Extending  length of DewBuster™ controller power cord.

The DewBuster™ controller power cord is sufficient for most applications. However, you can extend it by following the instructions below. Do not make it any longer than you need to because as the length increases so does the wire resistance. This translates into lower voltage at the heaters and thus less heat is generated.

1. Obtain a roll of low voltage cable in the landscape lighting section of your hardware store. This cable is relatively inexpensive because it is only rated for 12 volts. The wire is larger than what you have on your DewBuster™ controller which reduces the resistance in the wires. Use the largest cable practical and do not make your power cord any longer than necessary. 12 gauge wire should be sufficient for large scopes, 14 gauge for medium sized scopes, and 16 gauge for smaller scopes (smaller number = bigger wire).

2. Cut the DewBuster™ controller's power cord about 6 inches from the controller to get rid of as much of the smaller gauge wire as possible. Both the DewBuster™ controller's power cord and the low voltage cable have ribs on one wire. Solder the landscape cable to the DewBuster™ controller matching the ribbed wires (solder provides low resistance connections).

3A. If you really need the cigarette plug, then cut the wire off about 6" from the cigarette plug and solder it to the landscape cable, once again matching the ribbed wires.

3B. If your battery has screw terminals, then you are better off putting ring terminals on the end of the landscape cable so that you can connect directly to the battery. Since the cigarette plug was fused, if you switch to ring terminals then you will need to add a fuse holder and 10 amp fuse in the positive wire as close to the battery as possible. On most DewBuster™ controllers (those with MPD cigarette plugs) the ribbed wire is positive. On the early models with Radio Shack cigarette plug, the ribbed wire is negative.

4. With no heaters connected, power up the DewBuster™ controller and turn the knob until the heater lights blink. If the controller does not turn on you may have the wires reversed. Don't worry, no harm will be done because the DewBuster™ controller is reverse polarity protected.

Notes:

If the DewBuster™ controller's yellow Low Battery light starts coming on after extending the cable, then you either have poor connections or the wire gauge is too small for the length you extended it.

While it is tempting to add cigarette sockets to the extended power cord, a device plugged into these sockets would experience voltage drops and surges when the dew heaters turn on and off. If you want to add extra cigarette sockets then run a separate set of wires back to the battery.

If you would like a quick disconnect, join the low voltage wire to the DewBuster using a Molex plug. Just make sure the plug can handle the current. The "Y" DC power cables for computer disk drives can handle the current if you double-up using two pins for + and two pins for -.

If you have any questions, e-mail me  for assistance.