Dimming EL Panel

[martin_h]

Not realy a DIY project as such but worth a look.

The usual way to dim these panels is to sandwich a sheet or two of A4 between it and the scope, lowering the input voltage is not a good idea.

While searching the net I came across this little unit and decided to give it a go. Well It works!!!

DISCLAMER..... this unit is intended for powering EL wire and runs from 9V DC

My EL panel is A4 and runs from 12V DC so using this unit makes it run a bit dimmer at full brightness, BUT! dimming does work on it and will go right down to no output at all.

If anyone wants to give it a go .....

http://www.ebay.co.u...d=251230337259

[Gina]

I gather a dew heater controller or LED strip light dimmer will work with an EL Panel. However, I have a Gerd Neumann 160mm EL Panel which I use with my ED80 and Atik 314L+ mono CCD camera and have no problem. With the Baader L filter I use 0.04s exposure for around 25,000 ADU. That's running the panel from 12v - it's normal voltage. The other filters need more exposure for the recommended ADU value.

[Fordos Moon]

I have a Gerd Neumann 160mm EL Panel which I use with my ED80 and Atik 314L+ mono CCD camera and have no problem.

Hi Gina how does the GN panel work?

From the website it looks like you can put it over the end of the scope after taking lights and darks and it glows giving an even light to take flats without waiting til daylight? And how do you power it, will it connect to something like a 5 in 1 jump starter or the skywatcher power tank?

[martin_h]

I gather a dew heater controller or LED strip light dimmer will work with an EL Panel. However, I have a Gerd Neumann 160mm EL Panel which I use with my ED80 and Atik 314L+ mono CCD camera and have no problem. With the Baader L filter I use 0.04s exposure for around 25,000 ADU. That's running the panel from 12v - it's normal voltage. The other filters need more exposure for the recommended ADU value.

I have a CCD with a mechanical shutter which need esposures in seconds not 100ths, so usualy use the A4 paper trick.

[Freddie]

Fordos, the GN panel is powered from a std 12v cigarette lighter type socket. They are nice bits of kit though where the wires attach to the panel is not great and some people have had the wires snap on them. If you know this and take care, not an issue though.

[Fordos Moon]

Freddie, thanks mate. At the risk of it being a silly question, I assume you still need a daylight cloudy sky it doesn't work at night, ie when you have all your kit positioned and camera focused?

[Freddie]

Hi, the light panel provides all the light you need. You just pop it over the end of your scope (I just point mine straight up and sit it on the dew shield) when you are ready to take your flats, so can be done anytime you are ready during the night.

[Gina]

Best not done during daylight as some daylight will probably get in between panel and dew shield and spoil the flat light.

[Gina]

Hi Gina how does the GN panel work?

From the website it looks like you can put it over the end of the scope after taking lights and darks and it glows giving an even light to take flats without waiting til daylight? And how do you power it, will it connect to something like a 5 in 1 jump starter or the skywatcher power tank?

That's quite correct. I just rest it on the dew shield of the scope. Any 12v source will power it. It comes with banana plugs but you can easily take those off and use any other connector(s). Make sure you get the polarity right, of course.

[Fred_76]

Hy

I just made my flat screen with an EL panel (12"x12") :

As from now, the inverter is just a On/Off type, with 12 V DC input.

The 9V dimming inverter you indicate in the initial post is quite interesting to adjust the brightness of the EL Panel. But since february, what is your feedback on this idea ?

I also read that a PWM controller on the 12V input of the inverter may also be used to dimm the EL panel. We can get PWM controllers for a few euros on eBay (look for "LED dimmers"). Did someone tested that kind of assembly ?

Note that an EL Panel needs between 50 V to 130 V AC to run, with frequency between 400 and 2000 Hz. The brightness can be adjusted by whether changing the voltage (higher the brightest) or the frequency (higher the brightest). Changing the frequency may also change the colour of the light (it depends on the phosphor coumpound used). However, high frequency reduces the life of the panel, and input voltage only has a little effect (to a certain extent), so dimming should better be controlled by adjusting the voltage.

The idea is to connect in serie :

12 V DC power supply => PWM dimmer => Inverter => EL Panel

Do you believe it will work (I wonder how two oscillating devices will work in serie) ?

Fred

[Fred_76]

Its me again.

S

ince I asked the question (and received no feedback/answer), I received the PWM Led dimmer and tested : believe me or not, it works !!!

I am now able to dimm my EL panel just by turning the dimmer trigger right/left. At some positions, the light is flickering a bit, but most of the time, it is stable.

The intensity range is quite large.

It costed me only 3 USD (shipping including).

Fred

[perfrej]

You need to investigate this further before something burns up. An EL panel is driven by chopped DC, effectively AC. The little black box that comes with it generates a high frequency chopped signal (a few hundred Hz frequency) of approximately 75 volts. A power supply such as that may very well be destroyed if your regulating 12V thing in front of it is pulse-width modulated (PWM).

I suggest putting papers inside the panel to dim it. They are kind of bright as they come from the supplier.

/per