IC-PS35, IC-PS30 & IC-765 PSU Adjustment

by Adam M. Farson, VA7OJ/AB4OJ

General:

The IC-PS35 "bathtub" modular switching power supply is an accessory for the IC-751 and IC-751A. Variants of the IC-PS35 are used in the IC-PS30 system power supply, and also in the IC-765. The voltage and current-protector adjustments are identical for all three versions, with the exception of a difference in the adjustment-point designations.

Required Test Equipment:

Table 1: Adjustment points and parameters. (Refer to Figures below.)
ADJUSTMENT ADJUSTMENT CONDITIONS MEASUREMENTS VALUE ADJUSTMENT POINT
UNIT LOCATION UNIT ADJUST
OUTPUT VOLTAGE 1
  • Rheostat: 1.38Ω
  • AC power switch: ON
IC-765 REG,  IC-PS35
(Fig.2)
Connect a DC voltmeter
as shown in Figure 1.
13.8V IC-765 REG,
IC-PS35
R14
IC-PS30 REG
(Fig. 3) 
IC-PS30
REG
R5
CURRENT PROTECTOR
OPERATION
2
  • Rheostat: 0.55Ω
  • AC power switch: ON
IC-765 REG, IC-PS35
(Fig. 2)
Adjust pot. until output
 voltage just drops.
IC-765 REG,
IC-PS35
R19
IC-PS30 REG
(Fig. 3)
IC-PS30
REG
R10
IC-PS30 VOLTAGE
SCALE
3
  • Rheostat: 1.38Ω
  • AC power switch: ON
  • Meter switch: Vo
IC-PS30
METER
SWITCH
(Fig. 4)
Connect a DC voltmeter
as shown in Figure 1.
IC-PS35 meter: 13.8V IC-PS30
METER
SWITCH
R4
IC-PS30 CURRENT
ZERO
4
  • No load
  • AC power switch: ON
  • Meter switch: Io
IC-PS30
METER CAL
(Fig. 5)
Observe IC-PS30
meter.
IC-PS30 meter: 0A IC-PS30
METER
CAL
R15
IC-PS30 CURRENT
SCALE
5
  • Rheostat: 0.69Ω
  • AC power switch: ON
  • Meter switch: Io
IC-PS30
METER CAL
(Fig. 5)
Connect a DC ammeter
as shown in Figure 1.
IC-PS30 meter: 20A IC-PS30
METER
CAL
R14

 

Fig. 1: Test equipment connections.
Fig. 1: Test equipment connections. Image courtesy Icom Inc.

 

Fig.2: Adjustment points (IC-765 REG board & IC-PS35).
Fig.2: Adjustment points (REG board & IC-PS35). Image courtesy Icom Inc.
 
Fig.3: Adjustment points (IC-PS30 REG board).
Fig. 3: Adjustment points (IC-PS30 REG board). Photo courtesy K5JN.
 
Fig. 4: IC-PS30 meter switch, showing R4 (left).
Fig. 4: IC-PS meter switch, showing R4 (left). Photo courtesy K5JN.

 

Fig. 5: IC-PS30 meter calibration board, showing R14 and R15.
Fig. 5: IC-PS 30 meter calibration board, showing R14 and R15. Photo courtesy K5JN.
Copyright  2005 A. Farson VA7OJ/AB4OJ. All rights reserved.
Based on an e-mail discussion with Ralph Marrs K5JN.
Last updated: 11/08/2005.

Click for Microsoft FrontPage site.