AC/DC Little Giant
Solar Controller 
or
 Differential Controller with Temperature Monitors 

 

We don’t want to control the sun. We just want more of it's energy. This rugged yet sensitive differential thermostat solar controller knows when to turn on and off.  It does this to maximize a solar heat gain with a minimum expenditure of energy. The AC/DC differential controller will not only optimize the regulation of your solar collector pump but it will also provide continuous monitoring of both collector and storage temperature.  

 

 

To regulate an AC pump
A tiny 6 watt 9VDC wall transformer is used to power the controller.  BUT before connecting the AC pump and DC wall transformer and temperature probes  you should  install an AC outlet near the pump.

 







 

BUT I have a DC pump powered with a photo-voltaic system. ?

NO PROBLEM...

PV Systems with 12 Volt Battery :
Another feature of the AC/DC controller is battery protection used with PV power supplies. If the differential is set too low or the sunlight is insufficient to keep a battery charged the controller shuts down before the battery is depleted.  The controller will shut down when the voltage drops below 8 volts and will not come back on until  the battery has been sufficiently recharged (around 14 volts). The differential off adjustment allows the user to adjust the maximum heat gain with minimum power requirements. The best adjustment will depend on the size of the PV power supply and the demands made on the pump. Closed loop systems generally require less power than open loop systems. A PV panel with a maximum power output between 10 and 100 watts is good for most applications. I am using a 50 watt PV panel with my MTD solar heating system.

WITHOUT A BATTERY BUFFER between a PV panel and a pump the supply voltage could fluctuate between 0 volts and 18 volts. This extreme voltage fluctuation puts undue stress on most DC pumps. Some people think that a PV panel alone is sufficient to regulate pump speed with sunlight intensity. HOWEVER, total dependence on sunlight intensity for regulation is not a good idea. Scattered clouds can turn off a pump before heat is collected from a collector.  Bright sunlight in winter is another consideration. Without a differential controller bright sunlight turns on a pump at full speed before the collector has had time to warm up. This bright/cold condition could circulate cold water through a heat storage system and diminishes net heat gain.



This new (November 2008) AC/DC Differential controller fulfills a variety of needs at a competitive price. These are the features of the AC/DC Little Giant with monitors.

 




COMPLETE "Little Giant" Differential Controllers come fully assembled with two temperature monitors and two temperature probes...  Wall transformer available for $5


       TEMPERATURE PROBE                                                                                                                   $10

     TEMPERATURE MONITOR                                                                                                                 $39 

     AC "Little Giant" Differential Controller COMPLETE WITH 2 probes and 2 monitors                  $145      

    DC "Little Giant" Differential Controller COMPLETE WITH 2 probes and 2 monitors                  $145      


     &       &     &  

 

e-Books on Solar Heating are now available 

 Books
 Solar Collector Kits
MTD Solar Heating
Differential Controller Kits
Temperature Probes
MTD Solar Home 
MTD Data
Collector Efficiency
Alternative Energy Videos
Solar Controller


Powered by WebRing.


Hit Counter