a photoblog of what i did today.....

[xoxoxoBruce]

Originally Posted by BigV

This could go in the Interesting links to share thread, but it is relevant here and now.

It's so damn easy to find good info on the net I've given up saving links for that kind of stuff.

[chrisinhouston]

We had to put some money into our furnace last week... No fun!

We noticed we had hardly any heat, it would cut on and run and for a minute or 2 it was warm and then ran cold. Our furnace is a high end Trane model we put in about 8 years ago and winters here in Houston don't really put a big demand on it. Technician came out and tried changing out the sensor (kind of like a thermocouple) but that didn't fix it and the voltage from the circuit board was wrong which led him to suspect a bad board. He quoted $650 to replace the board. I looked on line and found some parts places would sell the board for $400 but it's a newer design so it has a new wiring harness and someone with the knowledge to transfer the 30 or so wires to the new board only made sense.

Not happy about the money spent but sometimes it's unavoidable.

The really frustrating thing is that we were told the unit had a 10 year warranty when we got it but later found out that it is a 5 year warranty unless the consumer goes to the trouble of registering it with Trane, then it gets a 10 year warranty. We used a different company to install the system from the repair company I use now so it's not their fault. But I don't remember the original installers telling us to register it, I think they either forgot or just failed to tell us because we would have done that for sure if we had know.

[glatt]

That's just ridiculous. A furnace should last more than 8 years, and if they are using cheap components in their circuit board to save literally a couple bucks per unit, they deserve to have their name dragged through the mud.

Did you get to keep the old circuit board? Was there anything obvious wrong with it, like bulging capacitors?

We have a 70 year old furnace, and I keep thinking I should get a new one that's more energy efficient, but if this is the kind of crap you can get today, then forget it.

[glatt]

I was inspired to order some cheap LED rolls and a transformer from China through ebay. I got these LEDs, and this power supply.

What does it mean that this power supply is a "switching" power supply? I ordered the stuff on Jan 3, and it arrived from China on Jan 13th. Very impressive for free shipping.

At first I was confused when trying to figure out what the brown, blue, and yellow/green wires were for. But with a little Google, I found out brown is hot, blue is neutral, and yellow/green is ground. Then I dug through my junk piles and found an old iMac power cord, and cut it open to wire to the power supply. It also used brown, blue, and yellow/green, so it was easier than I expected to wire it up. I had ordered a 45 watt power supply, and wanted to see if it would drive both rolls of LEDs wired in parallel. It did!

So here are some pictures. This shows both rolls lit up:

And for this one, I unwound one of the rolls a little and aimed at the counter so I can get a sense of the color and brightness. I like it. Not blue at all. A little whiter than the halogen hockey pucks under the cabinets now, but not obnoxiously so. And the brightness is good. This was taken with the ceiling lights turned off.

I'm going to use the existing halogen hockey puck wiring. They were wired years ago by an electrician who put switched outlets under the sink, and plugged the halogen power supplies into those outlets. I can just plug my new power supply into those same outlets and use the existing wiring to the halogens.

One thing I noticed is that after a couple minutes of being plugged in, the rolls of LEDs started to get a bit warm. I guess it's the cheap quality with the black resistors after every third LED on the strip. They were only $9 after all. I unplugged the power supply when I noticed the heat. I didn't want to melt the double sticky tape on the back of the strips. I am hoping that once the LEDs are installed, the heat won't be too bad because the strips will be unrolled and the heat not so concentrated. One of the reasons I wanted the LEDs instead of the halogens is that the halogens get hot and can melt forgotten chocolate chips on the bottom shelf of the corner pantry cabinet.

So this weekend, I'll have some time to install these permanently. I'll make sure to update the thread with better pictures that show before and after shots with identical white balance and exposure settings.

[xoxoxoBruce]

...the halogens get hot and can melt forgotten chocolate chips on the bottom shelf of the corner pantry cabinet

What is this "forgotten chocolate chips" of which you speak?

The power supply is sufficient to power both rolls(600 LEDs). Therefore you can cut them up into as many strips as you want, observing the groups of three, and power them with that one power supply, yes?

[glatt]

Yes. But with one caveat. The rolls say they can't be wired in series with another roll, only in parallel. So you'd have to be careful to not exceed the length of one roll with any one cut up strip. Not sure if I worded that correctly, but I bet you understand.

[xoxoxoBruce]

Clear as a bell. At 12 VDC, a whole roll (300) draws 24 watts, about 2 amps. In series it would bump the amperage up more than the designer is comfortable with.