From the dead letter office…
After all the letters over the years, I finally get a reply. And not a word about that Hot Wheels track I wanted.

This just in from “santa” …

Whoa! Santa?

You thinking about getting back at jack for what he did to you? Yikes! I’m pretty sure I don’t want to get into the middle of that war, but I suppose I can at least try to answer your question.

Troubleshooting circuits is easy and fun for the nerdy types who might have a degree in electronics (cough), but it stops being fun if the thing you’re working on basically runs on magic. In other words, if you don’t really grasp how the work of the circuit gets done by its components, then you’re screwed from the start. Luckily, this is a very simple circuit.

Do all the obvious (cough cough) things first.

• Does the light bulb work?
• Is the lamp turned on? (COUGH COUGH COUGH!)
• Plugs are in all the way?

Turn the CD player on and turn the volume all the way up. Plug in AC power and plug in your lamp. Slowly turn the adjustment potentiometer until it’s all the way to the right. Anything? No? Slowly turn it the other direction until it stops. Still nothing? Hmm.

Okay, go get another CD. Try AC DC or Iron Maiden (a personal favorite). Something loud and obnoxious (Sineaid O’connor is too obnoxious, but your thinking’s on the right track.) Repeat the potentiometer adjustment. If the lamp reacts this time, then your audio input is coming from a single channel, but the thunder soundtrack is playing on the other one (for some reason). Swap the channels.

How do I tell for certain that this is a channel issue? Pop the thunder soundtrack back in and listen. Is it only coming out of one speaker? That’s the channel you want to connect to the color organ.

Still nothing? Sigh. Okay…

1. Disconnect AC power so you don’t die.
2. Disconnect the lamp so you don’t die because it’s somehow conducting current.
3. Disconnect the CD player. I don’t think it’ll kill you, but do it anyway.
4. Inspect all solder joints. Is there any slop that is causing a short? Fix it. Are all your solder joints nice and shiny? If not, a cold solder joint may be blocking current flow. De-solder any dull joints and re-solder them correctly.
5. Are all the components installed correctly? (i.e. not upside down) Are any of them loose?
6. After fixing the slop and bad joints, run through the above test again.

Still nothing? Then you might have blown your SCR. This will happen if you try to drive a lamp that’s too large. I don’t remember what the rating of the SCR is for this circuit, but I wouldn’t try to push more than 60W with it. Anything more, and it’ll fry. Yeah, I know; it’s not a lot of voltage. I’ve been meaning to put together a beefier lightning machine for a while now and I haven’t gotten around to it yet. I’ll get there.

So, you’ve gotten this far and the thing still doesn’t work. Bummer, dude. Hire a neighbor kid to stand in the bushes with a flashlight.

Category: From The Undead Letter Office, Halloween   Tags: color organ, electronics, lightning machine, soldering