13
M-670V/673V/675V
4-4. IC Block Diagrams
IC101 BH3682FV
IC601 LB1979VS-TLM-E
12
11
10
9
8
7
6
5
4
3
1
13
14
15
16
17
18
19
20
21
22
23
24
PREVCC
PREINF
RFL
TOUT
RFL
TIN
REG
PRE1OUT
MICALCIN
VOR
TAU
VORC
VORIN
VOROUT
REC/BIAS
REC/SP2OUT
PWRVCC
PREIIN
GND
ALCNF
VORCTRL
MICALCOUT
ALCT
AU
ALCDETIN
REC/SPIN
REC/SP1OUT
SPGND
BH3682FV
TapeRecorder
PRE/PWR
MIC/REC
PREVCC
PWRCTRL
PRE1
31dB
MICALC/PRE2
delta: 40dB
BIAS
26dB
PWRVCC
INV
VORCTRL
PRE
PWR
POM
37dB
REC/POWER
22dBSE
0dBSE
REC
ALC
REG
RBC
VOR
RIPL
2
+
-
+
-
ZZ
INV
FC GND
VCC
VCC
FC
WB
VCC
NC
UOUT
VOUT
WOUT
P-GND
VB
UB
GND
TO
CONTROL
BLOCKS
TO
EACH
BLOCKS
RI
OUT
VSP
IN+
VREF
S/S
COM
OSC
7
5
4
3
1
2
6
8
9
10
11
12
13
14
15
16
18
20
19
STARTING
DETECT
POWER
SUPPLY
BIAS
OSCILLATING
CIRCUIT
SPEED CONTROL
REFERENCE VOLTAGE
REFERENCE
VOLTAGE
CURRENT
DETECT
SPEED
DETECT
WAVEFORM DETECT
COMMUTATION STARTING LOGIC
SOFT SWITCH
PRE DRIVER
+
–
17
Note on Schematic Diagram:
• All capacitors are in
µ
F unless otherwise noted. pF:
µµ
F 50 WV or less are not indicated
except for electrolytics and tantalums.
• All resistors are in
Ω
and
1
/
4
W or less unless otherwise specified.
•
A
: B+ Line.
•
H
: adjustment for repair.
• Power voltage is dc 3 V and fed with regulated dc power supply from battery terminal.
• Voltages and waveforms are dc with respect to ground in service mode.
no mark : PLAY
(
) : REC
• Voltages are dc with a VOM (Input impedance 10 M
Ω
).
Voltage variations may be noted due to normal production tolerances.
• Signal path.
E
: PB
a
: REC
• WAVEFORMS
IC601
qa
OSC
VOL/DIV : 20m V AC
TIME/DIV : 1m sec
1
40m Vp-p
1.6m sec
