1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Electronics holla, please help with lighting

Discussion in 'Modding' started by tipsterb, 10 Nov 2003.

  1. tipsterb

    tipsterb What's a Dremel?

    Joined:
    31 Jul 2002
    Posts:
    89
    Likes Received:
    0
    holla, at school im doin a project with making a light, and i was thinking of using a cathode or sumthink like that, cause it gives off alot of light in all directions, tho, i need it to run of the mains, 230v, now i get i will need a stepdown transformer to get down to 12v, but does the ac matter?

    thanks for readin, hopfully u can help:)
     
    tipsterb, 10 Nov 2003
    #1
  2. fuzzball172

    fuzzball172 What's a Dremel?

    Joined:
    29 Sep 2003
    Posts:
    126
    Likes Received:
    0
    As long as the transformer puts out DC it should be ok
     
    fuzzball172, 11 Nov 2003
    #2
  3. rich_bytes

    rich_bytes What's a Dremel?

    Joined:
    30 Aug 2002
    Posts:
    187
    Likes Received:
    0
    Cathode inverters need DC to operate and transformers by themselves always output AC. You could use a plug in 12v transformer or something like it that has a rectifier built in so it outputs DC and power the cathode from that.
     
    rich_bytes, 11 Nov 2003
    #3
  4. Xiachunyi

    Xiachunyi What's a Dremel?

    Joined:
    3 Nov 2003
    Posts:
    1,404
    Likes Received:
    0
    You should do something like this:

    Line voltage>Switch>Fuse>Transformer>Diodes>PI filter/Capacitive>12V Regulator>Capactior>Branch>Switch>Inverter>CCFL

    -Add in a fan/heatsink if you are pulling more than 1.5 Amp out of a power regulator.
    -Capacitors for the PI filter or capactior only will need to have at or above input voltage.
    -You may need a small capacitor across the leads of the output regulator (0.1uf) to reject high frequency noise caused by branch components.
    -When utilizing a a 12v regulator, keep in mind of the ripple rejection characteristics. eg LM317 has a typical rejection of 65dB, use capacitive input filtering to raise it to 80dB.
    -To find the capacitor requirement, use this equation:
    %Vr1=Vr/Vi*100 and Cf=2.4*I/V
    Ex: Powersupply must put out 10v at 200mA with maximum dilation of 1% of 10v either way.
    1*10/100=0.1v (Can only dilate either way plus or minus 0.1v)
    Put into capacitor equation which will equal 4800uF. (convert Farads)

    Note: This is for a linear power supply, switching powersupply will have greater effeciency(sp) and less heat output.
     
    Xiachunyi, 11 Nov 2003
    #4
  5. hydrogen18

    hydrogen18 Banned

    Joined:
    19 Jun 2002
    Posts:
    1,861
    Likes Received:
    0
    no real transformer puts out DC. Those ones with internal rectifiers dont really put out useful DC, it still needs filtering.

    Xiachunyi :

    overkill, he doesnt need to build a psu, just a 12 volts DC source

    all u need is a wall transformer with 12 volts output at about 300 ma or more to run that inverter.
     
    hydrogen18, 12 Nov 2003
    #5
  6. BlackMan

    BlackMan Minimodder

    Joined:
    12 Sep 2003
    Posts:
    325
    Likes Received:
    0
    just get a wallwart, i got a 12v one for $2 and it ran both my cathodes and a few 80mm fans easily, i picked it up from a second hand store
     
    BlackMan, 12 Nov 2003
    #6
  7. tipsterb

    tipsterb What's a Dremel?

    Joined:
    31 Jul 2002
    Posts:
    89
    Likes Received:
    0
    thanks guys, lots of help there :), ill go out get the stuff, and c what happens, thanks again guys,
     
    tipsterb, 12 Nov 2003
    #7

Share This Page