hi
any one know the values of condensators and resistances in the first post here? .........
http://forum.arduino.cc/index.php?topic=8386.0
R1/R2/C3/C4 form a Wien bridge oscillator I believe (180 degree phase shift network),
so try googlin Wien bridge. C1 is obviously decoupling and C2 is likely a snubber to prevent
over-high voltages on the transistor's collector. [The diagram omits the secondary winding
of the transformer.]
Most likely, blocking oscillator http://mysite.du.edu/~etuttle/electron/elect37.htm
Freq., and duty circle greatly depends on inductance of primary windings, than RC .
Mini USB Glass Plasma Ball Sphere Lightning Light Lamp
reference digram;-
OY-12-2 is flyback transformer.
sonnyyu:
reference digram;-
How are they getting 220V AC from a USB connector?
reference digram
C7's function as Capacitor Power Supply.
A Capacitor Power Supply uses a capacitor to interface between a “high voltage supply” and a low voltage – called THE POWER SUPPLY.
In other words a capacitor is placed between a “high voltage supply” we call THE MAINS (between 110v and 220v) and a low voltage of 5v to 12V.
Sorry for poor quality diagram. that is all I can get.
Magician:
Most likely, blocking oscillator Electronics 37
Freq., and duty circle greatly depends on inductance of primary windings, than RC .
So why is there a Wien bridge feedback network? 180 degree phase shift + 180 shift
from the primary (centre-tapped transformer I'd bet). Makes perfect sense to me and
frequency is stable.