I designed the painting for the art gallery. Then found out that our Canon Pixma MX870 Inkjet Printer no longer feels like printing yellow. So the images were basically unusable. I changed cartridges (although yellow was half full) and it was still not printing. Did a deep cleaning and no yellow. I'm left with two choices: pull the print head and attempt to clean it, or buy a new inkjet. Anyone have any good recommendations for a modestly priced, good-print-quality machine that can scan and fax (although I don't use either function very often)?
So… this meant that unless I find another approach to doing the interior, I'm hung up. I re-assessed putting the base and 2nd floor in from the bottom, and found that it would work. This frees me up to work on the entire top areas, windows, etc., and put the interior in bottom-up when I'm ready to do so. I removed the 2nd floor ledges since the 2nd floor will now be glued directly on top of the first floor walls.
I then got to work on the ceiling lighting. The steps to work with the surface mount LEDs are:
- Test each individually using a power source with the appropriate current limiting resistor on either the positive or negative lead. (the LED calculator shows the limiter on the negative side). You need to do this test since these tiny 3.3mm X 2.7mm packages are easy to kill and you need to know if the circuit doesn't work, that you did something on assembly and not that you had a bum LED in the first place.
- Tin the two opposing sides of each gap you cut in the copper foil. You can be a little generous here, but not too generous.
- Mark which direction is + and -. Place the LED across the gap sitting on the solder with the narrow + side facing the + end of the circuit and gently hold it there with the tip of a tweezers.
- While holding the LED in position, heat the foil adjacent to the LED and as soon as the tinning melts and the LED settles into it on that side, pull off the iron. Don't wait around! The LED will be destroyed with too much heat.
- Still providing some light pressure on the LED, heat the other side foil and do the same thing once the puddle melts.
- Using your test leads, put the + on one side of the LED foil and the - on the other and see if it lights. If it does, move on to the next LED.
- If it doesn't you killed it when soldering. De-solder it and get another one.
At the start of the circuit I soldered the CL2N3 LED driver chip. The first one worked for a bit and then stopped, so I got another one. This worked okay so I did wired in the power leads. I brought them up to the ceiling, through two holes, and then back down into the holes. You're looking at the ceiling upside down.
This is the first driver I installed. Didn't like how I did it, so when I replaced it I didn't bring it through the holes, but did all the soldering on the ceiling's face. This part of the ceiling will be out of sight in the back of the windowless side of the building.
I assembled the walls and ceiling to see what the light level is. My first test had 4 LEDS in the array since I wasn't sure about driving 5 with a 12 VDC source.
I didn't like that shadow cast by the mid-room partition so I cut one more gap and installed a 5th LED. It drove fine with the 12 Volts and eliminated the shadow.
Then the lights went out. When I tested each LED they all seemed to work, but not collectively. Then I noticed that LED #1 was intermittent. The solder joint underneath was not very good and it needed retouching. Then when I retested my lights were distinctly dimmer verging on yellow. What happened? I thought that maybe 12v was really NOT enough.
I went into my electrics box and found two 19 volt computer power supplies, one Apple and one HP. I cut off their ends and prepared them to drive my circuit. Remember: The CL2N3 driver doesn't care what the voltage is between 5 and 90, it just puts out 20ma to drive LEDs. The Apple power supply produced no voltage. I wonder if it's regulated in someway that it doesn't produce power unless the load is a computer battery. Any ideas?
The HP supply produced a steady 19.5 volts so I hooked it to the circuit which lit momentarily and then died. Again, I checked each LED and suspected that something happened to the driver so I replaced it. I also killed an LED when I accidentally connected my direct voltage lead to it and not the one protected with the 470 ohm resistor. So I replaced that one too.
I didn't want to use that heavy unit again so I went back to the 12v unit and guess what? All the lights were bright. I suspect that the poor solder joint was limiting the voltage in the circuit before.
Here's an upshot showing the lights all lit.
With the lighting working, I shot the walls with a coat of Tamiya Gray primer, masked the LEDs and sprayed that surface also, and then hand brushed three coats of antique white on the ceiling. It's now done and will wait for the rest of the interior to be finished including putting artwork on the walls and something on the floors. I might make the floors bare concrete with is used in lots of restored buildings like this one. There's a bit of electrical tape protecting the Driver and I put a small cable tie underneath as a strain relief. I also tie a know in the cable where it exits the floor to act as an additional strain relief.
Depending on when I get the new printer will determine when the interior is finished. So I'll be working up top for a while. At the end of the week we're heading back East for the Holidays. And on Thursday, I have a stress test and echo cardiogram to get a better idea why this Afib is being so stubborn.
