Switching Power Supply Circuit For Outdoor Control P.w.b.; Voltage Specification - Hitachi RAF-25NH4 Service Manual

(1) Switching power supply circuit for outdoor control P.W.B.

Input voltage
230V AC
Approx.
325V DC
Fig. 4-2 shows the switching power supply for the outdoor control P.W.B.
The switching power supply for the outdoor control P.W.B. generates the voltage of power supply to control circuits of the outdoor
parts.
The following table 4-1 shows the specification of each output voltage.
Table 4-1 Voltage specification
Output name
12 V A
12 V B
5 V A
5 V B
5V
17 V A
17 V B
In order to check the voltage shown in Table 4-1, measure at output-indicating point with the P.W.B. by tester.
A cycle and B cycle are isolated electrically, so the potentials of 0V are different between A and B.
When you measure the voltage in A cycle <B cycle>, connect the control terminal (usually black) of a tester to V-A <OV-B>.
Take care NOT to get an electric shock in measuring voltage of the circuit. The electric potential (from the earth) of the OV-
point is more than 200V. So measuring it is attended by danger.
Fig. 4-2 Switching power supply circuit for outdoor control P.W.B.
Output specification
12 (+2.0/ 1.5)V
12 (+2.0/ 1.5)V
5 (±0.5)V
5 (±0.5)V
4.5 (+2.2/ 1.0)V
17 (+2.0/ 1.0)V
17 (+2.0/ 1.0)V
SW transformer 1
Main load circuit
A cycle control system, (Each IC, Relay, Fan HIC)
B cycle control system, (Each IC, Relay)
A cycle control system, (Micro computer, Control circuits)
B cycle control system, (Micro computer, Control circuits)
Fan HIC (HIC3)
System power module A
System power module B
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