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  1. Hero999

    Static electricity eleminator

    I'm sure you know that the shock is caused by static electricity. The static electricity can damage sensitive semiconductors. You should replace the plastic mats with carbon loaded rubber anti-static mats and wear a grounded anti-static wrist strap when working with sensitive semiconductors.
  2. Hero999

    Design new 0 to 30V power supply.

    I think I answered this before but the site went down. The op-amp needs to be a to work from a single supply i.e. both inputs must work down to 0V and the voltage rating must be high enough. The LM324 will be find providing the hhigh DC voltage is kept below 36V. The 741 is not suitable because...
  3. Hero999

    Trigger an SCR to switch a negative voltage

    I don't see any need for a zener, the gate should clamp at around 0.7V and the secondary voltage depends onthe primary and the turns ratio. If it's a sensitive gate triac you can easilly use a pulse transformer which can be made from a ferrite bead and some hookup wire.
  4. Hero999

    100 amp power supply design

    A properly designed amplifier shouldn't require a regulated supply. Is it an audio amplifier? If it's designed to drive 4Ω speakers then the power output will be 23.8W per channel maximum. If it needs to output any more power per channel then the speaker's impedance needs reducing or the power...
  5. Hero999

    Equation for Draw on battery by electronic devices

    To answer your original question: there is not hard and fast rule to calculate how long a battery will last for. It depends on the device and how it's used. Take your PSP for example: How loud is the volume control? Do you have headphones connected or is the sound being played through the...
  6. Hero999

    50V, 50A H-Bridge IC needed

    The resistors form a potential divider which keeps the gate voltage to the top MOSFETs below the maximum rating (normally 20) but high enough to turn them fully on. V = 4.7*50/(10+4.7) = 16V If the supply voltage is too low the gate voltage will be too low to enable the MOSFETs to carry the...
  7. Hero999

    project

    It's easy just load up Google, enter what you want to search for and copy and paste the contents of you browser's address bar into the post.
  8. Hero999

    project

    You need to learn how to use Google. http://www.google.co.uk/search?client=opera&rls=en&q=low+voltage+alarm&sourceid=opera&ie=utf-8&oe=utf-8
  9. Hero999

    how do you think that nanorobot do really exist ?

    I doubt it, not something really useful - don't trust marketing material.
  10. Hero999

    need help in detecting signal transmitt to the satellite

    Don't post the same question twice and reduce the size of your avatar - I had to use adblock to remove it!
  11. Hero999

    passive or active filters !?

    Active is better because it gives amplification and the output is low impedance. You can download some software to help you design active filters.
  12. Hero999

    Custom Car Remote Possible?

    Why can't you just have two remotes? It sounds like too much trouble, then you have to consider the fact that modifying the remote will void the warranty.
  13. Hero999

    Mod 16 ripple down counter and Mod 12 ripple down counter

    You use logic gates to detect when the counter has reached 12 and connect to output to the counter's reset pin.
  14. Hero999

    Need help!

    So, it's better than the circuit originally posted? At least it works. The original circuit won't work because the aerial (antenna) is connected to the positive power supply which is pay-passed to 0V via C4 and C5. By the way this site is not a free PCB design service but an electronics...
  15. Hero999

    Building a Signal Transmitter

    Do you need to to transmit it on the broadcast band i.e. AM or FM?
  16. Hero999

    Capacitors

    No, a flux capacitor requires 1.21 gigawatts to work.
  17. Hero999

    bipolar transistors

    No you can't use any voltage you like. What if you're restricted to using a single AA cell? Then you're limited to 1.5V.
  18. Hero999

    bipolar transistors

    BJTs have the following advantages over MOSFETS: The input is not capacitive. They're cheaper. The turn-on voltage is only 0.6V which means they can be used in very low voltage circuits <1V. They have a higher gain. BJTs are more resistant to ESD than MOSFETs. I've answered your...
  19. Hero999

    0-30V Stabilized Power Supply

    Tantalum should be better than aluminium electrolytic. If you want to go with film, choose polypropylene over Mylar.
  20. Hero999

    schematic search

    What's the big deal? Why don't you upload your files somewhere else and post a link here? It's not hard, I've been doing that for years before forum attachments were invented - people are spoilt these days. The amount of advertising on this site is already unacceptable, if people were allowed...
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