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  3. Hi All, Does anyone have schematic, PCB layout of a modern day Power Supply? Regards, William
  4. Hi all, Finally after some months have gone by, my build of the Power Supply is done. I have used liquibyte schematic Rev. 8 and had made the cirquit board according to the Gerber files in file 30V.zip from his post above. I have plenty of boards leftover if someone has a need for it. There was only one mistake liquibyte made which have outlined in one of the pictures uploaded here. I was fortunate enough to get a big case with a Toroid transformer from the scrapyard. Also many parts are recycled from various sources. Regards, William
  5. I am thinking these are color coded capacitors. Short of part of an early computer.
  6. Hi friends I need to build this project for me and i need to guide me for the best schematic for this project and PCB with components. Thanks
  7. Last week
  8. Hello all, I am sure many have seen the debates on the internet by the car audio guys of the cheaper CCA wires vs pure copper wires when used to deliver high amp DC current. I am here to ask your opinion based on my situation. I have a 300w solar array, 400ah of 12v batteries, and a 50ft round trip circuit to my 2000w AC inverter using 1/0 AWG copper clad aluminum wires which I put together 2 years ago and is functioning off-grid correctly. I went with cheaper CCA vs welding wire or marine wire at the time because of the cost. After reading and watching many CCA (copper clad aluminum) vs OSF (oxygen free copper) videos, I was concerned my cables and crimp connections were a fire hazard. I went ahead and inspected all my connections and found zero marks of heat or corrosion. I also tried to run my circuit at maximum load (12V-150A) for a prolonged period and there was no heating up at any of the connectors or in the cables. The cons about CCA wire that people were mainly bringing up are: 1. the corrosion of the aluminum at the crimp terminals, which in turn creates resistance and heat. 2. higher resistance of aluminum causes higher voltage drop over distance, and heating of the lines. All my connections are heat shrunk, I found no signs of corrosion or heat damage after inspection after 2 years of use. The next thing is voltage drop. Many on the 'internet' claim that CCA cables have high voltage drop when it comes to delivering DC over distance. I did a volt meter test and this is what I found: All chargers and loads off: At the battery terminals: 13.01V At the inverter terminals 25ft away: 12.98V (50ft total distance including positive and ground lines of 1.0 AWG copper clad aluminum wire) My question is: should I go through the trouble of rewiring my entire setup ? Is it unsafe ? Am I losing performance ? It's about 600$ worth of cable, connectors and supplies where I am. All my wiring is nicely secured using adel clamps and terminated with quality connectors and I really don't want to rip it all apart.
  9. Hi, I am looking for a rotary switch/encoder or a pantometer that works via the USB HID class. So for each position of the rotary switch it should output a unique string via USB? I'll need a switch/ pantometer and a board that translates the serial input into USB (HID class - cause I cannot install any drivers on the media-computer I am using). Ideally 10 or more positions. An alternative would be a rotary switch that ouputs GPIO data, in that case I would of course only have 8 distinct positions. Some words about what I intend to do: I want to create some sort of "wheel". If its turned it should trigger videos/images on a media-computer. As already mentioned: I cannot install any drivers, but the computer works with USB HID devices and also has GPIO. Until now I am doing exact the same thing with an USB RFID sensor - it works fine, but could cause some trouble, because the RFID tags aren't read correctly each time, so I thought about doing it with a mechanical switch. I have looked quite a while now, but couldn't find anything useful. Does anyone know products to do that? Thanks a lot Tags: descargar tonos, nhac chuong mien phi, message tone
  10. To replace my overheating linear regulator DC-DC converter, I've designed this new board. This time I used a couple of switching 12V regulators .Here's the data sheet for reference: http://www.kynix.com/uploadfiles/pdf9675/LM2575-12BN.pdf I'm using two 1 amp regulators because my local supplier doesn't have a 2 amp version. Here are the schematics. Here's the board: There are no pictures of the board because it doesn't exist yet. This time, I did the math first and didn't blindly built the thing. The red arrows highlight the single-point grounding I tried to make, as recommended in the datasheet. Is that design correct?. Here is my math for calculating the temperature rise from ambient temperature. According to the LM2575 datasheet, the power dissipation is calculated as follows: PowerDissipated=Vin.Iq+(Vo/Vin).Iload.Vsat Vo=12V,Vin=18V,Vsat=1.4V,Iq=10mA,Iload=1A PowerDissipated=0.18W+0.93W=1.11W Again, from the LM2575 datasheet, its termal resistance (junction to ambient, in worst case) is 65°C/W, which would keep the regulators just below 100°C considering a ambient temperature of 25°C. If I use my heatsinks with 20°C/W and the regulator thermal resistance (junction to case) of 2°, that would keep the regulators under 50°C My questions are: 1. Is my heat dissipation calculations correct? 2. Is my board designed correctly, especially regarding the required single-point grounding for the regulator pins? These points are marked by the red arrows on the board image.
  11. This system consists of photodiode, microcontroller and motor circuit. The main aim of the system is to sense the output of photodiode from onboard IR sensor as soon as the crack is detected on rail track . So with help of infrared module, this will capture the instantaneous detection time & number of that respective crack, which can send to show on LCD display screen. The detection time is used to calculate the distance for particular crack by knowing the speed of moving robot. The supply is given to crack detection block, microcontroller & motor driver IC L293D through power supply block. Microcontroller block is interfaced to motor driver & LCD display block, while it takes inputs from crack detection circuit. Crack detection circuit consists of LED-Photodiode Assembly. This LED- Photodiode assembly detects crack and send signal to AT89S52 Microcontroller. The IR Sensor-general purpose proximity sensor We use it for collision detection. The module consists of an IR emitter and IR receiver pair. The high precision IR receiver always detects an IR signal. The module consists of 358 comparator IC. The output of sensor is high whenever it IR frequency and low otherwise. The on-board LED indicator helps user to check status of the sensor without using any additional hardware. The power consumption of this module is low. It gives a digital output. The sensitivity of the IR Sensor is tuned using the potentiometer. The potentiometer is tuneable in both the directions. Initially tune the potentiometer in clockwise direction such that the Indicator LED starts glowing. Once that is achieved, turn the potentiometer just enough in anticlockwise direction to turn off the Indicator LED..... etc i am trying to make a railway track crack detection system...how can i make this?
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  13. You forgot to say if the 10V output from your power supply must be AC or DC. You also forgot to say if the input is AC or DC and its voltage and frequency. Did you know that the output power from your power supply will be 10V x 1000A= 10000 Watts? Where will it come from? What will it be used for?
  14. For a small order, I'd suggest working with a company that does both board fabrication and assembly(sourcing also included). There are lots of companies who offer that kind of service. Personally, I get boards from PCBNPI (Fast Turnkey PCB prototype & PCB assembly service) and they do have an assembly service. Their service and quality are very good,while price is OK. Saves my time and money. I highly recommend. Fair warning: hardware has a significant startup cost. In most cases, having ten boards made will cost about as much as having a hundred made. In both cases the bulk of the price is due to setting things up, you're just distributing that cost across different numbers of boards. Jack
  15. Hi dear friend! Fast and cheap PCB prototype & assembly service provider here, exporting CUSTOM PCB and PCBA with competitive price and high quality(parts sourcing included), specialized in low volume quantity. All fabricated and assembled as per your requirments,no MOQ limited and exclusive customer service available here! Our Advantages >Most competitive price, no tooling cost; >One stop turnkey service saves your time & cost; >Components sourced and bought from authorized distributor with competitive price; >Free stencil cost for assembly order; >Full range of capacities to satisfy customers' requirements; >100% flying probes & AOI test; >No MOQ limited; >Quality guaranteed, you can focus on your core competencies; >Outstanding customer service and technical support ; Please just feel free to send file with specifications to sales@pcbnpi.com for a quotation,or you can submmit quotation on our site www.pcbnpi.com . We will reply you ASAP. Thank you for reading!
  16. How i can build transformer less circuit for 10 Volt 1000 Ampere Power supply.
  17. mAh is how long a battery will supply the current, not its maximum current. Besides, a load only draws as much current that it uses and not more unless it is shorted. Your car battery can provide hundreds of Amps to the starter when it is cold but the clock uses only a few thousandths of an Amp from the same battery and the clock does not blow up. A lithium battery cell is about 3V when it must be disconnected (or it is destroyed), to 4.2V when it is fully charged and no higher. Then two cells in series produce 6V to 8.4V. AA cells are 1.6V for new alkaline to 1.45V for fully charged Ni-MH. 8 in series produce 11.6V to 12.8V when new or fully charged. A special charger is needed for a Lithium battery. A low battery voltage must be detected and it turns off the battery. Use three Lithium cells in series for 9V to 12.6V or use a "boost converter" to boost the voltage of two cells.
  18. Li-ion batteries are so much better than AA batteries, with few of them we can get the energy of several AA my question is, would all the mAh damage the circuitry of ordinary toys and stuff? How can I use 2 3,7 v 1000mAh batteries to replace 8 AA batteries? what circuitry is needed for diminishing the amperage and rise the voltage? ------------------------------------------------ top ringtones, mp3 ringtones download, bollywood ringtones
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  21. Hi, I've been working on replacing the two 10k potentiometers for voltage and current control with two rotary encoders. The idea is to get (theoretically) arbitrarily fine control via software on an ATMega328P microcontroller. The microcontroller would also be in charge of outputting desired and measured voltage and current values to an LCD. Since I haven't found any suitable digital potentiometers I figured I'd simply generate the analog voltages for the non-inverting inputs of U2 and U3. U2 gets a voltage between 0 and 10V using the uC's PWM output, a low pass filter and an op amp. Points 5 and 10 are connected with a 10k resistor. This part is working brilliantly so far. However current limit control is giving me some trouble. Again points 6 and 11 are connected with a 10k resistor and the non-inverting input of U3 is fed with an analog voltage between 0 and 1.4V (again via PWM and low pass filter). To test the setup I shorted the outputs of the supply with my multimeter, turned up the voltage to about 10V and then slowly increased the current limit. Seemingly at random one of the following scenarios occurs: The current limit increases way too fast (the microcontroller sends the signal for .5A but the multimeter already reads 3A) The current limit increases fairly accurately as it should. The current limit gets stuck and then goes haywire at some 16A and Q4 lets the magic smoke out. Am I wrong in thinking I could generate U3's input voltage isolated from points 6 and 11? If I'm not just being stupid somewhere else my suspicion is that my approach kills some vital feedback path... I'd appreciate any input, thanks!
  22. Your attachments do not work. Usually a circuit built on a solderless breadboard with messy wiring all over the place and intermittent contacts does not work. I have designed and built thousands of prototype circuits, some VERY complicated, soldered together on a compact stripboard layout and they all work perfectly. Your voltage jumping at a steady low frequency indicates "motor-boating" low frequency positive feedback. It might be a part that fails when it heats (overheats?) then works again for a while when it cools. Your attachements are actually links to All-About-Circuits where we must join to see them. Instead attach them here to your replies.
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  24. Hi, I have recently built a dc-dc converter to convert supply voltage from 6V to 32V, the circuit diagram is as below: and the circuit on the breadboard is looks like this: My friend has built one with the same circuit diagram, I have double checked with him, both circuit connects exactly the same with same components, he circuit is working perfectly fine, but my circuit has a problem. my output voltage jump to the 42V, slowly drops to 32V, jump up again to 42V, slowly drops and it repeats this process over and over again. I have no idea what is wrong with it. Here is how my friend circuit looks like: Any help will be appreciate! Thank you!
  25. we have the inverter technology which gives us electricity even after long power cuts. Being the Microtek inverter battery with price and authorised dealer, today we will tell you want actually inverter is and what are its benefits.
  26. Hi, I'm working on a project for school and have been having a tough time getting these addressable RGBW LEDS to work. I've gotten the timing down to within 150ns of the time on the datasheets and within the 1.25us +/- 600ns per bit. I can make 4-5 work consistently. After if I add more in the chain the colors don't match, and not out of color in sequence of the LED strip, but randomness like the first and third won't work. I am coding them in C with no loops which is a bit tedious and makes for long code but it is what it is. I want to try and code it in assembly but I calculated the timings based off my clock (25MHZ Crystal oscillator) and the time I'm saving is still within the parameters of the datasheet just like my C code is. I need 25 to work for my project. If I can't I suppose I will just multiplex normal RGB LEDs but these are so nice and bright when they work! Does anybody have any experience with these and their tricky timing? I have the SK6812 but the WS2812 have very similar timing. There is also a neopixel library for arduino that is for WS2812 that somehow allows them to work with an uno that uses a 4MHZ clock. I found a youtube video of a guy who ported that library for a different PIC but I couldn't get it to work for my pic and changing the code for my microcontroller. Thanks in advance!
  27. I see on the internet where most manufacturers recommend a max charge voltage or absorption voltage of 57.6v-58.8v for flooded led acid battery. I have a nova 48v 3000watt 110vac pure sinewave inverter that allows a max of 57.1v input voltage. Because of this i cannot set my charge controller to 57.6v-58.8v according to what most manufacturers said you should charge a 48v flooded led acid battery to. If I set the charge controller to cut off at 57v or 57.1v which it will go in the absorption stage at that voltage and then afterwards it will cut down to a float charge voltage of around 54v will I still be able to fully charge the flooded led acid battery? Is there any pros and cons with charging the 48v battery bank at a lower voltage setting than the recommended charge voltage which is 57.6v to 58.8v? Is charging at the lower voltage setting increase my charging time to fully charge the battery? is charging at a slightly lower voltage better for the battery? Tags: descargar tonos gratis, nhạc chuông miễn phí, download iphone ringtone for free
  28. Electronics Advisor Wanted Hi, I imagine there are some electronics hobbyists out there that can help with this: Job Description: A prototype design for a consumer product currently being 3d designed for a Startup. It will contain a small circuit board, motor, and sensor etc. I am looking for someone to advise me on the electronic parts I've chosen. This person will be someone that tinkers with hardware and has experience using batteries, sensors, micro controllers, etc. Deliverables may include: Arduino code, custom circuit board design and supplier selection, battery size recommendation, PIR or other sensor type selection We will agree on the deliverables and a timeline up front. Experience in plastics/consumer products design preferred. Please respond with high your experience/resume and we will discuss. Full scope will be provided to successful candidate. Qualifications: Experienced hobbyist or technologist Experience in consumer products preferable Application Instructions: Please feel free to touch base with me about it - mintoft8@gmail.com
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