Dim Bulb

I finally got around to making a proper dim bulb limiter to keep me from blowing fuses. Much time was spent making sure that the indicator lamp blinks when the limiter bulb is engaged. A wholly unnecessary feature that allowed me to use some old-school point-to-point construction techniques and made the build a bit more exciting than just wiring up a switch to a couple outlets. The chassis was made first out of 20ga. steel and formed with a finger brake, then the holes were made with a hand punch.

After experimenting with the neon flasher circuit, I settled on a combination of parts that sustained blinking at lower variac voltages and also wasn't too fast at 120V.

Punched and riveted epoxy board to hold the components

The solder tabs under the rivets are for wire to board connections.

The board is mounted on standoffs and the chassis is fitted with fresnel lens inserts to hold the lamps. A rubber grommet ensures the lenses stay put.

The outlet came from an absurdly long industrial power-strip that was shortened. 14ga. wire runs from the outlet to a terminal strip secured with a rivet and then soldered to the chassis

The switch is installed and the wire is laced with waxed linen thread. The power cable and strain relief grommet are secured to the back of the chassis

The last hole is cut to hold the 2 prong outlet for the bulb.

Front panel with labels

Dead short and no blown fuse !