hybridfree/eevblog-posts huggingface dataset:
led vs fluorescent magnifying lamp - Page 1
Forum section: electronics / beginners

author: Xander
author_rank: Newbie
timestamp: June 19, 2012, 08:21:30 pm
content: which type of light is best for soldering

author: SeanB
author_rank: Super Contributor
timestamp: June 19, 2012, 08:28:58 pm
content: It depends.......... You need around 500 lux to get good views in fine work, and preferably a good big magnifier, or a microscope for ultra fine work. Both are available with LED and flourescent lighting, and the quality depends if they are a reputable brand or OHL knock off bland.The advantage of LED is that they dcan be made to fit in smaller enclosures, and can be dimmed with little colour shift, but are generally a point source of light. Nice in a ring light for close up working, but poor as general lighting.Florescent ( not CFL) is good for room lighting, as it is a diffused light with relatively gentle shadowing.

author: T4P
author_rank: Super Contributor
timestamp: June 19, 2012, 08:33:31 pm
content: LED's are okay for magnifying lamps but they tend to come pretty expensive and weak due to nobody taking up on LED magnifying lampsso the markup is a shitload higherLED's can be also good for room lighting, as they have even higher CRI then a fluoro of comparable specs, provided you point the light away from the object(Like how dave did his LED yard lighting)I use a CFL on my desklight just because it isn't on for 8 hours a day, if it is in that case i'm going to buy LED bulbs from chinaBut my panasonic CFL is 65lm/W (22W) ... Oh it's the Tertial from Ikea

author: gjh
author_rank: Contributor
timestamp: June 20, 2012, 04:13:06 am
content: I got a freebie single bulb halogen desk lamp I use... throws crap loads of light, and can see everything super bright... I guess it might be a bit hit during summer time if you have it on for sometime..

author: SeanB
author_rank: Super Contributor
timestamp: June 20, 2012, 04:46:13 am
content: Long ago went LED for desk lamp, the unit may give half the light, but runs 100C cooler.
LED Watch - Adding A Rechargeable Lithium Battery [Project COMPLETE!] - Page 1
Forum section: electronics / beginners

author: iamdarkyoshi
author_rank: Frequent Contributor
timestamp: June 13, 2017, 12:31:25 am
content: I've got a cheap ebay LED watch. It has enough empty space inside for a moderately sized lipo battery. It was originally powered by a CR2016 lithium cell, which ran low pretty quick, and I put a CR2032 inside instead. I'd like to make the inner watch module rechargeable once it goes dead, rather than replacing the battery.Bu this leaves me with an issue: Voltage. The original cell was max 3.0v, and the cell I want to put in will be up to 4.2vWhat regulator would be the best to use in a case like this? The watch is only on when I press the button, its otherwise sleeping. I chose red LEDs since they lit at a lower voltage than blue.Long story short, I need a linear regulator that can drive the 3V watch from a 4.2V lithium cell. I've never shopped around for low power linear regulators before, figured I'd get some input first.Thanks!

author: edavid
author_rank: Super Contributor
timestamp: June 13, 2017, 01:38:39 am
content: A fresh CR2016 or CR2032 can be 3.3V. You might compromise and charge your Li-ion cell to say 3.6V. I don't know if that would give you more capacity than an LIR2032.If you want to use a regulator, an HT7530-1 would probably work well.

author: iamdarkyoshi
author_rank: Frequent Contributor
timestamp: June 13, 2017, 01:53:28 am
content: Quote from: edavid on June 13, 2017, 01:38:39 amJust bought one of those and a 150mAh cell. Bought a 3.3v one actually. There is seriously more than enough space for a 150mAh cell in here... And space for a charge port...Thanks for the suggestion!

author: iamdarkyoshi
author_rank: Frequent Contributor
timestamp: June 24, 2017, 01:30:52 am
content: Wow, 10 days and the parts already cameImgur album:http://imgur.com/a/VyfTjWe'll have to see how long it lasts, but all I gotta do is pop the back cover off and plug it into a mini quadcopter battery charger rather than raiding another motherboard for a coin cell
led's using a 12 v supply - Page 1
Forum section: electronics / beginners

author: spike47
author_rank: Contributor
timestamp: October 18, 2015, 03:50:26 pm
content: how do I work out what resister to use to be able to light 14 led's , using my PC's power supply of 12 volts .cheersspike

author: jeroen79
author_rank: Frequent Contributor
timestamp: October 18, 2015, 04:18:08 pm
content: Determine the LEDs forward voltage and current required for the desired brightness.Calculate how often that voltage goes in 12V.That is how many you can put in series.The remaining voltage goes over the resistor.Use Ohm's law to calculate the value of the resistor from a knowm voltage and current.Or use:http://led.linear1.org/led.wiz

author: German_EE
author_rank: Super Contributor
timestamp: October 18, 2015, 06:35:38 pm
content: (Supply Voltage - (Voltage drop of LED x Number of LEDs))LED Current in Amps14 LEDs in series will be a problem because even at a 2V forward voltage drop that will need a 28V supply.

author: mariush
author_rank: Super Contributor
timestamp: October 18, 2015, 06:55:55 pm
content: You can split your 14 leds into smaller segments and use one resistor with each segment.
Led/Optocoupler protection circuit question. - Page 1
Forum section: electronics / beginners

author: hozone
author_rank: Regular Contributor
timestamp: January 10, 2016, 05:45:55 pm
content: Hello,I've a question about a protection circuit.First of all, I'm not a electronic eng, so excuse me for my lack of knowledge, and excuse my poor english tooMy home alarm have a status indicator LED, when the alarm is engaged that led is powered up. The led is powered up by a optocoupler and a indipendet supply. Led resistor is on alarm side. On the led and switch sockets I've just the led connected.I've a "strange" behavior:w ehenever i press the switch that turns my lounge on, the led emits some light.Led wires runs parallel to the main AC supply cables, 220V here in Italy.My thought is that when I switch on the room lights, induced EMF produces current on the led cables, and that makes the led blink.I've two questions:1- What do you suggest me to at least protect the led from overvoltage (led side)?2- Have i to build a protection circuit for the optocoupler too (alarm side)?thank you!

author: jeroen79
author_rank: Frequent Contributor
timestamp: January 11, 2016, 02:25:36 am
content: Exactly what kind of circuit is it?Like this?There is no resistor on the other side of the optocoupler or by the LED or it's power supply?What kind of wiring are you using for the LED?If it gets interference from the mains wiring then you could move it away from the mains or replace it with shielded wires.

author: hozone
author_rank: Regular Contributor
timestamp: January 11, 2016, 08:12:57 pm
content: Thank you for reply.Yes, one resistor is left in your image. It's something like the attached image.It's not twisted pair wiring the led one.The only way i can get that led out is by the power lines duct.
LEDs and Resistors - Page 1
Forum section: electronics / beginners

author: Brown
author_rank: Contributor
timestamp: February 16, 2014, 05:30:16 pm
content: So, that's the different between this. (I was looking at shift reg. and the arduino) Thanks!

author: mariush
author_rank: Super Contributor
timestamp: February 16, 2014, 06:08:29 pm
content: left side: each led is limited to a particular current by its own resistor ... ex each led is limited to 10mA , then total current is 10x8 = 80mA.right side: all leds are limited to a current value set by the resistor.... ex r9 limits the current to 20mA, then each led gets more or less 20mA / 8 = 2.5 mA . More or less because some leds will draw a bit more current, others will draw less.Also note that if one led burns out/gets damaged, the rest of the leds will share the same current, for example 20mA / 7 = 2.85mA. If you're unlucky, 1-2 faulty leds can cause a cascade and burn all the leds.=> the left version is preferred.note that a lot of shift registers can only do about 25-50mA so you might want to use npn transistors at the outputs of the shift register (with a suitable small value resistor between output and npn base) and get the current from another input, don't power the leds straight from the shift register if you want them to be bright.

author: Brown
author_rank: Contributor
timestamp: February 16, 2014, 06:19:40 pm
content: oh ok, thanks!

author: con-f-use
author_rank: Unknown
timestamp: February 16, 2014, 09:21:42 pm
content: Or if you voltage is high enough you can wire them in series and use one limiting resistor for all of them. Or you can construct a constant current source with a few passives.

author: Nerull
author_rank: Frequent Contributor
timestamp: February 16, 2014, 09:29:44 pm
content: Diodes can be subject to current hogging and thermal runaway when wired in parallel. The current through a LED is dependent on voltage and temperature. If one diode gets a bit warmer than the others, it will start taking up a larger share of the current - which makes it even warmer, leading to more and more current until the LED fails.Current limiting resistors on each LED prevent this.
LEDs for a slim aquarium lamp - Page 1
Forum section: electronics / beginners

author: lilmantis
author_rank: Contributor
timestamp: January 14, 2016, 03:26:16 pm
content: Hello everyone.I want to make a slim aquarium lamp and I was thinking about using the LM561B from Samsung. These LEDs are rated at 160lm/W, price/lm/W seems OK, CRI is about 80, the only thing that I don't like is that the thermal pad is connected to the cathode. Do you know of any other LEDs that would be better in regard to the characteristics from above?LM561B from Samsung:http://www.samsung.com/global/business/led/lighting/component/middle-power/lm561b

author: Audioguru
author_rank: Super Contributor
timestamp: January 14, 2016, 07:29:12 pm
content: The tiny LED is in a surface mount package.Can you solder to it?Can you attach a heatsink to it?

author: tooki
author_rank: Super Contributor
timestamp: January 15, 2016, 12:58:38 am
content: Just today, by pure chance, I put together a little board with 16 SMDs LEDs, practically the same as these. I think they're the same size.I just used some decent perfboard with plated through-holes, ran a line of solder paste down a row, placed the LEDs and resistors in place (touching where they need to) and then used my cheap Chinese hot air station to reflow it all. Then I ran a bit of thin bus wire to power it and tada! Works perfectly. The plated through-holes wick up all the excess solder, so you don't get shorts even on the heatsink pads. (The 2.54mm spacing of regular perfboard works well for devices around 5mm long like these.)That said, I only did it for fun. There's little reason to build these yourself when you can just buy LED strips ready made.

author: MarkS
author_rank: Unknown
timestamp: January 15, 2016, 07:42:23 am
content: Freshwater or marine? If fresh, will it be a planted tank? If marine, fish only or coral?Intensity is important, but the spectrum is critical. Just throwing a light over a tank will not cut it, if you care about the livestock. I spent over ten years in the marine aquarium hobby, BTW.
Legacy Controlled Impedance Chart - Page 1
Forum section: electronics / beginners

author: tarun172
author_rank: Regular Contributor
timestamp: January 18, 2024, 10:21:01 pm
content: Hi,I am finding the controlled impedance table on an old fabrication drawing hard to comprehend. The PCB design consists of six layers and includes both differential and single-ended signals. I'm used to layer-specific definitions of impedance needs. As an example, I looked over the PCB layout and could not find a specific trace width that was specified as an internal single-ended 50 ohm. The green box below shows that I was able to find the trace, while the red box shows that I wasn't able to find the controlled impedance trace. Has anyone encountered this before?Thanks,tarun172

author: MarkT
author_rank: Frequent Contributor
timestamp: January 19, 2024, 09:35:48 am
content: The table will be generated from the stackup data directly - no reason to suppose every entry corresponds to a trace in a particular design surely?

author: tarun172
author_rank: Regular Contributor
timestamp: January 19, 2024, 03:53:00 pm
content: That seems to be the case after analyzing the PCB design. I received an inquiry from the board house, and they requested that I remove impedance requirements that do not correlate to trace. I assumed that the created controlled impedance requirement had some significance? I don't have an explanation for establishing an impedance requirement that does not correspond to a trace, nor do I have one for eliminating it during manufacturing. Perhaps someone else has a better insight than me?
Legit BT4.0 LE modules - Page 1
Forum section: electronics / beginners

author: senso
author_rank: Frequent Contributor
timestamp: May 26, 2015, 10:54:50 am
content: Good morning, I'm going to use a BlueTooth 4.0 Low Energy radio/module for a project, but I can't find a lot of ready to use modules, there are a couple of modules from BlueRadios, but they sort of only sell in quantities, there is the RN4020 but at 10€ each they are pretty expensive.If possible I would like something available in Mouser/Farnell/RS, Digikey will end up much more expensive due to customs and VAT.I know I can use the CCxxxx chips from TI, but the antena design leaves me a bit uneasy with them, because I know I will botch it upAny ideas?

author: ElectricGuy
author_rank: Regular Contributor
timestamp: May 26, 2015, 11:08:22 am
content: Have you considered this?-http://www.cypress.com/ez-bleprocmodule/

author: senso
author_rank: Frequent Contributor
timestamp: May 26, 2015, 11:22:44 am
content: Sort of, in singles it costs 13€, but it seems that the trend is around 10€ for a BT-LE module that is ready to use.

author: Grapsus
author_rank: Regular Contributor
timestamp: May 26, 2015, 11:51:38 am
content: What's wrong with CCxxxx antennas ? Those TI modules are unbeatable in terms of price :http://www.ebay.com/itm/HM-10-CC2541-CC2540-4-0Bluetooth-UART-Transceiver-Module-Transparent-Serial-Port-/181651087019?pt=LH_DefaultDomain_0&hash=item2a4b3f9eab

author: senso
author_rank: Frequent Contributor
timestamp: May 26, 2015, 12:11:44 pm
content: Nothing wrong with them, its just that I would prefer to use a ready to use module than using the IC and designing myself the antenas.And I would prefer a better source than eBay, but thanks.

author: dferyance
author_rank: Regular Contributor
timestamp: May 26, 2015, 03:12:38 pm
content: I have been pretty happy with the Bluegiga modules. You can get ble113 from Mouser. It is small and uses the TI chip. Bluegiga has their own BT stack accessible over serial or through a scripting language but my understanding is you can use the TI tools / stack with C as well.
Leisure/Aux battery split charge circuit schematic. - Page 1
Forum section: electronics / beginners

author: castingflame
author_rank: Regular Contributor
timestamp: September 22, 2024, 10:23:54 am
content: I have searched quite extensively for a schematic to use as a starting point for a Split charging circuit design. I just wish to add a 2nd battery to my motorcycle to power no essential items like fog lights, sat nav etc.Function‐------------Just the same as a leisure battery in a camper.1) Aux battery can be used to help start vehicle if needed.2) Aux battery is only charged once the Main Battery is charged above a given level.3) Charging Switches back to Main battery once it falls below a given level.4) Aux battery is isolated from system when key is off.Requirements‐----------------------While I can buy a standard black box VSR solution, it is not suitable. I wish include this functionality in a bespoke form factor and include it as part of an auxiliary Power Distribution circuit design.Design thoughts and ideas-------‐------------------------------------I could go the microcontroller route and use ADC pins to sample each of the 2 batteries voltages over a shunt and then switch mechanical relays or MOSFETS to control battery switching in and out of the circuit.Question---------------Are there any existing examples of this circuit type that I could use as a starting point?Is there a better way to achieve this?Should I just go for it and go with my own idea of the solution written above?Thanks for any help you may be able to give.Paul

author: Solder_Junkie
author_rank: Frequent Contributor
timestamp: September 22, 2024, 10:42:27 am
content: The "normal" arrangement for a split charge arrangement is (a) to charge the aux battery and (b) ensure that aux equipment doesn't drain your starter battery, leaving you stranded if you over discharge by running equipment such as that found in a camper van.While it is probably not applicable to your intended (and rather unusual) application, this page gives a good deal of information.https://www.vanlifeadventure.com/campervan-conversion/campervan-split-charging-guideSJ
lelon capacitors - Page 1
Forum section: electronics / beginners

author: LaserTazerPhaser
author_rank: Regular Contributor
timestamp: January 27, 2019, 08:52:08 am
content: Recently received Meanwell 12v supply from mouser and it has 2 large Lelon caps and the rest of the ~9 electrolytics are Rubycon. Is this indicative Lelon makes decent capacitors?

author: oPossum
author_rank: Super Contributor
timestamp: January 27, 2019, 09:17:38 am
content: Low quality caps on the primary side are much less of a problem than on the secondary side. The 400V primary side caps don't fail very often.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: January 27, 2019, 09:26:46 am
content: Owtch, now you've got me thinking about Bjork, Post, track 8.oPossum's reply made me think some more.Meanwell is not famous because it makes the best power supplies ever, but because they make a very reasonable quality power supplies for a very competitive price.Ripple currents on the primary side are 20x lower then on the secondary side, (for 240V -> 12V) which means that internal heating by ESR currents is 400x lower, physical size of high voltage caps is probably larger, so more cooling for the Elco, and I think higher voltage Elco's also tend to have a lower ESR.Confirmed by the ESR tables in this thread:https://www.eevblog.com/forum/beginners/esr-values-for-electrolytic-caps/So it looks like Meanwell knows where they can save money.I dunno about Lelon, but my hat of for Meanwell.

author: mvs
author_rank: Frequent Contributor
timestamp: January 27, 2019, 10:06:18 am
content: Quote from: LaserTazerPhaser on January 27, 2019, 08:52:08 amLelon is a large manufacturer of electrolytic capacitors. I would asume, that they build their products to the specs they claim.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: January 27, 2019, 10:16:24 am
content: Lelon also makes a wide variety of capacitors.I would not be surprised if the best Lelon has better spec's and endurance than the cheapest rubycon/ panasonic / other brand.http://www.lelon.com.tw/en/product.php#5

author: LaserTazerPhaser
author_rank: Regular Contributor
timestamp: January 27, 2019, 11:47:11 am
content: Meanwell supplies are very small and compact for the power rating unlike the similar form factor Chinese supplies available on ebay and other retailers.
Length tuning in Autodesk Eagle - Page 1
Forum section: electronics / beginners

author: subzero
author_rank: Newbie
timestamp: November 15, 2017, 08:31:03 am
content: Hi all,I'm attempting to do length tuning in Autodesk Eagle, but it is giving me some degree of grief. Firstly, I'm trying to find the length of the longest net in the group with the Info icon. This only seems to let me get the length of a single segment of the Net, instead of the whole net, which makes it painful, but not impossible to get the full length (by adding up the length of all the segments). Secondly, the Meander tool only seems to work on a segment of the full Net.Any tips / ideas to make this experience less painful?Thanks!

author: subzero
author_rank: Newbie
timestamp: November 15, 2017, 08:35:46 am
content: So there's a script "run length-freq-ri" which gets the length of all nets... this solves the length problem. Just the Meander problem now.

author: james_s
author_rank: Super Contributor
timestamp: November 15, 2017, 06:58:50 pm
content: I'm surprised anyone is still using Eagle after that stunt they pulled switching to subscription only mere weeks after publicly stating they had no plans to do so.

author: subzero
author_rank: Newbie
timestamp: November 16, 2017, 02:49:39 am
content: Yeah, Eagle is pretty garbage. I've thrown the towel in on it, and started trying out Kicad instead - seems to have all the features that I need to start with (push-shove routing, differential trace routing, length tuning...)I will see how Kicad goes... better option than Altium (price-wise) to start off with.

author: james_s
author_rank: Super Contributor
timestamp: November 17, 2017, 07:43:20 pm
content: IMHO KiCAD is the future of the hobbyist and semi-pro EDA scene. I don't see it displacing the big pro tools like Altium any time soon but who knows, it may get there eventually.
Lengthening hot air hose?  - Page 1
Forum section: electronics / beginners

author: u666sa
author_rank: Frequent Contributor
timestamp: September 06, 2023, 06:32:13 pm
content: Anyone done it? My station is 2703A+. With microscope I need to hold it with my left hand and blow from the left, and work with scizors with my right hand. Station is on the right. Put it on the left? Then I'd get situation where I'd need to lengthen solder iron wire so I can work with my right hand.Where would I get the hose? I looked all over ali, nothing there.

author: gjvdheiden
author_rank: Contributor
timestamp: September 08, 2023, 04:27:05 pm
content: Not me, but this YouTuber MendItMark did:To the point for your question at timestamp 10:08.He's capable of repairing all sorts of stuff.His desolderingstation is quite a beast too.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: September 08, 2023, 04:52:27 pm
content: Why not use paste? I only use paste with my hot air.

author: BrokenYugo
author_rank: Super Contributor
timestamp: September 08, 2023, 05:55:59 pm
content: Much simpler to lengthen the iron's cable since it uses a standard connector you can just buy a mating pair of and terminate onto a suitable cable or wire bundle.
Lenovo laptop battery pack - Page 1
Forum section: electronics / beginners

author: tomeo.gonzales
author_rank: Regular Contributor
timestamp: February 25, 2019, 10:44:26 pm
content: Hi,Can anybody identify the integrated circuits from this Lenovo laptop battery pack?

author: Jwillis
author_rank: Super Contributor
timestamp: February 25, 2019, 11:19:49 pm
content: bq8030 is an EProm for battery management .contains firmware , bq29330 is Two, Three and Four Cell Lithium or Lithium-Polymer Battery Protection AFEhttp://www.ti.com/lit/ds/symlink/bq29330.pdf

author: Jwillis
author_rank: Super Contributor
timestamp: February 25, 2019, 11:26:48 pm
content: As a side note.If your pack isn't charging it's likely a bad cell.It only takes one cell to be a little off for the management circuit to disable the whole pack. This is a safety thing incorporated in all lipo battery packs to prevent possible explosion or fire caused by bad cells. Although new cells can be installed and the management system can be reset its often more economical to just replace the pack.

author: tomeo.gonzales
author_rank: Regular Contributor
timestamp: February 26, 2019, 02:22:11 pm
content: Thank you Jwillis.I plan to use the circuit with new cells as a power source for a 10V reference.And a LT3042 as low noise linear regulator ahead of reference

author: GeoffreyF
author_rank: Regular Contributor
timestamp: February 26, 2019, 02:28:21 pm
content: Quote from: tomeo.gonzales on February 26, 2019, 02:22:11 pmPlan on a fire extinguisher and sand bags around your project while you charge it. Read up on LiOn charging. I did not see, charging current, or, matching your new cells charging curves to the old ones, in your thoughts. Actually getting a charging circuit that goes with your new cells would not be that much more expensive than re-purposing an old circuit board with chips you can buy for a few bucks.

author: tomeo.gonzales
author_rank: Regular Contributor
timestamp: February 26, 2019, 05:35:23 pm
content: Thank you for your advice.Maybe it will be better to buy a 12V battery pack with dedicated charger.
Lens Focus Motor (Ultrasonic motor) - Page 1
Forum section: electronics / beginners

author: amirh
author_rank: Newbie
timestamp: September 18, 2024, 07:57:51 pm
content: Dear Electronics Community,I am new to the field of piezo technology and have developed an interest in piezo actuators. I came across a lens focus motor from Nikon and was considering running it without its original board. However, I do not have information on the required resonant frequency or the applied voltage. Based on my research on similar transducers, it appears that the typical voltage is around 20 Vpp, with a frequency range of 30 kHz to 50 kHz using a sine wave.I would appreciate any advice on what IC would be suitable for driving this type of motor. In the meantime, I came across the LT3572 chip from Analog Devices and was wondering if it could be a good option.
Lets play name that connector! - Page 1
Forum section: electronics / beginners

author: viperidae
author_rank: Frequent Contributor
timestamp: August 27, 2019, 08:59:59 am
content: This is the radio from a 2005 Honda Accord.It's 20 pin, contacts on top and bottom.The increments on the ruler are 0.5mm. It's 9.8mm wide, 4.75mm high, and 4.15mm deep.The depth of the hole is 2.15mm.Pin pitch looks to be about 0.78mm, or 0.030"

author: HwAoRrDk
author_rank: Super Contributor
timestamp: August 27, 2019, 06:15:27 pm
content: Are there any markings on the connector? They can usually be used to identify the manufacturer, which can give a good start to identifying the exact part. Markings may not necessarily be textual, just a logo. For example, the Japanese company Yazaki use a simple, easily-missed arrow shape.Also, knowing the OEM (i.e. not necessarily Honda themselves) of the radio itself can give a clue to likely connector manufacturer. If an Asian company, look at Asian connector manufacturers, and so on for European, American, etc.Also bear in mind that for a product more than a decade old, the manufacturer may have discontinued the part, so will not appear in current catalogues.

author: viperidae
author_rank: Frequent Contributor
timestamp: August 28, 2019, 09:41:07 am
content: I'm not sure who makes the radioIt's quite possibly AlpineLooks kinda like this stylehttp://www.townes.com.tw/product_detail/land-ctop-2/index.php?Product_SN=216307&PHPSESSID=&Company_SN=17325&Product_Site_Classify_SN=12173I couldn't see any markings on it at allUpdate: I may have found a winner winner, chicken dinner.http://www.wconconnector.com/sale-9429747-elevator-male-straight-headers-0-8mm-pitch-smt-pcb-to-pcb-connector.htmlNow... where to buy these from in less than 1,000qty

author: viperidae
author_rank: Frequent Contributor
timestamp: August 28, 2019, 10:25:25 am
content: ... or one of these...https://www.molex.com/pdm_docs/sd/533091070_sd.pdf

author: HwAoRrDk
author_rank: Super Contributor
timestamp: August 28, 2019, 09:24:41 pm
content: I'd say you're on to a winner there with that Molex part.Being a Molex Japan part also goes with it being in a product from a Japanese auto manufacturer. It doesn't happen to have an 'MXJ' marking anywhere on it, does it? That would confirm it.

author: viperidae
author_rank: Frequent Contributor
timestamp: August 29, 2019, 12:35:47 am
content: There may actually be something on the back of the connector. It's a pain to keep pulling the thing out the car though and I can't make it out on the picture

author: pcmad
author_rank: Regular Contributor
timestamp: September 03, 2019, 01:35:32 am
content: these connectors are found in small eletronics like digi cameras but dot know what they are called
Lets play name that smd component - Page 1
Forum section: electronics / beginners

author: viperidae
author_rank: Frequent Contributor
timestamp: March 28, 2019, 08:47:51 pm
content: I'm trying to trace out the schematic for part of this board, unfortunately it's 4 layer.I'm having trouble figuring out what this component in the SOT23-3 package in the bottom right corner is, marked with "563".The traces connected to the 101 resistors are two data lines that connect to two other processors on separate boards.I *think* the via's connected to the top (maybe...) pins goes to the +5V supply.The data bus works by having some kind of pull-up and each processor pulls the lines to ground via a diode. On this board those diodes are *next to* L9002 and L9003.The lines are read via the 103 resistors.I think this is the board that supplies the pull-up for the data lines an I don't know how it works - if it's just a resistor or if it's a constant current supply or something.My goal is to replace with board with my own. To do that I need to reverse engineer this proprietary communication bus.For reference this is a display controller board from a Honda Internavi navigation system. It is also responsible for the communication between the navigation computer and (via this bus) the HVAC system and (via a different bus) the radio. The big chip in the middle is an OSD controller, the one to the left is some kind of video interface chip, the components on the bottom left are RGBS input related.The other side of the board just has an RGB TFT controller chip and some flash rom for the OSD controller.Off to the left out of frame is an NEC microcontroller, an IEBus controller chip for the radio data bus and a high voltage backlight driver.

author: helius
author_rank: Super Contributor
timestamp: March 28, 2019, 09:02:18 pm
content: Philips PZM5.1NB3 5.6V Zener diodes

author: Pete66
author_rank: Regular Contributor
timestamp: March 28, 2019, 09:07:14 pm
content: Looks like5.6V 300mW Zenerhttp://www.marsport.org.uk/smd/mainframe.htm

author: viperidae
author_rank: Frequent Contributor
timestamp: March 28, 2019, 09:57:34 pm
content: Now i'm confused... I thought those via connected to pin 1 were going to +5V, which means that's a forward biased zener feeding power into the data lines.It would make more sense if pin 1 was ground, then it would be over voltage protection.Back to square one.
Level 4 Qualifications - Page 1
Forum section: electronics / beginners

author: Six
author_rank: Contributor
timestamp: May 24, 2013, 01:10:41 pm
content: Is it possible to get a start in the industry with a HNC style Level 4 qualification?I realise this is a technician level course and not a full degree. Is it enough or would you need a full HNC to be job ready?

author: 8086
author_rank: Super Contributor
timestamp: May 24, 2013, 02:22:35 pm
content: No level of study will make you 'job ready'.You may use it to get an interview but that is about it. I have an HNC and I'm now working in electronics design, and it wasn't too hard to do. The best thing you can have is a real interest and dare i say it, 'passion' for it.You mention a HNC 'style' qualification - are you referring to anything in particular?

author: Six
author_rank: Contributor
timestamp: May 24, 2013, 03:20:06 pm
content: I'm having problems securing the finance to finish my BEng (a health condition forced a prolonged absence in my second year)The local college do a 36 week HNC Electrical and Electronic Engineering that I should walk through. It's a certificate and something to show for my work if Student Finance don't play ball.
Level Shifter circuits  - Page 1
Forum section: electronics / beginners

author: foxabilo
author_rank: Newbie
timestamp: February 02, 2019, 01:43:00 pm
content: I've been into electronics for many years and even made a living out of it, today I put in my boggo standard low speed level translator for 1.8 to 3.3 volt systems and it hit me I have NO bloody idea how this actually works, when the INPUT (yes I know it's the wrong right to left not left to right) is low I get that the NPN base is at 1.8v (ok current is flowing through the 4k7 always on state) so both the input and output drag the 3.3V side to approximately ground through the 10K, but when the INPUT is high the base is still receiving current, is it that the Gate to Emitter differential is now 0 that lets the output side rise to 3.3V?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 02, 2019, 04:53:16 pm
content: It's a common-base amplifier, so the voltage gain is positive and can be greater than one (which of course is necessary to get more output swing from less input swing).Current gain is less than one, so the 1.8V logic has to be able to sink the 3.3V logic pullup.This is a saturating circuit, so the base supply has to be current-limited, and a speed-up cap is optional (although 1nF seems way too much -- 100pF would be enough for a 2N3904).For greater output voltage swings, this circuit has the advantage that Miller effect is nearly eliminated. So you can go from a very low logic level (1.2V or more), up to a full voltage swing, which might include applications from gate drivers (10-30V swing) to nixie drivers or CRT blanking (50-200V swing).Here's an example where I used a 1.2V logic level (set by D2 Vf + Q3 Vbe) into a common-base level shifter (Q4, D3, D4), with a current source pull-up for better speed (Q5, Q6 and such), then emitter follower for gate drive:https://www.seventransistorlabs.com/Class_D_Amp.pdfIt works just fine with MOSFETs too, with the difference that the gate voltage bias and input swing need to be adequate for the part. A 2N7002 needs 2 or 3V (gate to VDD, source to low-level logic, drain to pull-up). A depletion type would have gate tied to GND instead, which means an open-collector/drain pin can drive it and it supplies its own pull-up through drain-source current (though a pull-up from source to VDD will speed things up a bit).Tim

author: foxabilo
author_rank: Newbie
timestamp: February 06, 2019, 05:57:17 pm
content: thank you ..that explanation was perfect. I get it now
Level Shifter for Power Supply - Page 1
Forum section: electronics / beginners

author: metrologist
author_rank: Super Contributor
timestamp: March 06, 2018, 01:05:35 am
content: I bought some two channel level shifters to use with my 3.3V Nokia display. They are packaged in 2-channel format, so I will have 6 channels, 5 for data. Will the 6th channel work for power supply?They are similar to this device:https://www.sparkfun.com/products/12009component J1Y...

author: capt bullshot
author_rank: Super Contributor
timestamp: March 06, 2018, 11:07:39 am
content: No, these won't convert supplies, only signals.
Level Shifter - Page 1
Forum section: electronics / beginners

author: desowin
author_rank: Contributor
timestamp: March 29, 2011, 12:11:33 pm
content: How does theTI SN74CB3T3245determine which way the data flows?Have anyone used these? Does it work fine if some of the lines flow in the opposite direction than others?All other level shifters I've seen, require the direction input, but the TI's one doesn't.

author: deephaven
author_rank: Frequent Contributor
timestamp: March 29, 2011, 12:22:47 pm
content: Quote from: desowin on March 29, 2011, 12:11:33 pmThey are just FET switches which means they act a little bit like relay contacts where they join one i/o pin to another when enabled, and therefore pass data in either direction. They are called level shifters, because they are designed to be tolerant to input voltages uo to 5V but limit the output voltage to, say, 3.3V

author: scrat
author_rank: Frequent Contributor
timestamp: March 29, 2011, 01:34:37 pm
content: So is the trick simply a diode clamping of both I/O to Vcc?If I understand correctly, they are only down-shifting the level, which could have been done with a few resistors and diodes, but the IC provides 8 channels clamping and enable control in a single package.

author: deephaven
author_rank: Frequent Contributor
timestamp: March 29, 2011, 01:39:25 pm
content: Quote from: scrat on March 29, 2011, 01:34:37 pmPerformance will be better than using passive components, e.g. the on resistance is only 5 ohms. It also has an enable pin which could be useful - epecially if using more than one device for switching busses.

author: desowin
author_rank: Contributor
timestamp: March 31, 2011, 12:50:13 pm
content: If it receives 2.4V on input, would it put 3.3V (assuming Vcc=3.3V) on output of that line?

author: scrat
author_rank: Frequent Contributor
timestamp: March 31, 2011, 01:28:24 pm
content: From the internal schematic, it won't.

author: desowin
author_rank: Contributor
timestamp: March 31, 2011, 03:17:47 pm
content: Oh, there's even a uncharacteristic for Vout in function of Vin in that datasheet
Level Shifting: practical differences between these two components - Page 1
Forum section: electronics / beginners

author: vmallet
author_rank: Regular Contributor
timestamp: January 09, 2020, 06:54:17 am
content: I'm exploring the world of level shifting to interface 5v systems with 3.3v or vice versa, and I'm wondering what the practical differences are between these two components:TI TXS0108E8-Bit Bi-directional, Level-Shifting, Voltage Translator:http://www.ti.com/lit/ds/symlink/txs0108e.pdfTI SN74LVC2T45 Dual-Bit Dual-Supply Bus Transceiver With Configurable Voltage Translation:http://www.ti.com/lit/ds/symlink/sn74lvc2t45.pdfI can read the datasheets and see some differences but I'm lacking the basic knowledge of why would one use one vs. the other depending on applications. What are the fundamental differences?Could someone shed some light?

author: ataradov
author_rank: Super Contributor
timestamp: January 09, 2020, 07:23:21 am
content: The major difference is that SN74LVC2T45 is not bi-directional. There is a DIR input that controls which side is input and which side is output.TXS0108E8 is automatic. You put it between the rails and it does the shifting.

author: vmallet
author_rank: Regular Contributor
timestamp: January 09, 2020, 05:40:11 pm
content: Quote from: ataradov on January 09, 2020, 07:23:21 amThanks Alex. So in that case, why would one chose to use the SN74LVC2T45 when the TXS0108E8 does everything on its own? Is it a bandwidth difference?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 09, 2020, 05:44:09 pm
content: The "automatic" parts are notorious for glitching. The traditional directional bus driver is used when you have the requisite bus control signals available and require provable and repeatable functionality.Tim

author: ataradov
author_rank: Super Contributor
timestamp: January 09, 2020, 05:45:00 pm
content: Quote from: vmallet on January 09, 2020, 05:40:11 pmTheir architecture matters a lot. SN74LVC2T45 has a real push-pull output, so it also acts as a buffer for the signals.TXS0108E8 does not really buffer the signals. It essentially does what a typical MOSFET-based level shifier does.I assume price is also a factor, but I can't even find the price for TXS0108E8.

author: ataradov
author_rank: Super Contributor
timestamp: January 09, 2020, 05:47:33 pm
content: Quote from: T3sl4co1l on January 09, 2020, 05:44:09 pmTXS0108E8 is interesting in this respect. It looks like it is just a bunch of MOSFET level shifters, so it won't really glitch as long as both sides do not drive at the same time.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 09, 2020, 06:11:36 pm
content: At DC, yeah, but the "accelerator" thing is where the quirks happen.AFAIK, they usually work alright with normal, hard driven, logic level signals, but rapidly start to fall apart when long traces or analog levels are involved. Because they really aren't digital inputs or outputs, as such, they're some weird reactive thing.The bus gate has traditional logic inputs, so can be (ab)used the same as any other; they have the expected behavior.Tim
Level translator has fast edges. termination needed? - Page 1
Forum section: electronics / beginners

author: JPortici
author_rank: Super Contributor
timestamp: February 09, 2017, 09:11:06 pm
content: designing a pic32 board..there are seven signals that will go offboard and will control 5V logic.- a full duplex spi, this will go on a motherboard (this is a submodule) to shift registers, as IO expanders. Not expanding onboard because less connections.- three (slow) analog mux selectors, this will go on the motherboard as well as off board, on a ribbon cable, along other signals (i think 20 cm total cable lenght)to accomplish this i was thinking to use a TXB0108 by TI, which is a bidirectional level translator with push-pull outputs (all the others i've seen are open drain types)the datasheet specifies for 3V3 <-> 5V operation 10ns risetime and output impedances of 40 ohm on the 3V side, 50 ohm on the 5V side.i think i can be safe with the 3V line, the driver will be as near the mcu as possible. the SPI bus too because the shift registers on the motherboard will be near the connector.problem is, the three mux lines.I'm wondering if i should add termination to the line because of the edges, if so how to do it. i was thinking to terminate at the source, adding a resistor to match the other side impedance.so, if for example i put 60 ohm to have 100 ohm output impedance...assuming i had three mux connected to the line i should have 300 ohm impedance at each input to avoud reflections. correct?or, another way to slow down the edge, the switching rate will be far lower than the SPI line (400 kHz against 10 MHz)http://www.ti.com/lit/ds/symlink/txb0108.pdf

author: danadak
author_rank: Super Contributor
timestamp: February 10, 2017, 02:22:13 pm
content: Looking at datasheet I cannot seem to find a current drive spec. So i am thinkingtermination to 50 ohms will destroy noise margin ?One approach to de-Q-ing the parasitic LC problem is serial R, range 10 - 50 ohmsdepending on layout. I have used that on fast clocks with fairly good results. 50Mhz kind of speeds. Not a well controlled timing environment, in my cases almostall applications asynch. But simple to eval and use.Regards, Dana.

author: vealmike
author_rank: Regular Contributor
timestamp: February 10, 2017, 02:40:44 pm
content: If your propagation delay is equal to or longer than three times your rise time then you need to treat the system as a transmission line (think about it!)If you determine that you do have a transmission line, then you need to consider when you will be sampling the waveform. It could be that any reflections have died away by the time you sample.
LF Small sized CNC drilling/engraving machine. - Page 1
Forum section: electronics / beginners

author: gore
author_rank: Regular Contributor
timestamp: April 01, 2015, 01:16:23 pm
content: Hello EEVblog,The topic about sums it up. I am looking for a small scale CNC machine to do some precise drilling/engraving. 15x15cm square work area is enough for my purposes. I am not looking for top end equipment. Something with a reasonable price and acceptable performance. Let's call it a starter kit. I have to point out my complete lack of experience and knowledge with such machines. Most likely I left out a good portion of important parameters and things to consider. Like the maximum possible height of an object that the machine can accept. I would appreciate any information, suggestions or links to clear up my ignorance just a little bit. I know the 'reasonable price' is relative until I see the range of possibilities.

author: iamdarkyoshi
author_rank: Frequent Contributor
timestamp: April 01, 2015, 04:27:00 pm
content: I have experiance building a 3d printer, and for your purpose, I would get the linear drives out of flatbed scanners. This will get your X/Y movement, and perhaps a disk drive stepper assembly for the z movement. Not sure what controller to use.

author: Fred27
author_rank: Unknown
timestamp: April 01, 2015, 06:41:39 pm
content: A good starting point might be the CNC 3040 machines you'll see on eBay. Yes, the electronics are known to be a bit dodgy and might need some attention. For a typical eevblog member that shouldn't be a problem.
LFSR output drops at clock frequency? - Page 1
Forum section: electronics / beginners

author: dentaku
author_rank: Frequent Contributor
timestamp: March 26, 2017, 01:07:18 am
content: I built a LFSR with two 74164 shift registers and some XOR gates to generate some pseudo-random noise just because I find it interesting, not building anything in particular.In my example image (this is from a simulation but it does the same thing on a breadboard) I'm clocking it at 12KHz and you can see that there's a drop at that frequency.What is it about an LFSR that does this?

author: dentaku
author_rank: Frequent Contributor
timestamp: March 27, 2017, 01:16:49 am
content: Interesting.At a 5KHz clock frequency it's easier to see that it's "quieter" in audio terms, at 5Hhz, 10KHz, 15KHz, 20KHz. so that's 1x, 2x, 3x and 4x the clock frequency.The darker colours represent less content in the spectral image.

author: dentaku
author_rank: Frequent Contributor
timestamp: March 27, 2017, 08:40:05 pm
content: Quote from: evb149 on March 27, 2017, 04:25:30 amIn my last post I'm clocking it at 5KHz so it's easier to see more of the harmonics because I can't record anything beyond 22KHz with my soundcard.Thanks for those links.I guess if I actually cared about getting a signal that didn't have these drops I would just clock it at something above audio frequency and filter out anything above that too but I just asked because I found it interesting.This technique was used in old video games to create noise and it's also useful in certain synthesizers, especially for percussion sounds.The ETI Vocoder uses it so that's how I became interested in it.