but I was on my laptop and came across a few posts where people wanted something
similar to this.
First thing is a switch, this is the 'master' power, normally left on
It has a fuse, I use an external one for ease of replacement:
Fuse Holder
The next little part with the resistors, capicitors and diodes is a power indicator led, it is yellow and tells us that the master power is on.
You can get an ac indicator, but if you know how to make one (which you now do).
LED
with Bezel
470nF/400V Cap
1K 1W resistor, if you can't find a 1W, or it is stupid expensive, put two 2k .5W in parallel. a 2k can be made by putting two 1k .5W in series.
1M resistor (same link as 1k)
1N4148 Diode
This part of the circuit is duplicated after the branch to the SMPS (the power supply for the panel/controller)
The second one uses a green LED and tells us that the unit is powered up, which happens when you turn on the
controller via a button on the panel, or by the remote. If this light is on, and you see nothing on the screen, then
you most likely have a bad bulb.
After the green LED is a thermal switch that will turn off the lamp power if things get over 160 degree Celsius or 320 degrees Fahrenheit.
Thermal Switch
The thermal switch then goes through a relay. This relay is dependent on your controller. I have an MST7in1, it has both a backlight on output and a 12v backlight power. I chose to use the 12v power:
Relay
SPST relays or relays that switch only on and off are rare, because adding the second lead is negligible in price/difficulty. you just don't wire anything
to the 'default' lead.
From there, the power goes to your ballast->lamp/cap and then to your neutral line. Most people don't realize the difference between neutral and ground,
and in fact, in most houses, they are the same thing(they are wired together in the breaker box). But if you wire to the ground instead of neutral, those fancy GFI outlets in your bathroom/kitchen get all weird.
The above stated, DON'T CROSS your ground and neutral. The grounds in the diagram refer to the neutral on the AC in, not the green ground wire
Coming off the SMPS is a 12v and 5v lead. The 5v goes to the 5v standby/supply input of your controller. The 12V goes to the 12v supply on your controller and to another thermal switch. This thermal switch turns on at 50 degrees Celsius or about 120 Fahrenheit.
This switch controls the cooling fans. I use an array of 12V fans scavenged from computer cases, I realized after pricing them on this project, that I was lucky to do, I have a big old box of the things and they apparently run 10 bucks a piece. People often say they want a POT or thermistor to control the fan
speed. This would only be necessary if you have way too powerful of a fan set up
Also, a manually adjusted POT is never going to get adjusted If you set up 4 80mm CPU fans on your case, they will run plenty quiet and give you plenty of cooling. Hell, they work for my 1.8kW computer, they should
work for a measily 400W Projector
Some might disagree with my selection of temps for the thermal switch's. If you place the Fan-ON thermal near your bulb, and the the cutt-off thermal at your screen (but shaded from the direct light of the lamp) it should keep everything safe.
With this setup, you have one switch to turn on and leave on.
when you power down the projector end, the fans keep going until it has cooled off.
You can solder everything inline, just make sure you wrap everything up and don't have shorts.
This isn't an all inclusive circuit, the button panel for the controller isn't shown, the lcd isn't shown, and no audio amp is shown.
I cut up a Computer Power Supply to get the handy little socket to recieve a computer
power cord, which means I can transport the projector without anything dragging behind me.
All in all, if you scavange the fans, the electronics cost me:
$50 Ballast
$30 Bulb
$6 Bulb Base
$130 Controller
$0 SMPS (Scavenge from computer, or comes with Controller)
$10 Everything else
I am capable of making my own power supplies and ballasts, but those prices are for
most people reading this thread.
Also, if anyone knows of a supplier in the US that has as good of prices as the supplier
I listed, I would greatly appreciate knowing about it
I also have 90 or so extra of each resistor/diode, a few extra LEDs and spare fuses.
After talking to people, If I get 5 or so people asking for them at a time, I can make little
board with screwdown outs and ins for people. I'll do it for individuals, but it would be nice
to consolidate that international shipping.
--EDIT: A protection diode for the relay is beneficial, you can use the same 1N4148 that is
used in the led circuits. You hook it up 'backwards across the input leads. This compensates
for sudden voltage changes that can come from the operation of the relay. I will correct the
schematic when I get a chance.