Solar Tracking kit
Price - Stock No 215
Motors with Gearboxes
Price - Stock No 750 3v Gearbox 2.93RPM - 3000 RPM (6 configurations)
Price - Stock No 751 12V Gearbox 36 RPM
Price - Stock No 752 12V Gearbox 70 RPM
Price - Stock No 753 12V Gearbox 160 RPM
As the name suggests this kit is designed to track the sun - for use with a solar panel.
This kit monitors the position of the sun using two Light Dependant Resistors (LDR's), and makes the decision to move the solar panel to correctly orientate to the sun. The output configuration is called a H bridge which will drive a small electric gearbox up to 500mA at the input voltage (6 .. 15V), both forward and reverse.
It will not only track the sun, in the dark, it will track a bright light.
Light Tracking Crawler Video, Click to View:
IC1 - LM1458
Setup and Testing Technical Notes
Setup and Testing
|IC1a Output||IC1b Output||Motor Behaviour|
*or vice versa - depending on motor connection
The transistors work in diagnal pairs to provide +ve & -ve to
the motor terminals or -ve & +ve to the motor terminals for forward /
reverse. See Transistors.
The four power diodes protect the transistors from the voltage created by the motor in the instant(s) after the motor has been stopped. As the motor still has angular momentum, it will generate a voltage and current (Power). This power is capable of destroying the transistors and is bled off via the diodes. See Diodes.
The input stage uses two operational amplifiers (contained in IC1) to make a decision on the direction of light. The op-amps are fed by the junction of the LDR's. If both LDR's see the same amount of light, their resistance is equal. The junction of the LDR's would be at input voltage divided by two ie. 12V input - junction of LDR's at 6V. If the light on one LDR is greater than the other, than the voltage will move, higher or lower depending on which LDR has more light.
Limits are set by the four resistors in series from +V to 0V, and adjusted by the two trimpots. If the voltage moves outside these limits, the respective op-amp will activate the motor and move the solar panel appropriatly.
The 20K trimpot sets the sensitivity ie. the distance between these limits. The 100K trimpot adjusts so that these limits are symetrical around +V/2 (balance point).
For more information on the LM1458 see Datasheet for the LM1458.
Troubleshooting will consist of: