Kenwood DP-1100 B Service Manual page 120

D P - H O O D II
[ 1 ] T h e play start a b s o l u t e t i m e A 1 ( m i n , sec) of the sear­
c h i n g p r o g r a m is read o u t f r o m external R A M I C 1 4
( T C 5 5 1 4 P ) .
[ 2 ] T h e p r e s e n t address (absolute t i m e ) is taken as A 2
( m i n , s e c ) .
[ 3 ] T h e d i f f e r e n c e b e t w e e n the s e a r c h i n g position a n d the
p r e s e n t p o s i t i o n ,
c a l c u l a t e d .
[ 4 ] Each of the f o l l o w i n g processes is p e r f o r m e d d e p e n ­
d i n g o n the a m o u n t of A A .
[ 5 . 1 ] W h e n A A is m o r e t h a n 1 m i n . :
A 1 a n d A 2 are c o n v e r t e d t o n u m b e r s of t r a c k s , T 1 a n d
T 2 by use of t h e c o n v e r s i o n t a b l e . T h e n , the n u m b e r of
t r a c k s t o t h e s e a r c h i n g
c a l c u l a t e d .
[ 5 . 2 ] W h e n A A is 1 0 t o 5 9 s e c :
T h e n u m b e r of t r a c k s , A T , is d e t e r m i n e d d e p e n d i n g o n
A A .
[ 5 . 3 ] W h e n A A is less t h a n 10 s e c :
Search is p e r f o r m e d in t h e kick search system e x p l a i n ­
ed later.
[ 6 ] A T is c o n v e r t e d t o a n u m b e r w i t h a base of 6 4 , w h i c h
is t h e n set t o
( T M P 4 7 4 0 N ) . For e x a m p l e , w h e n A T is 5 1 2 t r a c k s ,
5 1 2 / 6 4 = 8 is set.
1 2 4
3. OPERATION OF MAIN MICROPROCESSOR
A A = | A 1 - A 2 | ( m i n , sec)
p o s i t i o n , A T = T 1 — T 2 ,
internal c o u n t e r EC1 in
[ 7 . 1 ] W h e n A T is a plus n u m b e r , i.e., w h e n search is per­
f o r m e d in the d i r e c t i o n of the disc e d g e , F W D - s e a r c h
m o d e (Code
( T 7 0 0 1 -
p i c k u p m o t o r . T h e n , F W D - c o n t i n u o u s kick m o d e (Code
F < K I C K > ) is o u t p u t to start kick o p e r a t i o n .
is
[ 7 . 2 ] W h e n A T is a m i n u s n u m b e r , i.e., w h e n search is per­
f o r m e d in the d i r e c t i o n of the disc c e n t e r , B W D - s e a r c h
m o d e (Code 6) is o u t p u t a n d t h e n
kick m o d e (Code E < K I C K > ) is o u t p u t t o start kick
o p e r a t i o n like step ( 7 . 1 ) .
[ 8 ] J u d g e s w h e t h e r or n o t the p i c k u p is carried by the re­
q u i r e d n u m b e r
is
( T 7 0 0 1 -
t i n u o u s kick o p e r a t i o n is s t a r t e d , t h e n u m b e r of t r a c k s
by w h i c h the p i c k u p is carried is c o u n t e d a n d signal
T T A C is inverted e a c h t i m e t h e p i c k u p is carried 3 2
t r a c k s . IC15 ( T M P 4 7 4 0 N ) has an e v e n t c o u n t e r f u n c ­
t i o n to d e t e c t the rising e d g e of the pulse i n p u t f r o m
outside t o p e r f o r m c o u n t - u p o p e r a t i o n . In this s y s t e m ,
signal T T A C K
( T M P 4 7 4 0 N ) , w i t h w h i c h the c o u n t value in its internal
c o u n t e r EC1 is raised.
IC15
T h u s , kick o p e r a t i o n is p e r f o r m e d until EC1 c o u n t s up
t o t h e n u m b e r set at step [ 6 ] t o carry the p i c k u p by the
required n u m b e r of t r a c k s .
[ 9 ] Brake o p e r a t i o n is m a d e t o stop t h e p i c k u p in a short
t i m e .
Fig. 3 - 1 F s h o w s this o p e r a t i o n t i m i n g c h a r t .
7) is o u t p u t to s e m i - c u s t o m
0 0 0 7 or T C 1 5 G 0 0 0 8 A P ) t o t u r n ON the
B W D - c o n t i n u o u s
of t r a c k s . In s e m i - c u s t o m
0 0 0 7 or T C 1 5 G 0 0 0 8 A P ) ,
is i n p u t as c o u n t pulse
IC15
IC15
w h e n c o n ­
to IC15