Building the Klingon Cruiser part 2 by Billy Lehner

Start with part 1

I bought two different brands of belly button lights at Ebay and found this no name brand to have the brightest and most random looking blinking effect.

Two reasons I like this brand of lights are, reason one, after modifications the electronics can be easily be placed back into its sturdy housing. The second reason is the casing has a built in magnifying lens to spread the small LED lights for better dispersion of light in the model.

Pry open the casing with your fingernail. Discard the small T-shaped rubber power shaft/switch. The left over hole for the switch will be used to feed the power wires out.

Push out the batteries with a pen and discard. Orient the back of the circuit board as shown and cut off the left battery clip. Leave one stub of the battery clip on so that when the modified electronics are replaced into the casing the stub will provide a stable base for the electronics. The pictures show how easy it is to modify the lights.

The electronics are very heat sensitive so go easy with the soldering iron! Use a low-powered 30-Watt iron that is well heated and only use the iron on the circuit board for a few seconds at a time.

Luckily the lights are self-energizing. When power is applied to the circuit they normally start on the on state. So one DPST switch is all that is need to power up the lights.

I used a 3-Volt, 500 milliamp (ma) DC transformer marked “Black and Decker” that I found at a thrift store for 99-cents. The belly button lights normally operate on 2.8-Volts and work directly off the transformer. Do not use a current-limiting resistor for the flashing circuits that you would normally use for LED circuits because the resistor cannot supply enough current to light the LEDs correctly.

Two other high intensity LEDs were used in the Klingon model. A white high intensity LED was used for lighting the front section. With the 4.5-Volt transformer I tested I set the LEDs to run at 20ma by using 110-ohm resistors in series with the LEDs. All static lights were used in parallel circuits because I barely had enough voltage to run them but I had plenty of excess current from the transformer. Another reason to use series connections for the LEDs is simply that if an LED should quit (unlikely) only one circuit would be affected and not the whole lighting scheme. If the lights were set up in series and should quit the entire static LED circuit would be affected.

on to part 3