Power Sources

The DewBuster™ Controller may be operated on a 12V Battery or a 13.8 VDC Power Supply (a fully charged 12V battery is 13.8V). As shown above, the DewBuster™ Controller's standard Powerpole® power cord allows you to easily switch pigtails to accommodate various power sources.

If you need help selecting a battery see my FAQ on power sources. If you normally use a battery, on occasions when 120 VAC available you can connect the battery charger while using the telescope. This allows the battery to supply large amounts of current when needed and the charger can replace the energy used so the battery never runs down. Use a normal charging rate, do not "Fast Charge" the battery.

If you normally have 120VAC available it is more convenient to use a 13.8VDC Power Supply to power your DewBuster. Power supplies fall into 2 categories:
  • Linear Power Supplies - older technology so they are heavy and not as efficient but they can handle the large current changes that a dew controller creates and they do not generate RF interference. They typically have a ventilated metal case that needs to be protected from moisture (can be placed inside a much larger plastic storage container). When choosing a linear power supply, get one rated for at least twice the maximum Amps that your heaters and other devices will use. See heater manufacturer's web site for the Amp rating of each heater and add them together.
  • Switching Power Supplies - newer technology that is lightweight and more efficient. The case usually has no ventilation so they are better for outdoors but it is still best to protect them from getting wet. The downside is they are slower reacting to the sudden current changes that occur when your dew controller pulses large heaters which results in output voltage dips (this can cause computerized mounts to lose their star alignment or exhibit other weird behavior). Also, switching power supplies change their switching frequency as the load current changes and the constantly changing current caused by a dew controller could result in the power supply creating RF interference (this can affect camera images). The best way to avoid these problems is to get a switching power supply rated 20 Amps or more so that it can better handle the current changes. It is also best to have a good return policy in case the power supply does not work out.
Whichever type power supply you use, be sure to power it through a Ground Fault Interrupter (GFI)  for safety. Also use a protective enclosure to keep it dry. You want the power supply warm to keep it dry, but you do not want it to get hot so use a plastic storage box at least twice the size of the power supply and you can leave the cover partly open to prevent overheating. This Hefty® 18qt Plastic Storage Container works well and the lid can be placed on the ground with the power supply sitting on top to keep it several inches off the damp ground, then the bottom of the storage box can be placed over the power supply protecting it from dew yet leaving a gap for ventilation. The dark gray color also shields other observers from the power supply's lights.

USA customers: Pyramid makes several reliable and reasonably priced power supplies (see below). If you find other reliable and reasonably priced units please send me a link.

International customers: there are many "HAM Radio" power supplies available. Try searching the internet using keywords like "Australia 13.8 Volt 10 Amp Bench Power Supply". If you find a reliable and reasonably priced unit please send me a link.

  • Pyramid Model PS21
  • Amazon link
  • Linear Power Supply, 13.8VDC, 20 Amp continuous current
  • Banana Jack connections (No Cigarette Socket).
  • This is overkill for smaller telescopes but a good choice for 14" and larger SCT's.
  • Pyramid Model PS14
  • Amazon link
  • Linear Power Supply, 13.8VDC, 12 Amp continuous current
  • Banana Jack connections (No Cigarette Socket).
  • Good choice for all telescopes and can handle a 14" SCT.
  • Pyramid Model PS15
  • Amazon link
  • Linear Power Supply, 13.8VDC, 10 Amp continuous current
  • Cigarette Socket and Banana Jacks.
  • If you need a cigarette socket go with this, otherwise the PS14 is a better bargain.
  • Pyramid Model PS9
  • Amazon link
  • Linear Power Supply, 13.8VDC, 5 Amp continuous current
  • Cigarette Socket and Banana Jacks.
  • Recommended only if space is tight and for no larger than 5" refractors or 8" SCT's.

Go to Top of Page