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FireGod
12-20-2007, 12:13 AM
I have been playing around with a new FGDimmer design.

The design includes:
An RJ-45 connection for connection to the current FGDimmer PC interface
and/or
A connection for a 9 pin serial cable
and/or
A wireless serial modem

On board 120VAC to 5vdc power supply
On board 5 vdc to 3.3 vdc power supply for the wireless modem
On board zero cross signal
Each of the 32 outputs is individually fused
The 120VAC power is rectified and instead of Triac SSRs using multiple parts, I am using IGBTs with PWM programming in the PIC (a much lower cost solution).

I have run a few PSPICE models and I am currently in the prototyping phase.

It looks something like this:

File deleted and topic moved to the Development section: FGII.

Wombat
12-20-2007, 12:48 AM
Looks good.

Thats alot of fuses

Will this be suitable for 240V?

Can it also be run on 24V

any schematics?

Wombat

FireGod
12-20-2007, 12:56 AM
You actually should protect each circuit with a fuse. I use a much much lower cost fuse holder than is currently used.

To run on 240VAC you just need to change the transformer.

I think to run on 24 VDC, the transformer would be bypassed and the PIC program would need a minor modification to ignor the zero cross signal.

avatar-it
12-20-2007, 09:34 AM
I like the idea alot.

not sure what a IGBT is but im sure thats a good thing.

Also is it possible to have multiple units? there doesnt seem to be an out serial port.

Peter

FireGod
12-20-2007, 11:21 AM
The modules are identified by addressing in the PIC. The current plugin allows 128 channels (four field modules).

I put a serial port on it for anyone just wanting one 32 channel unit without any additional hardware, mostly for beginners just getting started.

Trepidati0n
12-20-2007, 11:28 AM
FG, I understand your reasoning for wanting a fuse/trip on EACH channel. However, as long as the FET/BJT/etc can handle the current until the breaker upstream strips, you should be okay.

However...the wireless idea....booyeah!

FireGod
12-20-2007, 04:54 PM
The purpose of fuses is to protect the downstream wiring from fire hazards, not the upstream breakers.

Trepidati0n
12-20-2007, 05:27 PM
I understand that...but I think you are missing my point but maybe I’m missing yours.
If the gauge of wire used after the SSR is at the same or better rating to match the upstream breaker, there is limited value in the fuse. I would also be quite nervous if wires being attached between the board and the strings of lights would not survive a fault that would trip a normal wall breaker.

I do however see great value, if the fuses are properly sized, to limit the propagation of faults to the other channels. I would also see great value if you were attaching loads, like the MR16 lamps, which do not have fuses.

SgtPepper
12-30-2007, 12:25 AM
I've been lurking around for about a month, trying to decide what controller I'd want to use. I'm trying to put something together that will control my tiny display, but also my parents' acre of lights. They're considering putting up a 30' megatree. This seems like a good system.

I have a few questions and a few comments.

My understanding is that this would connect to the existing PC interface via RJ-45, or some updated design with wireless, and would replace the field modules? Would going wireless allow for a greater number of field modules, thereby increasing the number of channels available?

The wireless would be a great idea and starts to make placing the controllers a little easier, I think, since you wouldn't have to run wires through a wall if you keep your PC interface inside. Keeping the RJ-45 as an option would make it an easier/cheaper upgrade for existing FG users, though.

I also like the idea of moving to IGBTs. Not only are they a cheaper solution, but they also help reduce the noise the system creates, due to the way the power waveform is switched. This probably isn't that big of a deal, but I'm an electrical engineer, so that kind of thing matters a bit... :)

The only thing I don't like is the number of fuses. I agree with the need for the protection, but they seem like they add a lot of area to the PCB. On the other hand, I can't think of a better way to offer the same protection.

When it comes down to it, I think the system has a lot of potential. I'd be more than willing to help out with anything as you're designing it. I have done PCB layouts in the past, and can probably get access to Cadence to do some work if it would help any. I haven't done much simulation, though.

Let me know if I can help out at all.

FireGod
12-30-2007, 12:31 PM
Basically the FGII could be used with the current PC interface. Also, they can be their own PC interface and they can also send the serial data to other modules. As far as sending data to other modules, I have ignored the bi-directional communication.

I am planning to use the exact same PIC program and Vixen plugin.

As far as fuses, I have found some middle ground. I have placed fuse clip holders on the board that will accept the fuses that come with the current incandescent mini light strings. This way you can just use the spare fuses that come with your lights (3.6mm x 10mm) and they are FREE!! They also take up less room.

I am still cutting wood from the ice storm, I have 1.65 acers loaded with large trees and I am spending a bunch of my time cutting and burning so 2008 Christmas light designs have taken a back burner position for a little bit.

I have not completly stopped working on it. I have been working on a schematic and I'll warn you, I am not finished but here it is.

Edit: File deleted and topic moved to the Development section: FGII.

AI
12-30-2007, 08:24 PM
I understand that...but I think you are missing my point but maybe I’m missing yours.
If the gauge of wire used after the SSR is at the same or better rating to match the upstream breaker, there is limited value in the fuse. I would also be quite nervous if wires being attached between the board and the strings of lights would not survive a fault that would trip a normal wall breaker.

I do however see great value, if the fuses are properly sized, to limit the propagation of faults to the other channels. I would also see great value if you were attaching loads, like the MR16 lamps, which do not have fuses.

The light strings them selfs are of small wire and will burn befor your 15 amp or 20 trips. Thats why thay all now have fuses in them. This makes it a pain to extend the wires on your strings because you shold reuse the old plug for the fuse. The fused plugs are hard to water proof also. So if each channel in the box IE on the board had its own fues you would not have to use fused plugs and could use molded plug ends to extend your light strings and decorations.
Personly I spend far to much time putting extenshoin cords on stuff and trying to water proof them.
I have been slowly adding perminate longer plugs on all my yard decorashoins and have started to use the extenshoin cords for this becase I don't need so many now.

I would love to have fuses on every channel of every box but thats alot of reto fitting anyway the more fuses the better FG. AI

AI
12-30-2007, 08:36 PM
FG; looking good so far. You will need a lot of ground around the XBee, you may whant to put it in a corner by its self. It dosn't play well with others. :lol: AI

FireGod
01-15-2008, 11:38 AM
This thread has been moved to the Development Section.

Thanks for the interest.