"Whassamatter, Bill?" you ask. "Why didn't you ring the bell?"



"I pushed the button about a dozen times, but nothing happened. Saw your car in the garage, so knew you were still in. Here, sign for this, will you?"

"Bell doesn't work?" you mutter.

"Lemme try it." You do, and it doesn't. That evening you have a small repair job to perform. That is, it'll be small if you know your bell wiring arrangement.

In many older houses the source of power is a bank of No. 6 size dry batteries, usually three or four of them connected in simple series. The front door "button" is merely a momentary contact switch which, when pressed, closes the circuit to a bell. If a side or rear door is customarily used for deliveries, access to a yard or driveway, etc., another button is located here and it operates a buzzer. Any number of bells or buzzers can be hooked in to work off a single bank of batteries.

The bell-ringing transformer invariably is located close to the fuse box; to make a quick check on it, set Handitest to 30-volt AC range and connect test leads to binding posts.

If this transformer was shaken up a good deal it perhaps requires periodic tightening. Use lock washers or tie down with tape to remedy.

Exposed bell buttons are usual cause of failure of the signalling system. Inspect frequently; to get at connections, remove two mounting screws.

If short-circuiting button terminals with screwdriver makes bell ring, internal contacts are defective; new button is the simplest way of restoring service.

In most houses built during the last couple of decades the batteries are replaced by a small step-down transformer. The primary side, identified by its heavy black and white covered wires, is connected permanently to any of the branch circuits supplying power to the house. The secondary side, identified by its two knurled head binding posts, is connected to the bell, buzzer, or chimes through door buttons.

The transformer reduces the 115-volt line voltage to values ranging between 6 and 16. These have absolutely no shock danger, so it is not necessary to "kill" the transformer circuit, by opening the branch fuse to which it is connected, when you shoot trouble in the bell and button wiring.

"If the transformer is connected permanently to the line, doesn't it draw power all the time?" This question is probably framing in your mind. Yes, it does, but the amount is so small that it hardly overcomes the friction of the bearings in the watt-hour meter. When a door button is pressed, a bell or a chime takes a few watts, but for such a short time that they add virtually nothing to the monthly electric bill.

The case of the transformer may feel very slightly warm to the touch. This is normal. It does not indicate overloading, but only the internal molecular friction of the iron core of the transformer as the alternating current goes through its periodic reversals.

Because they are activated for only a total of perhaps minutes over the course of a whole year, the bells, buzzers and chimes themselves rarely give trouble.

Soon your bell will be working again.