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Thread: Neon/Fans/Anything controlled from your PC

  1. #1
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    Neon/Fans/Anything controlled from your PC

    Probably old news with the Fusion Brain now released - but this is cheap!!


    Too much research and a few hours thinking turned into this:








    small demo vid



    I'm trying to think of all the useless possibilities for this. Will be posting my source code and schematic some time in the future.

  2. #2
    Constant Bitrate
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    Why use a realy for this?
    Why not just use a MOSFET transistor instead?

  3. #3
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    I have no experience in using them. However from reading up they are simply transistors which accept very low current.

    Are there any reasons why I shouldn't use them? What about isolation of the parallel port?

  4. #4
    Variable Bitrate mayhembdm666's Avatar
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    You might want to look at using a Opto-isolator in the circuit and this will allow you then to use a mosfet.

    A opto is more or less a LED with a receiver, So by turning on the LED you are completing the circuit on the other side of the chip where the receiver is and this will allow you to switch a logic circuit while making sure its not connected to your delicate circuit.

    A common use for these chips are in computer PSU as most will have them.

    To me they are the best source of isolation, But have a look and see what you think.
    2004 Holden WL Caprice Auto GENIII
    Base System = Raspberry Pi
    Everything else is pending for now as switched from a Mini-ITX setup

  5. #5
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    .. and if your circuit doesn't use much current you don't even need a Mosfet connected to the isolator, just drive it directly

  6. #6
    Variable Bitrate mayhembdm666's Avatar
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    You will want to isolate it due to if there is a fault with the mosfet or a surge, It can short back into the parallel port. Using the isolate method, The most you will do is blow the opto.
    2004 Holden WL Caprice Auto GENIII
    Base System = Raspberry Pi
    Everything else is pending for now as switched from a Mini-ITX setup

  7. #7
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    Ooh, maybe I should have said. I have two concepts - the other one does involve the opto-isolator. I just need to put it all together.

    Any recommended part numbers for the MOSFET? I normally use 2N2222A transistors. Saving on components would be nice.

  8. #8
    Variable Bitrate mayhembdm666's Avatar
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    Here a few projects that are used for xmas lights: This is a common project
    SSR = Solid State Relay

    Project One:christmaslights.netbootdisk.com SSR
    Two: dv-fansler.com SSR
    Three: www.ksochristmaslights.com SSR
    Four: computerchristmas.com Channel Multiplier Style

    I cant remember what mosfet we ended up using when building the xmas lights controller, But the overall setup was running on 24v. The mosfets did not need any heat sinks so i think their rating would have been 48/120v or something.

    Have a google around on "Xmas Light controller mosfet", I jsut cant atm as my broadband has been throttled down due to a house mate who has no respect at all....
    2004 Holden WL Caprice Auto GENIII
    Base System = Raspberry Pi
    Everything else is pending for now as switched from a Mini-ITX setup

  9. #9
    Constant Bitrate
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    Quote Originally Posted by mayhembdm666 View Post
    You will want to isolate it due to if there is a fault with the mosfet or a surge, It can short back into the parallel port. Using the isolate method, The most you will do is blow the opto.
    Just put a resistor in between the PC and the gate of the MOSFET, then you wont destroy your PC if the MOSFET shortcircuits.

  10. #10
    Variable Bitrate mayhembdm666's Avatar
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    A resistor can short...So this is still unsafe.

    For proper protection, You need to have a safe gap for the circuit..
    2004 Holden WL Caprice Auto GENIII
    Base System = Raspberry Pi
    Everything else is pending for now as switched from a Mini-ITX setup

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