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Hero999

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Everything posted by Hero999

  1. It's not a standard part. Most transformers have mains voltage primary (typically 110V or 230V) not 24V. Yes, it should be easy to measure them with a multimeter: the secondary with the highest current rating should have the lowest DC resistance.
  2. Silly question. Off course Microchip won't write your program for you (unless you pay them lots of course). It's something you've got to do yourself.
  3. I agree, it's confusing. The transformer appears to have four windings: a 24V primary and three 15V secondary windings, two rated to 15mA and one rated to 40mA.
  4. http://pdf.dzsc.com/QM2/QM20.pdf What's the trigger voltage? Post a schematic.
  5. What parts of the questions are you struggling with? Have you attempted them yourself?
  6. The link doesn't work. What do you want us to do about it?
  7. No you can't achieve a very high current. Regardless of the capacitors used, the 555's maximum output current is 200mA, which limits the maximum current from the circuit to 100mA, at which point there will be a large voltage drop.
  8. You need a copy of the schematic or at least to reverse engineer the part of the circuit surrounding the resistor.
  9. Sorry, I don't know what you're talking about.
  10. You forgot to say what your question is.
  11. Of course you can. Why would you think otherwise? What do you think?
  12. Why do you need to switch it so fast? Is 100ns the minimum on, off time or both?
  13. What thank you for spamming the forum with some dodgy Chinese site probably selling fake components? Cheeky sod.
  14. Without a part number or datasheet there's no way of knowing. Generally infra red LEDs have a higher current rating than visible LEDs because their forward voltage is lower (1.1V to 2.5V, as opposed to 1.8V to 4.5V) and the maximum rated power dissipation is similar.
  15. Don't worry, it's normal for a power supply to have a slightly higher voltage when unloaded. If you connected the laptop and turn it on, you'll probably find the voltage drops to within 19V or so.
  16. No, it shouldn't be a problem.
  17. Why would anyone want to go there? It's just a load of crappy circuits copied from other sites, nothing new nor innovative.
  18. I don't know which circuit will work best for you, try them both.
  19. It seems like an overly complicated way of doing this. I think you should drop the MUX and three channel photodiode, use a single channel photodiode and turn the LEDs on, one at a time and take an intensity measurement for each colour.
  20. The same basic blocking oscillator circuit, normally used to drive a flyback transformer, can also drive a centre tapped or dual primary mains transformer. Here's an example of a capacitor charger using a mains transformer with a centre tapped primary. It should be able to drive a voltage multiplier circuit. C1 1 uF D2 1N4948 R2 +------||------+ T1 1.2kV PRV 1K 1W | | +-----|>|-----/\/\---+------o + | R1 4.7K, 1W | red ||( blk | +-----/\/\-----+------+ ||( | | yel )||( +_|_ C2 + o----------------------------------+ ||( --- 300 uF | red )||( - | 450 V | +--------------+ ||( | | Q1 | ||( blk | 6 to 12 | |/ C +--------------------+------o - VDC, 2A +----| 2N3055 Stancor P-6134 D1 _|_ |\ E 117 V Primary (blk-blk) 1N4007 /_\ | 6.3 VCT Secondary (red-yel-red) | | - o------------+------+ http://www.repairfaq.org/sam/samschem.htm#schssi
  21. The amplifier has too higher output impedance to power a 4R speaker. You need a power amplifier. The circuit you've posted is for a signal amplifier.
  22. The piezo needs to be driven by a 100Hz square wave. How can a voltage multiplier circuit (which will convert this to DC) possibly work? If the signal generator had enough current capability (it doesn't) a simple step-up transformer would work but that's not an option here. An amplifier is required, which means a separate 100V supply voltage.
  23. Kevin, A voltage multiplier converts AC to DC so isn't an option and the rest of your post doesn't make any sense. plukins, An audio amplifier may oscillate, as it won't be designed to drive a capacitive load. Are you looking to build this yourself or buy off the shelf?
  24. I was going to split the thread but his post is on topic so it doesn't matter. You may get more help if you post the schematic.
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