Low Voltage Controller

[P. Short]

Here is a little project that I'm working on. It's a low cost board for controlling low-voltage devices. The board shown below is assembled for 12V DC use to test some MR16 LED lights when they finally arrive. The board is missing the MOSFETs and the PIC, but is otherwise complete. In the DC configuration it should be good for up to about 0.5A per channel, or 2A total, which is enough for handling the MR16 lights in the group buy over at pc.

It can also be assembled for AC use at up to about 24VAC or so, by installing diodes in the open locations down at the bottom of the board, and using SCRs instead of the MOSFETs. The current capacity in the AC configuration is a little bit less than for DC, because the largest diodes that will fit on the board are good for 1.5A each.

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Phil

[AI]

Phil; Looks nice, are you intending to share your design? Can we see the schematic? AI

[Wayne J]

Cool! neat little enclosure too!

[P. Short]

Right now I expect that there will be too many other things on my platter. In particular, the basic Renard, Ren-T and the Ren-C boards will need a lot of suppot when people finally receive their boards and try to get them working.

So, for now, I am not inclined to share. Perhaps in very limited numbers, and perhaps later if things go well with the other projects.

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Phil

[AI]

Phil; Thats Fiiiiiine, I understand, and if some of the others are like me, well I have not started my Renards yet, still gathering parts, it will get busy agen in the fall. I dont have an ap for it yet but mite help with LED strobes if I ever get back to that project. for now I bought a case of curtain strobes when thay were on sale. May be the LEDS will get even better by the time I get back to them. I look forward to your progress when you have time. Never enough time!! Thanks AI

[A Marchini]

Here is a little project that I'm working on. It's a low cost board for controlling low-voltage devices. The board shown below is assembled for 12V DC use to test some MR16 LED lights when they finally arrive. The board is missing the MOSFETs and the PIC, but is otherwise complete. In the DC configuration it should be good for up to about 0.5A per channel, or 2A total, which is enough for handling the MR16 lights in the group buy over at pc.

It can also be assembled for AC use at up to about 24VAC or so, by installing diodes in the open locations down at the bottom of the board, and using SCRs instead of the MOSFETs. The current capacity in the AC configuration is a little bit less than for DC, because the largest diodes that will fit on the board are good for 1.5A each.

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Phil

Wow, using an 8 pin part too. I was just scribling down a single channel serial controller for running C7 lamps individually. Not a new idea of course, but one that people keep asking about.
I was going to use dual IRF830 to do the AC control. Which FET are you playing with?

Tony

[P. Short]

BSS170.

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Phil

[P. Short]

Make that BS170.

The difficulty, of course, is driving the gate with a sufficiently high voltage to obtain the current that the part is rated for.

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Phil

[tconley]

Hey phil would that board be a good solution for what i was trying to do?

[ErnieHorning]

The difficulty, of course, is driving the gate with a sufficiently high voltage to obtain the current that the part is rated for.

Just drive it with a small NPN bipolar transistor (2N2904 or the like). For AC just mirror everything.

[P. Short]

TC,

Yes, one of the objectives of that design is your type of application.

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Phil

[A Marchini]

Make that BS170.

The difficulty, of course, is driving the gate with a sufficiently high voltage to obtain the current that the part is rated for.

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Phil
I have seen in other low voltage applications, (watch batteries) that a voltage doubler was used for upping the forward drop across a diode (to actually get it to light in that case). I am sure a similar idea would work for a gate drive.

Tony

[john]

Oooohhh i like the look of that, can it do dimming?

[P. Short]

Yes.

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Phil

[Warlock]

Hey Phil since you got this idea working or at least the concept of it anyway why not build a bunch of em and sell em off and make a few bucks till everything else gets sorted out with the other boards.That way at least further testing can be done with these as well and enough people will have them working incase a coop or something gets set up later on.With the stuff I sent Ernie about a company here in Canada that does this stuff they use transformers to drop the voltage and use leds for like 50 foot treets etc...They also did the display at the Niagra Falls Winter Festival of Lights.So something has to be with this lower voltage stuff that even they use.

[P. Short]

It's not quite ready for prime-time yet. I'm still working on making minor changes to make it more usable by others. It will be some time before all the kinks are worked out.

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Phil

[Warlock]

Somehow I highly dought it Phil.You will have it up and running perfectly without problems in weeks...I'm crazy not stupid...lol.

[A Marchini]

Make that BS170.

The difficulty, of course, is driving the gate with a sufficiently high voltage to obtain the current that the part is rated for.

--

Phil

I was thinking maybe this could be introduced into the design for controlling a single C9/C7 bulb Panasonic part AQV210E http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=255-1143-5-ND
But they are so slow for switching. I thought it would be a good selection because I know your are sensitive to direct connections with AC.

I (as usual) haven't worked out the details.
Anyways, is an idea.
T.

[BuzzLightyear]

Hate to bump a months old post but here goes.
I know less than nothing about electronics and or electricity, my wife says I don't seem to know how to turn off a bathroom light switch. That said I was thinking I had read that LED's could be run off dc current without any real modification. My children have had lots of cheap toys with blinky flashy LED's. Got me wondering if an Led only DC controller could be built for even less money than an A/C controller?
I'm only getting started in this hobby and figured LED's are the wave of the future So I bought almost all LED's this year, at post christmas sales. Could have bought tons of incandesants but instead only picked up a few yard ornaments with incandesant in then.
So, my questions are, would a LED contoller be cheaper/easier to build and is there anything in the works at this time which would run off dc and work with Viven?

Thanks for the help in advance,
Buzz

[mrpackethead]

That said I was thinking I had read that LED's could be run off dc current without any real modification.


LEDS ( or light emitting DIODES ), are polarised.. Ie currnet only flows in them one way. They only work with DC power... theres more..

The strings of leds you buy, convert the AC from the mains to DC, by rectifying it.. This is either 'half' wave, or 'full wave'... The important this is that the current only flows in one diretion through the LEDS.

So, yes leds can run off DC without modifcation.



My children have had lots of cheap toys with blinky flashy LED's. Got me wondering if an Led only DC controller could be built for even less money than an A/C controller?


Thats a loaded question.. Answers are Yes, No, Perhaps and Maybe.. It depends what you are wanting to do.. However in general, a fair comment would probably be its largely the same cost.



So, my questions are, would a LED contoller be cheaper/easier to build and is there anything in the works at this time which would run off dc and work with Viven?


yes, there is.. as well as several systems that all ready do it.

[FireGod]

Not willing to share a schematic?

Why?