STANDARD DEWBUSTER
DewBuster™ Controller

The Ultimate Dew Controller
Precision temperature control keeps you dew free all night long while your telescope performs at its best. Easy to operate, stingy on power, built tough and reliable, and backed with a no-hassle 5 year warranty. Compatible with all major brands of heaters and 12VDC and 13.8VC power sources. Output configuration may be customized to your needs. Heavy Duty Power Cord with Powerpole® quick-disconnect accepts pigtails to accommodate most power sources.
Built To Last!
Designed for those who want the best and want it to last a long time. After 20 years of production 99% of all DewBuster™ Controllers are still in service! RCA jacks solidly mounted in quality powder-coated aluminum case so plugging/unplugging heaters won't stress circuit board and lead to cracked solder joints. Short-protected heater outputs protect controller from heater defects. I maintain purchase records so your receipt is not needed for the no-hassle 5-year warranty which even covers damage from home-made or defective heaters. And unlike other products, after the warranty period expires your DewBuster™ Controller is repairable at very modest cost!
Uncomplicated!
Spend time using your telescope rather than fiddling with your dew controller. Color-coded heater outputs simplify connections. No confusing controls to struggle with, simply turn one knob and forget about dew. Red blinking night-vision-friendly LED's assure you that your heaters are working properly. No programming to figure out and no need to recalibrate the when switching temperature sensors.
Temperature Controlled!
One Temperature Sensor cable measures both air and telescope temperature. Simply turn one control knob to power on and automatically control heater slightly above the air temperature, preventing dew while maximizing telescope performance. Sensor clips to heater strip so you can easily move sensor between telescopes. Swapping temperature sensors has no affect on calibration so you can order extra sensors for each telescope and move the controller back and forth while never needing to recalibrate. No reprogramming required when sensor is not used, if no sensor is plugged in controller automatically switches that output to Medium Power mode.
Stingy on power!
Temperature control doesn't waste battery power early in the night when telescope is cooling-down, applies just enough power to keep telescope from cooling faster than the air. Pulse Width Modulation (PWM) is efficient and synchronized heater outputs alternate current between heaters to reduce peak current and battery voltage fluctuations. Intelligent Low-Battery circuitry doesn't just shut off heaters, it gradually reduces power to heaters keeping your optics dew-free as long as possible while giving you time to switch power sources or conserve energy by unplugging less-critical heaters. And it will not allow your battery to run below the 10.5V battery manufacturers' recommendation.
No Risk 30-Day Satisfaction Guarantee
If you are not completely satisfied with your DewBuster™ Controller for any reason you may return it for a full refund minus shipping.

FEATURES
- 10 Output Jacks - Standard configuration shown above has 2 Temperature-Controlled outputs (one Left, one Right), 6 Medium Power outputs, and 2 pass-through 12V Power Outlets.
- Case-Mounted Output Jacks - plugging and unplugging heaters won't stress the circuit board and crack solder joints.
- Temperature Controlled Outputs - When used with Temperature Sensor, constantly adjusts heater power level to keep the lens just a few degrees F above the air temperature (as set by control knob). This prevents dew formation while ensuring optimal telescope performance and maximum energy savings so your battery lasts longer. On very large heaters the energy savings can be significant. If a Temperature Sensor is not plugged in, the Temp Controlled output functions as a Medium Power output.
- Medium Power Outputs - instead of using a sensor to measure temperature, Medium Power outputs apply 40% power which is sufficient to prevent dew but will usually warm the optic more than needed. Typically used for small non-critical heaters such as eyepiece, finder scope, Telrad, etc. where the extra heat will not affect telescope performance and the energy savings is not significant. Medium Power outputs will gradually increase from 40% to 100% when control knob is raised above 15.
- Pass-Through 12V Power Outlets - provide power for accessories such as Digital Setting Circles. These outlets are not voltage-regulated, they pass-through power from the battery and thus remain powered even when the DewBuster™ Controller is turned off or the Low-Battery or High-Voltage Cutout features activate.
- Heavy Duty Powerpole® Power Cord - quickly and easily switch between "pigtails" connected to different power sources. Self-resetting 14 Amp PTC fuse means no fuses to replace. Wide choice of pigtails to fit most power sources. Default length is 8 feet but may be customized if needed.
- Short Circuit Protected Heater Outputs - Heater outputs are short-circuit protected so heater faults can't damage controller.
- Synchronized Pulse Width Modulation - For maximum efficiency Pulse Width Modulation (PWM) is used to control power to your heaters, but the DewBuster™ Controller takes it to the next level by alternating current pulses between heater outputs to reduce peak current and fluctuations in battery voltage.
- Proven Technology - Industrial-Spec components for dependable performance 24/7 even in extremely cold weather.
- Longevity - In production for 20 years and 99% of all DewBuster™ Controllers built are still in service!
- No Camera Interference - The DewBuster™ Controller will not interfere with Camera equipment and the 30-Day Satisfaction Guarantee allows you to return it if you are not completely satisfied.
- Heater Status Lights - LED's are wired directly to heater outputs so if they are illuminating then you can be sure voltage pulses are being sent to your heaters. When the Temperature Controlled LED blinks you know that the temperature is being maintained at the control knob setting. Red LED's are easily visible at night yet dim enough not to disturb your night vision.
- Battery Warning Light - The yellow Battery Warning light flickers dimly when your battery is weak to give you time to switch power sources or disconnect less critical heaters or accessories. As the battery weakens further the blink grows longer and brighter giving you a visual clue of how fast your battery is draining. The yellow light will also illuminate if a power supply failure sends voltage above 15V which triggers the High Voltage Cutout shuting off heaters to prevent them from burning up.
- Smart Low-Battery Circuitry -- As battery nears 10.5V the heater power levels are reduced gradually to provide as much heat as possible while never allowing the battery to fall below 10.5V. This allows your heaters to run as long as possible while preventing battery damage. Please note that the red 12V power outputs are pass-through and thus are not shut off by the Low-Battery Circuitry.
- High-Voltage Cutout - If your power supply malfunctions sending the output voltage above 15V, the DewBuster™ Controller shuts off all heaters to prevent them from burning up. Please note that the 12V power outputs are pass-through and thus can not be shut off by the High-Voltage Cutout feature.
- Premium Enclosure - No plastic or thin metal, deluxe cast-aluminum enclosure finished in durable polyester powder coat with durable Lexan® front panel graphics. Enclosure measures a compact 4.4" x 2.4" x 1.2".
- Easy Mounting - Included industrial-strength Velcro® strip holds tight yet allows easy removal when breaking down equipment. For those desiring a more permanent mounting, the bottom cover screws may be replaced by longer 6-32 screws to allow mounting the DewBuster™ Controller to a plate or bracket.
- Customize Your Controller - I hand-build every DewBuster™ Controller to order which allows me the flexibility to customize it for your needs. Do not hesitate to contact me to discuss your needs.
- After-Sale Support - With a DewBuster™ Controller you are never stuck if your needs change. If you ever wish to reconfigure your controller outputs or power cord then contact me. In most cases you will only pay return shipping plus the cost of the options being added.

PRECISION THERMOSTATIC HEATER CONTROL
- Set & Forget - Just set the control knob at the beginning of the night and thermostatic controller does the rest. Controller may be left on 24/7 to help with daytime condensation in an observatory.
- No overheating optics - Keeps optics slightly warmer than the air temperature, just enough to prevent dew without hurting telescope performance.
- Combination Sensor - both air and telescope temperatures combined into one cable to reduce clutter.
- 2 Sensor Cable Inputs - two Sensor Cable inputs allow independent control of your main optic and a piggybacked telescope. Note that smaller items such as finderscope, eyepiece, Telrad, etc. do not require precise temperature control and are best used on the Medium Power outputs.
- Thermocouple Sensors - thermocouples do not vary sensor-to-sensor so no calibration required when switching sensor cables or moving controller to different telescopes.
- Clip-On Sensor - standard Refractor/SCT Sensor Cable clips onto heater strip so it is easy to install or move between telescopes.
- 6-foot Sensor Cable - cable length matches cord length of most heater strips.
- Newtonian Sensor Available - The standard sensor clips onto your heater strip. For applications where the sensor can not clip onto a heater strip, a special Newtonian Temperature Sensor Cable is available. It has a smaller "tip" sensor that can be glued or taped in place on the telescope. When ordering a Newtonian Sensor you will need to specify the dimension (CLICK HERE for the installation guide with additional information).
- Low Cost Sensors - extra sensors may be purchased at any time using the Accessories Order Form and are economically priced.
- Sensor Customization - for special situations such as needing the cable shorter than 6 feet, just contact me with the specifics. There is no extra charge for shortening dimensions, but when lengthening there will be an extra charge if additional materials are required.
HEATER VERSATILITY
- Heater Strips are not included with controller.
- Commercial Heaters - compatible with RCA-plug equipped 12V heaters such as those listed here.
- Home-Made Heaters - you can build heaters using my resistor heater or nichrome heater instructions and they will be fully compatible with commercial heaters allowing you to mix and match. For example, you could buy the corrector plate heater and build eyepiece and finderscope heaters. Note that instructions from other sources may be used, but if they do not produce the correct wattage you will have excessive heat or dew-up.
- Short Protection - shorted heaters can not damaged the controller.
- Unequaled 5-Year Warranty - unlike competitors who try to scare you into buying only their line of products (often in violatation of the Magnuson-Moss Warranty Act), I will never deny your warranty just because you tried to customize it for your needs and I will even offer advice to help you with special situations. You can also build your own heaters without worry because the warranty covers any damage caused by any mistakes you make constructing home-made heater strips.
BATTERY SAVER
- Conserves Battery Power - Temperature control applies only as much heat as needed to replace what is being lost to the sky. You can save energy by wrapping insulation around the outside of a temperature controlled heater which will reduce heat losses and the controller will automatically reduce power to the heater resulting in longer battery life.
- Efficient - Pulse Width Modulated heater output circuitry with Power MOSFET drivers for maximum efficiency and longer battery run time.
- Low Battery Warning - yellow Battery light flickers when battery gets below 11 VDC then brightens as battery weakens and remains on constantly when battery is exhausted.
- High Voltage Cutout - power supplies can sometimes fail with the output voltage exceeding 20V which will burn up heaters so the DewBuster™ Controller has a High Voltage Cutout that shuts off all heaters at 15V and illuminates the yellow Battery light to warn you there is a problem.
- Smart Low-Battery Circuitry - reduces heater power as battery becomes exhausted keeping dew heaters operational as long as possible yet preventing battery damage. Works in conjunction with Low Battery warning light so you can disconnect unnecessary items to conserve power. Provides peace of mind if you leave controller turned on when going to bed.
DIMENSIONS AND WEIGHT
- Approximately 1.5 pound with Heavy-Duty Power Cord
- Approximately 1 pound with Standard-Duty Power Cord
WARRANTY
- 30-Day Satisfaction Guarantee - If you are not satisfied with your DewBuster™ Controller for any reason contact me for return instructions. You will be given a full refund minus shipping.
- No-Hassle 5-Year Warranty - warranted to original purchaser for a minimum of 5 years against failures of any kind including reverse power hookup and damage caused by faulty heaters including home-made. I keep a record of your purchase so your receipt is not needed for warranty service. After the warranty expires, repairs will be done for a very reasonable flat-rate fee.
WHAT'S INCLUDED
- DewBuster™ Controller
- Velcro™ mounting strip
- Owner's Manual
- Heaters strips and power source not included.
- Since most users will need one Temperature Sensor Cable, the order form will automatically add one to your order, however you may change the quantity. Two sensors may be used simultaneously (to control 2 optics) and it is easy to move the sensor back and forth between different telescopes, however you may wish to add extra sensors for additional telescopes. See instruction manual for more information on using sensors.
HOW TO PURCHASE
- DewBuster™ Controllers are sold ONLY through this web site.
- Prices and options are shown on the ORDER FORM below.
- I ship ONLY TO USA OR APO ADDRESSES (international customers are welcome to ship to a "Package Forwarding Service" in the USA).
- If you need help, fill out the order form as best you can and hold-off making your payment. The order form sends you an email with a summary of your order, to which you can reply with any questions. I will personally assist you with configuring your controller and adjust your order as necessary. Then, if you wish to proceed, you can make your payment when you are ready.
Links for other order forms: | Newtonian DewBuster | Accessories | Fan Speed Controller |
Standard DewBuster™ Controller Order Form