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  1. Hero999

    Raising Ni-MH Voltage

    You're not doing very well if your 555 only works down to 5V. The datasheet says it should work down to 4.5V, perhaps you've not measured the voltage properly or have a fake, although I don't know why anyone would bother faking such a crappy IC. Discrete design isn't only for very low voltages...
  2. Hero999

    Solar Energy harvester, MPPT using FOC method ???

    It's not a full schematic diagram but a rough block diagram. It doesn't give enough information to enable you to build it or fully understand how it works. I've not seen the article because you've not posted it so I assume it's a about a proprietary technology and is intended to be marketing...
  3. Hero999

    Working on TV Tube

    No one's going to email, we only help people on the forum here. The tube is actually pretty safe as long as it's handled carefully. The voltage stored in the internal capacitor may be high but the value is really low (under 100pF) so the amount of energy stored is too small to give you more...
  4. Hero999

    Convert sine wave to square wave

    A 0 to +5V square wave is really a +/- 2.5V square wave with 2.5V of DC offset. In the simulation you've posted, you have a 0V to +10V square wave. Set the offset to 0V, connect the middle pin of the signal generator to 0V and the +V to the input for a similar waveform to what you'd get out of...
  5. Hero999

    Convert sine wave to square wave

    Don't post the same thing more than once, it's considered to be spamming, I deleted your other post. It's easy yo convert a square wave to a sine wave using a low pass filter, as long as the frequency doesn't change. A square wave is really a mixture of frequencies, you'll have 140Hz and its...
  6. Hero999

    Increasing the DC 5V 250 mA adopter volt & amp.

    His power requirements are too high. Transformerless power supplies are only any good for currents up to tens of mA, beyond that, the capacitor becomes as large and expensive as a transformer and they should only be used for fully enclosed circuits as the DC side is not isolated from the mains...
  7. Hero999

    GPS project, does it really have to cost this much?

    I don't think that's expensive, the price is probably pretty reasonable. Look at the price of commercially made vehicle tracker systems. http://www.onlinespyshop.co.uk/product.php/768/-gps-tiny-tracker- You might be able to buy an old satellite navigation system off ebay and hack it but at...
  8. Hero999

    90v DC Power Supply

    Yes, I've built a similar circuit to that before and it works well. In your case you have a problem: the maximum rating of the NE555 is 16V, so will need to be powered by a separate regulator. Tap 24VDC from the first PSU and connect it to the 555 via an LM78L12 or LM7812 with the appropriate...
  9. Hero999

    90v DC Power Supply

    No, the LM317 is no good as a speed controller at this power level, you need PWM.
  10. Hero999

    90v DC Power Supply

    Oh no, I've just figured out what you intended to do. I didn't notice the AC symbol on the motor controller you linked to but looking it again and your diagram make me notice it. No that won't work, the speed controller needs to be on the output of the power supplies (not the input) and...
  11. Hero999

    90v DC Power Supply

    That should work. The only issue is that the motor will have a higher starting current than 3A which might cause one of the supplies to current limit which might destroy it as it will be then connected to 48V backwards. To protect against this, connect a 3A diode in reverse parallel with each...
  12. Hero999

    Help nman po!... =)

    I'll try to help you if you post in English. I think you've confused this forum for another popular Filipino forum which looks very similar.
  13. Hero999

    HELP NEEDED WITH DC POWER NOISE

    I don't know. It sounds like the voltage is too low or the batteries have too higher impedance. Have you measured the battery voltage? Try connecting a 100
  14. Hero999

    Program launch: "Get Paid to Publish your Project!"

    Thanks for that. I think all projects containing programmable devices published on this site should have source code; not much can be learnt from a hex file, except disassembly, which is not easy.
  15. Hero999

    Program launch: "Get Paid to Publish your Project!"

    Yes I know and it also says it can't be published anywhere else on the Internet so it's not possible to get a peer review until it's published here. Yes I agree. I've attached the final version with all of my red pen removed. I have one more suggestion: perhaps a more common transistor could...
  16. Hero999

    HEX file for project

    It doesn't. It would only infringe on copyrights if you or someone else attached the HEX file or source code, assuming the licence says you can't do it.
  17. Hero999

    Programmable current source

    USA a DAC to convert the digital signal to a voltage i.e. 0 to 5V which is connected to a transconductance amplifier, a 500k resistor will give 0 to 10
  18. Hero999

    Increasing the DC 5V 250 mA adopter volt & amp.

    That's a bad idea for two reasons: the DC side will not be isolated from the mains and the resistor will have to dissipate 392W. A transformer would be a better idea but it's probably too large for what he needs.
  19. Hero999

    HEX file for project

    Who knows? It may have code protection so even if you bought the kit, you wouldn't be able to copy it. It's probably copyrighted anyway, in which case posting it would be against the forum rules: no copyrighted material, unless the owner has given permission to use it on the forum. I dislike...
  20. Hero999

    HEX file for project

    Have you contacted the web master of the site? http://electronics-diy.com/contact.php My guess is you can't get the HEX file: you have to buy the kit.
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