KERN DBS

3. Checking the Ele
c
tr
o
nic B
o
ard
The DBS boards and their signal allocations are summarized below. Numbers in parentheses ((1), (2), (3),
and so on) indicate pin numbers, and a checkmark
(  ) indicates a point that should be checked, if possible.
3.1 M
a
in Bo
a
r
d Assembl
y
(
B2)
3.2 An
a
l
o
g Bo
a
r
d Assembl
y
(
B
3
)
generator circuit
ASSY P/N 321-64556-14 (same for all models)
Board P/N 321-64558
Circuits Mounted
Mechanical sensor PID control (feedback) circuit
Measurement system (A/D converter) circuit and reference power supply
Magnet temperature correction and measurement circuits
Voltage for Checking
(when connected to
detector assy)







TPG Signal ground (0 V)
TP1 During pre-amp control signal output feedback: 0 V
TP2 Coil current control voltage
TP3 Voltage on output resistance end (about 0.6 to 2.3 V)
J2 (1) Beam sensor LED positive potential about -5.2 V
J2 (2) Beam sensor LED negative potential about -6.8 V
J2 (3) Magnet temperature sensor output voltage about 0.6 V
J2 (4) Signal ground (0 V)
J2 (5) During beam sensor photodiode output feedback: 0 V
J2 (6) Signal ground (0 V)
J2 (7) During beam sensor photodiode output feedback: 0 V
J1 (1) Signal ground (0 V)
J1 (2) Power supply for analog system: about -12 V
J1 (3) Power supply for analog system: about +12 V
J1 (4) Temperature A/D digital signal
J1 (5) Temperature A/D digital signal
J1 (6) Weight A/D digital signal
J1 (7) Weight A/D digital signal
J1 (8) Weight A/D digital signal
J1 (9) Weight A/D digital signal
ASSY P/N 321-71373-41 (same for all models)
Board P/N 321-71372
Circuits Mounted
CPU (calculates measurement data and controls key switches)
Dedicated LCD driver IC chip
EEPROM with connector J3 for writing with Flash Writer
Main clock (20 MHz), used to form a +5 V logic system
Dedicated calendar IC chip
38 DBS-SH-e-1210