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  2. There is a real necessity in a TeamSpeak server to organize communication channel between two and more people. Also, it needs to to be built in a cost-efficient and tech-savvy way. And so, I've come to the solution - build TeamSpeak 3 server on Raspberry Pi (or any other ARM device). Learn this case and try to do this on your ARM.
  3. 0-30V Stabilized Power Supply

    Hi Liquibyte, I have bought two of your PCBs from repairman2be (rev. 8.), awaiting them any day now. I have studied the schematic pretty thoroughly and tried to read up on the threads. Very interesting, and good to have something educating to do with my time :-). So far I have one question that I can't find a comment on in the forums. First, let me introduce myself. I'm a Swedish 30 year old mmWave/μWave/RF engineer (read: allergic to noise) and I just had a second son so I had to find something to do all the nights I stay up taking care of him. Designing a PSU seems like a good choice! It started with me realizing that I today financially can handle some of the ideas I had when I was 20, now time is more of an issue instead. But hey, it doesn't matter if it takes time to reach the finish line. I always wanted to build a boombox. I thought a good place to start was to design a PSU (to not waste battery when a socket is available) and a relay-circuit. I read up a lot on audio PSUs and actually designed a linear 10-18V, 10A supply, and hand drew the breadboard and everything. When I saw the end-price I reconsidered. This PSU is kinda useless for anything but the amplifer, it's better to have a 0-30V supply I can use for lots of things. Especially considering I have no use for or place to store a boombox. The reason I'm saying this is that I might be tainted by audiophiles in my way of thinking :-). That I'm tainted by my RF-world at work I don't see as a problem, RF is probably what I'm going to use it for. Then I found this design and got interested. But I still wanted it to be able to run the amplifier I had in mind for the boombox, which is something like 14V/6A. I considered paralleling two of these or use a LM723 regulator. I ended up with the idea of two 0-15V LM723 PSUs which I can parallel connect for 0-15V/0-10A or series connect for 0-30V/0-5A. I was pretty happy with this idea and started designing. However, I couldn't get the current limit to work as nicely as I desired for a bench PSU. Then I came back to this design, and here I am now. I'll start with building your 3A design pretty much identical to yours. To be able to do some measurements and see how it behaves before I try to improve it :-). After that I will start designing my own board. I'll probably stick to 3A or 5A for a while, if I need an amplifier PSU I'll design it for that purpose. My ideas for improvements is to reduce the voltage drop a little, have a look at the negative supply (it hurts my eyes that it doesn't load both lines symmetrically). If I reduce the voltage drop and feel that I can't find an optimal transformer I might reduce the output voltage a little. I feel 30VAC is a little too high and 24VAC apparently is not enough so there is some unused power wasted there. We will see how it goes. For later I might also take up the idea of LT1236 as reference. We will see. First I believe I have some startup transients to deal with! So, now to my question: Your R9 (original R17), is 68 Ohm. The original design says 33 Ohm but you changed it to 68 Ohm. Why did you change that? Have you found some issues with stability if it is too small? The reason I'm asking is that if I lower the current sense resistor I might want to increase this. Maybe I'm doing this wrong. I calculate the original design to give a minimum current limit of 10mA (while it says 2mA in the description), and your gives 20 mA. Edit: I found the change, it was just to get the voltage divider to give the correct minimum voltage. However I'm still confused, but this can probably anyone answer. It should be simple. I don't get the formula for the current limit. If we have a minimum of 5mV at the non inverting U3 input, that should allow for a 5mV drop over the current sense resistor right? That's 10 mA... Not 2.. Edit2: LTSpice seem to agree with me... I might have more questions but I'll search and think a little more before I speak :-) Best Regards Björn Ps. Thanks for the pdf with QA and other useful info. Would have saved me some time if I read that before I started study the circuit. But imI might learn it better by figuring things out on my own.
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  6. To emulate any type of software on any ARM development boards like Raspberry Pi a Virtualbox software is usually used. Learn the Virtualbox alternative for RPI (or any other ARM) with greater performance.
  7. Another and less complicated way to enjoy Plex on your Raspberry Pi (or any other ARM Device)
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  9. PCB manufactureres

    There a number of PCB manufacturer in the electronic industry who provide quality products in reasonable rates even their repair cost is also not too much.
  10. 0-30 Vdc Stabilized Power Supply

    The original Greek kit and the first Chinese copy wrongly said to use a 24V/3A transformer that does not work and becomes overloaded. Its voltage is too low for the project to produce 30VDC at 3A and its voltage is too high for the opamps with a low maximum supply voltage rating of only 36V. The original opamps also needed an additional negative supply with a fairly high voltage. We corrected the circuit and used opamps with a 44V maximum supply voltage rating and a 28V/4.24A transformer (the peak of 28VAC is 39.6V). With an output current from the project of 3A then the transformer must supply 39.6V x 3A= 188.8VA. Then the current rating of the transformer must be 118.8VA/28VAC= 4.24A. The improved circuit also works with a 30AC transformer and you can calculate its current rating needed. The current limiting is variable from about 2mA to 3A and has excellent current regulation. If the output is shorted then the current will not cutoff, instead it will be at the current setting. Many stores do not provide datasheets that are available online from the manufacturers. Wakefield is a heatsink manufacturer and has datasheets of all their heatsinks at their online site.
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  12. 0-30 Vdc Stabilized Power Supply

    i dont understand. in projects Bill Of Material said use 24v 3a Transformer for making 0-30v 0-30a power supply. but u said if i use 24v 4a i will get 0-30v 2.8a !? how can its possible ? so if we use 24v 3a transformer we will get less than 2.2a! so its not 0-30v 0-3a dc power supply! the circuit current cutoff (short circuit protection) is 2a or 3a? if its 3a and we use 3a transformer for making project (taking 2.1a) its never cutoff the output for short circuits! anyway my heat sink were bought from local stores and they do not provide datasheet for this items!
  13. Hello Everyone,We are pleased to announce the launch of our online store - Mynics.All of you are requested to check the website and do give us your valuable feedback.You can do the following at Shop for electronics and robotics- Blogs- Forums- Projects and VideosWe are soon rolling out some great competitions and offers, do follow us to stay updated to show your creativity and leave the rest to Mynics.Cheers,Team Mynics.
  14. Connect a 12 volt taillight, turn signal or any small 12 volt lightbulb to your 6 volt battery. Now connect a 12 volt charger to the 6 volt battery. Voltage at battery will be 6.7 to 7.02 volts. Unscrew the three caps on the 6 volt battery and observe the bubbles of hydrogen gas leaving the electrolyte from each cell. The cell on the + side will stop bubbling first as the 6 volt battery reaches full charge, then the middle cell will stop bubbling, then the cell on the -- side will just barely be bubbling when fully charged. The small light creates a drain and the charger continues to charge that cell. more: xe 2 tan hyundai A 12 volt battery connected to a 12 volt charger will cut out at 14.6 volts. Then the 12 volt battery will settle to 12.7 volts after 30 minutes. A 6 volt battery connected to a 12 volt charger with the small 12volt light WILL NOT cut out because you want a fully charged 6 volt battery to settle to 6.4 volts. You must observe and manually disconnect the charger. more: giá fortuner 2017 Do not connect the small lightbulb in series because the 12volt charger will sense too much resistance and then indicate a fault after two minutes.
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  16. 0-30V Stabilized Power Supply

    @mars Hi there, Look at Page 87 and 88 posts from Liquibyte and you will find PCB, schematic and gerber files to make a nice power supply that will work. How would I know you might ask. Glad you asked. I have had PCB's made from those gerber files and built a power supply. And it works well. Look here for my post: "" All credit goes to member Liquibyte. Thanks a lot Liquibyte for making all files available. Many thanks also to those who were actively involved in this thread and helped improve the original design. Hope that will answer your question. PS. I f you want to built one like I just mentioned, I still have some PCB's left. I only ask AU$2.50 per PCB plus shipping to your country in an envelope. Cheers, William
  18. Hello We have just launched a new UK website specfically selling Rigol products. offers a £10 Amazon Voucher with every order, however, if you want £10 off the price use "rigol10off" as a voucher code to receive £10 off the price instead of the voucher. For further updates from RigolOnline follow us on twitter @RigolOnline Thanks Mike
  19. Help with Audio Guru's Stethoscope.

    I think you can found the datasheet of TL072 at here, and this image explains all
  20. It's great when you've got your own cloud storage server. OwnCloud is the one, that can help. Especially, if set up on an ARM-device (like Raspberry Pi) it is also savvy and simple. Learn my experience how I have succeeded to install OwnCloud on Raspberry Pi (if you like it and have some other ARM device, go ahead and try this tutorial. Post the results to this topic)
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  22. I have a laser spirit level which takes two AAA cells. they slide lengthways into the side of the level, one positive end first, one negative end first. the battery compartment cover has a sheet of copper which connects the two exposed cell ends together, so that the cells end up in series once installed. more: xe dongben It occurred to me that with a 7 year old lad wandering round, I might be sensible to avoid leaving a laser device around that could be easily turned on and stared into. so, I took out one cell and turned it round so that both cells had the same polarity end facing the cover. I can't recall if I had the + or - ends both sticking out. figured, it might prevent an inadvertent retinal burn whilst still leaving the level ready for use at the drop of a hat, with the only inconvenience being, having to reconfigure the cells before use. at this stage I thought, hell, what you doing messing around, just stick the darn thing in the shed & lock the door, problem solved, no need to worry It did start me thinking though.. what actually would happen if one did that and then left the device lying around for say 6 months, with the device's 'on' switch in either position? simple thinking, two back to back fresh cells of the same type would cancel out, no voltage across the resulting battery, no current flow, the cells would just sit there and do nothing, as if they were entirely disconnected. they'd maybe discharge slowly at the normal self-discharge rate but otherwise would remain as ready for action as if they had been left in the unopened packet. more: hyundai 2 tan but i bet it's not as simple as that.. I mean if one cell were slightly more highly charged than the other then you'd have some small voltage being applied to the device, not enough to turn it fully on maybe, but perhaps enough to allow a nonsignificant flow of current. is that likely to be a situation that would be self extinguishing as the more highly charged 'winning' cell discharged more rapidly than the other? or would it go the other way with one cell doing some kind of runaway self-flattening? Could you end up damaging the device doing this, I guess the worst you could end up with would potentially be 1.5V the wrong way round across a circuit expecting 3V in the other direction (maybe for an extended time) Is it a recipe for a leak in the battery compartment? Thoughts?
  23. There are two emulators: ExaGear Desktop and QEMU. So, I've decided to carry out a fair survey and compare the performance of these two. Without the bias, here are the results in QEMU vs ExaGear performance comparison article ----------------------------- P.S. To make sure, carry out your own experiment and post the results to this topic. What if you will get the different output?
  24. Model : PD045105-2S 50 Ohm 2 way SMA-Female Power Divider From 0.45 to 10.5 GHz Rated at 30 Watts; 10.5GHz, SMA-Female Power Divider; Insertion Loss 1.0dB; Isolation 20dB; Operating Temperature -40 to +70℃. Frequency Range | GHz : 0.45-10.5 Impedance | Ω : 50 Input VSWR | Max. : 1.5 Output VSWR | Max. : 1.4 Insertion Loss | dB Max. : 1.0 Amplitude Balance | dB Max. : 0.3 Phase Balance | deg Max. : 3 Isolator | dB Min. : 20 CW Power | W Max. : 30 Peak Power | KW Max. : 0.1
  25. I've searched the topic of playing the retro PC games with Retropie and decided to make the experience of playing great PC games even better with the help of Raspberry Pi and an emulator. Read in my article, how I've improved the level of gaming on Retropie P.S. Raspberry Pi is just an example hardware. It's likely to work on any ARM. Anyone can give it a try at least and post the results here. Just for fun!))
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  27. BGA rework Process?

    Hello, everyone! I am from Rolling Meadows, Illinois. Can anyone tell me about BGA rework Process and the material required for that? Also, please suggest me best training institute nearby Illinois where I can learn BGA rework practically. I welcome all your answers.
  28. So many pcb manufacturers, found a few familiar ones, but I have tried only one of them ( ), their minimum order is at least one board, I ordered a small order of 10pc, 2 layers, five days mail to me, the quality of the boards are fine.
  29. I made a simple LED matrix with shift registers in both row and col(anode and cathode). Now I want to build a 8x8 RGB PWM matrix so that I can control the color of each LED in the matrix. One thing I'm struggling with is which IC to use on the cathode end. Previously, I simply added another 74HC595(here is the datesheet of 74HC595) and simply set row(cathode) that I wanted to light up and set RCLK. I was hoping to use the same approach, but I'm not so sure with the PWM. I also considered using another TLC5947 but I don't think it works as source current? EDIT: the micro controller I'm using is atmega32u4 at 16Mhz
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