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Old 13th October 2005, 11:53 PM   #61
diyAudio Member
Join Date: Dec 2002
Location: VA
Well what I was planning to do is connect the LCD power to the Lamp power. So assuming that your other components can be turned on just by applying power... incorporating a switched outlet for components outside of the projector could turn them on, if, you only wanted them to come on when the lamp was energized.

Oh Wait... that wont work....

During the boot phase, the controller energizes the ballast, then looks for light from the lamp. It has to see steady light from the lamp (for 20 seconds) to consider the lamp officially on. If it energizes the lamp, but doesnt see light, or sees unstable light, it Removes energy from the ballast and pauses for 20 seconds (fans still running), then starts the cycle over again.

What you would need would be a second relay closure that activates once the projector is officially in the RUNNING mode to power your other devices. Then when the running mode is exited (for whatever reason) that relay deactivates.
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Old 14th October 2005, 07:17 AM   #62
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Guy Grotke's Avatar
Join Date: Sep 2004
Location: Vista, CA
Default device activation

Actually, all my other video and audio devices are always powered. Applying AC power to them would just put them in the idle state. But they all do have IR remote controls, so a microprocessor-based projector controller could turn them all on and select the right settings by driving a single IR LED with the right commands.
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Old 14th October 2005, 03:23 PM   #63
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Join Date: Dec 2002
Location: VA
I did some experimentation a while back using a PIC to record/playback IR pulses from/to IR controlled devices... I was able to get it to work, but the problem I ran into was that every device (receiver/etc) gives some form of visual feedback to let the user know what state its in... this is impossible to get a controller to understand (without hardwiring the controller to the internals of the device), so you end up having to do some funky things in order to make sure the device is in the state the controller expects it to be in... It could work just for simple on/off though.

Well anyway, I modified the code to take into consideration a Button Press vs a Press and Hold... I just have a few bugs to work out before the weekend so hopefully I can do a real world test.

Im still considering adding a 120VAC relay activation that only triggers when the running mode is entered, and deactivated when the running mode is exited, I think connecting the LCD AC power to that would be better than connecting it to the Lamp AC which can get cycled on/off several times during boot mode.

Ive also been thinking about a Fans Only On mode... where you could turn on nothing but the fans and let them run as long as you wanted. Maybe what I could do is if you Press the power button in shutdown mode, you would enter Fans Only On mode.... but if you Press and Hold in shutdown mode, you would enter Booting mode.... We'll see
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Old 16th October 2005, 09:03 PM   #64
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Join Date: Dec 2002
Location: VA
Latest update...

I added the Fans Only On mode, so if the controller is in standby mode, and you press the power button it goes into Fans Only On mode.If you Press and Hold in standby mode you go to boot mode. If you press the power button in Fans Only On Mode you enter Boot Mode. If you Press and Hold in this mode you go to back to standby mode.

I also built a board.

I used a point to point soldering method on a piece of perf board with solder points, to wire up a board. I used wire wrap wire to make the connections.

I connected all the IO devices (Power Button/LEDS/Light Detector/Motion Detector/Fans/Lamp SSR/etc), and powered it up and guess what?


I only have one small problem.... for some reason my DANG buzzer gets hot!

Im using 12 volts (controlled via MOSFETS) to drive the buzzer and the fan circuits. I think the problem is that my buzzer is a transducer instead of a piezo buzzer...


I guess I wont have an In Projector test this weekend....

Oh Well!
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Old 18th October 2005, 05:20 AM   #65
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Join Date: Dec 2002
Location: VA
Minor Setback....

Some way I managed to blow my PIC16876! With it in the board I built, the 7805 regulator gets really hot really quick!

Oh well... I removed it, and after troubleshooting the problem with the pic (and nearly completely rewiring the board), I replaced it with a PIC 16F873....

So now Im back up and running with a working board.

This weekend its going into that dang projector if it kills me!

Luckily I never really "Finished" my projector (Im waiting on that new long throw lens thats coming out) The projector works, and gives a killer picture... but isnt all pretty like... so I wont have to worry about busting up a completed projector to install the P-Brain into it.

Im working on some pics.... unfortunately A) My ex girlfriend stole my digital camera (It was a cheapo gift so Im not worried about it) B) Before she took it, I wasnt able to find the cable to connect it to one of my Computers to download images anyway...

Oh Well... Its going to be really cool not to have to worry about shutting the PJ off if I decide to make a quick trip to the store....

Another couple of quick features Im considering: 1) If the lamp goes off at any time, the controller shuts down the PJ. 2) Adding a general purpose cut off that if it is ever activated will cause the PJ to shut off. This will let me eventually tie in a smoke alarm or other detector to the shutdown program. 3) A Running Mode activated Relay... which gets activated only when the controller enters Running Mode, and gets deactivated when the running more is exited.... I should do this one now....

On to next weekend!
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Old 22nd October 2005, 12:41 AM   #66
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Join Date: Dec 2002
Location: VA

I added the Running Mode Relay...

This is a 120vac Solid State Relay that gets activated only during Running Mode.... When running mode is exited for whatever reason the relay is deactivated. I think I will connect the power to my LCD to this relay instead of connecting it to the LAMP power relay...

Man Ive got to get another Wire Wrap Gun!!! Point to point soldering SUCKS!


Ive been considering developing a User Interface for the P-Brain. It would be used to set parameters show status/errors/etc

Im thinking either A) Making it self contained by using a character based LCD, and a keypad/array of buttons, or B) Implementing a serial interface that can be attached to a PC where you can run a PC based GUI (with the P-Brain attached to your serial port) to configure the controller/read stats.

Which would be better? Both Right? Hahhahahahahaha

My last test is to see how everything behaves with the 120vac coursing through the circuitry.... Until now, everything has been simulated in my development environment without actually connecting 12vac loads to the SSRs. I doubt this will be a problem though.... The 120vac loads will generate electromagnetic spikes, however, I dont thing those pulses will be enough to freak out the controller. Im using $20.00 solid state relays for AC voltage control.... I didnt measure the current draw on the lamp, or the LCD though... I know the LCD draw will be minimal, but I dont know about the Lamp. DAMN! If I had another electronic ballast and lamp setup I could do a real test... Oh well.... maybe Ill try attaching some other 120vac appliances and see how the P-Brain performs with an AC load...

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Old 22nd October 2005, 03:03 AM   #67
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Join Date: Sep 2004
Location: Vista, CA
Default lamp current

The lamp circuit's average line current will be about what you would expect, from the wattage:

250 Watts / 120 Volts = 2.08 Amps
400 Watts / 120 Volts = 3.33 Amps

(Of course, those are average RMS amps, since it is AC.)

If the ballast is 80% efficient, then you divide each of those values by 0.80 to get the total current. The ballast will probably kick a spike back into the line on each half cycle, like a fluorescent ballast. I would use a solid state relay that can handle an inductive load (e.g. a refrigeration compressor), to avoid damage from these spikes. Or maybe a 600 volt triac.
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Old 22nd October 2005, 04:35 PM   #68
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Join Date: Dec 2002
Location: VA
The SSRs Im using are rated at 120vac @ 3Amps so I should be ok there.

Now comes the hard part.... embedding this into the projector.

The way my projector is designed, (Horizontal/straight through) I have all of the electronics in an isolated "crawl space" under the projector, and the connections to the lamp/fans/etc are via holes drilled through the bottom, so the controller board will go under there too.
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Old 23rd October 2005, 12:59 AM   #69
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Join Date: Dec 2002
Location: VA
Ok... got the camera back from the X!!!

Time for some pictures...

Here is the P-Brain

Shown... on the far left is the Wired motion detector I ripped off of my Security system. Next to that is the Piezo Buzzer and the Power switch (big red button).... then a bunch of wires for other stuff (fans/light detector/power LED, running mode LED/etc) then on the right is the P-Brain board which basically contains the PIC controller, a realtime clock chip (DS1302), a few voltage regulators, a few Mosfets, and the SSRs.

Click the image to open in full size.

Only thing Im "Worried" about at this point is... it takes a bit of motion to trigger this motion detector. My hopes were to just be able to wave an arm to trigger it, but depending upon its position, it may take more than an arm wave to trigger it. If push comes to shove... Ill just integrate a wireless detector so that I can place the detector wherever I want instead of near/on the projector.

Sorry about the bad pics.... Remember... this is only a Prototype
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Old 23rd October 2005, 10:58 PM   #70
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Join Date: Nov 2004
Location: london
why does it take a idiot like me to solve world problems i have no idea.!!!

all you have to do is.......

1...get a fast battery charger (small one) (9v?)
2...get a battery (9v?)
3...get a small fan (4v?)
4...get a resistor (ohm?

now i'm planning to sell my pjs so.......when all power is switched off the battery will keep running the fan at a slow speed due to resist untill the battery is flat. when pj is swtiched on battery should charge at a faster rate than it is being drained!!!

i dont see any flaws in my plan....please tell me if u do thanx have a nice day!
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