Pioneer PRO-720HD Service Manual page 4

PRO-720HD, PRO-620HD, PRO-520HD
1.3 CHARGED SECTION, HIGH VOLTAGE GENERATING POINT AND X-RAY
PROTECTION
7 Charged section
The circuit in which the commercial AC power is used as it
is without passing through the power supply transformer. If
the charged section is touched, there is a risk of electric
shock. In addition, the measuring equipment can be dam-
aged if it is connected to the GND of the charged section
and the GND of the non-charged section while connecting
the set directly to the commercial AC power supply. In this
case, be sure to connect the set via an insulated transformer
and supply the current.
7 Charged section
(Power supply primary side)
1. The primary side of the AC IN assy
2. AC power cord
3. The primary side of the POWER SUPPLY assy
: Part is the charged section.
: Part is the high voltage generating
points other than the charged section.
High Voltage
generating point
High Voltage
generating point
Charged section
Fig. 1 Charged section and high voltage generating point
4
7 High voltage generating point
The place where voltage is 100V is generated.
1.Charged seciton
2. POWER SUPPLY assy (135V)
3. R. CRT DRIVE assy
4. G. CRT DRIVE assy
5. B. CRT DRIVE assy
6. CRT assy R (CRT service assy R) (30.5kV)
7. CRT assy G (CRT service assy G) (30.5kV)
8. CRT assy B (CRT service assy B) (30.5kV)
9. Focus variable resistor(VR1)
10. Deflection yokes (L1, L2 and L3) Approx. (1100V at peak)
7 X-ray protection
1. CRT assy R, G, B (Do not dismantle CRT assemblies
2. Each Lens assy
High Voltage
generating point
AC Power cord
DEFLECTION assy
(including FBT) (30.5kV, 1.2kV, 210V,135V)
(10.5kV, 210V)
(10.5kV, 210V)
(10.5kV, 210V)
Regarding the parts which are relative to radiation of X-
rays (There is the danger to radiate X-ray from the indi-
vidual CRT assy R, G, B), there are notifications of cau-
tion in the individual schematic diagrams. Be sure to read
them for safety's sake.
The component parts for X-ray protection are as follows :
When the current flows to the CRT assy R, G, B, be sure
to perform it with these parts being attached. Protection
from the X-ray radiation is maintained in the state in which
these parts have been installed to the CRT assy. R, G, B.
Accordingly, never supply current only to the CRT assy R,
G, B.
Moreover, the anode voltage of the CRT assy R, G, B
should always be kept not higher than the predetermined
value (in the minimum brightness and picture state when
non signal input is less than 30.5kV). Be sure to drive the
CRT assy R, G, B by using a completely functional DE-
FLECTION assy which have been adjusted completely in
the combined state. (When the voltage abnormally be-
comes high, the X-ray protection circuit will operate.)
under any circumastances)
Each Lens Assy
CRT Assy R, G, B
Fig. 2 Component parts for X-ray protection
(10.5kV)