hybridfree/eevblog-posts huggingface dataset:
Replacement for AD630 for the purpose of Lock-in Amplification - Page 1
Forum section: electronics / projects

author: john1998
author_rank: Newbie
timestamp: June 12, 2018, 07:18:01 am
content: I am making a lock-in amplifier which works in the gigahertz range(10GHz to be exact). AD630 does not work in this range. So can anyone please suggest some IC which does exactly what AD630 does but at a higher frequency range? Or do I have to use some other approach entirely?I am also attaching a circuit which I am working with (I got it from Instructables).

author: tomato
author_rank: Regular Contributor
timestamp: June 12, 2018, 07:29:29 am
content: Quote from: john1998 on June 12, 2018, 07:18:01 amrf mixer

author: DaJMasta
author_rank: Super Contributor
timestamp: June 12, 2018, 07:45:49 am
content: Uhh.... there is no way that circuit will work as intended at 10GHz, and there are a lot of reasons why.An RF mixer is the right direction - to get a lock in amplifier that can work on a 10GHz signal, the only realistic option is to down covert it, probably more than once, through mixers with LOs that will bring the signal you want into a bandwidth low enough that a lock in amp can work on it. In that case, the above circuit could actually do a reasonable job, but then the design portion of the project would be almost exclusively in amplifying, mixing, and filtering RF signals in a multistage downconverter as a frontend for your lock in amp.... and that's likely a much more challenging task. Dealing with fast frequencies is hard because the tiny parasitics in everything (the dielectric constant of the PCB and the solder mask, the length of the leads on components, etc.) have much more significant effects on a signal at high frequency.If you're really set on something like this, I would look into RF signal generators and mixers. Something like an RF signal generator (or two) and then a couple of modular mixers with the appropriate bandwidth and connected together using high quality coax is a good direction to look instead of diving into the complexity of laying out a board that operates at 10GHz. Since the lock in amp probably doesn't have a lot of bandwidth, it would be best to reference your RF source to a very accurate frequency reference to keep the downconverted signal from drifting out of the bandwidth of the lock in amp. What you've proposed is a very difficult task, but mostly for the RF design portion of the project, which I get the impression has not been considered yet.
Replacement for axial oil immersed capacitor - Page 1
Forum section: electronics / projects

author: ksb
author_rank: Contributor
timestamp: August 11, 2018, 03:19:43 pm
content: Dear Friends,I am searching for axial high pressure oil-immersed paper capacitors marcon cp-c 3a104m 1000v 0.1uf and marcon cp-c 3A474M1000V 0.47uF. Can someone suggest me the best replacement?

author: drussell
author_rank: Super Contributor
timestamp: August 11, 2018, 03:39:52 pm
content: Paper-in-oil capacitors generally last a very long time. Are you sure they're bad?What kind of circuit are they being used in? You should be able to replace them with an appropriately rated plastic film capacitor if those are bad.If theyreallyneed to be paper-in-oil for some reason, some of those Marcon capacitors are still floating around NOS, though I have a feeling United Chemicon doesn't make PIOs any more. (They bought Marcon years ago, as far as I know...)

author: ksb
author_rank: Contributor
timestamp: August 17, 2018, 02:31:55 am
content: Thank you for your reply. Please find my attachment. It's a power supply circuit using for large printing machine.

author: james_s
author_rank: Super Contributor
timestamp: August 22, 2018, 05:15:24 pm
content: I would expect a modern film capacitor to work fine here, they are inexpensive enough that it's probably worth trying anyway.

author: SeanB
author_rank: Super Contributor
timestamp: August 22, 2018, 08:13:42 pm
content: 1500V polypropylene capacitors will work there, and you can get them in that value. This probably is only used for mains snubbing, so they will be as effective as the originals. You can, provided you are only using them across 400VAC, use 400VAC rated class X capacitors instead, which will be easier to find.

author: floobydust
author_rank: Super Contributor
timestamp: August 22, 2018, 08:50:32 pm
content: These same Marcon oil-filled caps failed open in a Leader scopehttps://www.eevblog.com/forum/repair/leader-lbo-580-repair/msg1753268/#msg1753268For this printer PCB I would replace all of the oil and (four) electrolytic capacitors C11, C12 etc.Best to use film capacitors to replaceme the 0.47uF 1,000V and 0.1uF 1,000V parts. You can use boxed-packaged parts if you glue them down with silicone and add wires, or just get axial parts.ExampleKemet C4C 0.47uF 1200VDC/ 500VAC axial.Digikey399-13866-NDKemet C4C 0.1uF 1200VDC/ 500VAC axial.Digikey399-13865-ND
Replacement for NDP6020P P-channel mosfet? - Page 1
Forum section: electronics / projects

author: Peabody
author_rank: Super Contributor
timestamp: December 09, 2021, 11:59:39 pm
content: For years a go-to logic level P-channel mosfet was the NDP6020P in a hobbyist-friendly TO220 case that could be used with a breadboard without having to mount it in an adapter. With a typical Vgs threshold of about 0.7V, and RDSon of about 75mOhms, it was perfect for even 3.3V systems.Apparently this part has been discontinued. I've looked, and can't find an equivalent replacement among the active parts, at least in a TO220. Does anybody here know of one? Actually, it doesn't have to be a TO220, but has to be insertable in a breadboard.Any suggestions would be appreciated.

author: Terry Bites
author_rank: Super Contributor
timestamp: December 10, 2021, 12:25:54 pm
content: https://www.digikey.com/en/products/category/discrete-semiconductor-products/19?s=N4IgTCBcDaIHIBEAKA2ADGNSQF0C%20QA

author: Peabody
author_rank: Super Contributor
timestamp: December 10, 2021, 03:09:48 pm
content: Yes, but if you go to the actual listing, on the OnSemi version is says "this product is no longer being manufactured", and the other one is only available from Rochester. In any case, OnSemi shows its status as "last shipments". So it's not going to be available on an ongoing basis.
Replacement for OP279GP - Page 1
Forum section: electronics / projects

author: staze
author_rank: Frequent Contributor
timestamp: August 20, 2015, 10:18:17 pm
content: All,I've got an older piece of equipment that I'm looking to replace the OP279GP's in (PDIP). The specs aren't stellar, except the current output capacity at a minimum of mA.Anyone know a good replacement option? The closest I've found is the OPA2132, by TI, but it's listed as a minimum of 40mA output current, where the OP279GP is 50mA minimum.Thoughts?

author: moffy
author_rank: Super Contributor
timestamp: August 21, 2015, 01:28:20 am
content: You could use a SOIC OP279 mounted on a SOIC to PDIP adapter board. You might want to heatsink the OP279 if you go this way as the SOIC package usually has a lower dissipation figure.

author: staze
author_rank: Frequent Contributor
timestamp: August 21, 2015, 03:12:28 am
content: yes, it does look similar except the output current... but, I might have one of those on hand, so I can try it. now if I could just figure out what's actually broken on this unit...
Replacement for TDA0161 metal detection IC? - Page 1
Forum section: electronics / projects

author: BreakingOhmsLaw
author_rank: Frequent Contributor
timestamp: March 30, 2023, 10:58:43 am
content: Hey everyone,Does anyone have recommendation to replace a TDA0161?https://www.digikey.dk/htmldatasheets/production/111184/0/0/1/tda0161.htmlThe application is to detect a metal locking pin that goes into a hole. The hole has in integrated coil, so the pin changes its inductance when present.Simple metal detection really. I'm having a hard time finding a simple replacement.

author: coromonadalix
author_rank: Super Contributor
timestamp: March 30, 2023, 04:42:55 pm
content: https://tinkersphere.com/ics/2488-tda0161-metal-detector-ic.htmlhttps://www.electronicscomp.com/tda0161dp-proximity-detector-ic-for-metal-detectionhttps://www.ebay.com/itm/233299113481you may get some hits, and maybe some possible fakes too ? and maybe some absurd pricing too ?

author: BreakingOhmsLaw
author_rank: Frequent Contributor
timestamp: April 01, 2023, 11:02:32 pm
content: Thanks, but I'm looking for an active chip, as this is for a new product.Anyway, I'm now going with the Texas Instruments LDC series, the are "Inductance to digital" converters and are reasonably priced.
Replacement for the Maplin 1W metal film resistors - Page 1
Forum section: electronics / projects

author: perdrix
author_rank: Frequent Contributor
timestamp: February 22, 2021, 11:51:36 am
content: Maplin used to sell 1W, 50ppm, 1% resistors with a body whose size was that of a typical 0.5W part (6.3mm or thereabouts). I think they covered more than E24 values (but my memory may be faulty). They also did a 2W variant in a limited range of values (I think only E12 or E24) with a body the size of a standard 1W part.I've been pointed at TT's MFP series which are 5%, 50ppm E24 and are (apart from the tolerance) quite a good match.Does anyone know of a closer match?ThanksDavid
Replacement for TIP36 transistor - Page 1
Forum section: electronics / projects

author: IconicPCB
author_rank: Super Contributor
timestamp: April 09, 2019, 10:32:41 pm
content: The replacement issue is not too difficult to resolve however I am looking for a TIP36 like transistor with a lower beta than tip36.In fact I am presently using TIP36 however I am looking for similarly specced transistor with a beta of 15 to 20 at collector current of 10 amps.BD250 seems like a suitable candidate unfortunately it is obsolete.EDIT: obsolete according to some suppliers , element14 claims 600 odd pieces world wide.Element14 offers a Multicomp device which is different to some older sources... back to square one.

author: Cliff Matthews
author_rank: Unknown
timestamp: April 10, 2019, 12:48:21 am
content: Alltransistors.com is helpful. Search on TIP36, > 'find substitute', > search again results (after changing parameters desired).Here is similar devices, (without limiting results to a TO218 case) scroll down - there's a big list. - Hope that helps!

author: radix
author_rank: Contributor
timestamp: April 10, 2019, 06:52:01 pm
content: Why wouldn't you just put a resistor across the BE junction?

author: oPossum
author_rank: Super Contributor
timestamp: April 10, 2019, 08:02:46 pm
content: On Semi MJW21194https://www.onsemi.com/pub/Collateral/MJW21193-D.PDF

author: IconicPCB
author_rank: Super Contributor
timestamp: April 10, 2019, 08:19:18 pm
content: That is wha I have done. Effectively a 2.5 ohm resistor did the trick.
Replacement OCXO board for HP 3325A Function Generator - Page 1
Forum section: electronics / projects

author: SCSKITS
author_rank: Regular Contributor
timestamp: August 16, 2024, 09:13:55 pm
content: Recently made an OCXO board for my HP 3325A function generator.Turns out that the wiring was already there in the unit.The board mounts in the same place as the original OCXO board option
Replacement relay part XSR3002 - Page 1
Forum section: electronics / projects

author: sdancer75
author_rank: Frequent Contributor
timestamp: June 16, 2021, 07:17:15 am
content: Reading the service manual of the Pioneer VSX2014i I found a speaker relay XSR3002 that I have to replace.I found no datasheet for its characteristics as this part is obsolete.Does anyone have a datasheet or can recommend a replacement reliable part ?Regards,

author: sdancer75
author_rank: Frequent Contributor
timestamp: June 16, 2021, 07:34:43 am
content: Maybe Panasonic ALA2F24 or Fujitsu FA4K024T ?
Replacing 2 x AAA to LiPo in Bluetooth mouse. - Page 1
Forum section: electronics / projects

author: 3dgeo
author_rank: Frequent Contributor
timestamp: January 14, 2019, 11:09:50 am
content: Hello,Mouse PCB pictures bellow (got to love electrolytic CAP factory mod, and yes, apart from a few pubes that got caught over time PCB came from Gigabyte factory looking like this).My plan was to replace 2 AAA batteries (2.5V) with Lipo (2.9-4.2V) and low voltage step down converter, but when I inspected the board I found USB VCC, USB DP (guessing Data Positive) and DM (Data Minus?) , it does not have USB port, those traces goes straight to IS1616 IC, soI can assume that this chip is 5V tolerant? Battery wire goes straight fo that chip aswel, but battery and USB VCC are not connected together.I can't find any info on BT module apart HT24LC08 – it's CMOS 8K 2-Wire Serial EEPROM, operating voltage: 2.2V~5.5V.Is it safe to assume this module 5V capable? YOLO it and connect 5V directly to battery wires?Would be great if I can just plug directly LiPo wires to old battery connector....

author: 3dgeo
author_rank: Frequent Contributor
timestamp: January 14, 2019, 11:40:38 am
content: I YOLO it...............Aaaaand it worksTho I don't want to push my luck, LiPo will be max 4.2V, not 5V. This mod turned out way easier than I expected...Cheers

author: nsrmagazin
author_rank: Regular Contributor
timestamp: January 14, 2019, 02:11:26 pm
content: Its not safe, but riskable.This "2 AAA batteries (2.5V)" is "3VDC". It seems your entire circuit is 5V tolerant, but it was powered from less to spare batteries. A "5VDC" USB power supply can be "4.5VDC" actually. It will work most likely, but do it at your own risk as I want to wash my butt!

author: wasyoungonce
author_rank: Frequent Contributor
timestamp: January 14, 2019, 11:36:18 pm
content: Jeez that PCB and soldering is so bad it’s a wonder it works. From Gigabyte.... must be a sub-contractor. Many of those BT modules are either 5V or 3.3V. The 5V versions usually have their own 3.3 v regulator or use one off module

author: NiHaoMike
author_rank: Super Contributor
timestamp: January 15, 2019, 12:00:29 am
content: I think the USB test points are for the wired or combo wired/wireless version of the mouse.

author: 3dgeo
author_rank: Frequent Contributor
timestamp: January 20, 2019, 10:52:48 pm
content: Quote from: wasyoungonce on January 14, 2019, 11:36:18 pmYes, PCB looks bad, it got stains all over it. I found out it's a remake of a cheap very popular mouse in China, it's almost identical electrically, but with different shell. Tho it's very compact and comfy, don't want to trow it away, will be good for my laptop.If anyone cares I orderedthese bateriesand will DIY BMS frombut without boos circuit. I have TP4056 prebuild boards, but as I found out they connect battery again if it recovers above discharge voltage, "Great scotts" BMS reconnects only when it gets charger impulse.
replacing a mosfet irfp - Page 1
Forum section: electronics / projects

author: _Steven_
author_rank: Contributor
timestamp: June 08, 2013, 08:59:49 pm
content: dear friends,For a good amplifier i need tot change some blown parts. It is a given piece of equipment.I'm out of stock of the irfp140....can i change it with the irfp140A's? These seems to be an improved version of the -A versions.Is there anyone who had the same problem and can share it's opinion about the A type versions? There is a difference in output capacitance. And it is for audio equipment.

author: _Steven_
author_rank: Contributor
timestamp: June 10, 2013, 06:17:41 pm
content: nobody?

author: madires
author_rank: Super Contributor
timestamp: June 10, 2013, 06:22:31 pm
content: I'd download the datasheets for both and compare them.

author: c4757p
author_rank: Super Contributor
timestamp: June 10, 2013, 06:23:00 pm
content: The output capacitance isn't going to matter, it's fine. The two are nearly identical.

author: Ghydda
author_rank: Regular Contributor
timestamp: June 11, 2013, 07:45:53 am
content: As usual the N-version of the mosfet is a die shrink of the non-N version.This is confirmed by looking at the gate charge numbers and the SOA-graph.Depending on your application this could be a dealbreaker to go with the N-version.Smaller die means lower pulse power handling capability (and pulse power dissipation is what you get a lot of in a normal class AB amp).The A version looks like a die shrink as well (lower gate charge numbers) but the SOA-graph indicates it is a very good match to the original 140.I would say this is a near spot on candidate.As a sidenote Fairchild even characterized the SOA of this device at DC. Something IR never bothered to do with the original (one could suspect IR have something to hide there - pisspour performance @ DC maybe).

author: _Steven_
author_rank: Contributor
timestamp: June 11, 2013, 03:11:24 pm
content: Thank You very much for the clear explanations!

author: _Steven_
author_rank: Contributor
timestamp: June 15, 2013, 10:27:42 am
content: So I can replace it with either the IRFP140A of 140N. I have them both. Beybe just one A version and the rest are N versions.I will try it. Did'nt know anything about die shrink. thanx!
replacing a projector remote control - Page 1
Forum section: electronics / projects

author: p.larner
author_rank: Frequent Contributor
timestamp: December 17, 2023, 07:12:24 am
content: i have an epson xj-140m projector,i have lost the remote control,is it possible to make one with an arduino?

author: p.larner
author_rank: Frequent Contributor
timestamp: December 17, 2023, 10:36:42 am
content: dissregard this,i found the missing remote.
Replacing a vintage +8vcc shift register - Page 1
Forum section: electronics / projects

author: gkmaia
author_rank: Frequent Contributor
timestamp: July 14, 2019, 09:10:52 am
content: I got a bit of a problem. Got two 74 logic 164 shift registers that are faulty.The issue is. These registers run on a +8V rail and on the market today I can only find shift registers that will take 5V or 6V VCC.Has anyone had the same issue replacing these old shifters? Any tip?!

author: oPossum
author_rank: Super Contributor
timestamp: July 14, 2019, 09:19:14 am
content: CD4094 / HEF4094 / MC14094

author: tggzzz
author_rank: Super Contributor
timestamp: July 14, 2019, 09:27:46 am
content: I assume this is a one-off replacement. You have several options, but none are trivial...Find a secondhand supplier. There are several such dedicated companies on the web, but they will be expensive.See if there are 4000 series devices that have suitable timings and pinouts. Pinout could be dealt with using a carrier board.Use a modern small outline device on carrier board, together with a voltage regulator and level shifters. Be careful of the risetime of a 5V->8V shifter; some can be good up to 5V, and anaemic from 5V to 8VTiming: most people will verify the tPDand tStiming in their circuit, but tHis equally important and can be less tractable.

author: gkmaia
author_rank: Frequent Contributor
timestamp: July 14, 2019, 11:12:45 pm
content: Quote from: tggzzz on July 14, 2019, 09:27:46 amYes, I was afraid that was the case. I will get some NOS ones instead of tweaking another one as it is a precision device.But interesting. Half of the circuit uses 5v logic and other half uses 8v logic. Was that a common thing back in the past? What are the benefits of 8v logic?

author: tggzzz
author_rank: Super Contributor
timestamp: July 14, 2019, 11:57:17 pm
content: Quote from: gkmaia on July 14, 2019, 11:12:45 pmNothing per se.There may be advantages in the surrounding circuit, of course.

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: July 15, 2019, 12:23:10 am
content: I did not even know this 40H series. It seems to be 74nnn devices converted into standard CMOS. Did anyone except Toshiba make those?

author: oPossum
author_rank: Super Contributor
timestamp: July 15, 2019, 12:52:00 am
content: 74C series. Fairchild made the 74C164, but it is obsolete just like the 40H164.

author: gkmaia
author_rank: Frequent Contributor
timestamp: July 15, 2019, 01:01:26 am
content: The C164 can go to up 15v. But the thresholds are diferent. From what I can see only toshiba did those.I have a guy in china who I buy these old things directly and he is cheap and sell one or two.If anyone need I can share his contact.
Replacing an odd WIMA Capacitor - Page 1
Forum section: electronics / projects

author: Dipski
author_rank: Contributor
timestamp: May 18, 2014, 05:02:13 am
content: Hi guys, just wondering if anyone could help point me in the right direction. I'm replacing the capacitors in an old 1980's power supply I have, and I'm struggling to find an equivalent capacitor for one oddball. It's a WIMA MP3Y 250V 4n7 x5 Capacitor. I've been able to find various capacitors that are similar, but seemingly nothing that matches. I've got some Vishay 4n7 400V MKT capacitors (part no. BFC237252472) from RS but they don't have a suppression class rating.Reading the technical sheet for Vishay's MKP339 X2 series they list part numbers for 4.7nF versions but it seems to me they are just theoretical part numbers because they don't seem to be available for purchase anywhere.Are the unrated capacitors I've got an acceptable replacement or does anyone know where I might find a more equivalent replacement?

author: SeanB
author_rank: Super Contributor
timestamp: May 18, 2014, 05:10:26 am
content: You can use a class Y capacitor there, it is rated to withstand mains use but will fail open circuit. 4n7 is available in class Y and will work there.

author: Dipski
author_rank: Contributor
timestamp: May 18, 2014, 05:46:13 am
content: Thanks for the super-fast reply. Yep I found Y2 class caps straight away and had forgotten they can be used in place of X2 caps, thanks so much! After I found those I struck across a Vishay 339 series 4.7nF X2 capacitor on the RS site with a different manufacturer part number to the one on Vishay's datasheet so now I'm spoilt for choice!
Replacing backlight in a 1602 style LCD display - Page 1
Forum section: electronics / projects

author: e100
author_rank: Frequent Contributor
timestamp: September 11, 2013, 01:09:48 am
content: I have a power supply with an ammeter that has a failed backlight which appears to nothing more than a piece of plastic with LEDS.If I undo the bent metal clips on the back of the PCB, will it fall apart and more importantly will I be able to put it back together without any special tools? From memory, LCDs usually have a rubber strip that makes contact with the glass and the PCB. Is there anything else I need to be aware of?Mike

author: c4757p
author_rank: Super Contributor
timestamp: September 11, 2013, 01:17:03 am
content: Yes, it will come apart. Yes, you can put it back together with no special tools. Just make sure the strip stays clean (clean it with alcohol if you get your fingers on it) - also the contacts that mate with it, on both the LCD panel and the PCB. The parts are fragile, so don't let them go all over the place. And be warned, those metal tabs can only handle a couple cycles before they break off.

author: e100
author_rank: Frequent Contributor
timestamp: September 11, 2013, 01:40:53 am
content: Found a picture showing the cross sectionhttp://www.dkedisplay.com/images/lcd_connector_rubber.jpgThere's no backlight in this image, but presumably it sits between the polarizer and the PCB.If I were to snip the connections to the LEDs would it just slide out or, is it being squashed by the polarizer against the PCB?

author: c4757p
author_rank: Super Contributor
timestamp: September 11, 2013, 01:42:59 am
content: I think it's glued in. The couple times I've done this, I just pulled it out gently with a pair of pliers. You'll wreck the LED, but presumably it's already wrecked...

author: notsob
author_rank: Frequent Contributor
timestamp: September 11, 2013, 04:43:59 am
content: have a quick read on elastomeric-connectors (zebra strips)

author: pickle9000
author_rank: Super Contributor
timestamp: September 11, 2013, 05:02:23 am
content: A sheet of clean paper to work on and a photo or two while dissembling are always a good idea.

author: e100
author_rank: Frequent Contributor
timestamp: September 14, 2013, 12:51:55 pm
content: After taking the power supply apart I found that the display actually had a plastic frame instead of a metal frame with tabs.This popped off with a screwdriver and the backlight panel was loose under the glass panel.I ground off the dead LED with a Dremmel then ground the front off a 5mm LED and glued them together.

author: mazurov
author_rank: Frequent Contributor
timestamp: September 14, 2013, 09:58:16 pm
content: Quote from: wilfred on September 11, 2013, 04:33:55 amThe yellowish green ones are typically rated at 20ma. 100ma would likely be enough to kill them.
Replacing CH340C with FT232RL - Page 1
Forum section: electronics / projects

author: dastructhm
author_rank: Contributor
timestamp: August 23, 2022, 05:23:52 am
content: I have been using CH340C with no problems. It costs penuts. I want to take my work to the next level, thus thinking replacing CH340C with FT232RL, which is superior but more expensive. It even comes with the feature of blinking LED's when data are being transmittedbut the schematic for FT232RL seems difficut to fully understand...Like, what is a shield?https://pdf1.alldatasheet.com/datasheet-pdf/view/144591/FTDI/FT232RL.html

author: darkspr1te
author_rank: Frequent Contributor
timestamp: August 23, 2022, 06:24:45 am
content: Quote from: dastructhm on August 23, 2022, 05:23:52 amIf you are using the device in electrically noisy environments you may opt to place a metal shield around the device and also shield the USB wires and even the ttl serial signal. if you choose to also use a max232 ttl to rs232 converter then you can also include the shield from that to isolate your signals and improve signal to noise ratio's.darkspr1te

author: MarkF
author_rank: Super Contributor
timestamp: August 23, 2022, 06:46:44 am
content: You know you can buy these for dirt cheap?There is both a 5V I/O version and a 3.3V I/O version.This has 3.3V I/O:https://www.sparkfun.com/products/17831

author: coromonadalix
author_rank: Super Contributor
timestamp: August 23, 2022, 06:46:53 am
content: you have already made good shielded ftdi cables, shielded shell ...why re-invent the wheel ?? sure they cost more, about 20-30$ a cable, but never had problems, and some of them have an buffer ic to help in case of shorts, and they have all the "classical 8 rs232 pins"EDIT At rs232 or ttl levels
Replacing crystal oscillators with a global clock - Page 1
Forum section: electronics / projects

author: smashedProton
author_rank: Frequent Contributor
timestamp: February 10, 2015, 06:17:23 am
content: Hello all,I'm designing a 16 channel usb to UART board using 4 FT4232 usb to 4xuart chips and a TUSB2046B usb hub chip. The ftdi's want a 12mhz clock and the usb hub chip wants a 48mhz clock. I'm wondering if I can clock everything using one 12mhz crystal and an IDT ICS512. (datasheet:http://www.idt.com/document/512-datasheet) Would I be able to do this? What should I take into account when designing the circuit? Right now, I have the pll set to 4x multiplication, the reference clock is connected directly into the crystal input of the ftdi chips, and the pll output clock is going into the 48mhz imput clock of the usb hub chip. Is my specific circuit correct, or should I add more circuitry to condition the signal to work with the clock input of the ftdi chips?Thanks!

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 10, 2015, 07:00:52 am
content: Is that really cheaper than using two separate crystals?I've used that TUSB thing before; it bothers me that they don't document the "crystal" pins at all (same goes for basically any device, including that PLL). In my case, it was using two TUSBs on one board, where it would be nice to save a crystal by running the other chip from the first one's clock output. They don't say that it's a clock output, but as it turns out, the signal level on the CLKOUT pin seems CMOS-ey, so it may very well be practical to do that.Point being, maybe you'd still need two crystals, one for the FTDI and one for the TUSBs, but only one for them, not one each.Of course, it would be more applicable if what you were doing involved multiple hubs, rather than multiple UARTs... but maybe the same scheme can be applied to the FTDI chips. Dunno. You can try asking them; maybe you'll actually get a useful reply (unsurprisingly, the reply I got from TI's 'help' forum was terse and useless).Might also look into a hub that uses 12MHz rather than 48. As I recall, the TUSB has a 6MHz mode, but, that doesn't help very much. (On the upside: if you have a clean 12MHz, you can simply use a 74HC1G74 to divide it to 6!)Tim

author: smashedProton
author_rank: Frequent Contributor
timestamp: February 10, 2015, 08:25:46 am
content: Quote from: T3sl4co1l on February 10, 2015, 07:00:52 amI'm using 4 FT4232 chips so the crystal + pll solution would replace 5 crystals. It wouldn't save a whole lot of space, but I'm trying to cram my circuit into a small space so wouldn't want 5 crystals if I don't need to have them.
Replacing csr8630 with another csr module - Page 1
Forum section: electronics / projects

author: sino89
author_rank: Newbie
timestamp: November 12, 2020, 03:46:13 am
content: Hello,i own a Bluetooth Car Radio Adaptor and it lacks Apt-x codec, it uses a Csr8630 chip.i'm looking for replacing the module with another one with the same Pinout and Apt-x feature... just remove & soldering on.Handset free possibility, like Microphone input connectors for drive&talk with my phone, would be great!... it's connected to a "Carrier" board where the plug it's wired to the Car Radio, that's why i was looking on this idea in the first place.Otherwise, if you have another idea how i done this project, share your thoughts.I have a done already researches, there is no Apt-x Adaptors available for my Car Radio.regards,sino89
Replacing high power incandescent lamps. - Page 1
Forum section: electronics / projects

author: firewalker
author_rank: Super Contributor
timestamp: December 05, 2020, 01:52:17 pm
content: When testing a device that plugs in mains it it a common practice to use high power (~200 watt) incandescent lamps that acts a PTC that protects the device. It is now quite difficult to find an buy suitable incandescent lamp.Is there something else someone can use instead of incandescent lamp. A high power of the shelve PTC?Alexander.

author: Alti
author_rank: Frequent Contributor
timestamp: December 05, 2020, 02:00:15 pm
content: You can always buy a heat lamp.These range from 100W up to 375W. The most popular are 250W.

author: NiHaoMike
author_rank: Super Contributor
timestamp: December 05, 2020, 02:09:44 pm
content: You could consider halogen lamps, multiple smaller bulbs in parallel, or hair dryers.

author: firewalker
author_rank: Super Contributor
timestamp: December 05, 2020, 02:41:07 pm
content: There also appliance lamps (oven lamps), but I was wandering if there is an ad-hoc option.Alexander.
Replacing Microchip MCP2515 by a Tokmas MCP2515-I. 100% compatible? Experience? - Page 1
Forum section: electronics / projects

author: Pinkus
author_rank: Frequent Contributor
timestamp: July 23, 2024, 10:15:41 pm
content: I am currently faced with the decision to replace the Microchip CAN controller MCP2515 with a Tokmas MCP2515-I, because .... it only costs half as much. For 500 PCBs this is some significant saving.Does anyone have experience with the Tokmas MCP2515-I and can it be used 1:1 like the Microchip type?Sure I could purchase a few and try it out, though this would cost me another extra week for shipping. Maybe somebody already knows...Thanks in advance!

author: johnboxall
author_rank: Unknown
timestamp: July 23, 2024, 11:15:58 pm
content: Get a few and test yourself. You don't want to risk your project on the word of some random people, no matter how well-intentioned they may be. Also - some clients are aware about part brands - is yours?
Replacing Potentio with DAC - Page 1
Forum section: electronics / projects

author: aamir
author_rank: Contributor
timestamp: May 12, 2014, 05:47:21 am
content: I have this drive, that drives a BLDC motor, and it has a 10 k potentiometer which can be used to vary speed,and i replaced that with DAC(the one on the left in schematic) and it worked fine for a couple of days, but one day opamp U1a heated up, and i replaced it and now the drive shows erratic behaviour,normally the drive goes to max speed on 0 volts, and stops at 5, when the three pins of potentio are disconnected the signal pin shoes five volts, and now when i connect my dac to it, regardless of dac's output, output voltage is 3.3 V, and only increases when DAC's output is greater than 3.3 Volts.i though it was a current issue so i replaces the output stage with the one on the right so as to increase the current, but still nothing. What should i do?And also it is still working fine with potentiometer.

author: jpb
author_rank: Super Contributor
timestamp: May 12, 2014, 03:15:43 pm
content: I am no expert, but the port connections on the DAC seem completely wrong.You have one output going to ground and the other to a 5V rail, whilst you seem to be using the REF input as some sort of driving output.Either I'm reading things wrong or it is amazing it worked at all.

author: Thilo78
author_rank: Regular Contributor
timestamp: May 12, 2014, 03:34:20 pm
content: Quote from: jpb on May 12, 2014, 03:15:43 pmI see the same from the data sheet.Here's a link:http://www2.informatik.hu-berlin.de/~hochmuth/bvp/ad7524.pdfCheck this for connections.If you change that, it should work, I think...

author: aamir
author_rank: Contributor
timestamp: May 13, 2014, 04:24:18 am
content: i used the voltage mode operation mentioned of page 5http://www.ti.com/lit/ds/slas061d/slas061d.pdfthe one i am using is ad7524, so the max voltage i got was 2.5, i dont know why,must be some sort of resistor divider inside, but this guy had the same design,http://www.waveguide.se/?article=a-simple-dac-using-the-tlc7524read the comment thread.drive works fine with potentiometer, could it be a current issue?also do you think that it would work fine if i used unipolar circuit operation thingy? also i would need a bipolar supply for it, wouldn't i?

author: jpb
author_rank: Super Contributor
timestamp: May 13, 2014, 08:30:22 am
content: Quote from: aamir on May 13, 2014, 04:24:18 amLooking at the data sheet, Vref is typically twice Vout so in voltage operation mode I think you need to have the supply voltage greater than the output voltage so I think you need to either make VDD higher than the current 5V or set Out 1 to 2.5V instead of 5V. The test conditions on the data sheet for voltage operation mode have Vref at 5V and Vout at 2.5V so that is probably a good place to start.
Replacing Projector LEDs (RGB) - Page 1
Forum section: electronics / projects

author: Tobal
author_rank: Newbie
timestamp: January 23, 2014, 03:11:44 am
content: Hello everyone!I just wanted to know if anyone had any suggestions for Red, Green, and Blue SMD LEDs for projection.I'm looking for something high in lumens, to replace my older 3 bulb leds which are dedicated red, blue, green.Here are the dimensions in millimetres, I need something powerful yet similar in size.Any suggestions? In-store, or online, no problem!Thanks!
Can radio receiver (NRF24L01) interfere with sound amp, Bluetooth? - Page 1
Forum section: electronics / projects

author: 3dgeo
author_rank: Frequent Contributor
timestamp: June 06, 2018, 10:35:38 pm
content: Hi,I have a pair of Edifier R2730DB, I love them, but their remote control is really annoying due to it being infrared (I have to point very carefully and range of it is very bad).I want to replace remote/receiver to RF – NRF24L01, my biggest concern is that RF might interfere with sound quality, with other internal components or bluetooth, so my question iscan/will RF interfere?Side note: I'm not asking how to do it, I'm experience enough to implement NRF24L01 on my own, RF interference is what I'm worrying about.Thanks for help in in advance.Edifier R2730DB:https://www.edifier.com/int/en/speakers/r2730db-bluetooth-bookshelf

author: NiHaoMike
author_rank: Super Contributor
timestamp: June 07, 2018, 06:35:16 pm
content: Both that module and Bluetooth work at 2.4GHz so there is potential for interference. Maybe look into wireless modules that run on some other frequency?Also don't overlook the remote having weak batteries.

author: 3dgeo
author_rank: Frequent Contributor
timestamp: June 07, 2018, 08:33:10 pm
content: I know it runs on 2.4GHz, thats why I created this threadBut NRF24L01 will be active only while receiving , so I'm assuming if it interfere it will while receiving data?

author: NiHaoMike
author_rank: Super Contributor
timestamp: June 08, 2018, 12:25:16 am
content: What about modules that use 433MHz or 315MHz? In some cases, they're close to a drop in solution for replacing IR remotes.

author: 3dgeo
author_rank: Frequent Contributor
timestamp: June 08, 2018, 12:58:15 am
content: Quote from: NiHaoMike on June 08, 2018, 12:25:16 amI have few of those as well, but I want to add NRF24L01 to other things and make them communicate, simple RF modules goes only one way.I guess I have to put NRF24L01 in and see if it will interfere...

author: CJay
author_rank: Super Contributor
timestamp: June 08, 2018, 12:27:17 pm
content: Seems odd that they've implemented Bluetooth for audio and no incorporated a way to control it via Bluetooth as well?Might be interesting to see which Bluetooth chipset they've used and find out if it can be persuaded to carry some command data too?

author: xani
author_rank: Frequent Contributor
timestamp: June 08, 2018, 12:44:28 pm
content: Quote from: NiHaoMike on June 07, 2018, 06:35:16 pmIIRC you can just tell that module to use different channel

author: 3dgeo
author_rank: Frequent Contributor
timestamp: June 08, 2018, 03:15:51 pm
content: Quote from: xani on June 08, 2018, 12:44:28 pmMore details, please?My laptops WIFI and BT is on same chip, If I listen to music via BT my WIFI speed gets decimated, tho as I said remote receiver will not be on all the time.
Replacing SRAM with NVRAM - Page 1
Forum section: electronics / projects

author: ZotDitzMyo
author_rank: Newbie
timestamp: August 23, 2012, 09:59:46 am
content: Hello,I was recently on the receiving end of an old Peavey Pro Fex II guitar Fx module. It has an onboard SRAM chip (Sony CXK58257AP-10L) and a Varta NiCd Battery that has leaked all over the place. After looking on the net, this seems like a common thing.I found someone who used to replace the battery/SRAM combination with only an NVRAM chip (ZMD CXK58257AP-10L). Now it looks like ZMD was bought out by SimTek which was bought out by Cypress and I can't find suppliers of that part.How would I go about finding a newer/available NVRAM chip to drop in the circuit? From the specs I need a 32K x8bits in a 300mil DIP28 package with at least 100ns access time.How would you go looking for a part like this? what sites would you recommend?thank you!

author: Short Circuit
author_rank: Frequent Contributor
timestamp: August 23, 2012, 10:46:17 am
content: Almost match, this seems. Not in DIP, but you can get adaptors pcbs to get around that;http://www.ramtron.com/products/nonvolatile-memory/parallel-product.aspx?id=132

author: ZotDitzMyo
author_rank: Newbie
timestamp: August 23, 2012, 01:36:40 pm
content: Thanks! This sure looks like a viable candidate.I guess I`m still stuck in the 80s and was looking too hard for DIP packages :-)I read that the original chip replacement required a 10K resistor between pins 27 (!WE) and 28 (VDD) to prevent problems on power-ups. I am not at all familiar with memory chips, so I guess I will just try it out and see if it works!Thanks gain!

author: westfw
author_rank: Super Contributor
timestamp: August 23, 2012, 04:43:18 pm
content: Dallas semi used to be a major player. They were acquired by Maxim. It looks like the ds1230y is still available (sticker shock!)http://para.maxim-ic.com/en/search.mvp?fam=memory&489=NV%20SRAM&232=Yes&tree=memory

author: amyk
author_rank: Super Contributor
timestamp: August 24, 2012, 08:30:02 am
content: ^ And there's also TI's offering, the bq4011.A quick search for "32K x 8 nonvolatile sram DIP28" comes up with a bunch of possible parts, likeCypress STK16C88Cypress CY9C62256FM28V020...none of which are exactly cheap, but the expectation is that these parts shouldn't need to be replaced often.
Replacment for component DSC6083JI1A-032K768T - Page 1
Forum section: electronics / projects

author: rimda1985
author_rank: Newbie
timestamp: September 19, 2024, 01:40:17 pm
content: Hi everyoneWe have been producing a device with the specified component for a long time - DSC6083JI1A-032K768 , but I can't find the specified component anywhere.It is a 32.768kHz oscillator. There are many such oscillators on the market, but this one is specific in that its output signal is on PIN-1Does anyone know a replacement for the mentioned oscillator?https://ww1.microchip.com/downloads/en/DeviceDoc/DSC60XX-Ultra-Small-Ultra-Low-Power-MEMS-Oscillator-DS20005625C.pdf
Replacment for Si53314-B-GM - Page 1
Forum section: electronics / projects

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: July 11, 2021, 03:37:44 pm
content: Hi,Silicon shortage has got me tooI have designed a board that uses this Si53314-B-GM clock buffer from silicon labs, I want to know if any one know some where that I can buy it or do you know another part that's pin compatible, so I can replace this.Thanks
Report: removing DC link capacitance from a BLDC inverter - Page 1
Forum section: electronics / projects

author: Siwastaja
author_rank: Super Contributor
timestamp: June 29, 2018, 06:44:44 pm
content: I'll leave this attachment here.Abstract: We all "know" how important it is to shotgun ceramic caps on the DC link of a DC/DC converter or a motor inverter. Here's one very limited take, with clear limitations on what was measured and how. Take it as a grain of salt.
Reproducing ST Design Gate Driver - Page 1
Forum section: electronics / projects

author: stain
author_rank: Newbie
timestamp: August 25, 2021, 04:11:38 pm
content: I try to reproduce the buck-boost converter from the "STM32F334 Discovery" board. Therefore I have drawn a KiCad Schematic and assigned the appropriate spice models. But unfortunately, I'm not able to reproduce the behavior. Or at least I think so, because the gate p-fet (P1) is in my opinion not properly driven.[/stm.png]Picture form STM UM1735 Fig. 13[/kicad.png]KiCad schematic of the gate drive circuit.A 1n capacitor is added as gate equivalent.[waveform.png][/waveform.png]The waveform at the "gate-caps"I think something went wrong or I have a misunderstanding of the design.For my own purposes, I would like to drive the Ubatt form 3.0-4.2V 3.7 nominal.The logic level *_Drive may be at 3.3V but I would prefer 2.5V.Because the p-fet from the reference design is not available, there could be some parameters to change for the p-fet (Vgs threshold).

author: bson
author_rank: Unknown
timestamp: August 26, 2021, 08:37:46 pm
content: What if you add the D6/D8 zener from the original circuit? Without it there's no closed circuit on P1, so it's not surprising if it floats around the 1n cap.

author: stain
author_rank: Newbie
timestamp: August 27, 2021, 09:04:58 am
content: In my opinion the zener does nothing but protecting the gate against over voltage.The capacitor is meant to represent the gate of the MOSFET.I'm only interested in the gate-source voltage and the dynamic behavior.I don't see a "floating" problem.However, I did the simulation anyway with the "exact" diode model from the manufacturer:

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 27, 2021, 04:20:03 pm
content: What else is connected to P1, is this the entire simulation?Your riddle is, why isn't it pulling up to Ubatt every time. Q2-D voltage should be of interest.Tim

author: stain
author_rank: Newbie
timestamp: August 27, 2021, 04:58:52 pm
content: I agree with that.Here is the voltage at the gate and drain of Q2 together with P1.This is the complete simulation, nothing more connected to the nets.I have no clue, why the voltages are decreasing over time.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 27, 2021, 07:50:08 pm
content: Netlist?Tim

author: stain
author_rank: Newbie
timestamp: August 28, 2021, 11:01:50 am
content: There you go

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 28, 2021, 12:59:56 pm
content: Q4 doesn't show up, does it have a model?Can you also post the BC817 and 2N7002K models? (I'll assume SMAJ and SIGNAL_SCHOTTKY are big libraries, and working fine anyway.)Q3 and Q4 are probably wired wrong, with Q4 showing as a short circuit B-E (both sides are apparentlyNet-_Q2-Pad1_). It's still not obvious how that would give the waveform.Tim
Reprogram a bitcoin asic miner for something useful? - Page 1
Forum section: electronics / projects

author: teqmo
author_rank: Newbie
timestamp: June 10, 2014, 06:37:16 am
content: I have a bunch of these 330mhs asic miners wanted to know if I could reflash it to do something?

author: senso
author_rank: Frequent Contributor
timestamp: June 10, 2014, 06:40:05 am
content: If they are asic's the algorithm is set in silicone, you can only reuse them if they are FPGA based.

author: AndyC_772
author_rank: Super Contributor
timestamp: June 10, 2014, 07:15:44 am
content: The clue is in the name:Application specificintegrated circuit.

author: nuno
author_rank: Frequent Contributor
timestamp: June 10, 2014, 08:34:29 am
content: Quote from: senso on June 10, 2014, 06:40:05 amI guess you meant silicon

author: rolycat
author_rank: Super Contributor
timestamp: June 10, 2014, 09:08:46 am
content: Quote from: senso on June 10, 2014, 06:40:05 amI reckon setting algorithms in silicone is a great idea.Fuzzy logic is kind of old-hat now; this could be a whole new field - bouncy logic

author: amyk
author_rank: Super Contributor
timestamp: June 10, 2014, 11:02:48 am
content: Depends on how "specific" that ASIC is.... at best, it would probably be usable as a SHA256 accelerator, but not much more than that.

author: Dago
author_rank: Frequent Contributor
timestamp: June 10, 2014, 11:48:48 am
content: Quote from: amyk on June 10, 2014, 11:02:48 amI *think* Bitcoins use double SHA256 so AFAIK ASIC miners would only be useful for applications requiring two rounds of SHA256.

author: rob77
author_rank: Super Contributor
timestamp: June 10, 2014, 12:01:44 pm
content: you can use them as heating elementscontrolled by the clock - the faster the clock the more heat they will producesorry but there is no other usage for those devices.. the fpga is an fpga - you can burn in whatever you want... but asic is hardcoded silicon.

author: miguelvp
author_rank: Super Contributor
timestamp: June 11, 2014, 08:39:26 am
content: Quote from: nuno on June 10, 2014, 08:34:29 amI don't know I like my asic's voluptuous.

author: amyk
author_rank: Super Contributor
timestamp: June 11, 2014, 10:42:01 am
content: Quote from: Dago on June 10, 2014, 11:48:48 amLike I said it depends on how specific they are - if I remember correctly, the early ones could do single rounds too.
reprogrammation chip TI046B1 for lexmark cx317dn black and colors - Page 1
Forum section: electronics / projects

author: marcopolo47
author_rank: Newbie
timestamp: August 26, 2020, 02:12:26 pm
content: hello i don't speak english but i'm using google translator.I bought a lexmark CX317dn laser printer and I would like to know how to program the chip for black and color toners.I have 5 x TI046B1 blankswhat is needed as hardware and as software?what is the connection and the procedure sérial or usb2 ?can we read the information programmed into the chip?Thank you all in advancecordially