| 4 W. . . _______ _______U5 |----+-------270R-------100R---|k >>> c|-- "dim" U5 270R |----+------- ---- --- --- 100R | k>>> c | - "dim "_____| | . _____| |. . . +--------|a_____e|-- +--------| | A_____e -3K Z . 3K Z. . . | _______ | _______| +--270R-------100R---|k >>> c|-- "on" | + - 270R ---- --- --- 100R | k>>> c | - "pe"gnd | . GND |. . . | +-|a_____e|-- | + - | A_____e | -Y c . Y c. . . | | | |-------------b +5V----+------+ opto ------------- B +5 V --- -+------+ optoe . e. . . couplers cuplare+5V | . +5 V |. . . _______ _______| gnd gnd-------------|e