Panasonic KX-F1200 Service Manual And Technical Manual page 101

2- I,,'. ,.%UPP-.HVI,.%ION(51HUUI I I-OH I Hi::HMAL HF.AD ]EMPF'HATURE
i KX-F1200
1) Function
Thermal head temperature is disposed to convert voltage to digital data by using A/D cwwerter of IC404. The CPU decides
the strobe width of the thermal head according to this value. Therefore, this circuit can keep the thermal head at an even
temperature in order to stabilize the printing density and prevent the head from being overheated.
Circuit Diagram
TO THERMALHEAD
¢
IH-
HEAD
I
...... J
R420 1
29
I
,, 30
\ 31
\ 32
3_ NEWTHDAT THDAT 142 33
NEWTHCLKI0417 THCLK 144 35
THLAT h43 ,_ 34
8
C405
C407
STB1
STB2
STB3
STB4
THDAT
THCLK
THLAT
ADSEL1
AIN2
10404
Timing Chart
I
®
Effective signal
©
!: =-!
ref LEVEL CLAMP
measure effective signal level
1.82V
IC4 internal bias
CLAMP
- 101 -