DewBuster™ Controller Technical Bulletin

Performing a Trial Run at Home

Note: This bulletin assumes you are just trying to familiarize yourself with operating your DewBuster™ Controller prior to your first night under the stars. If you suspect a malfunction then perform the full test as directed under the  Troubleshooting Problems bulletin.

New DewBuster™ Controller owners may want to familiarize themselves with its operation prior to their first night under the stars. This is easy to do indoors and does not require setting up your mount. It can not be done outdoors with the sun shining on the telescope as that will warm the telescope well above the air temperature and the heaters will not turn on.

1. Attach the temperature sensor to the main heater and strap it onto the telescope as directed in the owners manual.

2. Plug the DewBuster™ Controller into a power source and turn it on to 5 degrees.

3. Assuming the scope is about the same temp as the air, the AUTO light will turn on solid for a few minutes as the scope warms up to 5 degrees warmer than the air temperature. When the AUTO light is on, heat is being applied, so the AUTO light allows you to "see" how much heat energy is being applied to your scope.

4. When the scope reaches a 5 degree differential, the AUTO light will start blinking slow or even go off to stabilize the temperature. After the temperature stabilizes the AUTO light will blink at whatever rate it takes keep the telescope at the set temperature differential.

5. If your home's A/C or heater cycles on while you will see the AUTO blink rate change as the DewBuster™ Controller responds to changes in air temperature.

6. Cup your hands around the air sensor and the warmth of your hands will trick the air temperature sensor into thinking the air is much warmer and you'll see the AUTO light blink faster trying to warm the scope up. Remove your hands and it will stop blinking until the scope cools back down.

7. Crank the knob up to 10 degrees and the AUTO goes to full power until the scope warms up.

8. Lower the knob back down to 5 and the AUTO turns off to cool down.

You should now have a good feel for how the DewBuster™ Controller works and the relation between the blink rate of the AUTO light and the heat being applied. The main thing to remember is that the AUTO and AUX lights should blink after the scope reaches the set temperature differential between air and scope. If it stays on something is wrong, maybe the sensor isn't clipped on the heater or maybe you forgot to plugged the sensor cable into the DewBuster.

You may have noticed that the AUX light normally blinks at a steady rate (40% power) but it will occasionally go to full power (on solid) or zero power (stops blinking) following the AUTO. This is because whenever the AUTO reaches one extreme it begins overriding the AUX too. This allows for maximum dew prevention of the AUX heaters without requiring sensors and yet still providing for rapid telescope warm-up when first turning on the DewBuster™ Controller. It also provides automatic shutoff of the AUX during the day when the sun is warming the telescope so you do not waste battery power.