CW arc lamp PSU design, now the rat has moved out.

[mixedgas]

I figured it would be a electric water heater element, which are common in the states and available in a array of voltages and wattages.
Do you put the 1KV boost across the lamp or just pulse the heck out of the ignitor?
Steve

[LesioQ]

As for the trigger part - the upper and right part of chaos#2 pic , I use 3 microwave caps, each 1uF/2kV. Two of them are in parallel and source a boost current via 22 ohm resistor. The third cap is a trigger pulse source.

The two capacitances are charged to ca. 1.5kV (each via his own 1Meg resistor) from HeNe supply turned-on for ca. 8 seconds (the relay to the right). I use hand triggering for simplicity (say finger triggering).
You hold the button for 8 like seconds to charge the caps, then release and get single shot to lamp. 90% works at first pulse.

after the lamp start I short the trigger-protecting diode (two in my case) - no need to heat them up when not in use.

Piotr.K

[Laser Zone]

Steve ! Say hello to your little friend !!!

[LesioQ]

It's interior that matters ! At least if You're allowed in
How about a peep or two ?
Piotr.K

[mixedgas]

Steve ! Say hello to your little friend !!!

Oh wow, I have that on loan??? Great, problem solved, at least So I can test the LBO.

But I'll still send the drawings to weartronix.

[mixedgas]

It's interior that matters ! At least if You're allowed in
How about a peep or two ?
Piotr.K

3 IR fets in to220, I have the schematia, on their way to you.

will gently measure inductors, if I can get at them.
Then I will distribute the cavity design of the linear greenie. rated 3.5 watts cw, known to approach 7 with good LBO, and decent divergence compared to a laserscope. Distribution will be somewhat limited.

Steve

[mixedgas]

It's interior that matters ! At least if You're allowed in
How about a peep or two ?
Piotr.K

Why?, you have pretty much recreated it!

What you probably want to see is hidden under the main board.

I just installed one for a local university. I can't understand why they discontinued it, great unit. rated to CW arc air as part of its testing, but I will NOT be doing that.

Steve

[weartronics]

Karl, though I would have wrung his neck out of frustration if I found him at the time, now I am happy that the little guy wasn't being deliberately malicious, he was just looking for somewhere to live .

Steve, thanks for the schematics, here are some inductor measurements you requested:





The giant inductor measures 1.7 mH, and the trigger transformer primary measures 3.5 mH, so the total series inductance is about 5 mH.

Here is a photo of the power supply, in case you want to see what it looks like!



This is after extensive dog biscuit excavation, complete disassembly, washing all parts with soap and water, lacquering corroded metal surfaces to try and stop further corrosion (though it doesn't seem to be working ), and reassembling all the power electronics (no logic electronics present, they are too far gone).

Unfortunately, while cleaning the power supply I washed off some of my markings, and I have one mystery capacitor that I am not sure where to connect it. I updated the schematic to show two additional 100nF capacitors (that I think are just spike suppression). The mystery capacitor is huge, 12uF 650V! Perhaps it is also part of some spike suppression. Can you determine it's function, and would you connect it in position A or position B? I am certain about the connection of the right hand side, only the left hand side is uncertain. I think it is most likely position A or position B, but it is possible it could go to one of the IGBT terminals instead . Anyway, I would like to know the purpose of this capacitor, any ideas?



Best regards,

weartronics

[mixedgas]

your mystery cap is most likely a start boost cap to dump 500 V into the lamp during start.

I'd guess B, but I'd listen to what LesioQ says.

Steve

[weartronics]

Hi Steve, if it helps, I was able to identify and remove all the triggering electronics including the SCR and it's related capacitors, I am saving that puzzle for another day . I think you are correct, it is probably a start boost capacitor, though I am unsure of the connection. I am also looking forwads to Piotr's comments if he is around . Cheers, weartronics