hybridfree/eevblog-posts huggingface dataset:
Newbie REQ: Design Feedback for Standing Desk Controller - Page 1
Forum section: electronics / projects

author: BuzzB
author_rank: Contributor
timestamp: January 26, 2021, 04:37:11 pm
content: (Hope this is the right place)I've got this (completely overkill) controller designed to control a custom sitting/standing desk height. If anyone has any design feedback I'd love to have it before I send off for boards. I am no EEThe desk has two linear actuators that I have modified to give me closed-loop control. (POS 1 & 2)The actuators are typically drawing between 1A and 3A.I am wondering if the protection diodes (D1-D8) are overkill. The MOSFETs (IRF9Z24N & IRFZ24N) have built-in diodes.Thanks,Buzz

author: robzy
author_rank: Regular Contributor
timestamp: January 27, 2021, 06:26:48 am
content: Quote from: BuzzB on January 26, 2021, 04:37:11 pmConsider using more off-the-shelf motor drivers instead of custom designing with MOSTFETs. Follow the sample application from the datasheet and bob's your uncle.: The below suggestions will not do 3A continuous. You might need to do some of your own research there.Sparkfun sell L298s for $4.25:https://www.sparkfun.com/products/9479Octopart's Common Parts List likes the TB6612 for $2.83https://www.digikey.com.au/product-detail/en/TB6612FNG,C,8,EL/TB6612FNGC8ELCT-ND/1730134?utm_campaign=buynow&utm_medium=aggregator&curr=usd&utm_source=octopartOr you can buy a whole off-the-shelf PCB. Sparkfun actually sell these for $5 that can do a constant current of 1.2A (peak 3.2A):https://www.sparkfun.com/products/14451Or something like this which can do currents up to 2A:https://www.sparkfun.com/products/14129Two challenges you might come up against: heat, and engineering a closed loop that behaves properly.

author: BuzzB
author_rank: Contributor
timestamp: January 30, 2021, 04:18:31 pm
content: Thanks for the feedback!I've already got the closed-loop working. I'm a software guy. And a 3d printing guy. I modified the actuators, adding a 3d printed gear train to the motor section that turns a rotary encoder. Works well. And this is an easy application.I think I am going to modify my circuit to use that L298N part though. Guess I should have done more research... that looks like it suits my needs perfectly.Thanks again.
Newbie, Treadmill speed control? - Page 1
Forum section: electronics / projects

author: a11mcr
author_rank: Newbie
timestamp: September 03, 2014, 07:29:59 am
content: hi im looking for some help making a cheap motor control circuitI have a treadmill with broken control board (so pulled it all out and binned it now just left with the motor and belt) so wanting to make a manual speed control?the motor is rated at 180 VDC 1200W 7A (but works with an 18V drill battery albeit slow) so looking for something I can make/buy to manually regulate the speed?I have seen some on the net but only rated to 500W 4A so could I modify one of these to suit?thanks in advancemark

author: Rerouter
author_rank: Super Contributor
timestamp: September 04, 2014, 08:24:00 am
content: You can use a large triac light dimmer with the output fed through a rectifier, but you may get some 120Hz hum, or vibration,
Newbie's bench power supply design: build on top of existing units? - Page 1
Forum section: electronics / projects

author: technix
author_rank: Super Contributor
timestamp: August 10, 2016, 08:53:06 pm
content: The M103v2 and M103v3 boards were both busts.Back to the drawing boards.I have an old Dell laptop power supply with a busted ID chip: it works properly otherwise, but the laptop won't properly recognize it any more. It outputs 65W maximum at 19.5V. Since my output power cap is 50W anyway, maybe I can build my bench power supply from this? Maybe I should use a modular design with hot plugging in mind.On the same note, another piece of equipment I may reuse is an old ATX computer power supply. What is the best way to repurpose it into a bench power supply with adjustable output voltages? And how to disable the minimum load requirement of the power supply, preferably without using a power resistor and burn away a few watts at all times? Is it a good idea to build the ATX-based adjustable power supply in some kind of standard form factor (like mini-ITX, 170mm-by-170mm board with four screw holes at specific locations) and put the build into a standard small form-factor computer case?

author: Mechatrommer
author_rank: Super Contributor
timestamp: August 10, 2016, 09:22:29 pm
content: Quote from: technix on August 10, 2016, 08:53:06 pmput adjustable LM317 on the ATX PSU outputQuote from: technix on August 10, 2016, 08:53:06 pmminimum load means energy you should waste for better regulation. use constant current circuit...

author: technix
author_rank: Super Contributor
timestamp: August 11, 2016, 02:53:50 am
content: Quote from: Mechatrommer on August 10, 2016, 09:22:29 pm

author: David Hess
author_rank: Super Contributor
timestamp: August 13, 2016, 01:53:48 am
content: If you use a 317, then the output divider normally also provides the minimum load current.
Newer ECL amplifiers - Page 1
Forum section: electronics / projects

author: RFsparkie
author_rank: Newbie
timestamp: April 25, 2016, 01:30:59 am
content: My application is in the design of a VHF preamp for a frequency counter ( 10MHz to 800MHz).Does anyone have any experience with the newer MECL differential line receivers?For a single-ended input I used to implement non-feedback biasing with the Vbb (on-chip) reference. (i.e. MC10H116)Some articles say that non-feedback biasing is not suitable with the newer versions (i.e. MC10EP16,SOIC-8 with 2 internal stages).They state that the input Vos is amplified by the next internal stage.But I think that may be OK if no output DC coupling is involvedI am just using one MECL device (2 internal amplifiers) and AC coupling to a MECL prescaler.Thanks in advance to everyone willing to read or respond.

author: Paul Price
author_rank: Super Contributor
timestamp: April 26, 2016, 04:16:08 pm
content: Correct, if you are using AC coupling, no problem, Vos will not effect the second stage.

author: RFsparkie
author_rank: Newbie
timestamp: April 27, 2016, 02:46:02 pm
content: Thank you for the support.As a previous analog/RF circuit designer I wish there where more Spice circuit models out there.Still, a lot can be accomplished with LTspice along with Eagle layout tools.Cheers
Nexem and Kemet link? - Page 1
Forum section: electronics / projects

author: Northy
author_rank: Regular Contributor
timestamp: October 07, 2020, 07:09:57 am
content: Is there a link between the two companies? I've searched but don't find anything really.I ordered some Kemet relays and they delivered Nexem.Thanks,G

author: Evan.Cornell
author_rank: Regular Contributor
timestamp: October 07, 2020, 01:54:46 pm
content: NEXEM was formerly NEC Tokin, which Kemet acquired in 2017.http://www.worldproducts.com/NEXEM-Relays.htmhttp://newsroom.kemet.com/news-releases/news-release-details/kemet-completes-acquisition-nec-tokin

author: Northy
author_rank: Regular Contributor
timestamp: October 09, 2020, 06:39:54 pm
content: Thanks!Hmmmm, that unfortunately means my relay just went single source!G
Nexperia discontinues NPIC6C596, how to replace - Page 1
Forum section: electronics / projects

author: alouko
author_rank: Unknown
timestamp: March 01, 2023, 09:15:34 am
content: Hello,I just got a notification from Digikey that Nexperia discontinues NPIC6C596. I would like to know if you have good suggestions how to cope with the situation? The point is that there are no actual replacements available, as I need 3.3V logic voltage feature of NPIC-series. I know that TPIC and related drivers are still available, but they require 5V logic levels and they cannot be directly controlled with 3.3V MCU outputs or logic.I see two solutions:Use a regular shift register and discrete MOSFETs. This solution doesn't have any short output circuit protection.Level shift 3.3V logic to 5V logic and use TPIC buffers. This requires 5V voltage domain even if it weren't otherwise needed.I think I go with the first one in my projects. I think that the days of general purpose kinda-jellybean driver ICs are going to be over as PCB assembly is becoming cheaper and cheaper so there is no real need for parts which would lower the number of components in BOMs has become less important than the BOM cost.

author: wraper
author_rank: Unknown
timestamp: March 01, 2023, 10:07:31 am
content: To not redesign anything on existing product or for one-off diy stuff you could buy a lifetime supply of them. It's not like you suddenly find they are not available anymore, so you can prepare.QuoteNPIC6C596 does not have it either.

author: wraper
author_rank: Unknown
timestamp: March 01, 2023, 10:22:55 am
content: I suggest looking for relay drivers with SPI interface like TPL9202, NCV7240, NCV7754. Also you get overcurrent protection in those.

author: alouko
author_rank: Unknown
timestamp: March 01, 2023, 11:18:52 am
content: Quote from: wraper on March 01, 2023, 10:22:55 amThank you very much! And I stand corrected that NPIC doesn't really have any output protection.Of these, TPL9202 seems best choice for me.

author: Infraviolet
author_rank: Super Contributor
timestamp: March 01, 2023, 06:07:36 pm
content: Isn't a 596 or 595 shift register (latching) a fairly generic part? Multiple manufacturers?

author: mikerj
author_rank: Super Contributor
timestamp: March 01, 2023, 07:31:53 pm
content: Quote from: Infraviolet on March 01, 2023, 06:07:36 pmThey have a low current push-pull output, not the 100mA open drain the OP is after.

author: fchk
author_rank: Frequent Contributor
timestamp: March 03, 2023, 09:02:57 am
content: TLC6C598 should continue to be available and seems to be a drop-in replacement.https://www.ti.com/lit/ds/symlink/tlc6c598-q1.pdf

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 22, 2024, 06:07:56 pm
content: Bit late, but just to add that ST have the STPIC6C595/6 which looks pretty much the same as the npic6c595
Next generation mobile chargers: a compact lab PSU? - Page 1
Forum section: electronics / projects

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 19, 2015, 06:28:40 am
content: http://arstechnica.com/gadgets/2015/09/qualcomm-quick-charge-3-0-goes-from-0-to-80-percent-in-35-minutes/QuoteI'm thinking that an alternative use would be to plug it into a little PCB that plugs into a breadboard, with a few jumpers or DIP switches to select the voltage. Since the PSU does the hard work of voltage adjustment, it more or less eliminates the issue of thermal dissipation on the plug in board.
Nextion, changing the system messages? - Page 1
Forum section: electronics / projects

author: xwintk
author_rank: Newbie
timestamp: May 21, 2020, 07:02:46 am
content: Remember like when you flash a tft and see that ugly english grammar? Well, is there anyway of changing them, I found the syscom.bin in Nextion Editor, modified the texts, but no effect.
Nextion LCD/Arduino Pulse Generator - Page 1
Forum section: electronics / projects

author: MarioGianota
author_rank: Newbie
timestamp: June 16, 2021, 07:41:11 pm
content: Hi all,I just got finished creating a handy pulse generator with a nice user interface provided courtesy of a 3.5 inch Nextion touch-sensitive LCD. It is suitable for low frequency applications. You can manually specify the desired frequency and duty cycle and also manually pulse the output pin.Video of the scope output of the generator:https://youtu.be/EwBbZ8XEvukProject details:https://create.arduino.cc/projecthub/mariogianota/nextion-arduino-pulse-generator-20c063?ref=user&ref_id=1350727&offset=0I hope it proves useful to someone.
Nextion NX4832K035_011 bulk capacitance - Page 1
Forum section: electronics / projects

author: negativ3
author_rank: Regular Contributor
timestamp: February 06, 2023, 06:35:04 am
content: Hi all,I'm seeking some advice from Nextion users, have you found they need any extra capacitance across power lines?I have not experienced any glitches thus far and given the operating current of 145mA at full brightness, I don't foresee the need.Asking just in case anyone has experience of issues.I'm thinking a couple unpopulated footprints near the power connector wouldn't be a bad thing.Thanks
NFC Open Webpage RTL8195AM - Page 1
Forum section: electronics / projects

author: MichaelZ2000
author_rank: Newbie
timestamp: June 25, 2020, 09:24:20 pm
content: Ameba RTL8195AM has onboard NFC tag and run on ARM Cortex-M3 core with WiFi, just nice to make use of all these 3 powerful tool to make an useful applicaiton.Many models of Android smart phone support NFC feature, and numerous of NFC applications are developed for inspection and modification of NFC Tag.In this example, we establish NFC connection between Ameba and a smartphone, and open a webpage on the smartphone via a NFC event.PreparationAmeba x 1Smartphone with NFC feature x 1Note: Make sure the onboard NFC antenna is safely connected to the module.Then open the example, "File" -> "Examples" -> "AmebaNFC" -> "UriWebPage" and upload, you will see this message when you tap your NFC-enabled phone on AmebaFor more details, refer to the offical website athttps://www.amebaiot.com/en/ameba-arduino-nfc-open-web/Also feel free to join the Facebook group to discuss with other makers!https://www.facebook.com/groups/AmebaIoT
NFC Payment SIM Redesign - Page 1
Forum section: electronics / projects

author: Jon86
author_rank: Frequent Contributor
timestamp: March 12, 2020, 12:24:29 pm
content: I've got a Barclays pingit device which is a neat little contactless card, designed into a standard SIM form factor to fit into a variety of wearables etc.My goal is to remove the chip from this plastic substrate and wrap a new coil into a ring (to wear), however...As you can see from the picture, this might not be so simple. Although I could snip out the center of the card and rewire an antenna, I can't actually see any bond wires on what I assume is the IC and I can see some microstrip-looking components (gap and pads) in the space inside the coil. Thanks to this I'm not sure what must stay and what can go.Can anyone with some experience around this shed some light on how I might get it working? All I want to do is get this card trimmed down as much as possible, so I can fit another coil.Cheers!

author: Jon86
author_rank: Frequent Contributor
timestamp: March 12, 2020, 12:29:05 pm
content: Obviously I forgot the picture...
NFC Tag Polling - Page 1
Forum section: electronics / projects

author: skipjackrc4
author_rank: Regular Contributor
timestamp: June 06, 2013, 12:55:54 am
content: I took some captures of a Galaxy S3's NFC polling output signal today using a homemade magnetic probe. Every 2 seconds, there is a long pulse, which is what I expected. The phone only responds to a tag during these long pulses. However, every 500msec, there is a much shorter pulse. Does anybody have any idea what it's doing with these? I wasn't expecting that.

author: Bored@Work
author_rank: Super Contributor
timestamp: June 06, 2013, 05:09:03 am
content: I think it is LLCP/NDEF/Android Beam/S Beam. However, I haven't verified this, so take it with a grain of salt.
NFC transceiver IC from ST - Page 1
Forum section: electronics / projects

author: SiliconWizard
author_rank: Super Contributor
timestamp: July 01, 2021, 06:00:29 pm
content: ST announced a new NFC transceiver IC, and I remembered there was a thread in which we discussed NFC transceivers (can't find it now.)I did suggest the ams AS3953, which I had used a few years ago, and which was nice and pretty versatile. Unfortunately, we saw that ams was going to stop producing it. At the time, I suggested that ST might take it over, as other NFC parts from ams had been handed over to ST.Looks like the time has come. Whereas ST already had NFC transceivers, none was as flexible and powerful as the AS3953. But... here it is!ST25R3918:https://www.st.com/en/nfc/st25r3918.html?ecmp=tt21882_gl_enews_jun2021&cid=stmDM44270&bid=435097367&uid=13RZcho5cQ2gQUqzWzQmIQ==Communication up to 848kbits/s, large FIFO, fast SPI. It's like an AS3953, but on steroids!So, anyone interested, especially the person with whom we discussed this in the other thread I mentioned... I suggest taking a look at this. I certainly will!

author: SiliconWizard
author_rank: Super Contributor
timestamp: July 01, 2021, 07:48:57 pm
content: Just a couple first thoughts after reading the datasheet:- It can act as a reader, or as a tag. The AS3953 could only act as a tag.- It has no embedded EEPROM as far as I've seen. The AS3953 did.- It has a 512-byte FIFO for data. The AS3953 only had a 32-byte one AFAIR.- It supports up to 848 kbits/s. Same as the AS3953.- It has apparently no energy harvesting ability. The AS3953 did; you could get up to a few mA from the NFC field, that you could use to power other stuff.- The power consumption seems higher than for the AS3953. I would have to dig a little further though, because in "tag" mode, it seems less straightforward to interpret the given figures than with the AS3953.You can refer to this for a comparison:https://ams.com/AS3953So, looks like I'll still be missing the AS3953. Damn ams, why did you discontinue it? Not enough market?
NGFF carrier for dummies, mechanical hole positioning and pcb nuts part name? - Page 1
Forum section: electronics / projects

author: hitech95
author_rank: Regular Contributor
timestamp: March 22, 2021, 12:50:41 pm
content: I'm designing a CM4 Carrier board, but I would like to have a NGFF (m.2 Socket 2) connector.What I don't understand is how know where the nut/post should be placed.Lets say that I want to have the following capabilities:224222602280Knowing the connector position how can I find the right location to add the nut?on The PCIE SIc M.2 Mechanical and Eletcrical specs there is only the daughter board mechanical specs and no info about the carrier.Lets take this connector as a reference:That said, how are the PCB nuts called? I've tried to search but I wasn't able to find the proper name.The PCB solderable nut is this (it is a part of some kind):Thanks in advance on who can help me on this dumb question.

author: hitech95
author_rank: Regular Contributor
timestamp: March 24, 2021, 11:14:11 pm
content: Found my answers:-1.75mm offset from the connector holes.the standoff are called SMTSO.

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: August 03, 2022, 07:42:10 am
content: Do you have some PCB template to share, I'm having the same problem want to design a carrier board for a M.2 SSD, I want to have the following capabilities:224222602280Thanks
ngspice/PSPICE power converter help... - Page 1
Forum section: electronics / projects

author: vectorotter
author_rank: Contributor
timestamp: September 08, 2021, 10:16:37 am
content: Hi there,I'm trying to perform a transient simulation of a PWM boost converter with XSPICE analogue components to handle the control loop.After lots of tuning such as pre-charging the output capacitor to start some closer to converter equilibrium, relaxing reltol and hence abstol and vntol, reducing maxstepsize, swapping out VSWITCH for real FETs, learning that a manufacturer model seemed to cause convergence problems (they supply an LTspice .asc so perhaps no such issues with the LTSpice engine) and swapping to a more basic FET model, I manage to simulate the boost converter with a fixed duty cycle and all is well.I now derive a PWM signal to perform average current control and no amount of tweaking seems to allow me to simulate for more than a few tens of cycles.Can anyone offer any systematic debugging techniques to try? Is there something fundamentally wrong with my circuit topology? I know my push-pull driver is reference to node 0 and my power FET is not. I tried floating the driver up to the source of the power FET but similar results.I attach the schematic and the netlist. ngspice 35 was used. I would really like to keep using ngspice so debugging techniques specific to ngspice would be preferred.
Ni DAQ Ghosting readings  - Page 1
Forum section: electronics / projects

author: caioau
author_rank: Newbie
timestamp: January 14, 2014, 04:39:50 pm
content: Hello from Brazil, I have a NI multiplexed DAQ but i have alot a problems with noise generated from the other channel's. So I tried using a unity gain amplifier (http://www.ni.com/white-paper/4494/en/)(i used LM741, but I am not using a variable resistor to null the offset) and it improved the source impedance but also injected some noise. Do you guys have any advice?

author: ejeffrey
author_rank: Super Contributor
timestamp: January 14, 2014, 05:16:48 pm
content: This is a common problem with multiplexed ADCs. Finding a totally satisfactory solution is difficult, but I think you should start with a better opamp, something with a larger bandwidth and able to source plenty of current. I have used OP27s in the past (10 MHz GBW) for single ended applications or pre-packaged instrumentation amplifiers for differential applications (don't remember which one). The key is that the amplifier needs to have high gain at the switching frequency of the multiplexer in order to block noise from it. You have to be careful with grounding too -- ground loops and noise can ruin your day as well as noise on the signal line. I bet one of the TI fully differential opamps with ~100+ MHz bandwidth would perform pretty excellently.Finally, don't discount passive filtering, either before or after the buffer. Filters after the buffer should be designed to avoid raising the source impedance too much, but can be very effective at blocking switching noise in the ~MHz range.
NI hardware not optimal for SPI communication - serial to parallel workaround? - Page 1
Forum section: electronics / projects

author: ikkaru
author_rank: Contributor
timestamp: January 29, 2024, 10:08:14 am
content: Hello everyone. I am working with an NI USB 6509(https://www.ni.com/en-us/shop/model/usb-6509.html) which utilizes a computer running a LABVIEW program to control some actuators. NI USB6509 has 96 digital I/Os (5V TTL/CMOS, 24mA). This device is software timed, that means the windows PC running it sets the clock for any serial communication.I am adding a new hardware component equipped with a thermocouple and use a thermocouple amplifier (MAX31855). I need to update the thermocouple reading (range:20-40 celcius precise to one decimal place) on the labview program every second (1Hz).But the NI USB 6509 may not be fast enough and/or may not have stable clock to communicate with my MAX31855 IC in SPI.Given that the USB 6509 has a lot of digital IOs, can I use a serial-to-parallel converter (e.g. 74HC595) to pass thermocouple reading to labview through digital IOs? Am I missing an easy fix here? I am not familiar with Labview.

author: Jeroen3
author_rank: Super Contributor
timestamp: January 29, 2024, 10:30:52 am
content: SPI is edge based, clock jitter should not be that much of a problem. There also isn't a minimum clock specified.Sure you can read the 14 bits using some bit-banging on that device? Otherwise it would be kind of a pointless device.Challenging is the maximum 1 KHz update rate of the USB (usb 2.0 max). But, I guess you can read both with <50 io changes in total, so once per second should be fine.Using a 74HC595 won't work because you need to be SPI master. More circuitry is required.You could program an rp2040 or something to do a spi to parallel conversion when you ask for it with a trigger line.But then you could also have the rp2040 task to labview directly over serialport...Maybe, to xy-problem this, you can find a DAQ970 for the termocouples, or is that not good enough?

author: moffy
author_rank: Super Contributor
timestamp: January 29, 2024, 12:52:27 pm
content: You could try using an Arduino, they have SPI and can do your SPI to parallel conversion, 8 bits at a time perhaps.
NI Multisim traffic light project - Page 1
Forum section: electronics / projects

author: vaidotas
author_rank: Newbie
timestamp: November 16, 2016, 12:07:09 pm
content: Hello guys,I'm studying physics, but I have a project in my extra subject and I'm really in a hurry. My electronics knowledge is really basic and I'm stuck. So any help/ideas/discussion is very very appreciated. I have to make a project with at least 2 traffic lights (I don't really know, because I'm not sure about the task). So the full task is:You are required to build a traffic light controller using NI multisim (at least I have this software and tried to make some basic circuits to work). The traffic light is standing in a standard four way crossing (I live in Europe btw). There is heavy traffic on the main road and there will always be green light when there is no traffic on the side road or at least 30 seconds. There will be green light on the side road if there are traffic and will be for at most 30 seconds. Also, there are velocity gauges on the both roads and if the car on any road is moving faster than the maximum speed limit, the traffic light turns to red. (It is also said that the timer can differ from the real 1000x, so it would be easer to demonstrate if it works).So it's the full task. I have to make it work until tomorrow and don't even have anyone to ask more specific about the task. So I'm interested in your opinions. Shouldn't be in this type of crossing the extra green pointer to the left on the main road , which turns on when there are cars who want to turn left and then all the traffic which are moving straight stops? But there are nothing in the task about turning? I don't think the task should be so hardcore. Maybe it's only about moving straight? What do you think? Please share with me your opinions. Any help to make a circuit would be ideal!P.S. As I said my knowledge in electronics is not too deep so please be in detail about anything
NI Ultiboard 12 Gerber file export help please - Page 1
Forum section: electronics / projects

author: Postal666
author_rank: Regular Contributor
timestamp: June 13, 2015, 05:22:16 pm
content: Long story short; I purchased the student version 12 of the NI software and at the time the school had 11 installed. The student version does not support gerber export, and I need to have some simple single sided boards made for some speaker cabinet rewires. I'm not on campus anymore and don't know what version they have installed, but if anyone here has the ability to load my v.12 files and export the gerbers for me it would be much appreciated. Link below. Thanks!!!https://www.dropbox.com/s/csz8vhjp6o2b6uf/JBL%20Speaker%20Board.ewprj?dl=0
Nice LED interference patterns through a glass jar - needs a slow actuator - Page 1
Forum section: electronics / projects

author: RoGeorge
author_rank: Super Contributor
timestamp: October 30, 2023, 09:17:57 pm
content: Was testing some 0.2W SMD power LEDs, and noticed interesting light patterns through the irregularities of a glass jar. The interference patterns are even more mesmerizing when the LED is slowly moved inside the jar. Almost any cylindrical glass seem to produce such patterns: jars, glasses, bottles, etc.Would like to make a few decorative light jars, similar with a lava lamp but with interference.Any idea for a slow and silent actuator, so to smoothly move a LED hidden in the lid of a jar?

author: ajb
author_rank: Super Contributor
timestamp: October 31, 2023, 01:00:10 am
content: Neat! The optical term for that effect is a 'caustic (video)', essentially the glass acts like a lens that instead of having a focalpointhas a focalcurve. When used for abstract visual effect, it's generally referred to as "lumia", after the work by Thomas Wilfred starting in the 1920s. He was of course using incandescent light sources and colored filters:https://americanart.si.edu/videos/thomas-wilfreds-lumia-unit-86-154416.In the 70s it became a key part of a lot of planetarium laser shows, taking advantage of the vibrant colors that Wilfred never had access to. There are still some dedicated folks building new and unique lumia generators for lasers:https://www.youtube.com/watch?v=uJrP585lT4A.Of course now you can also buy all kinds of cheap mood lights from the usual websites that use the LEDs and rotating lenses.Very low speed DC gearmotors would be the default actuator for this sort of thing, like 10RPM or even less, although the ideal speed depends on the optical components you're using and what kind of effect you want. I know a couple people who have seen good results with geared stepper motors for extremely low speed effects, although they require drivers. Most people move the lens rather than the light source, but either way works. You can also add a moving component between the fixed light source and the lens, which is a common technique for creating more intricate effects. Honestly a lot of this really comes down to playing around with variables until you get something that looks interesting.

author: themadhippy
author_rank: Super Contributor
timestamp: October 31, 2023, 01:20:09 am
content: How about a microwave turntable motor,low voltage versions are available reasonable cheap.
Nice Photos EPROMs - Page 1
Forum section: electronics / projects

author: TheEPROM9
author_rank: Frequent Contributor
timestamp: January 05, 2020, 12:41:26 am
content: TESLA EPROMbyTheEPROM9, on FlickrI am sure I am not the only person here that loves EPROMs, you are not just limited to EPROMs ether, really anything that looks cool. Post your photos here =-)

author: TheEPROM9
author_rank: Frequent Contributor
timestamp: January 05, 2020, 12:42:55 am
content: 27C512byTheEPROM9, on Flickr
nice smooth reel for IEC cable that can be fitted with custom cable easily? - Page 1
Forum section: electronics / projects

author: coppercone2
author_rank: Super Contributor
timestamp: December 20, 2018, 02:18:34 am
content: Are there any nice reels meant for indoor bench use that operate nicely, lock well and can be modified to accept a custom cable (shielded). Something like 6-8 feet so you can have it on a work bench always ready and neat.I have one for my garage and it makes things easier but I don't really like how it locks and stuff.Or plans for a good mechanism that can be fabricated yourself if you have tools. Preferably with a double switch.I don't like having to plug in cords or wrap them. I want a nice soft braid shielded cable for bench use (extra protection from open chassis) on a trouble shooting bench. I don't need something designed to be yanked on etc for hard use.
Nice state variable oscillator - Page 1
Forum section: electronics / projects

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 11, 2020, 06:56:16 am
content: This implements the differential equation of the canonical damped harmonic oscillator,\[ \frac{dx^2}{dt^2} + (1-A) \frac{dx}{dt} + B x = 0 \]First, it's turned into an integral equation, since integrators are better than differentiators for a number of reasons.The damping term has gain 1-A, being implemented as a negative feedback resistor in parallel with an inverting transconductance amplifier -- effectively, a negative resistor -- so the parallel combination has an impedance near infinity, plus or minus. Ideally, neither would be necessary, but small errors due to the op-amps, and circuit parasitics, mean that one way or the other is necessary. Also, in a perfectly linear circuit, there would be no amplitude control whatsoever, so controlling this -- electronically via servo -- will be required to maintain stable output.The gains are implemented using the venerableoperational transconductance amplifier(OTA) LM13700 (essentially the last of its kind -- hopefully it will still be around for a while!). This is operational in that the input is differential and the output is anywhere between the supply rails, but it's different from a conventional op-amp by having variable gain, and a constant current output (a Darlington follower is provided to optionally get a lower output impedance). It's implemented as a diff pair and a series of current mirrors, so you're really just using the gain of the input stage by itself -- and being a BJT pair, this gain has the form of a tanh function.In practice, the OTA is quite nonlinear, only being reasonable for inputs of 10 or 20mV. (Pre-distortion diodes are also provided, which when biased, extend that range to maybe 30-50mV, at the expense of lower input impedance, and, obviously, a lot of input bias current.) This means the average gain drops somewhat at high amplitudes. Which provides a stabilization mechanism, in lieu of any amplitude servo. Downside, the waveform approximates a rounded off triangle wave, or its integral (a roundedier parabola wave).The gain does indeed get ornery at low amplitudes, as we should expect from the linear case. That is, a very small turn of R6 causes the waveform to grow or decay quickly (in fractional seconds).As measured by my Tek 460, captured viaGPIB:Quantization noise aside, that's not a bad circle! A bonus of this type of oscillator is its quadrature outputs.Tim
Nichia NSHU550 370nm UV LED Identification - Part Number Always On LED? - Page 1
Forum section: electronics / projects

author: KJ-90
author_rank: Contributor
timestamp: January 18, 2017, 07:13:52 pm
content: I was wondering if anyone knows when Nichia made the first UV LEDs ( 370nm ) in about 2005 or so, with the part number NSHU550, if the company always printed on the LED case itself the Nichia part number. I have the opportunity to acquire some of these LEDs, but I would like to confirm this information.
Nichicon Capacitor Polarity Marking Question - Page 1
Forum section: electronics / projects

author: bostonman
author_rank: Super Contributor
timestamp: January 11, 2023, 07:36:59 pm
content: I'm sure this question has been asked/answered, and I am actually confirming since the board doesn't have any markings.This capacitor looks bulged, so I plan to replace it. Does the black stripe indicate negative? Also, this is a 470uF 6.3V. I don't have a surface mount and plan to use a regular aluminum 470uF 25V (and also 105 degrees C) with the leads soldered to the pads.Is there anything different in these surface mount caps than a standard through-hole that I should consider?

author: Benta
author_rank: Super Contributor
timestamp: January 11, 2023, 08:20:14 pm
content: I wouldn't bet on it.The base chamfer is a precise indication of the orientation.Check the data sheet.

author: mariush
author_rank: Super Contributor
timestamp: January 11, 2023, 08:28:50 pm
content: Flat side of the base is usually the negative :https://industrial.panasonic.com/ww/products/pt/aluminum-cap-smdYou could also desolder the capacitor and just follow the trace you think it's negative .... see if goes to an IC, then pull the datasheet for that IC and see if that pin is ground ... then you know that side of the capacitor is negative.Sometimes polarity is marked on the circuit board.Some manufacturers used the wrong markings on the circuit board on purpose ... for example Pegatron Group (Asus, Asrock) used to make their motherboards have drawings of capacitors with the black bar on the positive side... so don't rely on board silkscreen, always double check where possible.

author: TimNJ
author_rank: Super Contributor
timestamp: January 11, 2023, 08:36:55 pm
content: The can/shell is also 99.9% of the time connected to the negative terminal, so you can check continuity between can and pins and see what’s connected. But, best is just to find the original datasheet!

author: bostonman
author_rank: Super Contributor
timestamp: January 12, 2023, 01:41:19 am
content: QuoteReally? That's playing dirty.This board is a module from a car that a buddy gave me to resolder resistors that were falling off due to aged (?) solder. Apparently this is a common issue on this module, but I found the resistors to literally fall off the second I touched one side with the iron.I'm uncertain which points are ground and the chips seem to be either obsolete or special. They have 'Prince' on them.Any capacitor datasheet I found for Nichicon has the marking on it. As mentioned, I'll try measuring pin to can, and try finding an obvious ground. Does the plastic base indicate anything because one corner isn't round?
Nichicon capacitor reforming (JIS C 5101-4 clause 4.1 at 20°C) - Page 1
Forum section: electronics / projects

author: not1xor1
author_rank: Frequent Contributor
timestamp: November 30, 2016, 10:56:01 am
content: Hi,I'm new hereNichicon electrolitic capacitor datasheets refer to "voltage treatment based on JIS C 5101-4 clause 4.1 at 20°CI googled for more details but was not able to find any useful informationDoes anybody know what do they mean?thanks

author: Cliff Matthews
author_rank: Unknown
timestamp: November 30, 2016, 11:30:19 am
content: Looks like they sell it.http://standards.globalspec.com/std/1297553/jsa-jis-c-5101-4Some brief info here:http://www.qsl.net/g3oou/reform.html

author: not1xor1
author_rank: Frequent Contributor
timestamp: December 01, 2016, 08:41:44 am
content: Quote from: Cliff Matthews on November 30, 2016, 11:30:19 amthanksI thought it was just something like: "set the supply voltage to x%V of the nominal one with a series resistor of y ohm until the current gets lower than z A or for w hours"ok... I'll try to figure that by myself... I'm just an hobbyist...

author: EndlessSummer
author_rank: Newbie
timestamp: June 23, 2018, 03:50:13 pm
content: Hi, pretty ancient post, but here's some related info from Nichicon regarding V treatment.https://www.mouser.com/pdfDocs/UCC_ElectrolyticCapacitorTechnicalNotes.pdfRegards

author: not1xor1
author_rank: Frequent Contributor
timestamp: June 23, 2018, 04:48:36 pm
content: Quote from: EndlessSummer on June 23, 2018, 03:50:13 pmI had completely forgot about this thread of mine.At first I thought somebody else had stolen my ID.In any case thanks. I'll have a look at that pdf.
Nikko GP15 circuit board - Page 1
Forum section: electronics / projects

author: Lucky-Luka
author_rank: Unknown
timestamp: January 07, 2021, 09:46:15 pm
content: Hi allI'm new in the RC world.A friend of mine has an old Nikko GP15 with a circuit board that doesn't work anymore.Do you think there's a schematic of it? I've tried to but I couln't find it.Can anyone tell me what those 3 integrated circuits are for and what those 2 relays are for?Is there any similar board schematic or description that I can use to learn something about this board?Cheers

author: m k
author_rank: Super Contributor
timestamp: January 12, 2021, 07:23:06 pm
content: Are all elcap tops flat?Few looks a bit bulky but picture is less than optimal.

author: Lucky-Luka
author_rank: Unknown
timestamp: January 12, 2021, 08:49:43 pm
content: It's a good idea to replace them.
Nikon 600D external power / trying to find a compatible connector - Page 1
Forum section: electronics / projects

author: haggi
author_rank: Newbie
timestamp: April 05, 2020, 10:42:09 pm
content: TL/DR: I am trying to find a compatible connector. See picture.Hi folks,just like many other people, I am currently stuck in my "home office". I have a chair, my desk is okay, but the picture I get from my 10 year old potato webcam really makes me cringe. I do own a Nikon D600, but if I want to use it as a webcam stand-in, I really need to power it externally, otherwise I'm limited to the runtime of the factory battery, which is 6+ years old.There was an accessory battery grip (which I do not have), but the connector (image attached) should be great to power the cam externally. I've tried using digikey - but I could not even identify the right category.Can anybody help me to find a compatible connector?Just so you know, I am aware, that I can just connect an external power supply to the battery terminals, and I've been working on a printable 3d model of the battery to achieve just that, but that requires the battery door to be removed or stay open - I'd like a "plug-and-play" solution.Any help appreciated.haggi

author: olkipukki
author_rank: Frequent Contributor
timestamp: April 05, 2020, 10:48:42 pm
content: Why so complicated or have I missed something?Nikon's copy cat solution, for example,https://www.amazon.de/Smartpow-Netzadapter-Akkuadapter-Kompatibel-Stromadapter/dp/B07PLCGVHX

author: ANTALIFE
author_rank: Frequent Contributor
timestamp: April 06, 2020, 01:36:25 am
content: Can guarantee that's a custom connector. Your best bet would be to:Use an adapter like olkipukki suggestedFind a cable that fits the connector and splice it up

author: haggi
author_rank: Newbie
timestamp: April 06, 2020, 10:28:35 am
content: Quote from: olkipukki on April 05, 2020, 10:48:42 pmI've been looking at those, but they are a hassle to use. They require the battery door to be removed (which will wear out the mechanism) or left open (which restricts the mounting solutions I can use). I'd really like a solution that is easy to remove the camera from, so that I can just grab it, put the battery back in and to shoot some pictures.Quote from: ANTALIFE on April 06, 2020, 01:36:25 amI've dreaded that.So I should probably buy something likethisand tear into that to connect an external power supply.

author: olkipukki
author_rank: Frequent Contributor
timestamp: April 06, 2020, 11:31:53 am
content: Quote from: haggi on April 06, 2020, 10:28:35 amNo issues for me.I'm using the adaper with a camera on a tripod only, still need to detach it if would like take it back to my hands.
NiMH Balancing? - Page 1
Forum section: electronics / projects

author: ANTALIFE
author_rank: Frequent Contributor
timestamp: March 23, 2018, 09:44:15 am
content: M8'sI want to charge x3 NiMH's in series with a solarcell-DCDC converter (ST SPV1040). It has a programmable current limit but that's about it, so no temperature or -deltaV monitoring for charge termination.My question is which is the better topology for charging the NiMH's, is it even worth trying to use 1Meg resistors to try and balance the cells?

author: capt bullshot
author_rank: Super Contributor
timestamp: March 23, 2018, 10:00:55 am
content: There's no gain in using these 1M resistors1. they're way too large to do anything but slowly discharge the cells2. NiMH is equalized by slightly overcharging the "faster charged" cells. That's well within their specs, and common practice.The only alternative to series charging (identical) NiMH cells is to charge them seperately, each one with its own charge termination circuit. That's what the better chargers do.NiMH cells don't like continous charging (or trickle charging) for longer periods, this will kill them. So you definitively want some kind of charge termination circuit here.

author: ANTALIFE
author_rank: Frequent Contributor
timestamp: March 23, 2018, 10:10:30 am
content: Quote from: capt bullshot on March 23, 2018, 10:00:55 amRighto thanks for that. Will leave the 1Meg resistors out and just go with a series combination. Guess my charge termination for now will be the sun not shiningEDIT: Also if I was to leave the 1Meg resistors in there then they won't do much discharging, we talking ~1.2uA
Nimh CC charging circuit help - Page 1
Forum section: electronics / projects

author: sahko123
author_rank: Frequent Contributor
timestamp: February 17, 2022, 11:55:49 am
content: Heyo everyone I wanted to see if anyone can find any particular faults with the following cc charging circuit. The boost converter will take 5v from a USB qi charger and boost it. The feedback is handled by a diff amp on a shunt resistor to allow for a cc charging current of 500mA which is about 0.25c for the battery. The next opamp uses a zener to prevent overvoltage by increasing the feedback voltage and reducing the boost voltage. With a diode to prevent reverse current going back into the boost converter. Diagram shown below.Can anyone find any potential issues with the circuit as is? In terms of charging and overvoltage protection? Thanks in advance for any replies.

author: Vovk_Z
author_rank: Super Contributor
timestamp: February 17, 2022, 03:35:22 pm
content: You can use old good LM317 for that with both CC and CV modes without any opamp. Look at datasheet (or application note) for a needed circuit. Just set step-up converter for needed voltage plus 3 VDC for LM317 additionally.
NiMH Charger Schematic - Page 1
Forum section: electronics / projects

author: girishv
author_rank: Regular Contributor
timestamp: April 25, 2021, 04:24:12 pm
content: This is a NiMH discharge/charge circuit based on NXP application note AN3392, which can be found athttps://www.nxp.com/docs/en/application-note/AN3392.pdf.I have attached the simplified diagram posted found in the above mentioned application note.Will this work or need any changes?

author: Pineapple Dan
author_rank: Contributor
timestamp: April 25, 2021, 04:35:15 pm
content: You have no significant size capacitor on the input and none on the output. I'd put a few 100uF on both sides, but it depends on frequency of course. What are you using to drive Q1B and what frequency?

author: girishv
author_rank: Regular Contributor
timestamp: April 25, 2021, 06:27:56 pm
content: Quote from: Pineapple Dan on April 25, 2021, 04:35:15 pmThe original circuit has a 330µF and 0.1µF capacitors on input. None on the output side.I will add 3 x 47µF capacitors on input. I am planning to use a PIC16 running at 16MHz. The ADC acquisition and conversion time will decide the switching frequency. Probably I can make provision for capacitors on output and decide on values later.

author: girishv
author_rank: Regular Contributor
timestamp: April 26, 2021, 01:52:26 pm
content: I got a email notification saying @Le_Bassiste has posted a reply to this topic. The thread on the forum shows no such reply?Anyone knows what is going on?
Nintendo 3DS XL microphone type - Page 1
Forum section: electronics / projects

author: KRSO
author_rank: Newbie
timestamp: April 06, 2018, 01:23:36 pm
content: Hi.Do anyone know what type of mems microphone that are used in Nintendo 3DS XL?Analogue? Single or differential?Digital? I2S or PDM?There are 4 wires. The pads a pretty standard on mems mics, so I guess it's possible to assume what the different wires are as soon as I know the interface.The reason I'm asking is that the mix flex module is cheap and the PCB connector is cheap. So it could be a very nice mic to add on my own projects. But I would like to know the interface to the codec before I order a sample.Best regards..

author: KhronX
author_rank: Frequent Contributor
timestamp: April 06, 2018, 04:26:57 pm
content: After having browsed through a few datasheets on Mouser, my guess would be that it's analog.The digital ones seem to have 5 signals, while the analog ones have power, output and two ground pads (likely connected to those two outermost traces on the flex?).

author: SiliconWizard
author_rank: Super Contributor
timestamp: April 06, 2018, 05:01:04 pm
content: Quite frankly, I'm not sure it's worth the trouble trying to get ahold of any information on this. It may even be a customized part made for Nintendo, as they probably would do anything do save any penny on those consoles.You can find many MEMS microphones on breakout boards, such as this:https://www.adafruit.com/product/3421or this:https://www.tindie.com/products/onehorse/ics43434-i2s-digital-microphone/?pt=ac_prod_search, at least they are fully documented. And I2S microphones are easy to interface to microcontrollers having at least an I2S-capable peripheral, there's a lot of them.So unless you absolutely need those on flex to minimize footprint, or intend to build a high-volume series, I personally wouldn't bother.

author: KRSO
author_rank: Newbie
timestamp: April 06, 2018, 05:28:41 pm
content: I agree that it´s most likely a singel ended analogue mems.Even if it´s custom made for Nintendo, there is always a way to use it if you are making your own PCBs.And yes, the point was the flex PCB. Flex PCB are unfortunatily too expensive to custom make for DIY.

author: amyk
author_rank: Super Contributor
timestamp: April 07, 2018, 01:23:18 am
content: Pretty sure it's analog. Looking at other's teardowns and analysis of 3DS hardware, the mic is connected to a TI IC (AIC31xx family) with an analog mic input and ADC.