CO2 tube question

[The_Doctor]

It might work ok. While a lamp dimmer isn't stern enough to handle input to inductive loads, except maybe brushed motors, there is a similar thing made for various standard mains currents, used for brushed motors and transformers.

rswww.com (RS Components) have something, stock number 655-644, with datasheets you can get for free with no sign-up.

That needs a filter (with a larger inductance than in a lamp dimmer) added to reduce EMI and RFI though, and you'll probably still hear noise in the transformer and maybe have to watch that it doesn't overheat.

I don't know what else to suggest, apart from something like a neon transformer but smaller, fed by a chopper circuit with a frequency of a couple of hundred KHz. Which is probably what that circuit is doing anyway.

[Hemlock Mike]

Doc --

Looking at this circuit, it looks like a basic full wave bridge input supply ( like a computer supply) with a big cap at 250 volts. The supply then feeds an encapsulated module with volts in / out. The regulator acts as a limiter between the filtered DC and the module. Switching noise from a "dimmer" should get filtered out. Motor speed controlers for fans seem to rely on a power factor shift using caps but I don't think that's needed because of the input configuration.

Mike

[steve-o]

I think V b-e will always read .7 or .8 in a grounded emitter circuit (npn). Is the load on the collector side? I have a thyristor fan control module also (looks like a lamp dimmer) I've resisted using it for any kind of inductive load control because of the size of the power device. It is very small. Looks inadequate. Thyristors (scrs and triacs) turn on/ off / both (depending on the device) at zero crossing only, making for a less than precision control.
Ok for fans and heater elements. I'm sure you could try it for transformer control but Power Companies are funny about customers chopping their sine wave up-I learned this the hard way by removing the center out of the 60 Hz wave with an IGBT (@ 10A -powering an argon laser) and 2 seconds later a pulse came back, all the lights got real bright in the house, blew the movs out of all the power strips, took out the microwave oven and the stove. I had some repairing to do after that little experiment

[Hemlock Mike]

Steve --

Power factor is a wierd thing about AC power. Fan controls use it by adding capacitors into the feed to the motor.

All I want is a schematicfor this damn 941S power supply !!!

Mike

[steve-o]

I guess you are talking about the winding for the run cap, or the start cap for single phase AC motors?
I did a quick dogpile search for "Laser Lite" and couldnt even find the company. What country are they in?

[The_Doctor]

I don't think he is... I think he means that if a PWM type triac circuit can cope with such, it should cope with the input to his supply. I don't think that's the answer though, or at least not all of it. That supply appears to be trying to regulate. Either that needs to be understood and modifed (needs schematic or reverse engineering), OR the internal regulation must be understood at least enough to override it permanently so that another means of regulation can be applied, that won't be fighting with the existing one.

I can't advise further cos I'm in the same position as Mike, worse even, I can't even see a PSU in front of me. I can see several actually, but that's beside the point.

[steve-o]

Cheers, Doc Is it toddy-time over there?

[The_Doctor]

It should be. Dram time, at any rate... Sadly, not much whisky around. I must do something about that.

[steve-o]

Tch. A little over 2 hours and its a virginia gin for me

Mike--Can u take a close-up picture of this thing- we might be able to ident something or 2

[Hemlock Mike]

Steve --

It's an old PS from the alien country of Kalyforinia !! The regulator seems shot so regulating the input should work. I'll bring it up slowly !! I have to turn my coffee table now to average out the burns !!!!

Mike