110V AC

 

One of the main reasons I went up into the attic the other day was to figure out where the doorbell transformer was.

With my DMM (Digital Multi Meter) I tested for the voltage and current at the button. There was nothing on the meter.

Looked for the chimer and found it on a kitchen wall. Took it down and examined it. Played with the chimes and inspected the coil. It looked like it work.

I traced the wire from the doorbell in the attic and followed it to the chimer, and then followed the line to to a wall that looked like it was going down to the basement. I read most places put the doorbell transformer in the basement next to the panel. And that's exactly where it was. In the basement behind the wall where the panel would be outside.

I tested that the voltage going into the transformer was 120VAC and found nothing coming out of the step down side.

This thing must be really old. I've never seen a transformer look like this ever. The connectors are rusting. Notice the insulation is made of thick cloth instead of plastic, and it's that old industrial olive color (think color of WWII armor). The other interesting thing about this is it's rated at 110 volts (maybe the reason it blew). Current U.S. standard is 120 volts AC. 110 volts went away soon after Thomas Edison lost the battle to supply 110 volts DC to the residential sector.

Another reason that it may have blown is that the dielectric may have gone bad. I don't know what they use in transformers, then or now, but looking at the insulation they used for wires back then, I'm almost certain it wasn't anything good either.

So the people who updated the kitchen electricity seemed to just cut the old knob and tube wiring into the kitchen. So from the panel there was a two way split to the doorbell and then to the kitchen. That wouldn't bug me so much, except that the connection was handled with tape, and solder. And of course, everything was just hanging outside the junction box.

So I ripped that sucker out and went searching for a brand new one.

My first stop was Fry's Electronics. I remember walking into Fry's the first time a long time ago and thinking: "Wow! Shelves and shelves of discrete components!" It isn't like that anymore. Nobody knew what a transformer was, nobody knew where their discrete components were located, and there weren't shelves and shelves of the stuff. And the stuff they did have couldn't put Radio Shack to shame.

So I called a real electronics store that I found with the iPhone Maps app. Thank goodness we're in the bay area. Growing up in LA it was almost impossible to find an electronics store that wasn't Radio Shack. (Don't get me wrong. I like Radio Shack. I buy stuff their all the time. In high school, and going to Don Bosco Technical Institute, I easily knew more about electronics than the guys there did, and so I always had problems getting exactly what I needed. So I generally avoid going there if I feel I might need to ask the rep a question, because chances were more than good that if I didn't know, they didn't know either.)

So the local electronics store I called, Anchor Electronics, in Santa Clara, probably sold parts to guys that made battle robots in their spare time. The guy there said he probably had a transformer that'd work, except he wasn't sure if they'd be rated for use as a doorbell. There were no mounts or easy way to connect leads too. He told me to just go to my local OSH (Orchard Supply Hardware.)  He was right. OSH had it. It looked like a normal modern transformer, except it had screw-ins for the doorbell leads, a bracket to mount the thing, and a weird mount that held the 120VAC leads in place.

I got my doorbell working. I did things a little better than the last guy by not much. But at least things are somewhat sitting inside a junction box. I need to read up a little more on typical doorbell transformer installation housings and correct that later.