Deceptively simple, the EZSE is elegant, sensitive, has adjustable 
trigger level and best of all, does not lock up with high current 
solar cells. 

The secret is the way the solar cell is connected to charge the 
storage cap through the motor winding. Compared to many previous SE 
circuits, the EZSE is tolerant of, and adapts to, different operating 
conditions.

For some simple application like a flagwaver, charging the storage 
cap through the motor can have another benefit as the motor first 
turns one way while charging and then reverses when it triggers. I 
tried several different motors, capacitors and solar cells and seems 
to work flawlessly with everything.

The SE trigger level adapts to the light conditions or rather the 
solar cell output current, by charging up to a higher threshold in 
bright light and triggering earlier in dim light. This is also a 
function of the motor resistance as the voltage drop across the 
winding adds to the trigger level. 

I used a 500K trimpot in my EZSE prototype but a 100K trimpot is more 
readily available and should provide a little bit higher drive 
current. 

Have fun!

wilf