Well after a period of time enjoying my OHP build with 4.1 sound, I decided to check back to lumenlab.

Reading other people's plogs really make me want to start PJ building again. But what was putting me off a from scratch build before was the sheer size. However I have been inspired by Vendeta (http://www.lumenlab.com/forums/index.php?showtopic=28833) and sdubb (http://www.lumenlab.com/forums/index.php?showtopic=22294&hl=)
and have decided to go for a portable one which was one of the major issues with the OHP build so it stays on a shelf where it is perfectly set up.

[EDIT: Also loving Simul8r's 7"]

I will probably end up spending a bit more than the Ž£5 I got my last build done for, as I was very fortunate to get a free laptop and OHP.


Plan so far:

Case: Large Toolbox or opaque Really Useful Box (insides may need to be painted matte to avoid unwanted reflections)
Light Source: Like with sdubb, I dont really want to have to use a balast but his plog looks full of really useful info on bulbs. Only difference is that I will be using 240V.
LCD: Have an old 7" portable DVD player that works when you hit it. Going to take it apart and see if there is a loose connection or something fixable.

If the DVD player part is not fixable, does anyone know if i can get a controller that will hook up to the LCD and give me composite and/or a VGA input?



Wow. This PJ stuff is addictive

Just been looking for bulbs and a few things have popped into my head.

1. LEDs

I know they dont work as a traditional point source and was wondering if anyone has tried a wall of narrow focus LEDs to provide a wall of light?
EDIT: Just looked at electrodacus's LED project. Very interesting. I may experiment with LEDs after seeing the results achieved.


2. Colour Correction Gel

In the theatre, because the bulbs all have pretty low colour temps, to change the colour temperature of a bulb they use filters. I was wondering if anyone had experimented with any of these and if they block out too much light?





UPDATE:
Yet more searching and I have found THIS (CLICKY)
Looks interesting...150W incandescent, 6500K... Anyone used one like this before?

Have also found car headlights. Though they are only 55W

Have found THIS 'HIT' bulb.

Does HIT mean metal halide? It doesnt show a type in the specs like most of the bulbs on blt do.


Might also be getting another free OHP so I might be able to scrounge lenses from that

Just ordered a selection of LEDs and lenses to have a play with.

Can compare them to the OHP bulb. I might also get the 150W daylight bulb from blt for another comparison.

Yay. LEDs arrived today. Got to love next day delivery. Guess ill be spending the rest of the day soldering up a little tester board to compare them. Pics to come.

UPDATE ON TESTER:

Well Ive made a tester board, and am now walking around with red and green dots in my eyes

I tested 4 types of non-surface mount and 3 surface mount LEDs. Probably not too surprising that the one that cost the most (Ž£2.56) was the brightest. However it has a 90 degree viewing angle. I experimented with a few lenses and have pics of the results. The 5mm LEDs were better because they had a 15 degree viewing angle but werent as bright. However, being significatly cheaper (Ž£0.44), I am wondering whether a wall of the bright 5mm LEDs would work. There is no denying that a wall of the Ž£2.56 LEDs would be brighter... but by how much.

I dont particularly want to splash out for a wall of Ž£2.56 LEDs (would need an awful lot). However I dont want to pay for a wall of the cheaper ones and then find they arent good enough.

The price of the bright LED is also increased by having to buy lenses for each of them. I am unsure if the 'spot' or dome lens works best in this situation.

The brightest LED - http://uk.farnell.com/jsp/search/productde...jsp?SKU=1440707
Brightest non-surface mount - http://uk.farnell.com/jsp/search/productde...jsp?SKU=1648989

The surface mount LEDs:


The non-SM LEDs:


Wall with no LEDs:


Wall with bright LED and no lens:


Wall with bright LED and 'spot' lens


Wall with bright LED and dome lens (square shape is the emitter part)

Pics of a 500W incandescent bulb i have bought (with and without colour correcting filter) and a 150W daylight incandescent bulb to come...

Just started taking appart my 8" Matsui portable DVD player. See if i can find out what makes it stop woring 30 seconds into a film.

Well I have now stripped the LCD from the DVD player. I couldnt find the problem with the DVD player part but will try again.

In the pics you can see the connectors that link the LCD to the controller and the controller to the DVD player.

Does anyone know of a controller that i can plug in (somewhere in the chain) that will give me VGA and/or composite inputs? Manhattan LCD's page seems to be completely empty

The DVD player


The screen compartment opened


The connector on the controller that goes to the LCD


The connectors on the controller that go to the DVD player


The stripped 8" panel




PS: Ignore the random scribblings on the desk. The great thing about working on a sheet of hardboard is that I can just write on my work surface. But none of them have anything to do with the DVD player or projector

Looking good! I am watching and cant wait to see your screen shots! I really wouldn't worry about the new controller since the res on the screen is not that great (I don't think a PC will go that low???) just run the composite cable with it and it will be just fine

Oh suck I just read that it has no inputs. Sorry I am no help now. I guess just look for another one.

Yeah. I have found one on ebay that has no screen but sound. I might get it and hope that it is just the backlight that is broken. But ill do one more slog on google to see if i can find out more about the connector between the DVD player and the LCD controller.


I have got the OHP I am going to scrounge parts from . Unlike the one for my last projector, the lens is all in one piece rather than having a mirror between 2. This means that I can easily take it out. The fresnel also looks easy to get to. Im going on holiday tomorrow morning but I might get some more pics of taking it appart or the bulbs (if they have arrived).

As I have just said in the trouble shooting thread, I have found out that the chip used in my LCD controller is a very common one for small LCDs and with a pinout diagram, I should be able to connect up a composite, S-video or RGB video feed into it

INFO:
The website is here: http://www.freewebs.com/vgmods/playstationmodifications.htm
Pinout diagram here: http://www.mp3car.com/vbulletin/attachment...lcd-ir3y29b.jpg

Well its all very well me knowing which pin it is, but the track disappears, either under the chip or onto the other side of the board almost immediately.

I am now trying to locate the pin of the connector that is carrying the composite signal by using a pair of old headphones. If you put them across a composite signal you can hear the sync pulse (bit like a badly simulated machine gun). However because the DVD player is broken I dont think it is giving a composite signal because none of the pins are sounding like that. It used to also play 30seconds of a film before cutting out. Not it wont even turn on

So im going to keep trying to get the DVD player part to work for a bit. Otherwise I can try sending a composite signal down each pin in the connector until I get a picture but I dont want to risk damaging the controller or the source of the composite signal.

Last resort would be to try and cut/desolder the chip's pin directly but this would be nightmare because of the size. See picture

Taking a break from the LCD, I took a look at the OHP I got today. Seems the PJ builder's dream

The top clips off and the fresnel clips out really easily.
The triplet mounting unscrews and has a focusing mechanism in the housing already.
The bulbs have a nice little light box already with a reflector, precon, fan and the ability to swap between the 2 bulbs.
There is also a nice transformer that gives 24V, 23V or 18V for bulbs.

If possible I will leave the triplet in its focusing mounting but I think I will have a fiddle with the light box and compare different bulbs.

Well after hours of multimetering and trying to find out which cable carried the video signal, I think ive found it so I soldered on a socket and gave it a go. However it didnt work. The random white line that usually comes up when I turn the player on didnt come up. This was good because it meant the screen wasnt recieving anything from the DVD player. Unfortunately it wasnt showing the signal I was giving it either This could be for 2 reasons.


1. The control chip in the DVD player, as well as not sending any video, is not sending the voltages required to the control pins to set the screen up for composite input, brightness and contrast etc.


2. The LCD controller chip has been fried when the DVD player chip went dodgy.


I am thinking the first is more likely (i hope it is no. 1) becuase when it did work in 30 second bursts, there was nothing wrong with the LCD.

I am goign on holiday for a week now but when I get back I will do some more research into the values each pin should be for correct operation and then try and corrct any pins that arent getting what they should be getting.

It may even be that I can make a little brightness and contrast control - this was previously done by the DVD player via the remote (which I have lost) so was stuck on whatever I last had it on.

Oh come on that vacation can wait I want to see you get this thing working. Anyway glad to see you are still after it, I sure hope you are able to feed a signal to it.

Yeah, so do I. There is WiFi where im staying. So I can read about my projector and think what I want to do but cant try it out

Only 2 more days till I can play with my PJ again

Here's hoping that I can get the LCD working pretty soon because I really want to get on and make a mockup to test the OHP parts and my collection of possible light sources. Especially the 500W incandescent with a colour correction filter.

Only thing is that I have a physics project I have to write up for school and I need to get all my university entry stuff done when I get back

The summer holiday just isnt long enough!

Hey I just saw this at my local Home Depot. 100 Watt metal halide bulb socket ballast for $65 on sale (originally like$85)

Its kind of like this http://www.goodmart.com/products/1123393.htm

Oops never mind you are in the UK

Well im kicking myself at the moment. For 2 reasons.

Firstly, when I tried my new component socket last time, I forgot to plug in the LCD's power ribbon. This meant that or course, nothing would show up.
So I went to the trouble of hunting out and grounding, the switch pins that tell the chip to input from composite.

And it was during this moving around of the controller that I have ripped up part of the FFC that joins the controller and LCD. Its not the cabe however, just the connectr at the end that can be pushed down.

Good news:
I have got a picture to display on it from the external composite socket

Bad news:
It has moved the picture across about 1 inch and then added letterbox lines to get all the image in. This is a widescreen DVD player so it doesnt need the letterboxing!
It is also displaying in high contrast and low colour. Im going to solder a couple of potentiometers to the colour and contrast pins and have a fiddle.
The picture breaks up if I move the controller board
The block of black that it isnt displaying on doesnt have a nice dividing line, but has lumps in it. Perhaps there is a loose connection of fried component somewhere.
The image also isnt crisp and has moments when the horizontal elements get out of sync.


Lots of bad news but at im going to have a go at fixing it and see what happens.

Will try and get pics so you can see what im talking about.

Well the interference seems to have gone. And the FFC is playing up less.

Just the shrunken picture and the contrast/colour to sort out now...

Have some pics. There is still interference. It depends on the brightness of the scene playing.

I have a semi-decent picture showing but nothing that i'd be happy to watch a film on. Im going to have another play around but it may come down to buying another broken portable DVD player.

You can see the shrunken picture. Its worse in films because they use the letterboxing.


Example of some of the out of line horizontal parts


Some more horizontal interference. Here the lettering is causing a light patch across the rest of the LCD.

Going to make a mockup setup and see if I can get an image tonight so ive stripped the basics from the OHP. It all cmae appart really easily, the fresnel just popped out and the triplet came out with 4 screws. It also comes with a pair of mounting brackets and a focusing mechanism . The light engine looks really cool too. A reflector and precon all nicely set up. It also came with 2 bulbs in the projector and a spare. Because of the size, it may be difficult trying to fit a different bulb in there and I dont particularly want to dismantle a perfectly good light engine. Unfortunately the 24V transformer weighs quite a bit as the bulbs are 250W. Another disadvantage would be the lower colour temperature but it doesnt look too bad.

My 500W incancescent also arrived today. However there were no sizings on the ebay listing. The picture had it looking like a tupical 60W bulb. That it was, just about 5 times bigger. Would work great in a comedy sketch when someone has an idea But perhaps not in a projector.

UNSPLIT FRESNEL:


TRIPLET:


LIGHT ENGINE: (still in OHP housing)

I feel like a spammer in my own thread . Its been a long day but im pleased with how far ive got.

Bit tired so bullet points only.

- Sorted the uneven line on the left of the screen by grounding one of the input selector pins that was floating just above ground.
- Sorted the colour issue by shorting the 5V supply and the colour pin of the chip
- Tried grounding random contacts on the board to see if I could get rid of the interference. No luck - just some very unsual coloured images
- Tried cutting the wires going from the DVD player to the screen. Wire 3 moved the whole image to the left.
- Broke a potentiometer (smoke cam out :S) by trying to send a variable voltage to wire 3 in an attempt to move the image to the center. No luck
- Wire 4 sorted all problems and displayed the image in widescreen.
- Taped the screen and controller to a basic cardboard frame and leant the unsplit fresnel up against it. Then used OHP on its side (couldnt be bothered taking out light engine tonight.
- Rested the triplet on some DVD boxes and managed to get some very crude images of the Martix (upside down tho )


Left to do:

- Going to move the point of connection of the component feed so it doesnt bypass as much of the board before going into the chip. The extra bits (resistors and caps etc.) may help to stop the interference during bright scenes problem.
- Going to put a switch on the wire 4 connection so I can change between widescreen and non-widescreen. May also put a variable resistor on wire 3 and have another go at position adjustment.
- Need some more cardboardboxes to make a proper mockup so I can get an idea of the final length of the build and thing about a case. I'd love to make my own but i dont have the tools or time.
Speaking of cases. Im just looking at some 4U MDF flight cases I have. If someone could made a setup short enough, they would be a very nice and easy case. Only £40 on ebay (UK). Might save that for a 4th build if I ever get around to one

PICS:

Widescreen at last


The LCD Mount


The setup using a few cardboard boxes, my sisters shoes and some DVD cases


A very crude image achieved on the bottom of a wall. (Upside down )

Was just clearing out and found a box that will be perfect to move things around in the get angles right. Have put stuff in it but not wired up the bulb yet. For the moment I will be using the OHP light engine (reflector, precon and built in fan) I think ill just have to live with the weighty transfotmer.

So far my other options havent been too successful. LEDs - quite expensive to get enough that are bright enough with lenses and all that. Powerful incadascent bulb - ill let pic speak for itself. (no dimensions on ebay listing ). Daylight incandescent bulb - Seems rather dim and rather blue.

Pic: 500W Incandescent, 150W Daylight, OHP bulb, AA battery (for scale)

wow that looks dangerous lol


so long as u measure correctly , you should not need to mock it up in a cardboard fire trap
but hey ..... we have all done the exact same thing