Quote:
Originally Posted by AstroApprentice
Hi, I use the following USB dew heater:
http://www.teleskop-express.de/shop/...cm-length.html
I originally bought it as it was reasonably priced and no controller needed. Plus I have USB on mount. Works well, but if anything it gets a bit too hot. I've been planning to write a review on it as I have a thermal imager and a couple of thermocouples. Imager shows there are some cold spots, but heat distribution is otherwise pretty good. When Run off 2.1 A USB it gets to 40 C or so, but off 1 A, around 30 C so there is a limited ability to regulate heat.
Still, I'm thinking about upgrading to a USB-focus Dewpoint controller when I upgrade my imaging scope. |
The limited regulation is because you are using the current limit on the USB to control. Use the USB output to power a variable voltage power supply and control the power output from that. Cut the power cord off leaving some lead on each. Where you cut depends on where you want to mount the variable voltage controller. Buy a buck converter DC-DC converter like this. The more of these you order, the cheaper they are.
http://www.ebay.com.au/itm/LM2596-Voltage-Regulator-DC-DC-Buck-Converter-Adjustable-Step-Down-Module-/161934554531?var=&hash=item25b40d35 a3:m:mJyGflWXlgzVsxe5Xt0xQfw
Input Voltage: 3.2V-40V
Output Voltage: 1.25V-35V
Output Current: rated current is 2A, maximum 3A(additional heat sink is required)
Conversion Efficiency: 92%( highest)