When there is just a little light shone ( must be corrected to 'shown') on the solar cell on the link http://www.allaboutcircuits.com/vol_3/chpt_4/5.html

 

Hello,

Do you mean in this phrase:

Before, a small solar cell current saturated a transistor, illuminating a lamp. Knowing now that transistors are able to “throttle” their collector currents according to the amount of base current supplied by an input signal source, we should see that the brightness of the lamp in this circuit is controllable by the solar cell's light exposure. When there is just a little light shone on the solar cell, the lamp will glow dimly. The lamp's brightness will steadily increase as more light falls on the solar cell.

The "When there is just a little light shone on the solar cell" could be replace with "When there is just a little light shining on the solar cell".

Bertus

 

What bertus said. "Shone" is the past participle of the verb "shine".