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Everything posted by Hero999

  1. Ah is a unit of charge, normally used with reference to batteries, not current. It sounds like you need a 25Ah 4V lead acid battery. It will be very heavy though, 3.4kg (7 1/2lb) according to the data sheets I could find for batteries of this size. 4V is not a common voltage though. You may need to make if from two 2V cells.
  2. Please post the schematic. It' s difficult to help without seeing exactly what you're doing.
  3. It depends on the signals i.e. whether they're single ended, differential and the line drivers/amplifiers used. If the cable's impedance is matched the distance is limited by the: standing wave ratio, acceptable delay, signal attenuation and noise.
  4. A 555 timer can drive a relay as long as the coil current is below 200mA. A diode needs to be connected in reverse parallel with the relay coil to protect the 555 timer from the high voltage pulse generated when the relay is switched off.
  5. What PDF? You haven't posted it. A simple phase shift or wein bridge oscillator can be used as sine wave generator or a squarewave can be filtered to make a sign. Velleman do a kit (MK105) which gives a fixed 1kHz but can easily be modified to produce 2kHz.
  6. Pins 5 & 6 are connected together inside the relay, as per the pin out you've posted. You don't need a voltage regulator. The relay has a coil resistance of 162R so simple 1k 1W connected in series with the relay will do. http://teachmetomake.files.wordpress.com/2011/02/relay-g5v1.pdf
  7. Perhaps you've not received any replies because your question is so vague? How are we supposed to know what sort of capacitor is uitable for your project when we don't know what it is?
  8. That should work but you've draw it with the red and green LED the wrong way round. The convention is to show the contacts in the de-energised state. Why not skip the voltage regulator and buy a relay which can work off 36V in the first place? Alternatively, you could use a 24V relay and put a resistor in series with it.
  9. To get a +24V supply with respect to 0V, you need a 12V to 24V DC-DC converter. To get -24V with respect to 0V, you need a 12V to 24V converter with an isolated output. Digikey sell plenty of PSUs which meet your requirements. http://www.digikey.co.uk/scripts/dksearch/dksus.dll?FV=fff40009%2Cfff800df&vendor=0&mnonly=0&newproducts=0&ptm=0&fid=0&quantity=0&PV183=514&PV183=5506&PV127=3014&PV127=3033&PV127=3035&PV127=6718&PV127=2050&PV127=1386&PV127=4639&PV127=3049&PV127=698&PV127=4324&PV127=4822&PV127=4823&PV127=291&PV127=6220&PV127=6712&PV127=3699&PV127=1314&PV127=320&PV71=18&PV71=1021&PV71=1032&PV71=270 http://www.digikey.co.uk/product-detail/en/VHK200W-Q24-S24/102-1892-ND/1992349 http://www.digikey.co.uk/product-detail/en/2866284/277-1924-ND/1284250 http://www.digikey.co.uk/product-detail/en/VSD-50A-24/VSD-50A-24-ND/750842
  10. If you keep posting the same thing over and over, in multiple threads, people will see you as a spammer. If you appear to be trying to sell something (even if you're not) people may think you're a spammer. Parhap you should make a few posts introducing yourself and about other people's projects before making one about yourself and your website? It would be better if you actually posted some of your work on the forum, rather than just linking to your website.
  11. I would have thought it would be easier to measure the RC time constant, rather than phase difference. It's as simple as building a relaxation oscillator with Cx + the parasitics as the capacitor being tested and measuring the frequency which will be inversely proportional to the capacitance.
  12. Try to figure it out for yourself. My description should give you plenty of clues. Post the circuit and I'll check you've got it right.
  13. Have you asked your lecturer for help? Surely the purpose of the course is for you to write your own code? I hope you've included this site in your bibliography. Have you tried changing the IC?
  14. The unlabelled diodes aren't critical. You could use the 1N4001, 1N4148, 1N4448, 1N914, BAV20 etc.
  15. The simplist method is to use a microcontroller so the timing can be adjusted by modifying the software.
  16. It can be done using combinational logic, composed of logic ICs or a programable device such as a microcontroller. In this case discrete ICs (CD4000 or 74HC series) or even transistors will do. Here are a couple of links to some tutorials: http://www.ee.surrey.ac.uk/Projects/Labview/gatesfunc/index.html http://www.opamp-electronics.com/tutorials/digital_theory_ch_003.htm
  17. How much power does the LED lamp use? Run the TSOP1738 and CD4017 from a 5V regulator and replace the relay with the LED lamp.
  18. If you buy a 12V to 24V DC-DC with an isolated output, you can connect the +V out to 0V and you'll have a -24V supply.
  19. Read the datasheet fro he sound card. Sound card oscilloscopes aren't good for much. They're limited to 2kHz and if you exceed the input voltage you can ruin your sound card or even motherboard. It's much better to buy a second hand oscilloscope.
  20. You seem to be determined to stop people from opening your file. Please use a universal format such as PNG or PDF so that veryone can read it.
  21. I don't think lighting is responsible. The speed controller fails when run from the UPs because of the high voltage spike given off by the motor when the current is suddenly interrupted by the square edge of the modified sinewave. You could try a choke and smoothing capacitor but I don't think it'll help. You need to power the fan from a true sine wave, which involves upgrading the inverter.
  22. Sorry, you're wrong, Google for Tesla wireless power transmission EDIT: Thread closed by moderator because the original poster has never returned and it's just attracting spammers. If anyone thinks this is the wrong decision, please message me.
  23. i'm just a moderator so have no power to ban people. If i see a spam post I'll delete it but if I see loads of posts by the same spammer, I leave them for mixos to sort out as I see no point in wasting my time deleting them, when all they'll do is repost.
  24. It's a phase speed controller which will not work from a UPS which produces a modified sinewave. You need to upgrade the inverter in the UPS to a pure sine wave type.
  25. Hero999


    I've never heard of it an if you want pirate software then look elsewhere.
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