Dim Light Bulb Tester

Use a dim-bulb tester: a dim-bulb tester uses an incandescent bulb in series with the test load in order to provide basic current limitation and regulation, which is useful for initial soft. For more details, see my Variacs article. In contrast, a dim-bulb tester doesn't change the supply voltage.

However, by putting a light bulb in series with your device, it limits the amount of current supplied to your device, thus reducing the risk of damage if there is a power supply problem, etc. -1 grounded socket -1 socket -> standard light bulb converter -1 light switch -1 plastic in wall enclosure, I used an "old work" one meant to mount to sheet rock -1-2' of 14-2 romex or equivalent. I only ever used single strands out of this, but it's nice to have the color coding without having to buy multiple things and they strip easily.

-1. A dim-bulb tester isn't an in-depth diagnostic tool but it is effective, simple, and allows for a safe startup even if there's a serious problem like a short. Vintage Dim Bulb Tester: For those of you who restore vintage electronics, like radios or tvs, you know the importance of powering up an untested device slowly (for those of you who are new to the hobby see this article from antiqueradio.org).

You also know the high cost as. In this video I build a basic dim bulb tester, commonly used in repair of vintage hifi and electronics equipment, using parts that you can walk into a Lowes or Home Depot and buy. Here is a picture I just created on how to build a simple Dim Bulb Tester.

The top outlet is always on at the line voltage and the bottom outlet is where you plug in the radio that is in series with the light bulb. A dim bulb tester is an effective and simple tool that allows for safe startup even in the case of a serious problem, such as a short and keeps the magic smoke where it belongs. The dim bulb tester places an incandescent light bulb between you new "old" gear and the AC power in the wall.

A dim bulb tester is often used by people who repair old radios: connect an incandescent lamp in series with the equipment under test or repair. If the equipment has a catastrophic fault, e.g. a shorted mains transformer, then the lamp will light brightly, without blowing a fuse.

Different wattage bulbs offer varying levels of current restriction. Caption: A custom-built dim-bulb tester incorporating vintage analog meters and a metal front panel. A Labor of Love: Building a Custom Tester While rudimentary dim-bulb testers can be constructed with basic components, the collector opted for a more complex approach.