TREE

This project was used as a wireless light dimmer, but in principle can be used to dim resistive loads and wirelessly turn on/off loads. The current code includes a routine to dim a light bulb in a “heartbeat” pattern, with the heartbeat frequency remotely adjustable. The top left of the schematic shows the wall outlet (US 120VAC) being stepped down with a small transformer, then full rectified and regulated. This powers the entire board from the wall. The top right shows a microcontroller, ATmega48, its programming header, and a UART connection to the microcontroller (for debugging). The bottom right shows the XBee and its basic voltage regulation (it’s 3.3V), as well as an LED that indicates when the XBee is connected. [ ]

This circuit can be used to charge Accu and cells battery , the circuit can has a very stable output that would make the battery last longer  and maximize the added battery capacity. When charge was also quite fast , so it can optimize the time. A diac is used in the gate circuit to provide a threshold level for firing the triac . C3 and R4 provide a transient suppression network. R1 , R2 , R3 , C1 , and C2 provide a hase - shift network for the signal being applied to the gate. R1 is selected to limit the maximum charging current at full rotation of R2.