Energy Harvesting for Solar-driven Water Pump

Intro: Energy Harvesting for Solar-driven Water Pump

Solar pumps are popular to make a small fountain in the garden pond.
Unfortunately, during cloudy days there is not enough current to drive the pump motor. 

Present project describes how  get pump running also in cloudy days or in shaddow.
Energy  from a  solar panel (10W peak, 21V) charges  a car-audio super-capacitor (1F, 20V), that can drive a pump motor for ca 5 seconds at a time.  Circuit is based on a voltage comparator and a logic-level MOS-FET transistor (for example, IRFZ40, BUK555-60A ).

The construction is intended for small greenhouse irrigation. It is self regulating - in sunny days pumps more water to your tomatoes. Could be used for aquaponics.

This is an autonomous circuit and, in principle, could be used to make for example a solar RC boat, grass cutter, or  wireless telemetry transmitter.

Please read the attached word file.

Comments

[baudeagle]

Instead of using an Arduino to shut a low supply reservoir, why not use a float switch? Much cheaper and work than an Arduino.

Here is an example.


http://www.ebay.com/itm/New-White-SEAFLO-AUTOMATIC-Bilge-Pump-Float-Switch-12V-24V-or-32V-for-Boat-Yacht-/161069820135?pt=LH_DefaultDomain_0&hash=item25808268e7

[janisalnis]

Super! Thanks for hint about float switch. I see that my thinking is too much about electronics.
There could be another float switch in the pond to check when water is low and not to burn the pump when no water present.