[Alt-photo] 365 nm. UV-Densitometer. Part 2b of 7.

[Erich Camerling]

The clock-factory (Part 2)

Part list :

2x 74HC4060
2x 74HC4538
zenerdiode   6 V
crystal  4.194304 MHz
C1 = 33 pF
C2 = 120 pF
C3 , C14 = 0,47 µF
C4 , C5 , C7 , C9  = 0,1 µF
C8 = 33 nF
C10 , C12 , C13 = 68 nF        All these capacitors are ~ 40 V except

C6 = 470 µF / 16 V

R1 = 2k2
R2 , R3 , R9 =100k
R4 , R8  = 220 k
R5 = 43 k
R6 = 180 k
R7 = 470 k
R10 = 5k1

R 8 + C 13 determines the LED pulse time (now roughly 10 msec.)
R 5 + C 8  determines the pulse delay for the S & H (~ 1 msec.)
R 6 + C 10 determines the S & H pulse time (~ 8 msec.)

To be continued next week.