I have replaced the heater in the rain gauge, the old system consists of a halogen light bulb which did its job ,but struggled during heavy snowfall. the new system has a circuit board containing 3 of 20 watt wire wound resistors, The heater circuit board module is controlled by a Automatic Digital Temperature -50~110 Controller Thermostat Control Switch WST £9.29 from eBay These modules can be powered by different voltages. I am using a 12 V DC supply for the thermostat control and a separate 12 V DC supply to power the heater circuit board,
Made by Michael Parry-Thomas
I have mounted my control module and power transformer in my garage
alternative way would be to use a waterproof box with cable glands
I made a printed circuit board in-house which I then soldered the power resistors, if you do not have the facility to make your own circuit boards. You can use prototype project boards.. There are several different types. The one I am using here is called stripboard
My rain gauge heater uses a digital temperature controller, a temperature sensor from the controller is mounted inside the rain gauge cone
During autumn and winter, when the first frosts start I switch on the rain gauge heater and set a temperature of 15°c . This stops the rain gauge from freezing up when we move more into winter I raise the temperature to 25°c . This enables the rain gauge to melt snow. The control works by opening and closing a really which turns the power on and off to the heater circuit board ,when the temperature sensor reaches the setpoint temperature inside the rain gauge. The controller switches the relay off and switches on when the temperature drops below the setpoint . Inside the rain gauge around the outer wall has some foil type insulation and around the cone . This Helps to keep some of the heat inside the rain gauge. Please note the insulation material, must be fixed securely as you don't want any of the material to interfere with the tipping mechanism and keep clear from after funnel hole
Veroboard is a brand of stripboard, a pre-formed circuit board material of copper strips on an insulating bonded paper board which was originated and developed in the early 1960s by the Electronics Department of Vero Precision Engineering Ltd (VPE). It was introduced as a general-purpose material for use in constructing electronic circuits - differing from purpose-designed printed circuit boards (PCBs) in that a variety of electronics circuits may be constructed using a standard wiring board.