tag:blogger.com,1999:blog-1543389024527713336.post9155622561952728949..comments2024-02-14T10:44:15.547+01:00Comments on ArduPicLab: An isolated analog output for Arduino UnoGiovanni Carrerahttp://www.blogger.com/profile/04443703611514833137noreply@blogger.comBlogger24125tag:blogger.com,1999:blog-1543389024527713336.post-22271329345286301442021-07-25T07:59:52.116+02:002021-07-25T07:59:52.116+02:00If you don't want to use Arduino, you can use ...If you don't want to use Arduino, you can use a 4-5 kHz astable oscillator (for example with a NE555) that generates pulses of variable duration (PWM). You get zero output if you put R1 at 5V. The optocoupler is inverting, if you put it at zero, the output is high and if you put it at 5V the output is zero, but to have the intermediate values you must have PWM pulses, because the circuit is not linear, it works as a switch.Giovanni Carrerahttps://www.blogger.com/profile/04443703611514833137noreply@blogger.comtag:blogger.com,1999:blog-1543389024527713336.post-24705431090974588222021-07-24T15:46:58.084+02:002021-07-24T15:46:58.084+02:00You could probably put a pull-up or down resistor ...You could probably put a pull-up or down resistor on the input. Not sure if it's positive or negative flank, or depending on which input you're referring to, you also could experiment with an old 4066 logic circuit and either find some point in the circuit that holds a voltage around 5V (I believe the logic circuit accepts up to 12V or possibly more) and connect that to the gate for the internal switch. Not sure how signal integrity would hold up, but it's otherwise a neat way to switch signal sources. You could also control that via Arduino if you want extra control.<br /><br />I have not yet tried this circuit myself. I've put my project on ice since just before Christmas, so I've had little thoughts about it lately, but it's still on the table, so to speak.4c3Thttps://www.blogger.com/profile/01394100493763288233noreply@blogger.comtag:blogger.com,1999:blog-1543389024527713336.post-64446067799655389132021-07-24T08:29:06.673+02:002021-07-24T08:29:06.673+02:00Thanks Giovanni. Quick question, if I want want th...Thanks Giovanni. Quick question, if I want want the output to default to 0v (input circuit off or no power), how do I wire/change the circuit? At the moment if I remove the input, it defaults to 5.7v.Chris Vnoreply@blogger.comtag:blogger.com,1999:blog-1543389024527713336.post-70118091136942471652021-07-21T10:10:19.765+02:002021-07-21T10:10:19.765+02:00There are no problems with opamps if you use a Vi ...There are no problems with opamps if you use a Vi voltage of at least 12 volts. I don't want to change my scheme, but the changes are simple. Replace the 7805 with an LM317. Connect a 220 ohm resistor between its output Vo (pin 2) and ADJ (pin 1), connect a 620 ohm resistor in series to a 220 ohm trimmer (slider and one end) between ADJ and ground. Download the datasheet and see its pinout for connections. Capacitors C1 and C2 are unchanged.<br />The theoretical output should vary between 4.8 and 6 volts, by varying the trimmer. Calibrate at 5.7 volts, using a voltmeter.Giovanni Carrerahttps://www.blogger.com/profile/04443703611514833137noreply@blogger.comtag:blogger.com,1999:blog-1543389024527713336.post-45741407223208249652021-07-21T03:40:31.449+02:002021-07-21T03:40:31.449+02:00I have a LM317 on hand. My question is do I only n...I have a LM317 on hand. My question is do I only need this because the opamp loses 2v? I also have digital pots but these require multiple signals (from Arduino) to control which means multiple octo couplers. Your circuit was simpler and in essence doing what the analogue pot was doing - providing a 0-5.7v analogue signal.<br /><br />I am clueless with designing circuits so could you adjust your circuit for me that would work? Any help appreciated. Chris Vnoreply@blogger.comtag:blogger.com,1999:blog-1543389024527713336.post-41156220177905743792021-07-20T19:06:04.990+02:002021-07-20T19:06:04.990+02:00Yes, it's working properly, thank you.Yes, it's working properly, thank you.TomTomhttps://www.blogger.com/profile/04869740500023636470noreply@blogger.comtag:blogger.com,1999:blog-1543389024527713336.post-58613530678060853842021-07-20T06:57:36.946+02:002021-07-20T06:57:36.946+02:00Hi Chris, you can use my circuit, replacing the LM...Hi Chris, you can use my circuit, replacing the LM7805 with an LM317 (adjustable regulator), a couple of resistors and a trimmer to get the voltage you want (see datasheet). Of course you have to remove the motor governor potentiometer. A simpler solution is to use a "digital potentiometer" type MCP41100 or similar with the library and examples you can find on the net. But this simpler solution is not galvanically isolated because it uses an interface SPI bus with Arduino.Giovanni Carrerahttps://www.blogger.com/profile/04443703611514833137noreply@blogger.comtag:blogger.com,1999:blog-1543389024527713336.post-69988987532354671712021-07-20T03:17:25.200+02:002021-07-20T03:17:25.200+02:00Hi Giovanni. I want to follow your circuit design ...Hi Giovanni. I want to follow your circuit design to send a 0-5.7v analogue signal from an arduino pwm --> 4n25 --> motor controller. The controller currently supplies 5.7v to a variable resistor (pot) and I want to replicate the pot/wiper. So I have a source voltage of 5.7v I can use to supply the 4n25 and other components (opamp?) to achieve the same outcome that you have. Can you help?Chris Vnoreply@blogger.comtag:blogger.com,1999:blog-1543389024527713336.post-38830844274552531932021-07-17T09:52:31.667+02:002021-07-17T09:52:31.667+02:00Hi, a PWM signal is completely different from the ...Hi, a PWM signal is completely different from the DC generator in that it generates pulses of fixed amplitude and variable duration. Your Arduino won't get damaged if you follow my circuit.Giovanni Carrerahttps://www.blogger.com/profile/04443703611514833137noreply@blogger.comtag:blogger.com,1999:blog-1543389024527713336.post-75301134841666530102021-07-16T09:16:09.067+02:002021-07-16T09:16:09.067+02:00Hi, yes, to be sure I won't destroy the Arduin...Hi, yes, to be sure I won't destroy the Arduino, I used the DC voltage generator 0-5V. It has different behavior with the PWM pulses? I thought that I can test it by simulating PMW by the voltage generator. Ok, I will try it. Thanks, TomTomTomhttps://www.blogger.com/profile/04869740500023636470noreply@blogger.comtag:blogger.com,1999:blog-1543389024527713336.post-38565104049556157012021-07-16T07:48:54.899+02:002021-07-16T07:48:54.899+02:00hi, I don't understand what you did. Did you r...hi, I don't understand what you did. Did you remove the Arduino that generates the PWM pulses and complemented the output and put a 0-5V DC voltage generator? If you want to generate an output voltage of 0 to 10 volts, just replace the regulator 7805 with a 10V one and change the R2 from 5.1 to 10 kohm and, of course, use Arduino or similar to generate the pulses.Giovanni Carrerahttps://www.blogger.com/profile/04443703611514833137noreply@blogger.comtag:blogger.com,1999:blog-1543389024527713336.post-87574712082728678922021-07-15T21:42:24.759+02:002021-07-15T21:42:24.759+02:00Hi, I used this solution to get regulated 0-10V by...Hi, I used this solution to get regulated 0-10V by PWM. I have these parameters: Vin=22V, Vref=10V, C3=220nF, C4=104nF, R2=10k as you proposed. I tried it without Arduino on the optocoupler input, I used a laboratory power source 0-5V. On the output I got these values:<br />Vopto > Vout<br />0,0 > 9,84<br />1,2 > 9,82<br />1,5 > 8,00<br />2,0 > 3,53<br />2,5 > 0,27<br />3,0 > 0,23<br />5,0 > 0,19<br />It means that there would be 0V when PWM=125 (2,5V) and full 10V when PWM is 0. Please, can you tell me what to change to get linear regretion PWM 0 > 0Vout up to PWM 256 > 10Vout? Why I have it inversely, is it ok?<br />Thanks, TomTomTomhttps://www.blogger.com/profile/04869740500023636470noreply@blogger.comtag:blogger.com,1999:blog-1543389024527713336.post-23374628528622566612021-04-24T13:55:34.219+02:002021-04-24T13:55:34.219+02:00cool post, man! If you want to know more about Ard...cool post, man! If you want to know more about Arduino Mega, check <a href="https://nerdytechy.com/arduino-mega-pinout/" rel="nofollow">this article</a>. Thats awesomeUnknownhttps://www.blogger.com/profile/01435010404643248320noreply@blogger.comtag:blogger.com,1999:blog-1543389024527713336.post-84546293746731513702020-12-26T21:04:40.982+01:002020-12-26T21:04:40.982+01:00But, again, if I'm to use this schematic in an...But, again, if I'm to use this schematic in another version of this PCB of mine, I don't have to bother with the SPI-bus.<br /><br />It would, however, be very nice if I could get the existing one to work while I start to work on an upgrade.4c3Thttps://www.blogger.com/profile/01394100493763288233noreply@blogger.comtag:blogger.com,1999:blog-1543389024527713336.post-44314818293684602262020-12-26T21:00:54.325+01:002020-12-26T21:00:54.325+01:00Hmm... Just as I feared.
Yes, I've seen that d...Hmm... Just as I feared.<br />Yes, I've seen that datasheet. Only thing it did for me was to further confuse me and feeling reluctant to ever use that serial communication.<br /><br />I think that perhaps this could be a solution to my opto-couplers:<br />setClockDivider()<br />as described in this example:<br />https://www.arduino.cc/en/Reference/SPISetClockDivider<br />It doesn't say exactly what frequencies or so, but it would suggest that 16 MHz divided by 128 would land me around 125 Khz if my bad math got it right, and should work I think.4c3Thttps://www.blogger.com/profile/01394100493763288233noreply@blogger.comtag:blogger.com,1999:blog-1543389024527713336.post-17510194610670334252020-12-26T19:29:05.703+01:002020-12-26T19:29:05.703+01:00I saw there is an application note (AN2202) to con...I saw there is an application note (AN2202) to control the mc3phac chip with PC via serial interface, download from this site: https: //www.nxp.com/docs/en/application-note/AN2202.pdf<br />The PC817 optocoupler is not good for the SPI bus as it has a phototransistor which is slower. A photodiode optocoupler is needed to achieve smaller rise / fall times. You could use an Arduino connected directly to digital potentiometers and connected via serial with the optocouplers to your controller.Giovanni Carrerahttps://www.blogger.com/profile/04443703611514833137noreply@blogger.comtag:blogger.com,1999:blog-1543389024527713336.post-22628362176052699492020-12-25T15:05:52.718+01:002020-12-25T15:05:52.718+01:00Ok.
Well, I looked at the datasheet for the MC3PHA...Ok.<br />Well, I looked at the datasheet for the MC3PHAC, and found it very difficult to handle the serial interface.<br /><br />I have made an PCB, which I'm currently unsure about, as I added a couple of digital potentiometers, both with opto-couplers.<br />They are to be operated on the SPI bus.<br />I'm not certain that these opto-couplers (PC817) are fast enough to handle this bus.<br /><br />This is my 2:nd version, but I'm not feeling 100% about this, so I'm looking to possibly making a third PCB,<br />and this seemed like a good idea to skip the potentiometer.<br /><br />One of the reasons I wanted to limit the output voltage was that I want to limit the maximum output to<br />around 4V. so that I don't max the motor since that has a maximum input of 195V at 310Hz.<br />Current configuration has resistors to limit this.<br />I have tried this circuit and it was working, until I found a flaw in the design which made it dangerous to use,<br />so I had to redo the design.<br /><br />There are a few things that I'm not satisfied with on the new design, so I'm thinking of making a third version,<br />as I said.<br />I worked on the current one for about 5 months, and I sort of rushed the last of the design as I approached my<br />own set deadline, so a couple of things was messed up.<br />Managed to connect a bunch of Triacs all wrong, have a couple of IC's crammed into spaces where they<br />don't belong among high voltage and a couple of more things.<br />When I'll do this I don't know, so I'm looking for alternatives at the moment.<br />I have to re-order a bunch of stuff, so I'm saving myself until I have a proper design that I feel<br />pleased with.<br /><br />The (re)build is a washing machine that was a give-away due to water damage, so that's the reason for the odd voltage specs for the motor.4c3Thttps://www.blogger.com/profile/01394100493763288233noreply@blogger.comtag:blogger.com,1999:blog-1543389024527713336.post-25934322141211965042020-12-25T11:20:35.255+01:002020-12-25T11:20:35.255+01:00The maximum output voltage depends on the voltage ...The maximum output voltage depends on the voltage tolerance of the 7805 regulator which is +/- 0.5V. A potentiometer must not be put in place of R2 and the filter resistors that determine the cutoff frequency must not be modified. You can modify the maximum voltage by adding a resistor between pin 3 of U1A and ground: for example 51 kohm reduces the maximum voltage by about 1/10. The best solution is to control the MC3PHAC chip via serial.Giovanni Carrerahttps://www.blogger.com/profile/04443703611514833137noreply@blogger.comtag:blogger.com,1999:blog-1543389024527713336.post-40947639598815475562020-12-25T04:35:30.248+01:002020-12-25T04:35:30.248+01:00Question:
I'm thinking of perhaps using this f...Question:<br />I'm thinking of perhaps using this for a MC3PHAC-circuit as a means to regulate speed as it has (2) analog 0-5V inputs for speed and acceleration.<br />Now, my main concern is that this output mustn't exceed 5V, and I was wondering what the tolerances are with the currently supplied values?<br />I noticed that R2 was responsible for the voltage, as you mention 10k was appropriate for 10V, and this example for 5V uses 5,1k, which is almost half. I'm not much for analog electronics since it involves a lot of mathematics, a subject that doesn't agree with me, so to speak.<br />Therefore, I'm curious (at the time writing this), since I don't have these components on hand, it should be as simple as putting a potentiometer instead of R2 to limit the maximum voltage I think, but I'm also thinking one could be used on the output, after R3 towards ground to further limit the maximum voltage. But I don't know how that would affect the OP-amp U1b.<br />Thoughts on this?4c3Thttps://www.blogger.com/profile/01394100493763288233noreply@blogger.comtag:blogger.com,1999:blog-1543389024527713336.post-67426476165108952192020-08-31T15:02:33.294+02:002020-08-31T15:02:33.294+02:00Thank you very much for this great article and inf...Thank you very much for this great article and information. It is very useful to me, please provide more information or a good article like this again.<br /><a href="https://www.tejar.pk/arduino" rel="nofollow">Arduino</a>AlexAdamhttps://www.blogger.com/profile/07883827224731674118noreply@blogger.comtag:blogger.com,1999:blog-1543389024527713336.post-84470859382526940502020-04-03T15:45:18.200+02:002020-04-03T15:45:18.200+02:00Thanks For Sharing Great Information, Keep It Up S...Thanks For Sharing Great Information, Keep It Up Share Again & Again Great Post. <a href="https://www.3dvfxarch.com" rel="nofollow">3D Rendering Services in India</a>, <a href="https://www.3dvfxarch.com" rel="nofollow">3D Walkthrough Company</a>, <a href="https://www.3dvfxarch.com" rel="nofollow">Architectural Rendering</a>, <a href="https://www.3dvfxarch.com" rel="nofollow">Architectural Rendering Services</a>, <a href="https://www.3dvfxarch.com" rel="nofollow">3D Architectural Walkthrough Services</a><br />Thanks!!!!!!!!!Sanjay Rawathttps://www.blogger.com/profile/10111517660054682712noreply@blogger.comtag:blogger.com,1999:blog-1543389024527713336.post-50146309781180346282019-08-09T13:30:47.016+02:002019-08-09T13:30:47.016+02:00Liquid Level Sensor can be used to identify the le...<a href="https://iconprocon.com/product-category/levelpro/" rel="nofollow">Liquid Level Sensor</a> can be used to identify the level of substances that can flow. There are various types of liquid level sensor used to detect the point level of a liquid. Some types use a magnetic float, which rise and fall with the liquid in the container.Icon Process Controlshttps://www.blogger.com/profile/07462538814153661367noreply@blogger.comtag:blogger.com,1999:blog-1543389024527713336.post-21481013688527675362017-06-22T13:54:37.830+02:002017-06-22T13:54:37.830+02:00I was doing an online research on How to Write an ...I was doing an online research on <a href="http://albert22smith.comunidades.net/how-to-write-an-evaluation-essay" rel="nofollow">How to Write an Evaluation Essay</a> before I landed on this magnificent page and I have found interesting and intriguing article that has been written in a unique manner. Thanks so much for sharing this article with us. We are anticipation more articles. Anonymoushttps://www.blogger.com/profile/03762693089912796201noreply@blogger.comtag:blogger.com,1999:blog-1543389024527713336.post-91113072180144724632017-05-26T11:17:48.894+02:002017-05-26T11:17:48.894+02:00It is through research that new theories, concepts...It is through research that new theories, concepts and solutions to life problems are generated. I appreciate the blogger for disclosing that he has passion in electronic projects. This has really stirred up my spirit in the research work. <a href="https://www.article-webcontentwriters.org/19-seo-content-writers/81-keyword-adding" rel="nofollow"> Content Keyword Review</a> Anonymoushttps://www.blogger.com/profile/14463377539585539752noreply@blogger.com