1. Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
    Dismiss Notice

Project: Fluoro Lamp Power Inverter (12v)

Discussion in 'Electronic Projects' started by hsab, Mar 23, 2005.

Thread Status:
Not open for further replies.
  1. Sig239

    Sig239 Member

    Joined:
    May 25, 2006
    Messages:
    223
    Likes:
    0
    Location:
    USA-Ohio
    First this guy revives a year old thread with rubbish, then the next guy comes in two months later......next thing you know...A fine tale of two newbs triggering a frenzy over an old thread is all but written in the history books.:D :D
    I have begun to profile different threads. The first thing I do when I see a thread with more than 600 views is check the dates. If you see a thread with like 6 replies and 1500 views it seems to almost always be revived.
    EDIT: In this case 19 replies and 2023 views LMAO
     
  2. Hero999

    Hero999 Banned

    Joined:
    Apr 6, 2006
    Messages:
    14,902
    Likes:
    79
    Location:
    England
    Anywaym powering a fluorescent tub is a very common request, and it' easy to do but harder to do properly. If you have any more questions then I can point you in the right direction. Really the only hard part is the transformer which can be a bit experimental but it's not too bad really.
     
  3. Overclocked

    Overclocked Member

    Joined:
    Oct 10, 2005
    Messages:
    783
    Likes:
    16
    Location:
    CT, USA
    Its more efficent to go and buy a CCL for computer modding. You can get em cheap for 2 bucks at SVC when they have deals. All things for computers work for 12V, all you would have to do it modify the connector.

    http://svcompucycle.stores.yahoo.net/12vb2ccflwht.html
    White, they go for 6 bucks.
     
  4. dave

    Dave New Member

    Joined:
    Jan 12, 1997
    Messages:
    -
    Likes:
    0


     
  5. Hero999

    Hero999 Banned

    Joined:
    Apr 6, 2006
    Messages:
    14,902
    Likes:
    79
    Location:
    England

    They won't power standard fluorescent tubes though but I see what you mean, the idea is to use the CCL instead.
     
  6. Overclocked

    Overclocked Member

    Joined:
    Oct 10, 2005
    Messages:
    783
    Likes:
    16
    Location:
    CT, USA
    Right, The whole thing comes with an Inverter. But still it does make a good HV circuit, and they do produce nice arcs :)
     
  7. EDGE

    EDGE New Member

    Joined:
    Oct 2, 2007
    Messages:
    6
    Likes:
    0
    This is true about the differance of driving flourescents withpulsed d.c bias . It is also an apparently complex and overkill cicuit for the application which could be =effectivly implimented with 2 transistors driving a center tapped transformer with one hihg volt secondary and one intermediate winding to alternatly toggle the bases / gates . this scheme can be point to point wired withuot any p.c. board . Oh yea ,I forgot that you need 2 bias resistors and 1 capacitor.
     
  8. Hero999

    Hero999 Banned

    Joined:
    Apr 6, 2006
    Messages:
    14,902
    Likes:
    79
    Location:
    England
  9. delta06

    delta06 New Member

    Joined:
    Nov 28, 2007
    Messages:
    3
    Likes:
    0
    Built this one but I can't get it to work somebody please help.
     
  10. Hero999

    Hero999 Banned

    Joined:
    Apr 6, 2006
    Messages:
    14,902
    Likes:
    79
    Location:
    England
    Have you tried swapping the base connections to the transistors?
     
  11. IQBALSOUND

    IQBALSOUND New Member

    Joined:
    Feb 29, 2008
    Messages:
    25
    Likes:
    0
    Location:
    Karachi
    Nice oscilator section

    Hi hsab...nice tricky oscillator but is this circuit is reliable?
     
  12. Hero999

    Hero999 Banned

    Joined:
    Apr 6, 2006
    Messages:
    14,902
    Likes:
    79
    Location:
    England
    The circuit is quite reliable when properly designed and built. This sort of circuit has been used to power fluorescent lamps of DC power in busses, trains and military vehicles for years without any problems.
     
  13. HS3

    HS3 New Member

    Joined:
    Apr 6, 2008
    Messages:
    42
    Likes:
    1
    I know this is an old post but I believe this is fundamentally wrong.

    Speaking of forward mode transformers (not flyback) and assuming the transformer is designed so that it does not saturate in any case, then the addition of a DC current at the input does not affect the output at all and, in fact, there is NO way to tell by looking at the output if there was a DC component in the input.

    Look at the output transformer of a valve amplifier. It is carrying the plate DC with the output signal superimposed. The output is the AC signal with no DC. If I give you the output of two transformers and both give the same signal you cannot know which one is carrying DC in its primary. If the input is V = K + A sin(ω*t) The output will always be the same regardless of whether K is zero, positive or negative.

    The thing is that if you are carrying DC in the primary then you need a bigger transformer so it does not saturate the core. The DC current is creating a continuous flux which takes the core nearer to saturation so transformers (and chokes) which carry DC in their primaries need to be specially designed but you cannot see any difference in their outputs. None whatsoever. The DC is totally blocked and it is as if it did not exist.

    Just the same happens with a capacitor. If I have a signal input blocked by a capacitor, on my side I will see the AC variations but I have no idea from this side what the voltage may be on the other side of the capacitor. To know that I have to go to the other side of the capacitor. All I can see is the AC from my side.
     
  14. audioguru

    audioguru Well-Known Member Most Helpful Member

    Joined:
    Mar 16, 2004
    Messages:
    32,430
    Likes:
    933
    Location:
    Canada, of course!
    Good point.
     
  15. Hero999

    Hero999 Banned

    Joined:
    Apr 6, 2006
    Messages:
    14,902
    Likes:
    79
    Location:
    England
    The circuit I am critisising is a flyback so the core does saturate. What you're saying is true that there's no DC on the secondary but there will be just negative DC pulses and no positive pulses.

    I've uses a similar circuit to run a fluroscent tube from before and after a few hours of running only one end of the tube went black. This is because the current only flowed in one direction causing the cathode electrode to sputter on to the glass. Try connecting a neon lamp to this circuit and you'll see that only one electrode will glow.
     
  16. Ubergeek63

    Ubergeek63 Well-Known Member

    Joined:
    Apr 16, 2008
    Messages:
    1,886
    Likes:
    37
    Hero, is that guy a bit full of himself or what? In the industry that circuit is called a royer inverter and was the standard inverter circuit for many, many years.

    For him to say that he improved it is quite presumptuous. There has been nothing under the sun original that could be done with that circuit for almost as many years.
     
  17. hsab

    hsab New Member

    Joined:
    Nov 3, 2004
    Messages:
    8
    Likes:
    0
  18. Hero999

    Hero999 Banned

    Joined:
    Apr 6, 2006
    Messages:
    14,902
    Likes:
    79
    Location:
    England
    Where's the circuit?
     
  19. audioguru

    audioguru Well-Known Member Most Helpful Member

    Joined:
    Mar 16, 2004
    Messages:
    32,430
    Likes:
    933
    Location:
    Canada, of course!
    You need to search for it. I found it.
     

    Attached Files:

  20. Hero999

    Hero999 Banned

    Joined:
    Apr 6, 2006
    Messages:
    14,902
    Likes:
    79
    Location:
    England
    I've seen that circuit before. It uses an AM radio aerial so noise is broadcast everywhere, a single transistor and no DC blocking capacitor so one of the tube only gets driven with negative pulses causing one of tube the ends to blacken.

    It's simple and low cost but also illegal (it doesn't comply with the EMC laws) and gives poor efficiency and tube life.
     
    Last edited: Jul 21, 2008
  21. Ubergeek63

    Ubergeek63 Well-Known Member

    Joined:
    Apr 16, 2008
    Messages:
    1,886
    Likes:
    37
    Actual inverters use blocking caps before the transformer because they are less expensive in money and space than a larger transformer.
     
Thread Status:
Not open for further replies.

Share This Page