The Security Alarm

The house that I grew up in was built in 1925. I'm not sure when the garage behind it was built, but I assume it is close to original to that time, because while it has (had?) a big set of swing doors facing the alley, it was barely big enough to park my 1976 Toyota Celica in it, circa 1991.  The garage is still there as far as Google aerial imagery goes.

My parents separated when I was six, but I still have a bunch of memories of that garage when all of Dad's stuff was in it.  He was a world class DIY mechanic and handyman, there really wasn't anything he couldn't fix, as far as I knew.  He had a tool and supplies for everything in that garage, and it was packed!  There are so many stories about the things he repaired and fabricated, but those are for later.

As far as I know, when we got the house, the garage was basically nothing more than a small car shed sized to basically fit a Ford Model T.  He ran overhead wires out for power, and for a phone - the days way before cordless phones, let alone cell phones. I remember him extending the electrical system out there to add an exterior light for security, too, to the point that I remember him carefully sanding and rehabbing a light fixture (that he probably had rescued from the City Dump when he worked for Tacoma as a garbage truck driver), and then painting it a weatherproof gray before mounting it.  Last time I drove by there a few years ago, it was still there.

Here's how big the old garage is, as seen on current Google Maps aerials.

I'm not sure if there was a specific event that set this off the events of this story, or he was just being proactive. Having the mind of an electrical engineer, a good decade or so yet before he was hired at Tacoma City Light, it was easy for him to wire up an additional light fixture in the garage that would turn its bulb ON when you flipped the switch to turn the rest of the lights OFF.

Here is just one of untold lessons he taught me, long before I became a power company guy like him.

How it works is the concept of resistance.  Electricity wants to take the easiest path.  If you present it two options, it splits in opposite proportion to the resistance, favoring the easiest route.  All you have to do to make this work is tap the hot wire before the light switch, run it to the new alternate fixture, and then terminate the new circuit at the neutral wire back at the switch.  This makes a direct, non-switched circuit so anything you put in the new light fixture will just be on all the time.  Unless....

...unless the light bulb you put in there has a more resistance than the other lights, when the switch is on.

Low wattage incandescent light bulbs have more resistance than high wattage bulbs. This increased resistance means less electricity can pass through them, which results in them being dimmer.  Thus, a 25W bulb has a lot more resistance than a 100W bulb.

So Dad sets this up, and puts a red 15W light bulb in the special fixture, which he has mounted to the wall inside the garage's man-door, just above the adorable little 4-fuse panel and wall mounted rotary phone.  When the light switch is ON, the four 75W bulbs along the garage rafters are provided with power, and they offer ample low-resistance paths for electricity, so whatever remnant is finding its way to trickle through the red bulb when the switch is ON, it isn't enough to produce light from it.  But when the switch is OFF, the little red bulb is the only path, and so it lights up.

And then he makes sure, when the neighborhood hooligan kids are around or within earshot - not that they were all hooligans, but you know some of them are, sometimes, or will grow older and get that way - he makes sure they are aware of the security system he has installed, and that it is active when the red light is on, and the red light is real easy to see when you look through the little windows on the garage.  Mind you this is like 1976, an era when commercial consumer-level security systems essentially didn't exist, so of course the kids have no idea what this "security system" might entail, or what it might do if activated.  Call the cops? Set off a claxon?  Electrocute them?  Pre-internet, your imagination could be a powerful deterrent to risk because you just have no idea about stuff.

The "security system" was automatically "armed" just by performing the task of turning off the lights on your way out, making the red bulb light up. It was always "armed" when no one was out there.

Maybe the neighborhood was safe enough at the time that risk of crime was low (we never locked our front door in those days), or maybe the hooligans were adequately spooked, but Dad had a ton of expensive stuff in that garage and no one ever broke in while his stuff was in there, even though it would have been easy to do.

Success.