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Will1234

Sat Jul 07 2007, 12:50AM

Registered Member #846 Joined: Tue Jun 19 2007, 08:04PM
Location:
Posts: 40

How can I check the continuity of the thin red wire that enters the base of the trigger transformer? Where the lead enters the transformer seems to have a lot of free play in it and not stiff like the rest of the wire i...? Can I apply a small current, 9V, 12v, 24v and see if ANYTHING is registered on the main lead going to the lamp?

...

Sat Jul 07 2007, 01:32AM

Registered Member #56 Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445

seriously, you need to stop quadruple posting... If you need to have something to add modify the post, or if you want my attention pm/im me.

Your schematics didn't upload, try putting them in a .zip and then uploading them.

Concerning the power supply... When you fullwave rectify a 24vac transformer, you should actually get almost 35v out of it, because the transformer is putting out 24vac 'root mean square', which for a sign wave is 1/rad2 the peak-peak voltage, and when you have little/no load the output 'floats' up a few volts. As to the zener, I do not understand what you did... If you reverse a zener diode it clamps at a much lower voltage, not a higher one (unless you explode it...) In any case, the reason that the supply can charge the cap to a higher voltage than you read when it is freestanding probably has to do with the waveform coming out of the supply, I am guessing that it isn't a pure DC output, but rather short pulses of a high voltage. You meter doesn't accurately measure them, but the cap is still charged by them.

To test the trigger transformer primary, put an ohmeter from the red/brown leads at the bottom, it should read very low (no more than a few ohms). To test the secondary charge up the trigger cap to 200v, and short it across the primary, while the output lead is almost touching one of the primary leads. You should get a small spark (like a piezo igniter)

Will1234

Sat Jul 07 2007, 05:38PM

Registered Member #846 Joined: Tue Jun 19 2007, 08:04PM
Location:
Posts: 40

I attached a zip file with the two source files in it. If I reverse a 200V Zener should it cap the output at the knee voltage (200v) or subtract 200V from the total voltage already on the line? At this point I'm not sure how but if I put 2 160V and 1 200V Zeners backwards the power supply voltage shows up as 735vdc on my dmm with no load other than the dmm. ??

W
]1183829895_846_FT27163_ssy.zip[/file]

EEYORE

Sat Jul 07 2007, 05:53PM

Registered Member #99 Joined: Thu Feb 09 2006, 06:10PM
Location: florida, usa
Posts: 637

Your really making this more hard than it is...Just scrap the whole idea. Take out the main capacitor(you will also need its inductor so as to not wreck the lamp) and charge it via some sorta power supply. MOT's(on a variac and rectified), and CCFL inverters work great(use a DMM to watch the voltage). Use a piezo grill ignitor to trigger your flashlamp. Bodda bing, bodda boom! Oh yea, and close your eyes when you fire the laser!(Or get proper safety goggles.)
You will later decide you want more power and thus be collecting photoflash caps...

Matt

...

Sat Jul 07 2007, 06:56PM

Registered Member #56 Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445

The diode connected to pin 2 of the inductor needs to be in parallel with the tube, not in series with it. refer t the 2nd schematic.
The trigger coil is missing a wire, one of the small leads at the bottom needs to go from the contact between the 1m resistor and the trigger cap. (In addition to the lead going to the trigger switch)
I am a little unsure about 'large lead coming out of zener', the zener is a little diode looking thing on the trigger board (somewhat like this )
The circuit only needs 1 single zener diode, across the trigger cap. It should have no effect on the voltage the main cap charges to.

Will1234

Sat Jul 07 2007, 10:27PM

Registered Member #846 Joined: Tue Jun 19 2007, 08:04PM
Location:
Posts: 40

Alright, back to individual components to start over. What I was calling the Zener on the trigger board is the larger aluminum component opposite the coil from the trigger cap. Two leads out of the top and another at its base....

As always again, Thank you all.

Will1234

Sat Jul 07 2007, 10:48PM

Registered Member #846 Joined: Tue Jun 19 2007, 08:04PM
Location:
Posts: 40

I realize this has grown out of control so if you can look at the attached jpg of the trigger cap and clarify it for me I promise to ease back into the shadows and stop being so needy.....

Thanks......
]1183848498_846_FT27163_triggercap.zip[/file]

...

Sat Jul 07 2007, 11:07PM

Registered Member #56 Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445

The component you speak of is the SCR (q2 in the 2nd schematic), you need the grey/black diode labeled 1n4991

Will1234

Sun Jul 08 2007, 07:02PM

Registered Member #846 Joined: Tue Jun 19 2007, 08:04PM
Location:
Posts: 40

Finally!! I was missing the neg lead to the trig cap.

...

Sun Jul 08 2007, 08:52PM

Registered Member #56 Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445

so it fires now?

I would do anything I could to find a convex lens with a nice short focal point (<1" preferred, but anything is better than nothing) as the laser is notably more impressive when you focus it down to a nice small spot. If the lens is short enough, and the head in good enough condition, you can actually have enough power density to ionize air, which manifests itself by creating a small plasma ball floating out at the focal point of the laser.

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