TallyGenicom 2365, Руководство по обслуживанию

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Electronic Functions Functional Description
3-42
3.3.24
Theory of Adjusting
Printhead Temperature
There is no need to calibrate the Printhead since it is equipped with a memory. The
calibration rather is done at the manufacturer.
The resistance of each coil of the printhead is proportional to its internal temperature.
The temperature will change almost linear to the measured coil resistance. The resi-
stance is measured continuously. Therefore it is possible to monitor the printhead for
highest performance but to protect it in case of overheating. This control system must
be adjusted once in case of changing printhead or at changing main electronic (see
chapter 6.3.1).
U s ed form u l a : R
ϑ
= R
t2
∗
(1 +
α ∗ Δ ϑ
)
ϑ
= Temper a t u re
R = Re s i s t a nce
α
= 3 ,95
∗
10
- 3
Δ ϑ
= Difference of Temper a t u re (t
1
- t
2
)
t
1
= c a lc u l a ted temper a t u re
t
2
= a dj us t temper a t u re
Ex a mple: The printhe a d w as a dj us ted b y 20°C (t
2
)
.
The me asu red re s i s t a nce w as 5
Ω
(Rt
2
)
.
We w a nt c a lc u l a te the temper a t u re (t
1
) a t 7
Ω
(R
ϑ
).
( ) – 1
Δ ϑ = α ≈
102°C
t
1
= 102°C + 20°C
≈
122°C
1
K
R
ϑ
R
t2