Door Minder 6 2011 - 22:25

Door Minder :

. . () . 25 .

:

:

250Hz 38kHz . 38kHz . ( ) 250Hz 38kHz 250Hz . . 555 " " . IC1 250Hz R1 R2 C1 . IC2 38KHz R4 R5 C3 .

: D1 D2 :

C1 (C3) R1 R2 (R4 R5) R2 (R5) . . bypasses R2 (R5) R1 (R5) . .

" " :

THIGH = 0.693 x R1 x C1 (or 0.693 x R4 x C3)

" " :

TLOW = 0.693 x R2 x C1 (or 0.693 x R5 x C3)

The output frequency = 1 / (THIGH + TLOW)

IC1 D2 R3 " " trigger IC2 . IC1 IC2 IC2 ( ) . IC1 IC1 38KHz . IC2 . R6 . 12VDC 45ma . R6 555 200mA .

:

( module ) . . . : () 38kHz . 38kHz .

: 250Hz ( 250 ) . Q1 C1 D2 C2 . C2 . L1 R4 Q2 . C2 . . Q1 C2 . turn off R5 C3 . .

C1 DC Q1 C2 . 38kHz "" continuous ( ) 38Kh pulsed .

L1 . Z1 R6 C4 5.6V .