hybridfree/eevblog-posts huggingface dataset:
INA 326 and transducer - Page 1
Forum section: electronics / beginners

author: spintinas
author_rank: Contributor
timestamp: March 04, 2018, 04:25:27 pm
content: Hello, I have a question about INA 326 instrumentation amplifier and pressure transducer. I use a circuit from INA326 datasheet 9 page, except I don't use filtering at output of amplifier. R1=4,7k, R2=100k, so gain could be aproximetely 40-50. On the pin 5, I connect 100k resistor and 0,1uF condensator. Problem is that, when I apply pressure to my transducer voltage between data signals is 30mV. So, for my gain, output voltage could be about 1,2-1,4V, but when i check voltage with multimeter I see only 160mV, and when I applied more pressure to my transducer, voltage in the output of amplifier didnt change, still 160mV. Both, transducer and amplifier powered by Arduino, and I check voltage between amplifier output pin and common ground in the breadboard. What can be problem? I attach INA326 datasheet and my breadboard connected circuit, maybe there are some connection errors.http://www.ti.com/lit/ds/symlink/ina326.pdf
INA219, multiple sensors, Zanshin library - Page 1
Forum section: electronics / beginners

author: octavio
author_rank: Newbie
timestamp: October 29, 2019, 07:47:24 pm
content: Apologies in advance if this is posted in the wrong forum or if too rudimentary a question.I'm working on a DAQ system for an off-grid PV solar system w/ battery. I'm using an Arduino Micro to manage the data, SD card writer, DS3231 RTC, and seven INA219 sensors to measure various power flow at various points in the system. I'm using theseINA219 kits, basically an Adafruit clone. I've soldered the A0/A1 address inputs to create 7 unique addresses for the INA219. I've removed the included 100mOhm 2512 SMD resistor and replaced it with these20mOhmand30mOhmmetal foil 1% resistors. I can hook up all 7 INA219 simultaneously and read address, voltages, currents, power from all 7 usingZanshin's excellent library.- so far so good.I've run each INA219 individually thru a constant current PSU to measure in-situ resistance and have milliohm readings to match. I'd like to use the program registers in the INA219s to set the correct current range and resistance values so the output is accurate. Mind you I have 2 different nominal shunt resistor values in the 7 units; actually 7 unique shunt resistor values to be programmed. When the registers are set right, the accuracy and stability of these INA219 are really impressive. I think me and INA219 will become good friends.But here's where I have a problem, with I'm sure a simple solution. How do I instantiate unique classes of these 7 sensors so I can address them individually, and set their respective registers? I know, this is a code question more than an EE one, but I figured if anyone around the world would know, my fellow EEVbloggers would.Thanks in advance for any hints you might offer. I'd be happy to provide additional details or answer any questions you might have.

author: Zanshin
author_rank: Contributor
timestamp: November 01, 2019, 07:48:18 am
content: Hi octavio,the INA-Library allows you to set each device's shunt value separately - see the documentation for the "begin()" function athttps://github.com/SV-Zanshin/INA/wiki/begin()
Incomplete project - Page 1
Forum section: electronics / beginners

author: Neutronoman
author_rank: Newbie
timestamp: March 16, 2020, 03:57:09 pm
content: I would like to build a hot soldering station. I have found an instructible that I like, but no schematic was included, so it seems impossible. I have looked for other projects that do the same thing, but have had no luck. Is there someone here that could look this over and supply the missing information?Thankshttps://www.instructables.com/id/Home-Make-a-Cheap-Hot-Air-Soldering-Station/

author: senso
author_rank: Frequent Contributor
timestamp: March 16, 2020, 04:26:04 pm
content: There is a download link with the supposed board layout, but that seems like making a custom controller to a cheapo hot air gun, why not just grab the whole thing already made from eBay?Search for 858D:https://www.ebay.com/itm/858D-220V-SMD-Soldering-Desoldering-Station-Hot-Air-Rework-Gun-Tool-3-Nozzles/264476224394

author: Mechatrommer
author_rank: Super Contributor
timestamp: March 16, 2020, 05:07:12 pm
content: you can get the gerber file in original youtube link...https://www.youtube.com/watch?v=J1eeouylhaQ&feature=youtu.behttps://drive.google.com/file/d/19x51h-POU06XrHvHm_YVzNDjd1VOM2gC/view
incorrect DC analysis of JFET at university?? - Page 1
Forum section: electronics / beginners

author: gcgrant
author_rank: Contributor
timestamp: October 01, 2016, 03:51:44 am
content: Can somebody please check the sums below, I have a feeling our lecturer has made a mistake and we have an assignment due with similar questions this weekend need to know that I am doing it right. Here's the question I posted to the university forum:Cheers,G.

author: gcgrant
author_rank: Contributor
timestamp: October 01, 2016, 03:55:03 am
content: Here is a better screenshot of the lecture slide:

author: Andy Watson
author_rank: Super Contributor
timestamp: October 01, 2016, 08:55:43 am
content: Assuming you want maximum signal amplitude without clipping, the Q-point is not half of the supply voltage (I make it to be about 5.62V).

author: LvW
author_rank: Frequent Contributor
timestamp: October 01, 2016, 09:02:16 am
content: The shown circuit must fulfill two conditions at the same time:(a)the FET condition (shown quadratic relation): ID=f(VGS) and(b)the ohmic rule for the source resistor: VS=ID*RS.From both relations the corresponding value for the source resistor can be computed. Hint: Always start with the non-linear equation.

author: gcgrant
author_rank: Contributor
timestamp: October 03, 2016, 12:52:04 am
content: Thanks, so I am right that based on the shown resistor values and the VDDvalue given, the example is incorrect in the way the VGSand IDhave been calculated?

author: LvW
author_rank: Frequent Contributor
timestamp: October 03, 2016, 09:00:08 am
content: Quote from: gcgrant on October 03, 2016, 12:52:04 amYes - I think so.When (a) the FET characteristic is completely specified (as in your case) and (b) the value of Rs is fixed, you have not the freedom to select the drain current.That means: If the current is required to be Idss/2 there is only one solution for the resistor Rs allowing this current.The quadratic FET equation gives you the correspondig VGS value - and Ohms law gives you the Rs value.

author: gcgrant
author_rank: Contributor
timestamp: October 03, 2016, 09:21:37 am
content: Excellent, thanks, that's exactly how I see it. Now I'm concerned if I do it the right way I'll be marked wrong 😯😧

author: tec5c
author_rank: Frequent Contributor
timestamp: October 03, 2016, 10:43:08 am
content: If I were you, I would do it the right way (why practice doing things incorrectly? It's nonsense...)However, I think you should speak with your lecturer about this and see what he/she has to say.If you don't mind me asking, which Uni are you at?

author: gcgrant
author_rank: Contributor
timestamp: October 03, 2016, 11:00:30 am
content: I don't think it's right to name publicly, plus they'll most likely throw some policy at me. But yes I will be definitely doing it right. Have been having quite a few mistakes from the lecturer in this unit...

author: tec5c
author_rank: Frequent Contributor
timestamp: October 03, 2016, 11:26:37 am
content: Quote from: gcgrant on October 03, 2016, 11:00:30 amInteresting...
incorrect drilling file and missing dcode when import gerber file - Page 1
Forum section: electronics / beginners

author: printedcircuit
author_rank: Contributor
timestamp: January 29, 2016, 10:28:00 am
content: I have trouble to view the gerber file send by other designer.I use CAM350 to review gerber files sent by other designers. In some gerber files, i saw huge holes which stack on each other looks like a pool in the drilling file. i think there must be some measurement setting difference between my CAM350 and those gerber files. it always took me quite a while to guess the right settings. And i also have problem to import the dcode from those gerber files. it makes all the trace appear to be 0 width. any solution to those 2 problems?I have asked this question somewhere else. but nobody answered to my problem. any help?

author: uncle_bob
author_rank: Unknown
timestamp: January 30, 2016, 06:00:13 pm
content: HiThe first place to start is to ask what program the other guy used to generate the gerbers and the drill files. Often the solution is a switch setting on your end to make it "Stupid Program A" compatible. The root cause is related to a whole world of people working with a set of standards that are only loosely defined.Once you know what program does what, there often are things embedded in the comments on the files that will let you automate the switching process.There are a few dozen other things that could be going on, but that's where I would start.Bob

author: printedcircuit
author_rank: Contributor
timestamp: February 18, 2016, 03:00:41 am
content: Quote from: uncle_bob on January 30, 2016, 06:00:13 pmHello Bob,thank you for your suggestion. however, most of my customer does not include the gerber output setting in their file. It takes me and my customers at least another day to verify the setting of the gerber file. so, i have to guess the decimal, integer, English/metric units setting and so on of those files. it takes some time. but it still save the lead time than ask my customers. I would like to know if there is some sort of code in the drill file which tells the correct setting.

author: uncle_bob
author_rank: Unknown
timestamp: February 18, 2016, 03:06:24 am
content: Quote from: printedcircuit on February 18, 2016, 03:00:41 amHiThe drill file (nc drill) has drill size information in it. At least I think it does. I don't have one handy, but it's part of the coding. The file format is very much like a cad /cam instruction file in that regard. I'll take a look at one tomorrow.Gerber is similar in that it started as a machine instruction file (photo plotting) as you obviously know both files come in way to many variations and measurement unit combinations.Bob
Increase (Boost)  Clock frequency  - Page 1
Forum section: electronics / beginners

author: toinhatminh
author_rank: Newbie
timestamp: April 30, 2014, 03:22:26 am
content: Hi Pro,I have a question about Boost Clock Frequency.I really don't understand how people can boost the Clock frequency. Example from 32768 HZ to 24Mhz.The doc shows " In FEI mode, MCGOUTCLK is derived from the FLL clock (DCOCLK) that is controlled by the 32kHz Internal Reference Clock (IRC).The FLL loop will lock the DCO frequency to the FLL factor, asselected by C4 and C4 bits, times the internal reference frequency. See theC4 bit description for more details.I don't understand how does it work ? ( Bold sentence).if you have any document about this or please share with me,Thank you very much,Minh.

author: Skimask
author_rank: Super Contributor
timestamp: April 30, 2014, 04:00:33 am
content: Quote from: toinhatminh on April 30, 2014, 03:22:26 amWhat people?QuoteWhat doc?QuoteWe can't really understand the question (not a bold sentence)Quotehttp://bit.ly/1fOBGa9

author: cyr
author_rank: Frequent Contributor
timestamp: April 30, 2014, 06:08:52 am
content: http://en.wikipedia.org/wiki/Digitally_controlled_oscillatorhttp://en.wikipedia.org/wiki/Frequency-locked_loopAlso, good video on phase-locked loops (almost the same thing)

author: toinhatminh
author_rank: Newbie
timestamp: April 30, 2014, 08:40:57 am
content: HI CYR,thank you for your helpful links.Minh.
Increase gpio pins in esp32 - Page 1
Forum section: electronics / beginners

author: Rishles69@
author_rank: Regular Contributor
timestamp: January 05, 2024, 12:57:50 pm
content: So i got two PCF8574 ics for expanding gpio pins in my project. Each ic provides 8 pins so that 16pins. In one chip, im deciding to connect 4 switches and in another ic, im connecting the enable pins of 6 voltage regulators of 3.3 volt. How do the setup will be. And how can i use gpio pins to control the EN pins of these voltage regulators? And Does that actually work? and how much current does it draw, also, while connecting a switch with PCF8574 ic, Is the chip can wake esp32 from deep sleep?Thanks

author: tooki
author_rank: Super Contributor
timestamp: January 05, 2024, 06:12:13 pm
content: Quote from: Rishles69@ on January 05, 2024, 12:57:50 pm1. we aren’t designing the whole circuit for you, dude. In fact, you will need to provide a schematic (or at least block diagram) of your project in order for some questions to be answerable.2. What exactly is it you’re unclear on? You just drive the EN pin low or high. Whether it’s enabled when high or low you’ll have to read in the regulator datasheet.3. Does controlling regulators via EN pins with a microcontroller work? Yes. I’ve done it, controlling several different regulators to sequence their startup.4. How much current does what draw?5. The PCF8574 has an INT (interrupt) output, so it should be able to trigger the ESP32. Beware that the ESP32’s deep sleep is unusual, in that when it wakes up, it’s basically rebooting. So depending on your application, you may need to save your running state to EEPROM before going to sleep, so that you can resume it as it was and not reinitialize everything. If you need the ESP32 to respond very quickly, you may need to use regular sleep instead, though it uses more power.
increasing current peak for MC34063? - Page 1
Forum section: electronics / beginners

author: willbanks
author_rank: Contributor
timestamp: June 26, 2017, 01:01:23 am
content: I made a circuit that reduces 12V to 5V using the MC34063. I set it so it will provide 1 amp of current. The peak current is 2 amps, which is above the maximum current (1.5A).Could I increase the current if I put the 5V output to an LM317, which could provide that current boost?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 26, 2017, 08:45:42 am
content: A recommendation:https://imgur.com/gallery/SoYtht4

author: willbanks
author_rank: Contributor
timestamp: June 27, 2017, 01:19:05 am
content: $7 for a chip? hell no

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 27, 2017, 09:54:22 am
content: $7 where?
Increasing I2C bus distance limitation - Page 1
Forum section: electronics / beginners

author: mikes603
author_rank: Newbie
timestamp: December 31, 2013, 02:39:28 am
content: Ok, so my little project has 4 I2C sensors that need to travel around 3 meterseach, in a hub topology (uC/ master at the center). And I'm trying to size up my options to go past the ~2meter I2C spec based on 300pf.Should I use a I2C Port Extender? And do all of them require an IC at each end?Or should I use an I2C Hub?If anyone has any input, and an example schematic, that would be wonderful. Thanks gents.

author: Maxlor
author_rank: Frequent Contributor
timestamp: December 31, 2013, 05:36:37 am
content: Meh, just go ahead and try it. You might find the sensors work just fine. If you really do see errors, a couple of things come to mind that you could try before making the design more complex by introducing repeaters:Take advantage of the hub topology and use a microcontroller with several I2C controllers, and put only two (or only one) sensor on a bus.Slow down the communication rate. You can go way slower than 100kHz although some devices reset their I2C controller if nothing happens for some time.Use thinner wires.Play with the size of the pull-up resistors, or add an RC filter to the I2C wires if they pick up too much noise.

author: free_electron
author_rank: Super Contributor
timestamp: December 31, 2013, 01:14:45 pm
content: If you want to make it robust use the 82c815 (i may have that number wrong) it is an 8 pin bus extender that runs on high voltage. 5 or 3.3 one side and 12 to 15 other side. I have ised such extenders over very long distances. 300 meters and more over cat4 phone cable. Twist sda with ground and scl with power. The power in this case is 12 to 15 volt and use a local regulator to make the logic supply.

author: ConKbot
author_rank: Super Contributor
timestamp: December 31, 2013, 01:36:55 pm
content: Ribbon cable is pretty low capacitancehttp://multimedia.mmm.com/mws/mediawebserver.dyn?6666660Zjcf6lVs6EVs666Ua2COrrrrQ-(3M ribbon cable PDF datasheet)even between 2 ground conductors its 47.5 pF/m, but for a single pair its 26.7 pF/m. If if you pin it out so it would be SDA/GND/unused/SCL/VCC/ you would be marginal, at 320 pF.If you can slow your bus down to under 100KHz and add slew rate limiting(resistor in series would work, just make sure you the driver can still pull the bus down as needed , you can limit any issues with reflections. Do you have a scope so you can check your waveforms?I'm not 100% sure, but I suspect the bus capacitance would be limited so that the spec'd 2k2 resistors can pull the bus back to high quickly enough, and that by either slowing down, decreasing the value of the pullup, or using an active pull up (LTC4311 possibly? ), you could get away with extra capacitance.
Increasing the voltage output of a laptop SMPS - Page 1
Forum section: electronics / beginners

author: mosafet
author_rank: Contributor
timestamp: January 29, 2022, 12:37:24 am
content: I'm looking to modify a power supply to get a little more voltage out of it.The 19.5V version of my power supply's schematic ishere(not sure if I should attach it, it's watermarked).I have the 20V version. The primary differences I see are on the feedback circuit (lower right). R301 R315 and R306 are different values on mine, presumably to increase the voltage to 20V. I want to go to 23V or so. The output capacitors are rated at 25V so kinda questionable even with the stock configuration. 35V would make more sense but I don't think I can physically fit them inside the case.At first I thought it would be simple, just modify R301 but then I realized that would also change the 5V rail(?) and that can't be increased without possibly damaging something. Now normally I could experiment and test things to see how it's going to work but this is complicated by the fact that there are multiple parts all interacting and it's not possible to test individual modules(?). I think I might try tweaking R301 a very tiny amount and see what happens. Probably decrease the resistance and see how much that lowers the 5V. Though testing the 5V side is not my idea of fun because it's on the high-voltage side with tiny parts.Is there any way to calculate the approximate resistor values I would need so I don't have to test a live system?

author: PartialDischarge
author_rank: Super Contributor
timestamp: January 29, 2022, 04:54:57 am
content: You would be also modifying the bias of the optocouplers. Don’t change the output voltage more than 10 or 15% max, overall there is not going to be much room, these designs are more tricky than they seem

author: magic
author_rank: Super Contributor
timestamp: January 29, 2022, 09:11:36 am
content: https://www.eevblog.com/forum/projects/modding-switchmode-psus-for-different-output-voltage-and-why-it-sucks/The auxiliary rail is tied with the secondary by turns ratio. Increasing the secondary by 15% increases AUX by about the same. The limiting component is Q065, whose power dissipation will increase. Hard to tell more without knowing the exact voltages and Q065 package type and power rating.R301 (and R302) set the regulated secondary voltage.R306 sets the secondary current limit, yours must be different than 19V.R315 sets bias of the internal reference in TSM103; range tolerated by the IC is likely pretty wide.For peace of mind I would scope the circuit above the output rail, which appears to be synchronous rectification control. Make sure that the zeners aren't being permanently overloaded.

author: mosafet
author_rank: Contributor
timestamp: January 29, 2022, 06:11:40 pm
content: Thanks! I had searched but somehow missed that post.I was worried it was way more complicated than I thought which is why I posted. I may have to reconsider especially considering if changing the design requires so many component changes it's not going to be worth it.
Individual Led bright match - Page 1
Forum section: electronics / beginners

author: Matrixx
author_rank: Newbie
timestamp: February 01, 2014, 12:38:05 am
content: Hello, I'm working on a project where I use 3 leds to indicate alarmc light status inside a vehicle.So I have green, yellow and red, and my voltage should be from 3.0 to 3.2 max as I'm using a Li-ion battery rated at 3.7V,. 3.3 regulator is used.Happen that with the 20mA as indicated, the leds brightness is not equal. Green seems to be brighter, yellow mid bright but red is kind dimmed. each one has its own resistor, of course.I'm using an Atmega328p to control the leds. What I did is to do PWM for each one, so I can adjust for "night" time (dimmed), so the leds do not cause vission problem in the car cabin, and "day" as many bright is need to be seen.PWM worked ok, but I still have the problem of uniform brightness: green is the strongest. Also I find green starts to be vsible with lower PWM values while the yellow and red are still off.I decided to increment the green resistor, and for the low level, it worked, say in "night" mode. But raising the yellow and red, now the green lacks of bright, due to the incremented resistor.Someone has dealed with this situation..?Also I'm looking for a led part number 3mm to have enough brightness using Li-ion available voltages (not the richness of 5V).Any comments welcomed.

author: Psi
author_rank: Super Contributor
timestamp: February 01, 2014, 02:16:58 am
content: Part of the issue is that the human eye is very sensitive to green and not very sensitive to red.So a green LED will always seem brighter than a red when they're emitting the same amount of light.If you only have a few set brightness levels just hardcode the values so they look correct.If you need fine brightness control you will need to write a simple formula to correct for the brightness variations of each LED.Work out 5 brightness levels with equal looking RGB values and plot the actual PWM values on a graph to help you visualize the problem. You can then work out some math to generate a corrected PWM value from a brightness value.

author: lapm
author_rank: Frequent Contributor
timestamp: February 01, 2014, 05:43:44 pm
content: Also different color leds has different forward voltage. You better refer to datasheets of manufacturer.

author: Matrixx
author_rank: Newbie
timestamp: February 02, 2014, 02:26:45 am
content: Thanks!!I think will have to run in the formula to adjust dinamically.Great forum!
Individually switched leds and dimming - Page 1
Forum section: electronics / beginners

author: StyxF2
author_rank: Contributor
timestamp: April 11, 2023, 01:45:04 pm
content: Hi All,I have a circuit as in the attached pic. Each of J2 pins 1-8 are switched with 28V, activating each led individually. Additionally, theres a 'test' switch on J1 that will light all the leds as the same time to test them.Im looking at a method to dim all these leds (together, not individually) for low light conditions, while when the test switch is pressed, they all display at full brightness. The dimming is going to be controlled by a 0-12V signal. Im thinking the best way is to find an MCU with 8pwm outputs, hopefully supplying enough current to run all the leds (Or switch them with a transistor if not), and ADC for the dimming input and GPIO for the test switchHowever does anyone know of any options that could run this without an MCU and code?

author: drvtech
author_rank: Regular Contributor
timestamp: April 12, 2023, 01:46:45 pm
content: You could take the common point of the LEDs to ground through a transistor and apply a pwm waveform to that and then override it with the signal from the test button.

author: StyxF2
author_rank: Contributor
timestamp: April 16, 2023, 12:40:51 pm
content: thanks drvtech!! that worked a treat, not sure why i ddint see it, but very happy it works!
Inductance - Page 1
Forum section: electronics / beginners

author: lastwarrior
author_rank: Contributor
timestamp: April 27, 2015, 07:24:47 am
content: Please help me) . I'm studing now about inductance , and there is a moment that i really can't figure out. I know that passing a current through an inductane generats a magnetic field , that this field stores energy that form induced voltage Vl . And that this voltage generate a current that try to minimize changes , when the applied current is rising , the field expands and induced voltage produce a current in opposite direction and vise-versa , when applied curent is falling , vl is same polarity and generate a current that is trying to rise it up. But reading further i saw this little graph where aplied current , rate of current change and induced voltage are plotted. And looking on the Vl graph i really cant understand what is happening there. What i mean? for example : in 1 part (0 to 90 degrees) applied current is rising and it has it's normal polarity , Vl is falling but it does not have opposite polarity to I , as i understood Vl must generate a opposite direction current to applied one to minimize changes. I cant understand why in the 1st an d 3rd quarter-cycle Vl hassame polarity and is deacreasing while it must oppose to I?

author: RobertHolcombe
author_rank: Frequent Contributor
timestamp: April 27, 2015, 08:29:23 am
content: I'm not going to try to explain it in my own words because there are plenty of resources available already so I will just point you in what I hope is the right direction, this was the most concise explanation I could findhttp://hyperphysics.phy-astr.gsu.edu/hbase/electric/phase.htmlhttp://hyperphysics.phy-astr.gsu.edu/hbase/electric/acind.html#c1Also check out Lenz's law

author: lastwarrior
author_rank: Contributor
timestamp: April 27, 2015, 10:19:48 am
content: thank you .

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 27, 2015, 03:44:09 pm
content: Umm...the plot shows VL negative in quadrants II and III?

author: lastwarrior
author_rank: Contributor
timestamp: April 28, 2015, 07:32:15 am
content: I finaly understand what is going on there. Thank you for your response.
Induction Cooker - Page 1
Forum section: electronics / beginners

author: rufzal
author_rank: Newbie
timestamp: April 13, 2013, 04:30:03 pm
content: I couldn't find any books or website regarding troubleshooting/repair of induction cooker over internet.Please help me to repair Induction cooker whose time of heating up of bowl of water has become very much large i,e;heating became too slow. I replaced the coil but it didn't made any differnce
induction heater schematic needed thank you - Page 1
Forum section: electronics / beginners

author: TechnicsHiFiFan
author_rank: Newbie
timestamp: March 24, 2020, 06:35:30 am
content: Hello All,I can do basic repairs on my amplifers, and am able to read circuits, to some degree, and do fine solderingI want to build an inductor for my dynavap ( for cannabis)I have seen some around the internet using cheap parts from china ( pre assembled). I have been trying to find a schematc for them, so i could build it with better and more reliable partshttps://www.ebay.com.au/itm/5V-12V-Low-Voltage-ZVS-Induction-Heating-Power-Supply-Module-Heater-Coil/333435637761?epid=6026505883&hash=item4da2501001:g:nKgAAOSwewJd8MefThanksSam

author: Weston
author_rank: Regular Contributor
timestamp: March 26, 2020, 05:43:32 am
content: This website has some details + schematic for the ZVS induction heater oscillator, the listing you linked to is probably pretty closely based on it:https://spaco.org/Blacksmithing/ZVSInductionHeater/1000WattZVSInductionHeaterNotes.htmYour biggest electrical concern with parts / kits from China is going to be fake power transistors. However, the power level you need for a vape is going to be pretty low, so you should have a lot of leeway. I expect anything sold as an assembled kit is going to work long enough to allow the seller to reject any return requests.Also, based on your youtube I can not tell if you have a fuse. If not, add one! LiPo battery packs can source a large amount of power into a short and DIY power electronics have a tendency to go boom.
Induction Motor speed control idea and question? - Page 1
Forum section: electronics / beginners

author: cimmo
author_rank: Frequent Contributor
timestamp: January 20, 2014, 07:54:45 am
content: I have recently built a standard triac chopper circuit to provide speed control of a permanent split capacitor induction motor driving the fan in a rangehood. It works well except for the hum (that was not a surprise).My question is: if one full mains cycle was fed to the motor in every x number of cycles (with switching at the zero crossing point), would this drive the motor without significant hum?Using optocouplers and a picaxe, I think this pseudo PWM control would work, but I am interested to hear any ideas yay or nay on the proposal?Edit: Further thought: intermittent triggering of a zero-crossing solid state relay?
Inductive sensor with microcontroller - Page 1
Forum section: electronics / beginners

author: Veketti
author_rank: Regular Contributor
timestamp: January 22, 2023, 03:09:53 pm
content: Hi,I'm trying to connect PNP inductive sensor pepperl+fuchs NJ5-18GM50-E2-V1 to 5V microcontroller for reading its state. I made following connection to protect the input as the sensor will be supplied with +24VDC and micro 5VDC. However I'm seeing 2,5V in the UC input when sensor is not sensing and not 0,5V of the Vf of diode. If I connect the +24 directly to pin 4 removing the sensor it works as I was expecting. Eg. no supply, uC input 0,5V and 24V supply uC input 5V. I don't understand why it wont work with the sensor. Could someone explain what's wrong?I could also use voltage divider for the input but I'd see this is safer.Thank you in advance.

author: langwadt
author_rank: Super Contributor
timestamp: January 22, 2023, 03:32:57 pm
content: it is a PNP sensor it only pulls high, when it is off or the sensor disconnected you have a voltage divider between the 15k and the 12kthe 12k needs to be a lower value

author: Veketti
author_rank: Regular Contributor
timestamp: January 22, 2023, 04:10:01 pm
content: Ah, yes indeed. Stupid me. Thanks.What would be the ideal/better way of reading the sensor? I wouldn't want to drop the 12k value too much as it would consume much power when sensor is active..

author: BeBuLamar
author_rank: Super Contributor
timestamp: January 22, 2023, 04:10:21 pm
content: Check pin 4 of the sensor with the sensor powered up (pin 1 and 3 connected) and the sensor is off (not sensing) and measure the voltage between pin 4 and pin 3 and see if you have any voltage there. There may be some leakage current that cause a small voltage reading when the PNP transitor is off. But to be honest I use those type of sensors a lot and not notice the problem.

author: langwadt
author_rank: Super Contributor
timestamp: January 22, 2023, 07:43:04 pm
content: Quote from: Veketti on January 22, 2023, 04:10:01 pmyou can reduce the 12K and add another resistor in series with the input from the sensor to limit the current

author: Kim Christensen
author_rank: Super Contributor
timestamp: January 23, 2023, 04:27:41 am
content: The uC could still get damaged from static electricity or if a negative voltage was applied on the input. A much safer method would be to use an optocoupler which would also give you the benefit of eliminating ground loop problems if the sensor was some distance away. Or, if you're not worried about ground loops, a simple voltage divider with a 5V zener in parallel with the lower resistor could work also.

author: BeBuLamar
author_rank: Super Contributor
timestamp: January 23, 2023, 02:03:59 pm
content: I think a 5V zener between pin 4 and 3 is a good idea. The sensor is capable of 200mA so with some current going thru the zener isn't bad.
inductive spiking - Page 1
Forum section: electronics / beginners

author: joblessalex
author_rank: Contributor
timestamp: May 22, 2013, 10:38:31 am
content: Simple quick question(maybe). If you switch an inductive load with a transistor or fet, you get a spike. Is it possible to somehow capture this spike and store it in a capacitor? I'm thinking hv generator in a very small package here. All the attempts I made ended up in dead shorts.... So, is this possible? Think low current, high voltage.

author: Psi
author_rank: Super Contributor
timestamp: May 22, 2013, 10:42:00 am
content: That's exactly what a switchmode boost converter is.http://www.instructables.com/id/High-Voltage-Switch-Mode-Power-Supply-SMPSBoost/How many volts do you want to get out of it?A high frequency transformer maybe more suitable and smaller if you want really high voltages.Or perhaps a combination of either plus a tiny inverter and diode/cap multiplier.

author: joblessalex
author_rank: Contributor
timestamp: May 22, 2013, 10:50:51 am
content: Quote from: Psi on May 22, 2013, 10:42:00 amArgh! I knew I was missing something major here. I was looking around the 300-400 volt range. Just something to experiment with. If it is possible, 1000-2000 would be nice as well, then add a multiplier to it.
Inductive Throttle Sensor (ITS) rated DC 0.8V-4.2V on Alltrax rated ITS 6-10.5V? - Page 1
Forum section: electronics / beginners

author: Torxed
author_rank: Newbie
timestamp: July 13, 2021, 08:18:00 pm
content: Hi.Probably an oddball question but this is the only electrical forum I know of so I'm winging it hoping for the best.I've got aAlltrax SR 27300controller that is rated for/supposed to work with"6-10.5V & ITS Throttles".And I've been looking around for any decent twist throttle that operates in the 6-10.5V ranges, but all I can find is throttles with a working voltage of ~0-4V, for instanceGeneric Aliexpress Throttlesthat has a working voltage of 0.8-4.2V.I don't know much about inductive throttle sensors, but I assume the inductor inside them converts the 72V from the batteries across the positive and negative terminals and outputs the working voltage on the signal, in the above aliexpress product that would output 4.2V at full throttle? Or do I need to step down the voltage myself from 72v down to the operating voltage that the controller supports (6-10.5V)? And if so would a 0.8-4.2V throttle work despite it not living up to 6V minimum?The schematic I'm working with is theSR Generic Wiring (No Reverse)and a 72V battery system if that makes it easier to read than my summary.Apologies for any wrong wording or if the question isn't fully clear. The electrical field is not my main area of expertise.I might have misunderstood the whole inductive throttle setup entirely.Thank in advance, //Anton
Inductive/Capacitive sensor - how it works - Page 1
Forum section: electronics / beginners

author: nForce
author_rank: Frequent Contributor
timestamp: November 19, 2018, 06:20:20 pm
content: I have found this diagram (it's in german) but I think from pictograms you will understand what it means.This diagram is for an inductive sensor, so what does it mean and how does it work? I have read about it, but this diagram I don't understand.

author: SeanB
author_rank: Super Contributor
timestamp: November 19, 2018, 06:43:18 pm
content: From left to right is the sense coil and it's associated tuning capacitor. Then comes the oscillator that drives the tuned coil. Then the comparator that measures the amplitude of the oscillator signal, and finally the output stage that gives a signal that external units use.Basically the oscillator uses a tuned circuit, and as ferrous material ( or basically any metal) gets brought close to the coil, which is in a ferrite cup so there is a large air gap on the one end used for sensing, it has 2 effects on the oscillator. First is it changes the oscillator frequency, as it changes the magnetic circuit, and second it damps the oscillation as it extracts energy from the oscillator due to the loss in the metal. This is then detected by the comparator as a variation in either amplitude or frequency ( depends on the actual type) and this then is used to drive the power output stage. Output stage in industrial applications will be one of a variety. Either a NAMUR output dfor intrinsically safe sensor types, or a NPN or PNP type output stage, which either switches the output to ground or the supply rail respectively. Final type is AC only, and can be either 2 wire or 3 wire, 3 wire having a separate output line, and 2 wire relying on there being an actual relay coil, with a range of current between limits and also a range of AC supply voltages, so that when the sensing limit is reached operates the coil, with a small voltage drop when energised providing enough power to keep the sensor powered.
Inductor adapter for a digital multimeter. - Page 1
Forum section: electronics / beginners

author: merishi
author_rank: Newbie
timestamp: January 06, 2012, 03:07:38 pm
content: Have any one around here tried building or using any inductor adapter for a multimeter ? Is it worth trying or is this concept just a rubbish. I have seen some adapters on the webpages and thought of giving it a try. But wanted to hear from you guys whether it is worth giving a try or its just useless.http://www.electro-tech-online.com/content/464-inductance-measuring-adapter-multimeter.htmlI just wanted a simple decent DIY inductor meter because I couldnt find one on the market in my country...

author: eternal_noob
author_rank: Regular Contributor
timestamp: January 06, 2012, 07:54:31 pm
content: I won't say it's useless, but there are too many components that can affect the measurement result IMHO. It will need frequent calibration I'm afraid.There is a better method and that is to mimic many of those LC meters out there already, by using the Shifted Frequency of an oscillator, but this require that you have a frequency counter of some sort available. A counter on a multimeter will work just fine since it is thedifferencein frequency we are after, not an accurate one-spot frequency. We then manually calculate the C or L based on the difference. This method is accurate within 1 to 3 percent as long as the Q of the capacitor or inductor is reasonably good.It is also easy to inject a current through the measured inductor on different frequencies to see whats happening with all those ferrite cores scrounged over the years. Way more flexible!I have created a simple javascript calculator to use with this circuit but the coding is absolutely horrible and will make me stand out as a complete fool here on this forumBut, I will give it to you if you PM me. I can also help out with a calibrated inductor and/or capacitor (L1, C1) if you need to.
Inductor and capacitor selection for quarter wavelength switch - Page 1
Forum section: electronics / beginners

author: anvoice
author_rank: Frequent Contributor
timestamp: May 18, 2020, 08:51:17 am
content: I'd like to make a quarter wavelength T/R switch that will work at roughly 0.5-1MHz, to switch between transmitter and receiver signal. The simplest choice seems to be to use an equivalent representation for the roughly 50 to 100 meters of cable that I'd need for this. Such a representation requires at least one inductor, which I calculated to be about 8-16uH, from H = 50 / (2 * pi * f) for a 50 Ohm coaxial cable. It also needs two capacitors which I calculate to be approximately 3-6nF according to the formula: C = 1 / (2 x pi x f x Xc), where if I understand correctly Xc is 50.My problem is I don't know how close the inductor and capacitors need to be to the calculated values. After all, while I can wind my own inductor, the capacitors will be fixed, and due to tolerances will not even be exactly their nominal value. Do I need to use inductance and capacitance values that are exactly as calculated by the formula for the switch to work properly? Or will approximate values suffice? If so, how close do they need to be?
Inductor and radio module - Page 1
Forum section: electronics / beginners

author: r4r
author_rank: Contributor
timestamp: April 25, 2019, 09:03:38 pm
content: Hi everyone!Nice to be here!I'm very junior in PCB design and circuitry. In my first project I've placed shielded inductor (10uH - part of buck dc-dc converter) right next to SIM800L GSM module antenna. Is it acceptable?Thanks.

author: iMo
author_rank: Super Contributor
timestamp: April 25, 2019, 09:37:59 pm
content: The basic rule is to have the antenna placed at least lambda/4 off any conductive or feromagnetic part (lambda is the wavelength).

author: radiolistener
author_rank: Super Contributor
timestamp: April 25, 2019, 10:34:32 pm
content: if antenna loss is not important for you, it is acceptable.If it is important, then place your antenna at the distance not less than R = 2 * D^2 / lambda, but for very short antennas not less than R = lambda / (2 * pi). Where D is antenna maximum dimension size. Usually minimum distance is about lambda / 2, but it may depends on antenna size.

author: r4r
author_rank: Contributor
timestamp: April 26, 2019, 08:26:30 pm
content: Thanks, guys!If I get it right, shielded inductor doesn't emits radio interfering?

author: Zero999
author_rank: Super Contributor
timestamp: April 27, 2019, 09:27:53 pm
content: Quote from: r4r on April 26, 2019, 08:26:30 pmBut it absorbs or reflects radiation around the antenna, which will affect its performance.
Inductor ? Choke ? Do I need it? - Page 1
Forum section: electronics / beginners

author: made2hack
author_rank: Frequent Contributor
timestamp: December 22, 2014, 03:57:22 pm
content: Hello,So here's this little model train engine from way back in the 70s.I noticed on the inputs, it has what looks like cylindrical inductors? Chokes? They are cylinders wrapped in magnetic wire with what looks like a ferric core (it is not magnetic). I'm not sure what, but, do I need them?I mean the engine runs fine with or without them. I remember reading somewhere that DC engines need or it is preferable to have some kind of inductors on the input?But I'm not sure so I figured I'd ask.Thanks

author: Zero999
author_rank: Super Contributor
timestamp: December 22, 2014, 04:00:24 pm
content: It's always a good idea to connect inductors in series with a DC motor because it helps suppress radio interference. It may with without them but it could interfere with radio reception and some electronics, especially if you're using an electronic train controller.

author: SeanB
author_rank: Super Contributor
timestamp: December 22, 2014, 04:51:08 pm
content: Normally also with these small brushed motors there are 2 capacitors of between 10n to 220n from each terminal to the case along with the chokes. These are all to reduce RF noise and with the capacitors to prolong brush life as well by reducing arc voltage on the power lines.If they are not there you can hear the motor using an AM radio tuned off a station next to the layout.

author: Simon
author_rank: Unknown
timestamp: December 22, 2014, 06:02:02 pm
content: It's no different to what scalextric cars have.
Inductor code question - Page 1
Forum section: electronics / beginners

author: ivan747
author_rank: Super Contributor
timestamp: June 26, 2015, 11:16:28 pm
content: Quick question, cause I am uncertain and right now don't have access to many tools. I have an inductor that is marked 222J. What value would that be? I calculated 2.2mH but the circuit is not working as expected.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 26, 2015, 11:44:34 pm
content: You don't put an unknown inductor in a circuit. That's like using a 10 ohm pull-up resistor when the circuit calls for 10k. Or getting 10M instead!You test the inductor, using whatever measurements you can. An LCR meter is a good start, though the cheap models don't work very well for unusual parts. If you have a frequency generator and AC voltmeter, you can do a good job, by resonating it with a capacitor and using a calculator likethisto find L and losses.Once you know the value, even quite roughly, the "222" in the part number is pretty suggestive it'll be 2.2uH or mH, or 22 something or other. The trouble is, manufacturers have complete freedom on what they mark a part as, so you're not guaranteed to get a exact representation like you will with a resistor.Tim

author: ivan747
author_rank: Super Contributor
timestamp: June 28, 2015, 07:04:54 pm
content: Yeah... I'll have to measure its reactance at some test frequency.

author: LukeW
author_rank: Frequent Contributor
timestamp: June 29, 2015, 03:07:53 am
content: It's *probably* 2.2 mH.222 generally means 22 * 102, like a resistor, and that number is read in units of uH, so it's 2200 uH.

author: bktemp
author_rank: Super Contributor
timestamp: June 29, 2015, 05:13:37 am
content: Power inductors use uH as the base value, small SMD inductor or rf inductors nH. So it is either 2.2mH or 2.2uH.

author: Zero999
author_rank: Super Contributor
timestamp: June 29, 2015, 11:34:19 am
content: Measure the DC resistance. If it's under an Ohm or so, then it's 2.2uH. If it's much higher then it's 2.2mH.
Inductor color code?! - Page 1
Forum section: electronics / beginners

author: DrHumberto
author_rank: Newbie
timestamp: February 20, 2022, 06:03:12 pm
content: Hi everyone,this is my first post here and I hope I set it in the right category. I am working on an older oscilloscope at the moment. A Philips PM 3340. The Power Supply is down, I have figured out some defect components by now for example bad npn power tranni and a high voltage diode and... maybe an inductor. Here is my problem by the look of it I am pretty sure it is an inductor but what value? I looked through the common color code charts but couldn't find this color combination. White Blue Green , so 9 | 6 | and then? Green as a multiplier seems very high to me and is listed nowhere on the color code charts.Can anyone help me?

author: ledtester
author_rank: Super Contributor
timestamp: February 20, 2022, 07:08:47 pm
content: Could the white band actually be silver (x0.01)?

author: DrHumberto
author_rank: Newbie
timestamp: February 20, 2022, 07:19:58 pm
content: That would make sense, thought so too, I rechecked it now with different type of lightsit is still pretty damn white... and all in all in terms of color the component looks in good shape. What can't be seen on the picture is that it is a little out of shape ( bubbly beany) that is the reason I would like to check the value of it but without knowing what value it should be.. nope

author: Benta
author_rank: Super Contributor
timestamp: February 20, 2022, 07:26:40 pm
content: More likely a 5.6 pF tubular ceramic cap. That would explain one end being thicker.

author: madires
author_rank: Super Contributor
timestamp: February 20, 2022, 07:27:28 pm
content: That seems to be an old marking method with two bands for the value (56µH) and one band for the tolerance (silver = 10%). White wouldn't make any sense as multiplier, nor as tolerance.