hybridfree/eevblog-posts huggingface dataset:
Multiple receivers on a differential line - Page 1
Forum section: electronics / beginners

author: FrankT
author_rank: Regular Contributor
timestamp: July 24, 2019, 06:14:14 am
content: I'm wiring up a quadrature rotary encoder with differential outputs to the spindle of my mill drill.I'm running a 1 meter shielded twisted pair from the encoder to my speed controller. The encoder outputs using a uA9638C differential line driver, and the speed controller receives using a uA9637C differential line receiver, with a 100 ohm termination resistor.What I need to do now is add an additional connection to my rotary table controller, so I can synchronise the motion between the rotary table and spindle. This cable will only be connected when the rotary table is used.What do I need to do with the termination resistor? The datasheet seems to imply I should only have one termination resistor in the circuit. Is it ok to just have it in the first receiver and not on the 2nd one 2 meters away?

author: Ian.M
author_rank: Super Contributor
timestamp: July 24, 2019, 06:27:58 am
content: Depending on the speed of the signals and the rate the speed controller samples them, you may get away with an unterminated 2m stub contributing reflections, however if you want to be certain, put a termination resistor in the rotary table and also in a dummy plug so you can properly terminate it when the rotary table isn't in use. or make the termination resistor in any device with a daisychain connector switchable.

author: FrankT
author_rank: Regular Contributor
timestamp: July 24, 2019, 08:13:28 am
content: Thanks. The dummy plug is a great idea. I just finished 3d printing a cap to cover the socket, so a dummy plug will be even better.
Multiple regulators in the same circuit - Page 1
Forum section: electronics / beginners

author: permal
author_rank: Regular Contributor
timestamp: September 17, 2017, 01:41:33 pm
content: Hi,I don't have a practical use case for this, but I'm curious - is it possible to have multiple regulators, such as two LM1085IS-3.3, in the same circuit to power different parts of the circuit or would they somehow interfere with eachother? If it is possible, what is needed to make it work?

author: IanMacdonald
author_rank: Frequent Contributor
timestamp: September 17, 2017, 01:57:12 pm
content: Yes, this is quite standard practice for low currents.Less practical for higher currents though, since the unnecessarily high input voltage on the lower voltage regulators will mean a lot of waste heat.

author: Benta
author_rank: Super Contributor
timestamp: September 17, 2017, 02:03:11 pm
content: This is normal practice. It's called "point of load" or POL regulators.

author: Zero999
author_rank: Super Contributor
timestamp: September 17, 2017, 02:04:23 pm
content: As mentioned above, that's common practise. The only thing to be wary of, is connecting the regulator outputs together can cause problems with stability, such as oscillation. Of course the 0V connections needs to be connected together, as with any non-isolated circuits, which need to interface with one another.

author: permal
author_rank: Regular Contributor
timestamp: September 17, 2017, 02:48:37 pm
content: Love the quick responsesSo a circuit like in this image would be OK, as long as the two rails are not directly connected?

author: KuroZ
author_rank: Contributor
timestamp: September 17, 2017, 02:54:22 pm
content: Quote from: permal on September 17, 2017, 02:48:37 pmYes, there should be no problem with this. Just avoid powering the same device from more than one rail.

author: permal
author_rank: Regular Contributor
timestamp: September 17, 2017, 02:55:43 pm
content: Thanks to you all

author: Zero999
author_rank: Super Contributor
timestamp: September 17, 2017, 04:47:33 pm
content: Quote from: KuroZ on September 17, 2017, 02:54:22 pmYes, the two 3.3V rails should be treated as different power supplies. If an IC has more than one VDD pin, they should all be connected to the same 3.3V rail. It doesn't matter which one, as long as the VDD pins on each device, all go to the same regulator.

author: Ice-Tea
author_rank: Super Contributor
timestamp: September 18, 2017, 10:09:58 am
content: Quote from: permal on September 17, 2017, 02:48:37 pmYou may want to add some capacitors on the 12V line, though. Preferably local to each LDO
Multiple relays and their flyback diodes - Page 1
Forum section: electronics / beginners

author: jsi
author_rank: Regular Contributor
timestamp: October 11, 2016, 03:27:39 pm
content: I am working on a design that uses 3 separate isolation relays wired in parallel. Right now each relay has its own flyback diode placed as close as possible to the relay coils. According to my oscilloscope they are doing their job and there are no extreme voltage fluctuations when the relays switch off.My question is do I need 3 diodes or is 1 sufficient. (assuming of course that the one diode is of sufficient capacity to handle the load.)ps - the basis of this question is my belief in the KISS principle, or put another more eloquent way "Everything should be made as simple as possible, but not simpler."

author: oldway
author_rank: Super Contributor
timestamp: October 11, 2016, 03:41:08 pm
content: I think that are freewheeling diodes and not flyback diodes.For max eficiency, you must choose fast recovery diodes of the same or greater current than the coil current of the relay and place them as near as possible from the coils.If the relays are not far from the others, you can use only one fast diode of current = or higher than 3x the coil current of each relay.

author: Richard Head
author_rank: Frequent Contributor
timestamp: October 11, 2016, 05:34:43 pm
content: A normal single diode is fine. It doesn't have to be fast recovery in this application. Just ensure that the freewheel diode is placed directly across the wires feeding the relay coil.

author: SeanB
author_rank: Super Contributor
timestamp: October 11, 2016, 06:00:38 pm
content: If you do not want to use a diode, and your driver transistor can withstand it, you can use a MOV across either the transistor or the relay coil. Rating for the MOV is selected by using a MOV with a DC voltage withstand rating that is just a little above your supply voltage, and with a max clamping voltage that is below the transistor voltage rating ( or the suplupply plus the max rating if across the relay coil), which has the advantage of being faster in turn off, as the coil can generate a higher back EMF and dissipate the stored energy faster.
Multiple sequential inputs into ADC - Page 1
Forum section: electronics / beginners

author: OrangeBrick
author_rank: Newbie
timestamp: January 22, 2022, 10:25:50 pm
content: Hi all,Making a transmitter for R/C project, which will have 2x joysticks.However in using the Pi Pico, this has only 3 accessable ADC inputs.Therefore I'd like to measure 2x joysticks (each with 2x potentiometers for X/Y axis) and if possible the battery voltage + another potentiometer.Summing this up:ADC1 -> Joy-1_XJoy-2_XADC2 -> Joy-1_YJoy-2_YADC3 -> Voltage from potential dividerExtra potentiometer1) Is it possible to use MOSFETs to modulate the input voltage supplied to the potentiometers on these joysticks, such that you'd measure one (powering it, and not the other), then the other. Measuring each Joystick in sequence, Joy1-X on ADC1 and Joy1-Y on ADC2, then Joy2-X on ADC1 and Joy2-Y on ADC2.2) It follows if above is true that ADC3 should be able to sense voltage and a extra potentiometer, again in sequence.Right now I'm looking at BSS138 for transistors, operating at 3.3v (or 0v) gate voltage supplied from Pico GPIO, to power on/off potentiometers or allow current from potential divider circuit to flow. From my basic understanding these should be sufficent even at the relatively low gate voltages (3.3v).I hope this made some sense, and apologies if not, I'm happy to explain more (or try to) if needed! Many thanks.

author: Kim Christensen
author_rank: Super Contributor
timestamp: January 22, 2022, 11:55:46 pm
content: Typically you would use an analogue multiplexer like the cd74hc4067, 74HC4051, LTC1391, etc. Depends on the voltage range of the signals you want to switch.

author: OrangeBrick
author_rank: Newbie
timestamp: January 26, 2022, 05:44:17 pm
content: Ah didn't know they existed, they look like exactly what I need! Cheers.
Multiple Signal Connectors PCB Design - Page 1
Forum section: electronics / beginners

author: ipek.grgc
author_rank: Contributor
timestamp: May 24, 2020, 09:55:29 am
content: Hello everyone, hope you are doing well.I am designing an STM32F1 board with an IMU and many signal connectors on it. These connectors are mostly for plugging external sensor modules. I know that unconnected wires can act as antennas, but i don't know if this is a big deal while working with a relatively slow MCU like STM32F1. So, if i don't plug any sensor modules to the connectors would it cause a big problem? I attached a screenshot showing the situation.Thank you :)

author: Vovk_Z
author_rank: Super Contributor
timestamp: May 24, 2020, 10:47:30 am
content: If it is only extra 10-20 mm I would not care.If it is some sensitive input - you have to use some filtering in any case (simple RC for example).

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 24, 2020, 11:26:19 am
content: analog sensor will feed mcu adc and no hi speed signal right? so should be no issue. the sensor with serial comm line you can program mcu to detect existence right? and shut off comm if no sensor detected, so no issue again. why you want to keep sending spectrum rich into a dead end line?
Multiple SMPS, low noise? - Page 1
Forum section: electronics / beginners

author: ifonlyeverything
author_rank: Regular Contributor
timestamp: May 31, 2024, 06:22:45 pm
content: I have a project where I need to make four offline (120VAC input) independent floating/isolated SMPS delivering 3-33V, 0-5A. My goal is to feed them into four separate linear post-regulators to act as a quad output 0-30V, 0-5A CC/CV bench power supply. I know this is a viable idea since a few commercial supplies use this approach (R&S HMC804x) but I don't know how exactly it's done.That said, with the goal of having as low noise as possible on the SMPS:1) Is it appreciably beneficial to bother with making 4 separate EMI filters for each SMPS input?2) Is it ideal to use a SMPS PWM IC that supports synchronization?3) Any thoughts on topology? Given moderate power levels I was thinking 2 switch forward converter.4) Given #2 and #3, any thoughts on a reasonably priced current mode PWM IC? SG3525 and TL494 are old as hell but it natively supports sync and can be hacked to current mode. UC384x might support sync (reading conflicting things w/r/t the sync hack mentioned in the data sheet) and it is natively current mode. And of course there are much more modern parts... which likely cost $7-10 each.

author: aliarifat794
author_rank: Regular Contributor
timestamp: June 01, 2024, 11:31:12 am
content: For the best performance, modern ICs like the LM5035 or UCC28950 offer advanced features, including better synchronization capabilities and improved efficiency.
Multiple solid-state relay mounted on single heat sink? - Page 1
Forum section: electronics / beginners

author: renz.bagaporo
author_rank: Newbie
timestamp: July 05, 2021, 04:57:37 am
content: The back-plates of both SSR are now electrically connected, and I'm wondering if that's OK.

author: Berni
author_rank: Super Contributor
timestamp: July 05, 2021, 05:32:16 am
content: The rear plate on solid state relays should be floating. Tho you can never be sure with cheap Chinese knockoffs from some questionable ebay store. Just use a multimeter to make sure none of the terminals have conductivity to the back plate.EDIT: Oh and do also earth the heatsink in case one of those SSRs blows up and gets live voltage onto your heatsink.

author: Terry Bites
author_rank: Super Contributor
timestamp: July 06, 2021, 04:05:41 pm
content: A multimeter won't check for poor insulation, only continuity. You need to measure the leakage at double the working voltage (at least) Rather than a massive earth surge blown fuses etc, it would be wise to use heat sink insulation material if you're unsure of the device.
Multiple transformers mixed ground reference - Page 1
Forum section: electronics / beginners

author: advark
author_rank: Contributor
timestamp: March 06, 2016, 04:15:36 pm
content: Hello everyone,I'm currently building (at least trying) to build a bench power supply 0-20V @ 3A. In order to reduce the heat on the regulator, I'm using a relay to switch from 12V to 24V tap. The voltage and current selection is done via a MCU running at 5V from a second transformer so my big transformer is all dedicated to the output source. In order words, transformer A provides the power to the output posts and transformer B provides the power to the internal logic and display circuitry. Until now, I was able to isolate both from each other but I'm having some concerns about the tap selection. As you can see, the relay is feeded by the transformer A (+5V rail) but the LM393 is feeded by the transformer B (+12V rail). I have a feeling I should not flip the switch on that one.Any hint will be appreciated.Thanks

author: Simon
author_rank: Unknown
timestamp: March 06, 2016, 04:33:21 pm
content: You will need a ground reference between the 2 transformers. To sense the voltage you need a negative and a positive you have to connect the negatives together. The some reason you have your comparator connected to 5 V on the output. Your comparator will go up in smoke. At least you need a pull-up resistor to 5 V from the output not a direct connection. Your relay is connected to the base of the transistor so that will not work either in fact you need to scrap your whole circuit and start again there is nothing about it at looks like it will work.
Multiple voltage power-supply question - Page 1
Forum section: electronics / beginners

author: dsharp02
author_rank: Contributor
timestamp: October 04, 2017, 05:31:04 pm
content: ATX supplies have multiple voltage rails. If you need 7 volts, can you just hook something up between the 12v rail and the 5v rail? I'm assuming the 5v rail has a diode or something to prevent power from flowing back into the power supply, so where would the current go?Thanks,Dave

author: katzohki
author_rank: Frequent Contributor
timestamp: October 04, 2017, 06:06:11 pm
content: You would hook something up between 12V and ground, such as a voltage divider. Even better would be a voltage regulator.

author: David Hess
author_rank: Super Contributor
timestamp: October 05, 2017, 03:25:40 am
content: What you suggest may be done if the current load on the lower voltage rail exceeds the current load between the rails. The various power supply outputs will normally only source current and not sink current so a load between the +12 and +5 volt rails will pull the +5 volt rail positive unless an equal or greater amount of current is drawn from the +5 volt rail to ground.
Multiple vs single instrumentation opamp. - Page 1
Forum section: electronics / beginners

author: pharaoh_04
author_rank: Newbie
timestamp: September 08, 2015, 08:19:19 am
content: Dear all,I am very newbie to the electronic field. However, I am constructing an amplifying circuit for strain gauge measurement.Then, this question comes to my consideration. What are the differences between using a single op-amp with high gain when compared to a multiple op-amps connected-in-series (with an identical total gain).For example:[a op-amp with 6,000-gained ] vs [three of 2,000-gained op-amps]It should be also useful if there is any recommended books or articles on this topic.Thank you in advance,Regards,pharaoh04

author: Landrew2390
author_rank: Regular Contributor
timestamp: September 08, 2015, 08:49:54 am
content: Dave covered this a while back. If you have room, multiple opamps can give you better performance.

author: pharaoh_04
author_rank: Newbie
timestamp: September 08, 2015, 09:26:22 am
content: Thank you very much!This is extremely interesting information for me
Multiplexed custom LCD - Page 1
Forum section: electronics / beginners

author: Daxxin
author_rank: Regular Contributor
timestamp: March 30, 2014, 06:08:26 am
content: Hi , my question is , there is a standard about connection beetwen segments and common gates building multiplex custom LCD or dependsfrom the projects? hope Dave have lesson on youtube about this kind of LCD and the techniques to make them working es. shift registers3 state operations and how to check with scope even for reverse eng to understand

author: han
author_rank: Frequent Contributor
timestamp: March 30, 2014, 07:34:17 am
content: What type of LCD?Character LCD? Grapical LCD?LVDS?Parallel?SPI?

author: Daxxin
author_rank: Regular Contributor
timestamp: March 30, 2014, 09:57:17 am
content: custom lcd , i mean transparent glass lcd's with big segments or words customized for some particular applicationssomething like this just for example

author: mariush
author_rank: Super Contributor
timestamp: March 30, 2014, 02:39:00 pm
content: These types of lcd screens don't have any driver to light up the elements on the panel. You need a driver to run them and make sure the elements are not damaged (you can't just turn them on and off like a led, they require a somewhat special signal).There are microcontrollers which have LCD drivers built in along with multiplexing capability and all that, go for example on Digikey and select microcontrollers:http://www.digikey.com/product-search/en/integrated-circuits-ics/embedded-microcontrollers/Then select LCD at peripherals and you'll find microcontrollers that have built in lcd driversThere are also application notes explaining how to drive such plain lcd displays (without driver on the back) from various companies, just go on Microchip's site or Atmel's site and look up the application notes and see the explanations.For example, just by searching "application note lcd" I stumbled onto these:LCD Fundamentals Using PIC16C92X Microcontrollers :http://ww1.microchip.com/downloads/en/AppNotes/00658a.pdfAVR241: Direct driving of LCD display using general IO :http://www.atmel.com/Images/doc2569.pdfBasic Operation of an LCD, LCD Direct Drive Techniques , Multiplexing LCD's , Multiplexed Liquid Crystal Displays etc :http://www.lxdinc.com/application_notes/indexDave has a video somewhere in which he searches for a microcontroller capable of driving a LCD without built in driver and explains some things, but really I can't be bothered to search for it in close to 600 videos. Do some work yourself.
Multiplexing 8 RTD - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: April 12, 2015, 06:29:35 am
content: 1. I am using Max31865 , resistance to digital converter for interfacing PT100. (for 2 wire & 4 wire only)2. I want to multiplex 8 rtd to it so that I don't have to use separate IC for each.3. I have searched for analog mux like ADG708(internal resistance is 3 ohm) & DG408(RDS = 100ohm).4.They have large internal resistance. I think these will effect the acuracy of PT100 since it have 0.4ohm/C.5. Or they won't effect the accuracy since I am using PT100 is 4 wire configuration so drop across wires won't effect the accuracy?6. Also for 2 wire configuration, I will use it as 4 wire only by connecting two RTD wires across RTD+ & RTD- & shorting FORCE+ with RTD+ & FORCE- with RTD-.7. Schematic is attached. What should be best way to multiplex.8. I think I will need 3 (8:1) multiplexer as shown in schematic. Because 4 wire of all RTD can be shorted together. Or I should use 4 (8:1) mux.

author: tszaboo
author_rank: Super Contributor
timestamp: April 12, 2015, 07:50:26 am
content: If you use 4 wires than the mux is part of your wiring assembly so it doesnt effect the accuracy. You only need 4 wire if you are aiming at extreme precision, usually self heating and other sources of noise, EMF etc. will be bigger source of error.

author: SeanB
author_rank: Super Contributor
timestamp: April 12, 2015, 08:17:24 am
content: For each RTD use the switches from a single package, so that the on resistance is equal for each switch. The resistance differs from package to package slightly, and you really want then to be both close and to track with temperature of the switch. You want a mux with lower resistance, or to use a Pt1000 sensor, which will have reduced error from the switch resistance.
Multiplexing, making sure only one transistor is on - Page 1
Forum section: electronics / beginners

author: Ontaelio
author_rank: Contributor
timestamp: August 09, 2016, 06:07:57 pm
content: Hullo there!I guess this stuff is common knowledge, but I wasn't able to find it googling.Is there any _hardware_ way to make sure only one P-Channel MOSFET is conducting in any given moment?Say, I have an LED matrix. Grounds are connected to the LED drivers, Vccs to P-Channel mosfets. Is it possible to design a board that will prohibit two or more of the MOSFETs to open up simuntaneously because the programmer screwed it? I know I can protect the LED drivers with N-mosfets, but this seems to be a bit excessive when talking about fool-proof. I have an itch there is a solution involving diodes or something, but am not able to nail it down. Please, anyone?Thanks in advance!

author: Signal32
author_rank: Frequent Contributor
timestamp: August 09, 2016, 06:28:26 pm
content: I can't think of any simple solution using diodes or similar, but one thing you can do is use an analog demultiplexer like CD4067 ro CD4097 and control that with the micro.You select which of the 16 outputs is active on the CD4067 with 4 inputs. You control the 4 inputs using the micro. No matter what the micro will output, only one of the outputs of the CD4067 can be active.Disadvantage is 80ohm internal resistance of the CD4067 + perhaps some latency = slower MOSFET switching speed.Perhaps someone can suggest a digital equivalent to the CD4067 .

author: Ian.M
author_rank: Super Contributor
timestamp: August 09, 2016, 06:30:14 pm
content: Sure. Instead of running one P-MOSFET from each I/O line and requiring the programmer to only set one pin low out of N, use one or two 74HC138 active low 3 to 8 line decoder chips, with your MCU providing a binary MOSFET number and a strobe. They have two active low enables (/G2A, /G2B) and one active high (G1), so you can use two chips for 16 lines, feeding an extra high address line to G1 on the high chip and G2B on the low chip. However you do need an enable/strobe signal from the MCU to both chips /G2A pins so you can shut off all the MOSFETs to avoid glitches when changing the selected MOSFET number.You could also do something with diodes and series resistors summing into an analog comparator. If more than one gate is low, the comparator input would be pulled below its setpoint, and the comparator output could be used to reset the MCU, clearing the too many gates low condition.

author: Ontaelio
author_rank: Contributor
timestamp: August 09, 2016, 07:19:06 pm
content: Thanks a lot, people! I'm on my way to dig the datasheets.Just to clarify, though, I actually want to drive the matrix with the LED driver, no input from the MCU. Both X and Y axis; to make sure the switching takes place simuntaneously. Seems like the 74HC138 will not only do that, but also multiply Vcc sources, good. Or multiply LED driver outputs... maybe good too.Anyways, on to datasheets. Thanks again!
Multiplexing Power and Signal through Wireless Power Transfer  - Page 1
Forum section: electronics / beginners

author: 6E5
author_rank: Regular Contributor
timestamp: March 14, 2014, 03:00:41 pm
content: Hi,I was thinking the other day about building a simple capacitance or inductive wireless power setup that would power a USB device using a computer USB port. This has been done many times, however I was thinking of also transfering the USB signal through the same source. I'm not too concerned with bit rate, however I would like at least USB 1.0 speeds.I was thinking about time divison multiplexing. Do you think this would be sutable? Would capacitance or indutive based transfer have more advantages?If this has any promise, I would assign this as a long term project, at least a year or so.Paul

author: magetoo
author_rank: Frequent Contributor
timestamp: March 15, 2014, 09:14:50 pm
content: I vaguely remember Maxim having an app note about this sort of thing, presumably using their NFC parts. Reasonably sure it wasn't up to USB speeds, but it might be interesting to look at anyway for inspiration.
Multiplexing RTDs with MAX31865 - Page 1
Forum section: electronics / beginners

author: honeybadger
author_rank: Contributor
timestamp: February 14, 2020, 02:54:08 pm
content: Hi,for my next project I need to measure up to 8 temperatures with a reasonable accuracy. I don't want to mess with thermocouples because wires will be few meters long. DS18B20 has a 125°C maximum, I need 150-180°C.I guess PT100/PT1000 is the best/only choice and MAX31865 is relatively cheap and available. 3-wire method to get the accuracy and low wire count.Because I don't want to use 8 separate MAX31865 chips I need to multiplex the RTDs somehow - don't care about slow measurement, 30s sampling rate is more than enough.What chip would you recommend to do the multiplexing? CD4097B for example?I am not sure about the circuit design. Should I use a one MUX to switch the FORCE+, other chip to switch the RTDIN+, etc.?I think this is not a good idea because Rdson is matched inside the chip but every chip might be different and with 3-wire you rely on the same resistance of all 3 wires.So would be a better idea to use for example CD4066B as a switch and use a separate chip for each RTD so all 3 wires go through the same chip?I am not sure about that but is it necessary to MUX the FORCE-/RTDIN- line? They are connected together in 3-wire mode. Would the MUXing be better for, I don't know, interference protection?

author: honeybadger
author_rank: Contributor
timestamp: February 15, 2020, 01:14:06 am
content: Update:I do need all 3 wires to be MUXed and all 3 wires needs to go through the same chip - that is the price I have to pay for 3-wire PT100.NX3L4053PW - 3.3V , Ron 1ohm - one for each two PT100.TS3A44159 - 3.3V, Ron 0.45ohm - NO, it does not have EN pin!TMUX1574- 5V, Ron 2ohm - one for each two PT100.TMUX1511 - 5V, Ron 2ohm - one for each PT100.Any other suggestions for 3/4 pole switch with low Ron, preferably double throw (so I can hook two PT100) and with EN pin (so I can disconnect both)?
Multiplying voltage - Page 1
Forum section: electronics / beginners

author: rafalpilat0077
author_rank: Contributor
timestamp: March 09, 2014, 12:58:02 am
content: So, i need to power something running at 24v , from a 5v power supply, (The arduino). Is this possible? And if so, how?

author: lewis
author_rank: Frequent Contributor
timestamp: March 09, 2014, 01:02:35 am
content: https://www.google.co.uk/search?q=BOOST+CONVERTERor...http://uk.farnell.com/jsp/search/browse.jsp?N=213129+110457907+110537112+110536750+110536929+110537277+110536598+110537606+110537430&No=0&getResults=true&appliedparametrics=true&locale=en_UK&divisionLocale=en_UK&catalogId=&skipManufacturer=false&skipParametricAttributeId=&prevNValues=213129+110457907&mm=1004310||,1004792||,1004799||,&filtersHidden=false&appliedHidden=false&autoApply=false&originalQueryURL=%2Fjsp%2Fsearch%2Fbrowse.jsp%3FN%3D213129%26No%3D0%26getResults%3Dtrue%26appliedparametrics%3Dtrue%26locale%3Den_UK%26divisionLocale%3Den_UK%26catalogId%3D%26skipManufacturer%3Dfalse%26skipParametricAttributeId%3D%26prevNValues%3D213129

author: rafalpilat0077
author_rank: Contributor
timestamp: March 09, 2014, 01:05:56 am
content: Where can i find this on DigiKey?

author: IanB
author_rank: Super Contributor
timestamp: March 09, 2014, 01:24:16 am
content: You might be going about this the wrong way. The Arduino is a computer, not a power supply. It consumes power, it does not supply it. If you want to control something running at 24 V it is best to provide a dedicated 24 V supply for that item and then have the Arduino send control signals to it (while making sure you don't feed 24 V back into the Arduino and blowing it up).

author: Taburn
author_rank: Newbie
timestamp: March 10, 2014, 09:33:47 am
content: As lewis said, a boost convertor would work, as long as the Audrino's ability to supply current was respected.http://forum.arduino.cc/index.php?topic=121675.0Or you could do what IanB said. Approaches include using a transistor as a switch or using an OpAmp.
Multirotor motor durability / continuous used as fan? - Page 1
Forum section: electronics / beginners

author: sam1275
author_rank: Frequent Contributor
timestamp: November 16, 2014, 07:01:30 pm
content: Hello everyone, I have an idea of using multirotor motor as a fan, because it's small, brushless, very powerful, and good at controlling the speed, but I have a few questions about this:1. Is it OK to use them as a long-term powered fan? Most multirotors will fly for just 10-20 minutes and have a rest, so will it shorten the life if I power it on for a few hours without stopping, or even 24*7?2. If it's fine to run them continuously, then what is the MTBF of a good motor, such as DJI or so? I cannot find this specification online.Thank you for any helping!

author: mzzj
author_rank: Super Contributor
timestamp: November 16, 2014, 08:12:56 pm
content: Bearings are usually the weakest link and those can last anything between 0.1 and 10000 hours. This is also depends how well your prop is balanced.I wouldn't use for anything even partly critical.

author: BradC
author_rank: Super Contributor
timestamp: November 17, 2014, 10:37:31 am
content: Quote from: sam1275 on November 16, 2014, 07:01:30 pmNo. Those motors are designed for intermittent use and will just smoke up and die if you run them continuously. There is no ventilation and the bearings are too small to conduct any heat away from the armature/commutator.I've got several heli's (both multi and single rotor) and I killed my first one by flying it back to back with several batteries in a row. Now I have several of each model and rotate them and the batteries. This allows the motors time to cool down between runs.

author: sam1275
author_rank: Frequent Contributor
timestamp: November 17, 2014, 12:26:23 pm
content: Thank you everyone!

author: ivan747
author_rank: Super Contributor
timestamp: November 17, 2014, 02:52:17 pm
content: Well, they are burshlessDoesn't take that much to try one. You should put the prop so that it directs airflow into the motor, and use a prop that actually blows air to the motor.Put the ESC in the way as well.And of course, derate the motor a lot.Tell me about the results because I'm curious

author: BradC
author_rank: Super Contributor
timestamp: November 18, 2014, 01:18:52 am
content: Quote from: ivan747 on November 17, 2014, 02:52:17 pmMy bad. I missed that entirely. All mine are brushed and its the brushes that are the weak point.
Multisim 3D Breadboard - Page 1
Forum section: electronics / beginners

author: Electro Fan
author_rank: Super Contributor
timestamp: September 19, 2015, 07:36:12 pm
content: I just discovered the 3D Breadboard in Multisim. I can get the regular 2D simulation to run but I can't get the 3D view to run. One related item is that the toolbars don't seem to populate. This is all likely to be a user error but it might in part be due to some problem with installing or configuring the software. Also, the property values don't display (in the blue box). Below is a screenshot showing the greyed out tool bars and the empty property box. Any suggestions? Thanks

author: Vgkid
author_rank: Super Contributor
timestamp: September 19, 2015, 11:54:53 pm
content: What version/ edition of ms do you have?

author: timofonic
author_rank: Frequent Contributor
timestamp: September 20, 2015, 02:52:46 am
content: I just wish KiCad would merge with Frizing and provide a serious breadboard simulator/router/autorouter.I get insane trying to wire breadboards.

author: Vgkid
author_rank: Super Contributor
timestamp: September 20, 2015, 05:00:01 am
content: I messed around with mine, the greyed out boxes are for different components. Those seem to be only useful in the non breadboard view. I never messed around with the 3D components in the design viewwe really need the throwing up smiley for that.NOTE I have MS11 edu edition
Multisim help, h-wave rectifier - Page 1
Forum section: electronics / beginners

author: Jimbz
author_rank: Contributor
timestamp: November 01, 2013, 02:13:24 am
content: Hello all, using Multisim in my school, first time doing it so. Was given an assignment to write and calculate all kinds of things regarding to rectifiers and different types of methods.Anyway, nothing over the top, but I ask for your help in Multisim. The circuit here was supposed to be with ideal diodes, but it appears to be not. Is there an ideal diode in Multisim somewhere ? Also, what is up with the multimeters, why do they give me such readings ? And lastly, is there a way to project voltage/current vs time on the same screen ?Thank you for your time

author: Abstr7ct
author_rank: Regular Contributor
timestamp: November 01, 2013, 07:29:25 am
content: There's no an existing ideal diode model in Multisim. If you want one, you've to create a custom component through the component wizard in the software. As for the voltage readings, you've two equations in the top left corner and they would be enough to tell you why they're like that.Use transient analysis to project voltage/current vs time on the same screen. See the following link for how to:http://www.ni.com/white-paper/5399/en

author: Kremmen
author_rank: Super Contributor
timestamp: November 01, 2013, 09:53:33 am
content: Well, if i check the Multisim 11 i use, when placing components there is in group "Diodes" a subgroup DIODES_VIRTUAL containing a virtual diode and virtual zener. I cannot recall if this is a standard subgroup or if it came in some extra package or plugin, but there it definitely is.

author: Abstr7ct
author_rank: Regular Contributor
timestamp: November 01, 2013, 11:26:45 am
content: A 'virtual diode' model in Multisim /= an ideal diode. You can test it in a circuit and still find a voltage drop.
Multisim oscilloscope output - Page 1
Forum section: electronics / beginners

author: kos99
author_rank: Newbie
timestamp: April 07, 2015, 10:18:25 am
content: Hi,First time on the EEV Blog forum but have been on the youtube channel for awhile now. I am trying to use multisim to test the wave form of a fixed voltage regulator with different caps but every time I run it the out put is always a smooth 9v output even when I have no caps on it. Is this normal on multisim or have I not built the circuit correctly I have included a picture of my setup and output. Hope you can help.Thanks Alex

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: April 07, 2015, 12:04:35 pm
content: There's no load. Try a 9 ohm resistor at the output.

author: kos99
author_rank: Newbie
timestamp: April 07, 2015, 12:22:35 pm
content: Thanks for the response that solved it.Quote from: Alex Eisenhut on April 07, 2015, 12:04:35 pm
multisim question - Page 1
Forum section: electronics / beginners

author: xxngo
author_rank: Contributor
timestamp: July 04, 2015, 07:23:06 pm
content: Dear forum,I was testing capacitors as voltage divider with dc voltage using 1uf and a 2uf all in series with 12Vdc . Sure enough my measurments checks out, the smaller value cap gets more voltage drop on it. but when i generate the same loop on multisim, i get 12V across the 1uf but nothing on the 2uf. can anyone please tell me why? I'm using multisim 10 and i'm pretty sure there's nothing wrong with the program, since most of the measurement i've done on it checks out fine when i breadboard 'em.

author: 3roomlab
author_rank: Frequent Contributor
timestamp: July 04, 2015, 09:41:32 pm
content: set simulation initial condition to zero and run (master setting)

author: xxngo
author_rank: Contributor
timestamp: July 06, 2015, 04:28:34 am
content: ohh thnx bro, I will try that....yah I realized that multisim sees the two caps as one, doesnt matter which position the cap is i can only get a reading across both of them no different than measuring directly at the source.but yah thank you

author: LvW
author_rank: Frequent Contributor
timestamp: July 06, 2015, 08:05:09 am
content: Quote from: xxngo on July 04, 2015, 07:23:06 pmYou cannot test (ideal) capacitive voltage dividers - neither in the lab nor with a simulator.In practice, the voltages across the capacitors are determined by the parasitic parallel losses only!That is the reason, each simulator requires that each node has a dc path to ground - and this is not the case BETWEEN both (ideal) capacitors.Didn`t you get any error message?
Multithreading python,tkinter; basic start - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: October 31, 2015, 04:54:15 am
content: I have made a python code & using multithreading in it. this is very basic code, not using queues & other stuff.Code has three files:main,analog,screen. Files are attached.1. Main code just make three threads.2. analog.py has two analog sensor connected. (right now I have only connected randint to generate values, otehrwise analog sensor will be connected).one sensor update every 1 sec & other every 10 seconds.3. screen.py has tkinter function. It keeps on self updating every 100msec. Whenever valid value comes in analog sensor it prints.Check update_reading function in App class.4. I want to know if its correct way to do, at very basic level.Code is working fine, I have checked.5. I will connect other sensor also, whose values will update in every 500msec or 2 sec & so on.6. One additional query: update_reading function in App class, calls every 100msec. What if this function takes itself more than 100msec. What will happen then?

author: krish2487
author_rank: Frequent Contributor
timestamp: October 31, 2015, 10:40:39 am
content: No No No...Please respond to the other threads where you have asked, received responses and did not bother replying to them.Netiquette please.It is only a matter of time before people stop replying altogether.Secondly, this is not a school for learning how to code. No spoon-feeding, no hand holding.If you need help, show, demonstrate and ask help for a particular section. Not a general critique my code.This is a electronics forum. Wrong place to post and request help on python. You have different python forums for that.(Not that others here don't know python, but this isn't the place)

author: tec5c
author_rank: Frequent Contributor
timestamp: October 31, 2015, 11:16:00 am
content: Well there's that, and the OP post is basically not even asking anything and done so in a confusing way. Numbered points? Really?The only real question you actually asked can be answered with knowledge of your previous statements.Better yet, go ask your questions here:http://www.python-forum.org/as this is not a software "engineering" forum.
Murdering ssd1306s - Page 1
Forum section: electronics / beginners

author: mortderire
author_rank: Newbie
timestamp: March 01, 2020, 10:08:59 pm
content: Hi folks,(more or less a complete electronics newbie).I have been playing around with ESP-01's and an ssd1306, for fun.The ssd1306 is now completely un-responsive - when I connect VCC+GND it gets very hot.(is this the classic sign the VR is fecked?).So I have managed to kill it some how.In this case I haven't done my usual tricks of supplying too much voltage, so it is something else.I can only conclude that I may have accidentally reversed GND and VCC.Could this have done it?Ray K

author: amyk
author_rank: Super Contributor
timestamp: March 01, 2020, 10:13:41 pm
content: Don't forget ESD as another cause of such failures.

author: mcovington
author_rank: Regular Contributor
timestamp: March 01, 2020, 10:14:29 pm
content: Yes.

author: mortderire
author_rank: Newbie
timestamp: March 01, 2020, 10:19:13 pm
content: Scratch that, it appears to be ok.

author: atmfjstc
author_rank: Regular Contributor
timestamp: March 02, 2020, 12:00:49 am
content: This reminds me of that time when I discovered I had installed an ATMEGA328 in reverse, which, if you look at the pinout, means VCC and GND will get reversed. Oops. By the time I figured it out, the chip was scorching hot and I was pretty sure I killed it. Since I had soldered it raw (had no socket at hand), extracting it was a pain and it also suffered some pretty scary mechanical abuse in the process.Turns out, after all that, it still worked like a charm when re-soldered in the proper position (and still does to this day).Meanwhile, a pristine ATMEGA328 I was storing in the same box and had never seen any action, turned out to be stone cold dead upon testing.Such are the ways of this Universe...

author: mortderire
author_rank: Newbie
timestamp: March 02, 2020, 09:53:38 am
content: LoLThinking about this later ...I had the SSD1306 connected to WeMos D1 mini's SCL, SDA, VCC and GND.And it worked like a charm.It was when I connected it to a ESP-01, I connected SSD1306's SCL and SDA to the ESP-01.I then connected the SSD1306's VCC and GND to the power rail and ground on the breadboard.This when it got really (really) hot, so I presume it was getting way too much power from the "ywrobot breadboard power supply" I was using.I was just assuming that the SSD1306 didn't need a resistor on it's GND line - was I in error?Ray K

author: SmokedComponent
author_rank: Regular Contributor
timestamp: March 02, 2020, 03:31:01 pm
content: I recommend getting a power supply with current limiting and/or overcurrent protection. Doesn't have to be expensive, networked one, just some which allows you to set maximum current down to tens of milliamps. It's a circuit-saver. Not always, but helps a lot of times; especially overcurrent protection, which turns off the output immediately rather than just lowering voltage.Even if you've been doing electronics for a while, it is easy to accidentally short something out on a breadboard.
Music/studio circuits and books. - Page 1
Forum section: electronics / beginners

author: MrZwing
author_rank: Regular Contributor
timestamp: August 12, 2015, 09:48:33 am
content: HelloDoes anyone have any good webbsites /videos or books that explain audio circuits and electronics.i mainly aim to understand how to create studio / pedal effects and equipment maybe how to rebuild and change existing equipment to suit my needs.i know its a wast subjekt but something to get started and understanding the basics and some motivating and fun curcuits would be a good start./MrZ

author: Hideki
author_rank: Frequent Contributor
timestamp: August 12, 2015, 10:34:22 am
content: Here are some links to get you started:http://sound.westhost.com/articles.htmhttp://www.freestompboxes.org/http://web.archive.org/web/20140528083348/http://www.beavisaudio.com/http://www.runoffgroove.com/http://groupdiy.com/index.phphttps://www.gearslutz.com/board/geekslutz-forum/http://www.diyaudio.com/

author: MrZwing
author_rank: Regular Contributor
timestamp: August 12, 2015, 11:51:58 am
content: I will look through them ASAP. Thank you.
must be taking the "P" - Page 1
Forum section: electronics / beginners

author: p.larner
author_rank: Frequent Contributor
timestamp: March 20, 2024, 04:41:22 pm
content: are these valueable or is the seller having a laugh?https://www.ebay.co.uk/itm/386673728906?itmmeta=01HSEBMY9EW2FN0H1FQGV9EAZ9&hash=item5a078cdd8a:g:txgAAOSwFJ5lq1b6

author: Zero999
author_rank: Super Contributor
timestamp: March 20, 2024, 09:09:31 pm
content: I wouldn't know. Some old test equipment can be valuable, even for parts, as it's the only way to get spares.This reminds me. I need to get around to flogging my old analogue oscilloscopes I no longer use.

author: vk6zgo
author_rank: Super Contributor
timestamp: March 21, 2024, 12:00:36 am
content: Quote from: p.larner on March 20, 2024, 04:41:22 pmAt 499 quid?----"Tell 'im he's dreaming!"Some years back, I nearly bought the next model up with the delayed timebase at a Hamfest for less than $100 Oz.It was a nice little 'scope, but only 35 MHz-----that said, I recently bought a BWD 845 for $A200, which is also only 35MHz, but in my defence, is something of a "collector's item".

author: thm_w
author_rank: Super Contributor
timestamp: March 21, 2024, 12:46:36 am
content: Quote from: p.larner on March 20, 2024, 04:41:22 pmUse the "Sold" filter to see what stuff is actually worth:https://www.ebay.co.uk/sch/i.html?_from=R40&_nkw=Cossor+CDU&_sacat=0&rt=nc&LH_Sold=1&LH_Complete=1In this case $40-80 for good condition units.

author: Terry Bites
author_rank: Super Contributor
timestamp: March 21, 2024, 07:59:13 am
content: Yeh, overpriced all rigth.Still ebay istheplace to try it on.Cossor made a dual beam kit scope. I lost mine years (decades) ago- still waiting to see one of those up for grabs.

author: CaptDon
author_rank: Super Contributor
timestamp: March 21, 2024, 08:04:14 pm
content: If the seller bothered to take all those photos why didn't they at least attempt to get a shot powered up with a trace on the C.R.T.? When I see "For parts or not working" or the ever famous "We don't know how to test it, sold as is" generally means "We turned it on and smoke rolled out" or "Some dweeb with a diddle stick turned every possible adjustment screw inside and it still doesn't work". That scope looks so much like a Telequipment scope with a different name on it. Don't you just love the vacuum tube fools with items like "Rare military radar tube 9003 $65.00 Buy it now"!!

author: Bud
author_rank: Super Contributor
timestamp: March 21, 2024, 08:22:15 pm
content: You must pay for the authentic 60 year dust and dirt, which the seller did his best to preserve for you.
Must Read Application Notes - Page 1
Forum section: electronics / beginners

author: Thewafflication
author_rank: Contributor
timestamp: July 21, 2018, 07:55:51 am
content: I seem to recall looking at a 100+ page application note that discussed working with high frequencies. (I read the portion that talked about high impedance paths to ground.) I can not find it. Does anyone recall which note I am talking about, or can you recommend any other must read application notes?I thought this one was interesting:http://www.itck.co.kr/bbs/download.php?bo_table=d01&wr_id=5&no=0