hybridfree/eevblog-posts huggingface dataset:
Can I connect my multimeter probe into a DC power supply terminal - Page 1
Forum section: electronics / beginners

author: renzoms
author_rank: Regular Contributor
timestamp: December 12, 2021, 03:34:43 pm
content: I need a third banana plug (to get + and - Voltage). I don't have one.But I have these handheld multimeter probes that have a banana plug on one end and (attachable) alligator clips on the other.I guess the difference here is banana plugs have negligible resistance and my scope probe introduces 1X resistance. Not sure, yet.

author: renzoms
author_rank: Regular Contributor
timestamp: December 12, 2021, 04:39:05 pm
content: Gonna guess that made sense.Went ahead and went with this videoGenius use of op-amp feedback.

author: rstofer
author_rank: Super Contributor
timestamp: December 13, 2021, 02:36:21 am
content: That rail splitter is intended to provide a REFERENCE voltage, not high current output. That's why so many people buy 3 output power suppliesFor power supply leads, I use the Pomona banana to grabber style leads:https://www.digikey.com/en/products/detail/pomona-electronics/3782-24-02/736648Sometimes I use them with my DMMs, they work fine when I can't find the gripper attachment for the factory DMM leads.They are available in other colors which is quite handy when using multiple outputs from the supply. +15V, -15V and +5V - very handy!I bought this power supply from Jameco to provide +-15V for op amp projects:https://www.jameco.com/z/PD-2515-MEAN-WELL-Power-Supply-Dual-Output-Open-Frame-15V-1A-Negative-15V-1A-24W_2100857.htmlIt would be nicer if it had an enclosure but for $15 you can't have everything. If you decide to buy one, don't forget the connectors.

author: rstofer
author_rank: Super Contributor
timestamp: December 13, 2021, 02:39:13 am
content: Quote from: renzoms on December 12, 2021, 03:34:43 pmThe 1X impedance of the scope lead is 0 Ohms, the 1M Ohm input impedance of the scope is inside the scope. The 10X setting introduces a 9M Ohm series resistor to the scope lead before it hits the BNC connector.

author: ledtester
author_rank: Super Contributor
timestamp: December 13, 2021, 02:50:41 am
content: You can also just use two 9V batteries:https://www.instructables.com/Dual-Voltage-Supply-9V-batteries/or use whatever batteries you have put in series.+/- 9V is good enough for most op-amp projects. Modern op-amp circuits even use +/- 2.5V or +/- 1.7V rails.

author: tooki
author_rank: Super Contributor
timestamp: December 13, 2021, 05:45:19 pm
content: Quote from: renzoms on December 12, 2021, 04:39:05 pmThe first post? Nope, I can’t figure out what you’re trying to say.

author: renzoms
author_rank: Regular Contributor
timestamp: December 13, 2021, 05:51:59 pm
content: tooki,I understand. We can move on from this post and I will try to be clearer in future posts. I resolved the reason I made for this post, too. I mean, I didn't hash out all the details of probes and impedance, but it's alright. I want to walk away from this, right now.

author: radiolistener
author_rank: Super Contributor
timestamp: December 13, 2021, 06:55:58 pm
content: yes, you can
Can I connect my Tesla coil to the my homemade power supply - Page 1
Forum section: electronics / beginners

author: DiDBoGDaN
author_rank: Contributor
timestamp: November 30, 2023, 08:25:22 pm
content: Hi, I'm going to make (just for fun) a simple tesla coil using a circuit like the one in the attached picture. I have already bought everything I need for this project, but then I saw that in the video he connects it to a car battery. So I had a question: Can I connect the Tesla coil to my homemade power supply? Is it safe?My homemade power supply is just a 24V 4A AC-DC module + XL4016E1 1.25-24V DC-DC step-down module, up to 9AAnd one more question, I have a ground connection at home, so can I connect the 0V/ground/black output of my DC-DC module to the ground wire of my house? Why yes or why no? thank you

author: BlownUpCapacitor
author_rank: Frequent Contributor
timestamp: November 30, 2023, 10:14:45 pm
content: Your power supply will probably work, though interference from the tesla coil may pose a problem. Personally I'd use an ACDC wall transformer. Not a switching one, but a linear one.And yes you can ground the ground on your circuit. As long as it's galvanicly isolated from mains.

author: DiDBoGDaN
author_rank: Contributor
timestamp: November 30, 2023, 11:47:51 pm
content: Okay, thank you, tomorrow I'll connect ground to the ground) and unfortunately I don't have ACDC transformer, so I'll try my luck with my own power supply

author: Jwillis
author_rank: Super Contributor
timestamp: November 30, 2023, 11:52:37 pm
content: Give your power supply some distance from the coil. I know I had some problems with a Tesla coil causing all kinds of weirdness with other digital circuits including LCD and LED displays. Even causing some instruments to turn on by them selves.

author: DiDBoGDaN
author_rank: Contributor
timestamp: December 01, 2023, 12:08:09 am
content: okay, thanks) i have like 50 cm wire connectors, i hope this is enough)
Can I connect the two 30V outputs of my DP832A in series? - Page 1
Forum section: electronics / beginners

author: loiphin
author_rank: Contributor
timestamp: August 28, 2014, 12:02:55 pm
content: Hi all,This may be a stupid question, but I better ask... Can I put the two outputs (30V) of my DP832A in series, to get 60V? All I really need is 34V to drive a monster LED.Bad idea?Thanks,loiphin.

author: Wilksey
author_rank: Super Contributor
timestamp: August 28, 2014, 12:11:17 pm
content: Probably, you can put a link between 0V on one and 30V output on the other and measure the two outer points with a meter, on mine if I set it to two 12V outputs I get 24V, but they are isolated supplies.another option if you only want a bit extra is to use a boost converter, you can get these from Ebay quite cheap if you only want one.

author: loiphin
author_rank: Contributor
timestamp: August 28, 2014, 12:15:45 pm
content: The problem is that even if I used a boost converter and one output of my bench supply, I could only draw 90W (before any losses from boost converter) from my supply, before any losses (30V @ 3A). I suppose I don't need to run the 100W LED at full power

author: Artraze
author_rank: Contributor
timestamp: August 28, 2014, 02:20:21 pm
content: You probably can, but I'm not 100% certain. In the past I scanned the datasheet for a specific figure and couldn't find one, but the front panel has "max 240V to ground". That normally means the outputs should be floatable to +/- 240V with respect to the case/mains ground.Just keep in mind that outputs 2 and 3 aren't isolated from each other, so you would have to use outputs 1 and 2 and would probably want to leave 3 disconnected. I would suggest you double check the datasheet to see if you can find anything about floating / series connections. If not, it would probably be a good idea to test it yourself by wiring a high value resistor and ammeter between the supplies in order to ensure that there are not unexpected (and bad) current paths.

author: radioFlash
author_rank: Regular Contributor
timestamp: August 28, 2014, 11:50:36 pm
content: I've done exactly that-connected both 30v outputs in series to drive a high power LED without any problems.
Can I damage a linear regulator by leaving Vin open and connecting Vout? - Page 1
Forum section: electronics / beginners

author: 0xdeadbeef
author_rank: Super Contributor
timestamp: June 23, 2013, 04:04:01 pm
content: Let's say I want to put an existing CPU board with an onboard LM1117-33 linear regulator on top of a larger motherboard. Now the motherboard should provide the 3V3 voltages for the whole system including the CPU board and the 5V supply of the CPU board (Vin of the LM1117-33) is left disconnected. So the 3V3 supply from the mainboard is directly connected to the output (Vout) of the LM1117-33 on the CPU board.My question is: could this damage the LM1117-33 or have other unfavorable side effects?From what I can see in the LM1117's datasheet, a floating Vin should mean that all the bipolar transistors are inactive and so nothing bad should happen. I also did a small experiment with a LD1117V33 I had at hand: the (open) input could be measured at ~2.9V with 3.3V connected to the output, which I guess is the voltage drop over the NPN transistor between Vin and Vout. I measured ~4.8mA going into the output. On a scope, the output looked flat (no oscillation).So does anybody have either the insight or experience to tell me if there are issues to be expected with this constellation?

author: SeanB
author_rank: Super Contributor
timestamp: June 23, 2013, 04:34:00 pm
content: Really depends if there is a load from the input to ground that will pull current and the actual regulator. Best is to place a low drop diode across the regulator so input is at near the same as the drive side, or disconnect it completely.

author: 0xdeadbeef
author_rank: Super Contributor
timestamp: June 23, 2013, 05:48:26 pm
content: Problem is that the CPU board has a fixed layout and before soldering diodes on it, I would cut the trace on the 3V3 regulator output or lift the according pin.This is my emergency plan, but I'd prefer to keep the board unaltered.

author: SeanB
author_rank: Super Contributor
timestamp: June 23, 2013, 06:04:38 pm
content: If it does not fry or stop working just leave it be, or connect the 3v3 rail to the input of the regulator as well to keep it happy. That way it will just sit there drawing quiescent current with the output drive shut off.
Can I drive a 5v TTL input (Z80 bus) via SN74LVC245? - Page 1
Forum section: electronics / beginners

author: Peluko
author_rank: Newbie
timestamp: July 26, 2023, 12:33:20 pm
content: Hello. My knowledge of electronics has been rusty for many years, and I would like you to help me solve some doubts.I want to connect an ESP32 (GPIO 3.3v) to the address and data bus of a Z80, through the cartridge slot of an MSX computer. As far as I know, the slot directly exposes the Z80 buses and lines (TTL 5v logic).For the output lines (Z80 -> ESP32), like the address bus and the control signals, no problem, I use some SN74LVC244 that I have lying around. My doubts are for the other two situations:- For the input lines (ESP32 -> Z80), I understand that the connection could be direct, since the 3.3v of the ESP32 is enough to be recognized by the TTL logic of the Z80, is this correct?- For the data bus, which is bidirectional, I have thought of using a SN74LVC245 that I have available. It's clear to me that the direction Z80->ESP32 will work, since the 245 works at 3.3v but accepts 5v as input. But will it work the other way around? In the SN74LVC245 datasheet it states that 'outputs should not be pulled above VCC'. VCC is 3.3v and I don't know if connecting to the Z80's bus will pull the 245 outputs to 5v.As I said, my knowledge of electronics has been rusty for many years, and I don't know if I'm making a mess by forgetting some basic concept.Greetings and thanks.

author: dobsonr741
author_rank: Frequent Contributor
timestamp: July 26, 2023, 01:04:42 pm
content: Take a look at page 28-28:https://www.ti.com/lit/ug/scba010/scba010.pdfIf your LVC part is 5V tolerant, the levels lining up fine both ways.

author: ledtester
author_rank: Super Contributor
timestamp: July 26, 2023, 03:30:20 pm
content: Quote from: Peluko on July 26, 2023, 12:33:20 pmPerhaps this is relevant... in tri-state mode the outputs are tolerant up to 6.5V:

author: MarkS
author_rank: Unknown
timestamp: July 26, 2023, 03:59:43 pm
content: Quote from: dobsonr741 on July 26, 2023, 01:04:42 pmThat document is invaluable! Thank you!

author: Peluko
author_rank: Newbie
timestamp: July 27, 2023, 09:31:22 am
content: Quote from: dobsonr741 on July 26, 2023, 01:04:42 pmWow! Thanks! this document makes things quite clear.Quote from: ledtester on July 26, 2023, 03:30:20 pmYes, I missed this part.Then... can somebody explain what means the sentence 'outputs should not be pulled above VCC' stated in the datasheet?Thanks!

author: tooki
author_rank: Super Contributor
timestamp: July 27, 2023, 09:34:02 am
content: Also take a look at the ’LVC4245 mentioned in the datasheet, which has two separate voltage domains.
Can i extend range in radio device ? - Page 1
Forum section: electronics / beginners

author: rozer
author_rank: Newbie
timestamp: November 28, 2019, 11:21:49 pm
content: Hello everyoneI have RFremotech RF-32C - it is 32 channel wireless detonator.In set with device i received basic remote with almost 100m range :https://ibb.co/HVckvJqIn 2010 as option was available 200m range remote (with telescope antenna, on below image you can see new version with FSK modulation, old is unavaiable) :https://ibb.co/wpC3pW2Operating frequency : 433.92 mhzModulation : Probably ASK (OOK) (new versions runs on FSK).Inside device :https://ibb.co/z8kQH1hReciever board :https://ibb.co/KFY1zXkRecieve board is probably this (CWC-10) -https://www.alibaba.com/product-detail/CWC10-315MHz-or-433-92MHz-4_1103295522.htmlAntenna slot at panel :https://ibb.co/26zpg70Is there any simple and not expensive way to extend range ?I haven't knowledge about radiotechnics.I have idea to install external antenna sma in remote (there is solder pin ANT and 2nd wire to battery GND) :http://www.programatory.com/produkty/anteny/Antena-WIFI-433MHz-3dbi-SMA-86mm.jpgWill it improve the range or only distort signal and give the opposite effect ?Other idea is to improve reciever plate (to buy stronger one).I hope you will help me solve this problem.Greets
Can I find product information on the back/behind of an SMD part? - Page 1
Forum section: electronics / beginners

author: zdelarosa00
author_rank: Regular Contributor
timestamp: February 25, 2019, 09:50:51 am
content: Normally they have the code on the top, obviously, but I've seen to find really no information on this fluke laser distance meter, every and each part has an unknwon code on every manual and site, so this house-numbered custom parts are black boxes, but there is a particular one that reads GHH and I'm interested in it since it is in the laser output stage.No need for explaining what am I doing, but I really would like to know how can I know more about this part.I don't know the brand logo on it as I didn't find it in the manufacturer logo tables. So my next bet is removing it and see if it has something on the back, I know it looks like a transistor, but the combinations of GH- Ghh and so on and so fort don't correspond to the pinout this one has with his ground connection.

author: mikerj
author_rank: Super Contributor
timestamp: February 25, 2019, 10:00:19 am
content: It's an LDO manufactured by BCD Semiconductor.Datasheet.You will not normally find any identifiers on the reverse side of an SMD IC.

author: zdelarosa00
author_rank: Regular Contributor
timestamp: February 25, 2019, 10:04:12 am
content: Jesus how did you find that?. I mean, I really did search on a lot of places.Btw I really thought looking for an SMD code on the back was a far cry.

author: mikerj
author_rank: Super Contributor
timestamp: February 25, 2019, 10:19:33 am
content: Quote from: zdelarosa00 on February 25, 2019, 10:04:12 amGoogle "SMD code GHH" and follow the first link which lists a bunch of devices, but only one is a SOT-23-5. The pinout matches up to your circuit, as does the logo on the device so pretty sure that's the part you have.
Can i Hakko FX100 + MX-H1-AV - Page 1
Forum section: electronics / beginners

author: Free_WiFi
author_rank: Regular Contributor
timestamp: June 15, 2017, 10:37:15 pm
content: Im looking at Hakko FX 100 soldering station.I want to buy it for my self ,but before i wants to know if i can use the metcal MX-H1-AV handpiece instead of the original one of hakko.Another question is regarding the stand for auto sleep function,can i also use the metcal stand ?The original hakko's stand would not be compatible with metcal tips ,as the metcal tips demands for an different spot of the magnet which makes the tips to go in to sleep mode .

author: MosherIV
author_rank: Super Contributor
timestamp: June 16, 2017, 07:01:02 am
content: I doubt it. The Hakko has some kind of temp senor by the looks of it but Metcal relies on thermal magnetic properties only to control the temp.The connectors will be different for a start.Usually, it will be more expensive to buy them seperately so why would you try?Not sure why but Hakko seems to be popular in the hobby market. Companies tend to use Pace, OKI/Metcal, JBC or Weller. I have yet to see a Hakko in a company here in UK.Hakko and Metcal stuff are not compatible, so you cannot use the hakko stand for the metcal handle.FYI Thermatronics and Mtecal/OKI are compatible because some of the Metcal engineers went off and started their own company called Thermatronics. Do not ask me how they got round the patents.

author: GreyWoolfe
author_rank: Unknown
timestamp: June 16, 2017, 11:37:31 am
content: "Not sure why but Hakko seems to be popular in the hobby market."At least. here in the USA, Hakko is inexpensive. You can catch a FX-888D on sale for as little as $68 USD and they work. They are a bit toy like in appearance, but are built well and the tips last. I had a 936 for 7 years before I got my FX-951 and Metcal MX-500. I use them both and enjoy them both. It's a shame that anything Hakko is so expensive on the other side of the pond. Hakko could make inroads to the JBC market if they were priced competitively.

author: helius
author_rank: Super Contributor
timestamp: June 16, 2017, 06:24:12 pm
content: Yes. They use the same F connector and work the same way.Quote from: HakkoThe cartridge barrels are shaped differently and will not fit the other manufacturers' handpiece: seehttps://www.eevblog.com/forum/reviews/suggestions-hakko-fx-100-vs-metcal-mx500-or-mx5200for discussion.As far as the auto-sleep stands, my guess is that the FX-100 relies on the station's microcontroller to detect the hysteresis B/H loop of the tip becoming altered by the magnet and reducing power. The old Metcal MX-500 is completely analog and the magnet reduces power output by changing the impedance of the tip and the VSWR. So they both use magnetism but you'd have to test if the combination auto-sleeps as desired.
Can I have some examples for Humidity/temperature sensor - Page 1
Forum section: electronics / beginners

author: abhipoints
author_rank: Newbie
timestamp: October 26, 2016, 11:28:19 am
content: I need some examples ofHumidity Sensoravailable in the market. Can anyone help me out? I am writing an article on it and I needed it badly.

author: Aeternam
author_rank: Unknown
timestamp: October 26, 2016, 12:51:35 pm
content: I have recently built a project using one of thesehttp://sensing.honeywell.com/index.php?ci_id=142285Works reasonably well, chose it primarily because of the I2C bus.

author: JacquesBBB
author_rank: Frequent Contributor
timestamp: October 26, 2016, 02:33:04 pm
content: Let me quote a recent postQuote from: JacquesBBB on October 17, 2016, 09:35:23 am

author: ebclr
author_rank: Super Contributor
timestamp: October 26, 2016, 03:18:38 pm
content: Humidity is one the most hard thing to measure accurate.Basically have 4 kinds of sensorResistive ( a real piece of sh.... ) Minimum 5% typycal 20%Capacitive, widely used limited acuracy 2% good and expensive brands 20% cheaper chinese onesChilled Mirror expensive and good,Psychometric chart processing, Dry wet buld temperature sensor most reliable one at medium price

author: grifftech
author_rank: Frequent Contributor
timestamp: October 28, 2016, 03:11:45 pm
content: eBay auction: #Durable Analog Hygrometer Humidity Meter Power-Free Indoor Outdoor High QualityW
Can I load Windows 7 onto the DSO80604B ? - Page 1
Forum section: electronics / beginners

author: jpg8989
author_rank: Newbie
timestamp: August 08, 2017, 12:12:32 pm
content: Hey gang,Kind of a strange for you all but I am hoping someone can help.Is it possible to take Windows 7 disk and load it onto the DSO80604B ?I have never updated the OS before, only firmware updates.Any help is apprecited!

author: Gyro
author_rank: Super Contributor
timestamp: August 08, 2017, 06:05:22 pm
content: Double post.https://www.eevblog.com/forum/projects/updating-a-keysight-dso80604b-from-windows-xp-to-windows-10/
Can I place Agilent E3644A power supply on its rear? - Page 1
Forum section: electronics / beginners

author: Matthematik
author_rank: Contributor
timestamp: October 11, 2016, 02:01:55 am
content: I just got a gorgeous 3644A power supply and I'm really excited but it has a much bigger footprint than I expected, and I don't really have room for it on my bench at the moment. Was thinking about turning it and setting it on its rear since it has those feet which seem to be for that purpose. There are issues though. the ground clearance is only about 3/4'' and it has a fan with rear exhaust so I am concerned that this will hinder airflow and cause overheating. So I guess the real question is, did Agilent intend for the unit to be used this way? I've tried googling it and looking through the manual which just says not to block ventilation. Technically this is not blocking ventilation. One clue suggesting that the manufacturer did not intend this is that the power cord actually prevents me setting the unit in this way because it protrudes too far out of the unit's arse. BUT, I got this supply off of ebay so I am unsure if the cord is OEM and I think if I got a cord with a 90 degree connector I could set the supply on its rear. Does anyone have any experience placing a power supply from this family in such a way?

author: bitseeker
author_rank: Super Contributor
timestamp: October 11, 2016, 02:37:24 am
content: I believe those rear feet are primarily to protect the connectors on the back panel. They do, of course, ensure that the back of the unit doesn't press directly against a wall, but it is a rather narrow gap. As long as you're not driving it at minimum voltage and maximum current continuously, it'd probably be OK.Can you fit it on your bench if it's sitting on its side? Although there are vents on the sides, at least they exist on both sides, so you'd probably end up with better airflow that way than standing on its rear.If you have a digital thermometer or a DMM with a thermocouple, you could compare different setups with different loads.

author: Matthematik
author_rank: Contributor
timestamp: October 11, 2016, 02:45:28 am
content: I could probably set it that way, I'll consider it. Great idea about testing the temps with different setups. I've been looking for an excuse to use the thermocouple, thanks!

author: bitseeker
author_rank: Super Contributor
timestamp: October 11, 2016, 11:07:41 pm
content: Sure thing. I look forward to hearing about your findings.
Can I please ask advice on my scoreboard circuit? - Page 1
Forum section: electronics / beginners

author: BlueSmokedAgain
author_rank: Contributor
timestamp: August 23, 2025, 10:22:58 pm
content: Hi everyone,Thank you for a great forum and all the information!I am an inexperienced hobbyist looking to help a local club revive an LED scoreboard. The original circuit doesn't integrate with the software giving the data to the scoreboard do we have decided make a new circuit. It'll be a raspberry pi pico given data via USB to display on a large 10 digit 7 segment display. Each segment is 10 discrete LED's. Would also like to be able to control each segment individually to allow some other non standard animations.Please find attached my schematic. My basic idea is a Raspberry Pi Pico driving 2 digits via mosfet for each individual segment. Then daisy chain via serial 5 picos driving 2 digits each. Once master Pico and then 4 slaves. To save cost of have 2 separate boards spun up I am trying to make it so in the field a module can be selected as a master or slave via some male header jumpers. Wiring to the digits themselves will be via connectors too. LED voltage is 9v. It'll be 80cm ish between modules. The bit I'm mainly looking for a sense check on is the mosfet control layout, there seems to be loads of ways of doing it online! I also added a selectable RC filter incase I experience interference on the serial. It'll be somewhere with lots of radios.Any comments or suggestions greatly appreciated!Thank youTom

author: themadhippy
author_rank: Super Contributor
timestamp: August 23, 2025, 11:26:14 pm
content: Id come at it from a different angle with something like 5 x MCP23017 to get 80 outputs out the 1 pico

author: PGPG
author_rank: Frequent Contributor
timestamp: August 23, 2025, 11:48:27 pm
content: First look at your schematic suggests that transistors switch current from GND somewhere down (toward negative voltage).

author: BlueSmokedAgain
author_rank: Contributor
timestamp: August 24, 2025, 11:49:05 am
content: This is a good suggestion, I need PWM dimming, but taking this idea, I could possibly use a PCA9685 and do a similar thing… thank you

author: BlueSmokedAgain
author_rank: Contributor
timestamp: August 24, 2025, 11:52:18 am
content: Ah ok, so I need to switch around GND and the link to the cathodes, as I want to switch to ground. I think I’ll use this same mosfet idea but drive from a PCA9685 as suggested above, thank you both!

author: xvr
author_rank: Frequent Contributor
timestamp: August 24, 2025, 03:31:08 pm
content: Use TPIC6A595 - 8 350mA outputs. Can be daisy chained to any required length.Required 1 SPI from Pi pico

author: BlueSmokedAgain
author_rank: Contributor
timestamp: August 24, 2025, 07:40:44 pm
content: I'll see if that also would be an option!
Can I program a W27C512 with a pickit2? - Page 1
Forum section: electronics / beginners

author: prefim
author_rank: Newbie
timestamp: August 31, 2022, 10:27:47 am
content: Hi Guys,Beginner here. did electronics as a kid but only really dip in when I need to now with retro computer mods and repairs.I need to program an EEprom W27C512 and found I had a really old PICKIT2 (minikit 2 programmer / debugger and a Sure elecronics ZIF module with an ICSP port and cable to link to the minikit2.Is it possible at all? On the zif module theres a silkscreen saying 'Close JP1-6 for pic programming, remove for other programming' so it suggests the kit is multipurpose.Next, what programming software could I use? something free and simple as this is for one chip!Many thanks,

author: Gyro
author_rank: Super Contributor
timestamp: August 31, 2022, 10:42:11 am
content: Welcome to the forum.Unfortunately not. The Pickit supports ICSP, this is a 5 wire interface (including ground) which is used to program microcontrollers with a serial data protocol. The W27C512 is a parallel interface device, which requires the full width of 8 bit data and all address pins controlled in order to program. The Sure ICSP socket board that you have there simply connects the ICSP signals to the relevant pins on different sized PIC microcontrollers.You might try buying a TL866 programmer, but there are several variants of this and, not owning one, I don't know whether the W27C512 is supported and on which variants.

author: prefim
author_rank: Newbie
timestamp: August 31, 2022, 11:09:35 am
content: Thanks for confirming.Had a look on RS components and they want £200 for a TL866!! started looking on ebay and found I can get one in the UK for £56 so thats much better. Might even be able to borrow one from a friend so even better still.

author: rooppoorali
author_rank: Regular Contributor
timestamp: September 02, 2022, 01:58:28 pm
content: No. PIckit2 is for PIC microcontrollers. For W27C512 you can make an Arduino EEPROM programmer by using this library:https://github.com/StormTrooper/eeprom_programmer

author: MikeK
author_rank: Super Contributor
timestamp: September 02, 2022, 06:12:45 pm
content: Quote from: rooppoorali on September 02, 2022, 01:58:28 pmThe PICKit2 was designed to program some EEPROMS too...not just PIC micros.

author: Ian.M
author_rank: Super Contributor
timestamp: September 02, 2022, 06:15:53 pm
content: Yes, but only serial EEPROMS. It can also be used with AVRDUDE for many Atmel MCUs
Can i put a voltage into a gm amplifier output? - Page 1
Forum section: electronics / beginners

author: Faringdon
author_rank: Super Contributor
timestamp: June 06, 2022, 02:00:08 pm
content: Hi,Is it ok to connect the output of an opamp buffer (with 3v on its noninv pin) straight onto the output of the transconductance amplifier of the UCC28070A PFC controller?UCC28070Ahttps://www.ti.com/lit/ds/symlink/ucc28070a.pdf?ts=1654454066831&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FUCC28070ADatasheet says ABS max is 7V, but maybe that means with a certin impedance into the amp output?

author: Zero999
author_rank: Super Contributor
timestamp: June 06, 2022, 02:19:58 pm
content: Generally two outputs shouldn't be connected together.What are you trying to do?Post a schematic.

author: Faringdon
author_rank: Super Contributor
timestamp: June 06, 2022, 02:51:19 pm
content: Thanks,I am using UCC28070A as a Boost PFC controller ...it also gives the fet gate drive signals.........so, before i let the Boost loose on the load, i wish to see the gate drive waveforms, so we can check the fets arent being permanently held on whatever..........so i have a series gate resistor we can unsolder for that......trouble is, when that is done...the Boost would go into shutdown, and not give the gate signals that we want to inspect......so we want to put 3v direct into VAO pin so the boost controller still sends gate drive signals even though the fet gates arent actually attached....

author: dmills
author_rank: Super Contributor
timestamp: June 06, 2022, 03:40:49 pm
content: gm implies a transconductance (current) output so you should be able to have it drive current into or out of a resistor to some voltage, there will be a limited compliance voltage range of course.Look at the sorts of voltages you get across the compensation cap, that will probably tell you what the transconductance amp is expecting to drive in terms of compliance voltage.

author: TimFox
author_rank: Super Contributor
timestamp: June 06, 2022, 03:54:02 pm
content: Two general statements:--One can drive a high/medium input impedance voltage-gain input from a low/medium source impedance voltage output, or a low/medium input impedance current-gain or transimpedance amplifier input from a high/medium source impedance current output.--Current outputs may be connected in parallel, but voltage outputs should be connected in series if direct connection is to be made.

author: Faringdon
author_rank: Super Contributor
timestamp: June 06, 2022, 05:19:35 pm
content: QuoteThanks, yes, VAO (transconductance amp output) has a value range of 0-5V in operation.So may we say that putting an opamp buffer output, set for 3v, into it at least wont harm the gm amp?
Can I replace big trafo with small SMPS? - Page 1
Forum section: electronics / beginners

author: FriedMule
author_rank: Frequent Contributor
timestamp: April 14, 2022, 03:19:17 pm
content: I have the possibility to get an old class A amplifier and I like it, but it'll suck power out of my sockets as if it had been in a dessert for months.My idea is to remove the trafo only but keep everything else, and then "just" connect a SMPS's output leads to where the old trafo's leads did connect.Is there anything wrong in doing that?Should that not save a lot of external power usage?

author: TimNJ
author_rank: Super Contributor
timestamp: April 14, 2022, 04:16:18 pm
content: I mean, Class A is inherently inefficient as is. Always <50%, probably in the area of 25-35% for most designs. If you are worried about efficiency, look at Class D.

author: Kleinstein
author_rank: Super Contributor
timestamp: April 14, 2022, 04:32:01 pm
content: At higher power level a SMPS is not more efficient than a transformer. There is some advantage with regulating the voltage, but the difference is not very large.At low power (like < 5 W) a SMPS can be more efficient, but at higher power the difference is not large anymore. It is there more a cost advantage.The problem is the class A amplifier. The allways <50% and normally worse is hiding the real evil: the problem is that a class A amplifier has a high power consumption even when low output power is needed and for audio this is the normal case nearly all the time. The point to compare is more the idle power, not the best case efficiency.For a comparable power level a class A amplifier may draw 100 W , a class AB more like 10 W and a class D maybe 5 W.

author: CaptDon
author_rank: Super Contributor
timestamp: April 14, 2022, 09:20:25 pm
content: The transformer itself is not inefficient and probably has filament windings, high voltage windings, mid voltage windings and possibly even a bias voltage winding. SMPS, not worth the effort by a long shot!!!

author: strawberry
author_rank: Super Contributor
timestamp: April 14, 2022, 09:52:37 pm
content: SMPS may not help if circuit is sensitive to noiseclass D one and only benefit is efficiency 85..95% and price. min THD 0.1% , bandwidth limited to 20kHz,

author: james_s
author_rank: Super Contributor
timestamp: April 14, 2022, 10:17:24 pm
content: You are misunderstanding the reason a class A amplifier is inefficient, the culprit is not the power transformer but the inherent characteristics of the amplifier topology itself. If you want to save power, turn it off whenever you're not using it.
can i replace CEP3205 with IRF3205  - Page 1
Forum section: electronics / beginners

author: tonny_cassidy25@yahoo.com
author_rank: Newbie
timestamp: June 10, 2015, 06:02:07 pm
content: when i experimenting with my inverter and accidentally blow all the mosfet in there ,its the N-CHANNEL CEP3205 from CET semiconfuctors,but i can't find the exact same mosfet at local store,and i don't want to buy it online because it tooks so long for the product to arrive,and i found another 3205 mosfet from international rectifier its a IRF3205 ,since theyre from the different company the datasheet looks very different,from the datasheet i find that the VDSS are the same on both which is 55V ,while the RDS(ON) and the ID is a little bit different irf3205 have 8.0 mOhm RDS(ON) AND 110A ID while CEP3205 have 8.5 mOhm RDS(ON) and 108.5A ID ,and a lot of difference on the VGS ,so can i just use the irf or i need the exact same as the original ?

author: PSR B1257
author_rank: Frequent Contributor
timestamp: June 10, 2015, 06:14:39 pm
content: They are basicly the same, therefore no problem to choose the IRF3205.As far as MOSFETs for switching application goes, you can choose more than only one type of MOSFET. If the designer was a tight-arse he had most liekley choose the MOSFET which barley meets it's requirements. To replace this one with a better MOSFET is no problem, far from it!
Can I replace the LCD on my UMPC? - Page 1
Forum section: electronics / beginners

author: sam1275
author_rank: Frequent Contributor
timestamp: October 14, 2016, 08:13:42 pm
content: Hi everyone. I have a Panasonic CF-U1A, the only bad thing for it is the LCD, which have incredible low view angle, I cannot find a replacement solution online, can anyone help me? Thanks!

author: senso
author_rank: Frequent Contributor
timestamp: October 14, 2016, 11:23:05 pm
content: Maybe, but I cant find the part number of the lcd used in it, could you remove the lcd a take a photo of the sticker that is in the back?It might be a custom-ish panel with a custom connector..

author: sam1275
author_rank: Frequent Contributor
timestamp: December 04, 2016, 04:54:42 pm
content: Quote from: senso on October 14, 2016, 11:23:05 pmThank you.Just found Dave made a tear down here:https://www.eevblog.com/forum/blog/eevblog-925-panasonic-cf-u1-toughbook-teardown/Please look at 17:50-18:04 for the LCD part, my model is a bit older than his, but maybe this will still help.

author: Buriedcode
author_rank: Super Contributor
timestamp: December 04, 2016, 11:03:41 pm
content: If the colours change at wider angle, then of course the viewing angle is down to the LCD itself, if it just appears very dim, then the narrow viewing angle is intentional for power saving, and possibly security.Often displays for laptops/tablets use prismatic films that focus the backlight to a narrower angle. This means you can use less power for the backlight to achieve the same brightness when viewing it directly in front. They use really narrow prismatic films for things like ATM's, where security is an obvious concern and you don't want people looking over your shoulder, for the most part though its far reducing the backlights power consumption.So again, as its very likely to be a TFT which already have quite good viewing angles, rather than replace the display, you may wish to prize it apart and remove a couple of films - there will be several: polarized diffuser, prismatic films horizontal/vertical, and possibly another diffuser on top of that. Its an arse to do as there will likely be lots of tape around it, but at least its a reversible mod.

author: sam1275
author_rank: Frequent Contributor
timestamp: December 05, 2016, 12:41:20 am
content: Quote from: Buriedcode on December 04, 2016, 11:03:41 pmThank you, in my casethe colours change at wider angle, and when I saidverynarrow I meant it, it's narrower than my 12 years old 17" desktop monitor. One will never know what I feel when reading a LCD like that, combining with a high DPI and not-good contrast ratioIt really hurts my eyes, now I trained myself to hold it at a preciously angle, and adjust at a precious brightness, and it feels better... I tried to set the display at black and white, but found the graphic driver do not support that mode, I think my AT&T graphic card(yes AT&T brand) can do that in Windows 98. I think your mod is interesting, but will it work in my case? It's notappears very dim. I think maybe not, because if it's that easy, the more expensive things like IPS will not as shine as today
can i run a 13.8v cb/ham Transceiver on 12v - Page 1
Forum section: electronics / beginners

author: rickselectricalprojects
author_rank: Regular Contributor
timestamp: April 18, 2015, 02:31:26 am
content: hi everyone!i was wondering if you could run a 13.8v ham/cb transceiver on 12v. i know it would still work but i was wondering if it would draw to much current on 12v and damage the transceiver and if it would affect performance. sorry if this question sounded stupid but i am only just getting into ham/cb radio.thanks everyone!

author: Vgkid
author_rank: Super Contributor
timestamp: April 18, 2015, 02:43:38 am
content: make and model, what does the manual say.(should be ok I guess). after all 13.8 is the alternator charging voltage of a 12v battery.

author: rickselectricalprojects
author_rank: Regular Contributor
timestamp: April 18, 2015, 02:54:38 am
content: Quote from: Vgkid on April 18, 2015, 02:43:38 am+- (plus or minus) 15% but i was wondering if it will decrease performancethanks

author: Psi
author_rank: Super Contributor
timestamp: April 18, 2015, 02:55:17 am
content: na, will be fine.It will have been designed for 13.8V because that's the float charge voltage of a 12V lead acid batteryTherefor we can assume it will be fine with a flat 12v lead acid. ~10.5 - 13.8V will be the intended voltage range.In general a lower voltage doesn't damage things.An exception is badly built switchmode power supplies that don't auto cut-off at low V and instead try to run with way to much current flowing through the components

author: miguelvp
author_rank: Super Contributor
timestamp: April 18, 2015, 03:06:48 am
content: Think about it this way, you don't have to have the car running to use the cb radio.
Can I safely power TWO 12v devices from ONE power adapter? - Page 1
Forum section: electronics / beginners

author: Tenhorse
author_rank: Newbie
timestamp: March 06, 2024, 08:22:45 pm
content: Hi folks. I need to provide power to TWO Lutron powered window shades from ONE 12v power adapter. The adapter provided by Lutron is meant to provide power to one shade only. It is a 12v 700 ma adapter.Can I safely replace the 700 ma adapter with a 1.5 amp adapter, splice on a second 12v barrel plug termination, and plug both shades into this one 12v adapter?Thanks!

author: Majorassburn
author_rank: Regular Contributor
timestamp: March 06, 2024, 08:39:54 pm
content: Yes. Be sure to observe polarity of the conductors. Also, I'd use a 12V 2A adapter - very commonly available.

author: radiolistener
author_rank: Super Contributor
timestamp: March 06, 2024, 09:04:22 pm
content: Yes, you can but it's better to select 2A power supply so it will have some reserve margin.

author: Tenhorse
author_rank: Newbie
timestamp: March 06, 2024, 09:07:54 pm
content: Thanks much, fellas. I appreciate you taking the time to answer something so basic.I’ll go fetch a 2 amp converter —

author: CaptDon
author_rank: Super Contributor
timestamp: March 06, 2024, 09:09:10 pm
content: I am guessing the only time the shade draws current is when you run the motor up or down. You could use the adapter you have and split it out but you can only operate one shade at a time. That doesn't seem like a problem.
Can I damage my PSU by PWM LED dimmer? - Page 1
Forum section: electronics / beginners

author: yin
author_rank: Newbie
timestamp: August 20, 2015, 11:13:21 pm
content: Hello,I have a cheapo 12V 100W power supply from eBay and another cheapo LED dimmer. It dims my 6W bench LED strip and uses PWM to do so. When powering anything, which switches rapidly, the powersupply makes these squiky sounds, like old transformers do.Are there any power supplies out there, which can be damaged by a rapid switching action? How can I decide, if the sound is not an indication of potential problems?

author: rickselectricalprojects
author_rank: Regular Contributor
timestamp: August 21, 2015, 04:06:21 am
content: Quote from: yin on August 20, 2015, 11:13:21 pmno there should be no problem with power a pwm dimmer, those power supply's are designed to do that. the squeaky sound is probably (don't quote me on this) the power supply drawing current. i have the same power supply and it powers my UHF CB radio (my radio draws 1.5A) but it doesn't make that sound when i transmit. maybe a problem with the power supply.i hope this helps

author: yin
author_rank: Newbie
timestamp: August 21, 2015, 09:51:22 pm
content: Thanks rickselectricalprojects, I find it helpful. The problem is, the sound is not user friendly, which is a requirement with my project (I'm rebuilding my bench).If there's a way to make the circuit more quite, I'd try it out. Maybe it is possible to filter out the resonance with some caps and such. I'll update the thread if I find a way to do it.
Can I substitute an induction motor for a compressor for testing - Page 1
Forum section: electronics / beginners

author: Eamon
author_rank: Contributor
timestamp: October 08, 2022, 04:11:55 am
content: I'm trying to debug an inverter fault on a heat pump and to make it easier I want to substitute the compressor that is normally connected to the inverter module for a spare motor I have so that I can set the inverter module up inside on a bench (it reports a fault if nothing is connected to it's outputs).The compressor is a Mitsubishi TNB220FLHMC; 3 phase, 38-200v, 20-220Hz and I've measured the winding resistances, it is ~1.1 ohm between each.The candidate motor is a 3HP, 415v, 50Hz induction motor from an wood lathe. It measures ~5.5ohms between each winding.Will it work or am I likely to damage either the inverter or motor? I don't expect to run the motor for more than about 30 seconds at a time.Alternatively is there something else that I could use in place of the compressor?

author: Chriss
author_rank: Frequent Contributor
timestamp: October 08, 2022, 07:50:34 am
content: Probably you won't kill anything, but you could get an error also, cos the resistance of the spare motor.But maybe you won't gett the error, it's depends how the error handling is made up in the compressor.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: October 08, 2022, 07:50:15 pm
content: Motors designed for higher frequencies (and RPM) have lower self inductance.If you connect your 200V 220Hz motor to 200V 50Hz, it's likely to get damaged because of overcurrent.One of the (most important) parameters to set up an inverter is the voltage to frequency ratio, and this is motor dependent.But of course you can use the inverter itself as a fancy motor overload preventor. You can limit the max motor current (Which is what ultimatily determines (ohmic) heating) You can also limit your testing to lower voltages and frequencies. And use some common sense. Induction motors are quite robust, and the main failure mode is overheating, so keep an eye on the motor temperature. As long as you can touch it it's cool enough. Also note that at lower RPM's the fan on the motor axle it'self does not work very well, and this can also be a cause of overheating.

author: Eamon
author_rank: Contributor
timestamp: October 08, 2022, 10:33:04 pm
content: Well I tried and while nothing blew up, the motor barely turns at a very slow speed with a bit of a high pitch for a second or two before the inverter faults out with a "PFC fault". Time to find a plan B.
Can I supply PWM module with stabilized lab power supply ? - Page 1
Forum section: electronics / beginners

author: boo9
author_rank: Contributor
timestamp: February 26, 2015, 02:51:57 pm
content: Can there be a strange interaction between PWM module and lab power supply unit due to fast (22Khz) load changing ?I purchased PWM module to drive a motor. The spec for the module stated input 10-40V up to 24A, switching frequencey control in range of 700Hz-22kHz . THe states 1W @ 10A and 6W@24A generated on MOSFET.During my test with resistive load the MOSFET burned at around 10A. My test bed was as follows- radiator 50x50x15mm screwed to MOSFET on silicone paste.- the input connected to the lab power supply set at 24V (monitored with DM (V)),- the output I connected a load of three 24V/75W bulbs, I started with one bulb and added (parallel) one at a time.- I monited the current on the output using analog A-meter (A)- PWM frequency at 22Khz.During the test I was changing DC using a potentiometer attached to the cirucuit.- 5A - ok- when I added tree bulbs around 10A the radiator became warm and the cirucuit stop responding to pot settings, outputing full voltage at the output.I checked the MOSFET and all pins are shorted.Major IC has erased markings, However the IC pins in the circuit appear to be matching SG2524/SG3524 IC. Mosfet gate driven by push-pull driver SMD FZOE SOT-23 which I figure matches mcp1415 IC.Is it possible that fast load switching (22Khz) would 'confuse' the lab PS would supply to output V that would destroy the mosfet ?Something along the lines - PS voltage changes was off of phase of changing load phase.

author: HalfSpace
author_rank: Regular Contributor
timestamp: February 26, 2015, 08:59:57 pm
content: Hi Boo9,Using bulbs is a cheap way to make a dummy load, but they have a high surge current at turned on.Your 24V/75W bulb should have a resistance of 7.68 ohms when its filament is hot, but when it is cold it could be as low as 0.7 ohms. So when you connect your bulb to your circuit it could draw ten times the current at switch on and this may have over loaded your MOSFET.HalfSpace