Homebrew PCBs

What you described with a series of 3 LED's and a Series resistor is OK most likely your problem is too much current so you may need to resize you resistor value.  Take your supply voltage (-) the voltage of your LED's (x3) for the voltage drop of 3 LED's then use that voltage to figure your resistor value to limit the current to the rating or lower of your LED.

Ben

--- In Homebrew_PCBs@yahoogroups.com, Tom Biery <judsquare@...> wrote:
>
> Chris, 
> Â 
> The Glass Plate should work.  Not sure if the LEDs you are using need a driver chip if they burn out then you probably need one.  The ZXLD1362 for example holds a constant current thru a series of LEDs.  Do you have any idea what the exposure time will be can you do a quick test exposing a piece of PCB before its all built.  Just some thoughts I am sure that once you get it built you will have allot of fun with it, UV makes a big differeence.  Are you going to use it for thru hole components or SMD mostly I do all SMD,  If you do SMD you might want to check out my video series on the SMD Toaster Oven.  Reflow Toaster Oven PART 
> 2. SMTÂ Â Â  http://youtu.be/kyphQ1WUIsk
> Â 
> Tom
> 
> From: Chris Kleeschulte <laconia@...>
> >To: Homebrew_PCBs@yahoogroups.com
> >Sent: Monday, September 26, 2011 6:49 AM
> >Subject: Re: [Homebrew_PCBs] Two Videos demonstrating the Kinsten UV Exposure Box
> >
> >
> > Â   
> > 
> >Tom:
> >
> >Your questions lead to me to believe that I have no idea what I am doing
> >with this UV led exposure box. My design is not using a driver chip..just a
> >75ohm resistor to drive 3 leds. This circuit will be in parallel with many
> >other ones just like it. Would I need a driver chip? To secure the artwork,
> >I was thinking that the glass plates would "sandwich" the artwork against
> >the glass plates. Would there be a problem with this?
> >
> >On Sun, Sep 25, 2011 at 9:23 PM, Tom Biery <judsquare@...> wrote:
> >
> >> **
> >>
> >>
> >> Are you driving the LEDs with a driver chip like a ZXLD1362?
> >>
> >>
> >>
> >
> >[Non-text portions of this message have been removed]
> >
> >   
> >     
> >
> >
> 
> [Non-text portions of this message have been removed]
>