variations between theone they tested for the book,& your one.You could test R6,as high value resistors are prone to increase of resistance with age.VK6ZGO
Heathkit porn...a personal collection or every heathkit item sold  - Page 1
Forum section: electronics / beginners

author: Priestblood
author_rank: Contributor
timestamp: September 08, 2022, 12:15:15 pm
content: Youtube link to the best collection of heathkit equipment I have ever dreamt about it has taken him decades to collect and I think the Engineer used items in his everyday work job.Here is the link Enjoy :

author: coppice
author_rank: Super Contributor
timestamp: September 08, 2022, 12:25:36 pm
content: Growing up the Heath Robinson cartoons, it felt like HeathKit were sometimes trying to turn his ideas into reality. Some of the other HeathKit products were really good.
Heating paper/cardboard (thermochromatic ink) - Page 1
Forum section: electronics / beginners

author: Moriambar
author_rank: Unknown
timestamp: June 04, 2021, 08:54:02 am
content: Hi,a friend of mine has bought some thermochromatic ink (I hope the English term is correct) which goes transparent when heated to ~40 °C.I was wondering how to design (mostly: where to learn about) a circuit that heats the paper or cardboard where the ink is used in order to control when to make it "disappear". Hopefully not becoming a fire hazard.My main problem is that I don't know what to use to heat. Knowing the component to use it will be fun trying and designing a circuit and then coming back for further insight.So can you point me towards some informative material? And to a heating component?Thanks

author: beanflying
author_rank: Super Contributor
timestamp: June 04, 2021, 09:34:36 am
content: The simple thing to use is a resistor and push it toward it's rating.Keeping the maths simple a 1001/4W resistor running on 5V will draw 50mA. This gets you P=VI of 5x0.05 or .25W Should see the Resistor at 80-100C on the surface (a guess) well below any danger point for your paper catching fire. So any old USB power supply or power bank a 100resistor and play.If you want a larger flat surface area than the round resistor chop up an aluminium can and wrap a bit of it around the resistor as a crude heatsink with a flap hanging out. It should still hold over 40C if you don't make it to large.From there you could use several Resistors and make a simple PWM (pulse width modulation) controller. This could be as simple as a 555 timer switching a FET feeding your resistors or an Arduino and a bit of code to generate the PWM to then feed a FET.There is plenty of ways to generate heat including the likes of theseeBay auction: #254795972487go to something solid state like a Transistor or Fet as a load on a supply but these all add complexity.Just a few ideas to start you looking/playing.

author: Moriambar
author_rank: Unknown
timestamp: June 04, 2021, 11:02:37 am
content: Resistors pushed to 100°C sound a bit scary, but thanks for the ideas.

author: beanflying
author_rank: Super Contributor
timestamp: June 04, 2021, 01:06:52 pm
content: You haven't lived until you have let an appropriate level of smoke outWithout checking to much Resistors are generally rated to 70-80C at full load so if you tweak the number to the next Resistor you have available higher you will drop down in Temperature. Generally the worst case with Resistors is a pop and a fizz and nothing to exciting. You are more likely to get an ouchie because you touched it and found it to be hot
Heatsink design question - Page 1
Forum section: electronics / beginners

author: made2hack
author_rank: Frequent Contributor
timestamp: July 14, 2014, 05:21:41 pm
content: Hello all,It is my understanding that the majority of heat sinks are extruded aluminum. Does anyone know if heat sinks are also cast? As in, hot molten aluminum in a shape?If yes, no, why the extruded? Cost consideration? Standardization? Is an extruded aluminum any better than a cast model? (Assuming 0 porosity of the final mold)Also, how is the aluminum attached to the copper (in a copper/aluminum) combination? Simply "glued" together? Or soldered?

author: PE1RKI
author_rank: Regular Contributor
timestamp: July 14, 2014, 05:33:59 pm
content: i have never seen cast heatsinks, only extruded.you cant take the mold appart after the alu settles with casting. or it is difficult at least.extruding can be done in pieces of 6 meter or much long and saw off at length. so easy.other methods are soldering the copper vins to a copper base, much used in cpu heatsinks.fisher elektronik pressfits extra fins into the base to create a more efficient cooling design.

author: Monkeh
author_rank: Super Contributor
timestamp: July 14, 2014, 05:41:05 pm
content: I could be wrong, but I believe the heatsinks on HP's E36xx series power supplies are cast alu.

author: KJDS
author_rank: Super Contributor
timestamp: July 14, 2014, 05:47:47 pm
content: I've sen cast heatsinks, but only when a specific shape is required.If you're making enough, then extruding is much much cheaper.

author: made2hack
author_rank: Frequent Contributor
timestamp: July 14, 2014, 05:52:07 pm
content: I imagine extrusion will be cheaper, since I guess if you have a giant press + die, it goes faster.However, I want to prototype a heat sink, and, whilst I can cast aluminum at home (with some effort), I don't have a multi-ton press + die.Any idea what AL alloys are used? Or do i just pick the one with the highest conductivity?

author: SeanB
author_rank: Super Contributor
timestamp: July 14, 2014, 05:59:53 pm
content: Most castable alloys will do for this casting, as they are generally quite conductive. You do need to take care of surface finish to get all the sand off, and you will have to mill the actual device mounting areas to get them flat.The copper plugs are generally added by a press into a machined hole, and then the whole assembly is surface finished in the area to get the smooth flat surface required.The reason most use an extruded heatsink is because you just cut to length, and the as extruded surface is generally smooth enough to use without further machining if used with a thermal pad or heatsink compound. As well you can get a very complex high surface area in the one dimension from the die, using a minimum of material, and can easily have slots for mounting hardware. A casting can do this, but the moulding will be complex and prone to cracking during casting as it cools faster with large surfaces compared to the thicker areas.
heatsink footprint for pcb using eagle - Page 1
Forum section: electronics / beginners

author: amateur_25
author_rank: Regular Contributor
timestamp: April 10, 2012, 06:54:09 pm
content: I'm looking for some advice on how to create my own footprint for this aluminium heatsink I stripped out of a psu. How can I ensure the footprint allows perfect alignment of the regulator with the mounting holes on the heatsink? It has 150A4Y number which doesn't seem to return any results on google.

author: mariush
author_rank: Super Contributor
timestamp: April 10, 2012, 07:39:25 pm
content: It's probably a custom heatsink, made for that specific power supply manufacturer.I'd say get a caliper and start measuring the distances between the holes, the diameter of the holes, where those support pin are relative to the corners...As a tip, you can also use some warm wax (from candles) to make a small rectangle in which you can press the heatsink just as if the wax was the PCB. Afterwards, you can use the impressions in the wax to determine the distances.
Heatsink for GSIB-5S - Page 1
Forum section: electronics / beginners

author: dcbrown73
author_rank: Regular Contributor
timestamp: September 07, 2019, 09:23:29 pm
content: Hey all,For the life of me, I cannot seem to locate heatsinks that are made for the GSIB-5S package rectifiers.Is there a standard type of heatsink package for these or do you just "make due"?

author: malagas_on_fire
author_rank: Frequent Contributor
timestamp: September 07, 2019, 09:28:12 pm
content: Hi for reference are you looking for something like this? It is from a ATX power supply.https://www.techpowerup.com/review/corsair-ax760i/4.htmlMy point is as long as it fits the heasink ( check datasheet measures) and the heasink it is properly designed for the application, it could be a custom design, an existing one and maybe drill a hole.

author: dcbrown73
author_rank: Regular Contributor
timestamp: September 07, 2019, 09:36:58 pm
content: Yes, something like that would be perfect. I just cannot seem to locate any heatsinks that are similar. Most are for TO-220, TO-3, or for CPU/GPUs.I've got a bunch of all different sizes heatsinks for mosfets / voltage regulators and similar, but the gap where you bolt it to the part isn't wide enough for the rectifier.

author: malagas_on_fire
author_rank: Frequent Contributor
timestamp: September 07, 2019, 11:04:34 pm
content: Sorry for my delay i've searching only on fleebay and got more results using dimensions or supplying the to220 in the search. here is an example which you could drill a hole:https://ebay.us/WwmtBDor use this as reference;https://ebay.us/cRO7qo
Heatsink Question - Page 1
Forum section: electronics / beginners

author: DDCE88
author_rank: Newbie
timestamp: December 03, 2020, 04:53:38 am
content: Ok so I have designed a circuit and drawn up its PCB and I have a slight question about the heatsink I'm going to use.Now you'll see in the images below the place where I generally want to place my heatsink. (The yellowish green area.)My questions are:A) Is it okay to utilize a monolithic heatsink to service multiple parts (provided you use proper electrical isolation.)B) You will see in the second photo a highlighted area a trace falling under where the heatsink will be placed. Will this be a problem (Again assume I will be using some sort of electrical isolation.)I already have done calculations based off of thermal resistance to to test my idea I'm just not 100% if it will work. The last image is an example of my basic modeling. I am basing it off of Dave Jones' thermal resistance tutorial videos. I know he only ever did it for one part to a heatsink, but since he said the system could be modeled like an electrical circuit (Replacing current for Power and Voltage for temps) I figured this would work. The node where every thing meets is the Sil-pad or thermal compound touching all of the components before it hits the heatsink.

author: m k
author_rank: Super Contributor
timestamp: December 04, 2020, 09:55:56 am
content: With few cases I've seen it's clearly not a concern what is finally underneath.Though I'm not sure, maybe they were just mechanical insulations.
Heatsinking/Cooling Notebook Graphics Card - Page 1
Forum section: electronics / beginners

author: L3P3
author_rank: Newbie
timestamp: September 20, 2020, 10:30:55 am
content: Hello, first post. Be aware that this can probably be deemed ashacking.A year ago, I've found a Packard Bell KAYF0 in a dumpster. I was happy to see it had a dedicated graphics card which means that "in theory" I could upgrade it.I went on ordering a much much better and bigger card.https://www.ebay.de/itm/254399734398I had to remove a little plastic pile off the housing and then it fitted in just fine. And it even works --almostperfectly. But after some minutes of very graphics-intensive gaming, the machine turns off, obviously it is some thermal issue. If I limit the CPU to minimal frequency, it does not turn off and I can also play with pretty good settings.The graphics card gets cooled by a copper bar which is interconnected with a heatsink at the back of the device. The previous card had the same main chip location (appears to be part of the graphics card form factor spec) so the heatsink fitsalmostperfectly mechanically. The inductor coils and the memory ICs on the original card had an additional metal plate attached to the copper bar but this plate did not fit since the secondary components on the new card have different locations.So the current situation is: The new card is just mechanically attached to the heatsink on its main IC. The inductors and other ICs on the graphics card are just very passively cooled by some little airflow, there is a small air slot on the opposite end of the housing.I have the suspicion that the machine turns off because the other components on the graphics card get too hot.Now my question: Is there any thermal compound / gue I could put on the entire card to thermally link all components together to the copper bar at the core? Would this make sense? I would give it a try if there is something like this and you think that thismayhelp. It is really cool to play somewhat modern games in high settings on a 2010 notebook.Thanks a lot for anything.L3P3

author: Jwillis
author_rank: Super Contributor
timestamp: September 20, 2020, 08:14:49 pm
content: Thermal compounds , glue and pastes only transfer heat in very small distances by filling in the very small gaps , which transfers heat more effectively from component to heat sink . They don't dissipated heat very well in large globs but in fact can do exactly the opposite. Metal transfers heat much much more effectively . What you can do is attach small heat sinks to the other components or modify heat sinks that attach the components to the heat pipe (Bar) . Better if you can attach the modified heat sinks to the heat pipe with low temperature solder .Aluminum will not solder so use copper heat sinks it you intend on soldering to the heat pipe.

author: L3P3
author_rank: Newbie
timestamp: September 21, 2020, 04:23:58 pm
content: That helped a lot already. Thanks.
heatsinks for LM317/337? think chunk or thin with larger surface area? - Page 1
Forum section: electronics / beginners

author: dentaku
author_rank: Frequent Contributor
timestamp: April 15, 2014, 06:26:12 pm
content: Which heatsink would be better for an LM317/337?The thick chunk or the thin one with the larger surface area?I'd probably cut the part that sticks out at the right of the thin one so it's the same width all the way.I'm assuming larger surface area is better than larger mass in this case?

author: Simon
author_rank: Unknown
timestamp: April 15, 2014, 06:31:03 pm
content: well depends on how much heat you want to dump and your ambient. Many heatsinks are made to mechanically suit their enclosure. A small chunky heatsink will be good for absorbing occasional bursts on power as they can "store" it and then release it over time whereas for continuos dissipation you need surface area, you want reasonable thickness near the device so that heat is moved away quickly. I had a heatsink once with a thick centre that thinned out as it went from centre to outer edges.

author: dentaku
author_rank: Frequent Contributor
timestamp: April 15, 2014, 06:40:06 pm
content: Quote from: Simon on April 15, 2014, 06:31:03 pmWell, my power supply ( +/- 20V down to around +/- 1.25-ish V ) will have a wide open back with the heatsinks sticking out so I guess the finned ones would be best because I don't want to store the heat inside the enclosure.

author: mariush
author_rank: Super Contributor
timestamp: April 15, 2014, 06:53:16 pm
content: Use this page to figure out how many C/w should the heatsink have for you extreme cases (ex 20v in, 1.25v out , 500mA or something like that) :http://www.ef-uk.net/data/heatsinking.htmI'd guess the small heatsink is about 25-25 C/W and the larger one is probably about 15-20 c/w but the second one is better used with a fan blowing over the surface.note also that lm317 , lm337 .. at least some of them ... can only dissipate about 15 watts ... so no 24 in , 3v out @ 1A .. just too many watts dissipated in the regulator.Digikey has a huge inventory of heatsinkshttp://www.digikey.com/product-search/en/fans-thermal-management/thermal-heat-sinks/1179752pick to-220 , to-247 etc and look at the "thermal resistance at convection or natural column and then at the pictures of the heatsink to get an idea about how large a heatsink without fan would have to be.

author: dentaku
author_rank: Frequent Contributor
timestamp: April 15, 2014, 08:13:15 pm
content: I just weighed them and the finned one actually weighs much more than I imagined. It's quite a bit heavier than the thick one plus it will stick out the back of the enclosure much further so that's what I'm going to use.
Heatsinks for transistors - Page 1
Forum section: electronics / beginners

author: Discotech
author_rank: Regular Contributor
timestamp: August 16, 2018, 10:36:12 pm
content: Is thermal paste needed for these or is just the heatsink screwed raw to the tranny enough for heat transference or does it need the extra contact provided by TP to dissipate the heat ?

author: mdszy
author_rank: Unknown
timestamp: August 16, 2018, 10:47:47 pm
content: You should definitely use thermal paste or a thermal pad if you're dissipating enough power to need a heatsink in the first place.

author: Discotech
author_rank: Regular Contributor
timestamp: August 16, 2018, 10:53:01 pm
content: Quote from: mdszy on August 16, 2018, 10:47:47 pmWill this stuff do ?https://www.aliexpress.com/item/10PCS-New-Original-Thermal-Grease-Paste-Compound-Silicon-CPU-Heat-Sink-CPU-Processor-Cooling-paste-silicone/32506142564.html?spm=2114.search0604.3.1.64bc60b5Ibu2cI&ws_ab_test=searchweb0_0,searchweb201602_3_10152_10151_10065_10344_10068_10130_10324_10342_10547_10325_10343_5012915_10340_10548_10341_10696_5013115_10192_10190_10084_10083_10618_5013015_10307_10820_10301_10821_10303_10059_100031_5013215_10103_10624_10623_10622_10621_10620,searchweb201603_51,ppcSwitch_5&algo_expid=5590c5c6-83d7-4148-9e40-a3952f940e33-0&algo_pvid=5590c5c6-83d7-4148-9e40-a3952f940e33&transAbTest=ae803_2&priceBeautifyAB=0I really only know about PC Thermal paste for CPU's and the stuff I normally use is too expensive for a transistor or 10

author: mdszy
author_rank: Unknown
timestamp: August 16, 2018, 10:54:13 pm
content: Quote from: Discotech on August 16, 2018, 10:53:01 pmI definitely think it will. You don't need anything fancy. The entire point is just to make the contact between the transistor and heatsink have as much surface area as possible, and putting a liquid between those surfaces is what achieves this.

author: Discotech
author_rank: Regular Contributor
timestamp: August 16, 2018, 11:18:40 pm
content: Ok thanks

author: james_s
author_rank: Super Contributor
timestamp: August 16, 2018, 11:53:57 pm
content: It really depends. In a lot of cases thermal paste is not absolutely necessary, however given it's cheap and readily available it's rarely a bad idea to use it. Just don't use too much, a little goes a long way and if you smear it on thick like toothpaste it can actually impede heat transfer.
HEEEEEEEEEEELP! atmega8a instad of 328p - Page 1
Forum section: electronics / beginners

author: abdullahseba
author_rank: Frequent Contributor
timestamp: May 22, 2017, 10:27:09 pm
content: HiI order the smd version of atmega 328p and soldered it on (my first time for SMD) and it turns out its a atmega8a. The 328 has more memory and features but looks like the pinout is the same.I need all of them as digital pins. Is there any way to get the bootloader on to it? Is there an arduino that uses this chip?Or should I desolder it and but the 328p?If it helps I'm just connecting and lcd and 4x4 keypad to it.Thanks In advance.

author: sleemanj
author_rank: Super Contributor
timestamp: May 22, 2017, 10:29:36 pm
content: https://github.com/sleemanj/optiboot/blob/master/dists/README.md

author: abdullahseba
author_rank: Frequent Contributor
timestamp: May 22, 2017, 10:55:28 pm
content: Thanks a LOTI stared your repo.

author: retrolefty
author_rank: Super Contributor
timestamp: May 22, 2017, 11:28:54 pm
content: I haven't tried it due to no ATmega8A here, but the current arduino IDE still lists Arduino NG board with an additional option for processor choice as AT168 or ATmega8. So you might well be able to burn the bootloader within the arduino IDE using a hardware programmer and selecting NG board with mega8 as the processor, worth a try as it's quick to find out.
Helipot teardown - Page 1
Forum section: electronics / beginners

author: JacquesBBB
author_rank: Frequent Contributor
timestamp: March 22, 2015, 01:47:56 pm
content: I had an helipot that was not working properly.I thus took the opportunity of a quick and dirty teardown to see the insideand share it with you.The resistive wire is quite nice and could be used to design specific valuesresistors.
Hello ! - Page 1
Forum section: electronics / beginners

author: neovanne
author_rank: Newbie
timestamp: May 13, 2025, 01:32:57 pm
content: I'm happy to join the EEVblog Beginners Forum! I'm looking forward to learning, sharing ideas, and connecting with fellow electronics enthusiasts. Thanks for having me!

author: BILLPOD
author_rank: Frequent Contributor
timestamp: May 14, 2025, 01:17:12 pm
content: Good Morning Neovanne, Welcome to the forum. It is the BEST electronics forum on the 'Interweb', but remember: it is addictive, (in a good way). HAVE FUN

author: ahsrabrifat
author_rank: Regular Contributor
timestamp: May 15, 2025, 11:25:24 am
content: Hello and welcome to the forum.
Hello - Page 1
Forum section: electronics / beginners

author: jbeach
author_rank: Newbie
timestamp: March 05, 2018, 06:14:06 pm
content: Hi,I hope this isn't the wrong spot to put this. Most forums I have joined have had a welcome new person section. I did not see such a section here.I just signed up.I have a multimeter that has quit working correctly. It was shorting between the volts and ohms range on the selector switch. Attempts to clean the conctats have made it worse. Now the mater is useless. That is fine, becuase I have already purchased a replacement. The new Meter is an Extech 330. I was glad to see Dave do both of these meters against each other in his shootout.I have had the meter since about 2007. It was purchased with part of a tool kit/set that I got through my Aircraft Mechanic School.Throwing the old meter into the trash just doesn't seem right.What would anyone suggest I do with my old Elenco M2625.

author: Wimberleytech
author_rank: Super Contributor
timestamp: March 06, 2018, 01:54:58 am
content: Does any range work?For example, if capacitance range works, just use it as a dedicated capacitance meter.Make it a dedicated instrument using one of the ranges that still works.Otherwise, toss it....and...WELCOME

author: Old Printer
author_rank: Frequent Contributor
timestamp: March 06, 2018, 02:24:34 am
content: Welcome. I keep everything, never know when you will find a use for some doodad. If the amps section works then defiantly put it to use. Most of us have at least two DMMs and one of the most popular uses for the second is to monitor amps while the other is watching volts.

author: tooki
author_rank: Super Contributor
timestamp: March 06, 2018, 03:41:22 am
content: Quote from: jbeach on March 05, 2018, 06:14:06 pmhttps://www.eevblog.com/forum/chat/new-member-please-introduce-yourself/