SoundCraft CPS275, CPS250 User Manual

SOUNDCRAFT CPS250

CPS275

Console Power Supply

User and Technical Manual

For your own safety and to avoid invalidation of the
warranty all text marked with these Warning
Symbols should be read carefully.

IMPORTANT: please read this manual carefully
before connecting your Soundcraft console power
supply to the mains for the first time.

© Harman International Industries Ltd. 1997
All rights reserved

Parts of the design of this product may be protected by worldwide paten ts.

Part No. ZM0195 Issue 3
Soundcraft is a trading division of Harman Intern at iona l Industrie s Ltd .
Information in this manual is subject to change withou t notic e a nd doe s not

represent a commitment on the part of the vendo r. Soundcra ft sha ll not be lia ble fo r
any loss or damage whatsoever arising from the use of information or an y error
contained in this manual, or through any mis-operation or fault in hardware
contained in the product.

No part of this manual may be reproduced, stored in a ret rie va l syst em , or
transmitted, in any form or by any means, electronic, electrical, mechanical, optical,
chemical, including photocopying and rec ording , for any purp ose without the
express written permission of Soundcraft.

It is recommended that all maintenanc e and service on the product should be
carried out by Soundcraft or its authorised agents. Soundcraft cannot accept any
liability whatsoever for any loss or dam ag e c a use d by service, maintenance or
repair by unauthorised personnel.

Harman International Industries Ltd.
Cranborne House
Cranborne Industrial Estate
Cranborne Road
Potters Bar
Herts.
EN6 3JN
England

Tel: [phone]
Fax: [phone]

Table of Contents

Introduction 1

Introduction 2
Short-circuit Protection 2
Mains Voltage Selection 3
Replacing Mains Fuse 3
Warranty 4

Recommendations For Installation 5

Recommendations For Installation 6
General 7
Dimensions 8
PSU Linking (CPS275 Only) 8

Technical Specification 9

Technical Description 11

Circuit Diagram (1) 12
Circuit Diagram (2) 13
Circuit Description 14
Servicing 17
PCB Layout 20
Output Pinouts 21

Parts List 23

i

ii

Introduction

Introduction 1

Introduction

WARNING: THIS APPARATUS MUST BE EARTHED

The CPS250/CPS275 are linear power supplies which, like other linear supplies,
produce DC voltages by rectifying, smoothing and regulating AC voltages from the
secondary windings of a mains transformer. Soundcraft mixing consoles employ a
number of dc voltage supply levels in their op eration and these are all provide d at the
output of each supply unit.

The CPS275 provides higher currents than the CPS250. The CPS275 also has the
capability of being linked to a second CPS275 to provide a utomatic power backup in
the event of one of the units failing.

In regulating these voltages there is considerable heat generated, the dissipation of
which is achieved through a substan tial internal heat sink. A fan is incorporated which
draws air over the heatsinks to provide adequate heat dissipation for the regulators
and reduce the outer case tempera ture .

The CPS250/CPS275 is designed for installation in a 19" rack unit, oc cupyin g 2U of
rack height. Refer to the section "RECOMMENDATIONS FOR INSTALLATION"
on Page 5.

LED indication is provided on the front panel to show operation of the regulating
circuits.

SHORT-CIRCUIT PROTECTION

The +/-17V rails can withstand a short to ground or each other for up to one second;
if the short circuit remains for longer than one second then both of the 17V ra ils will
be shut down. To reset them the supply must be switched off for 6 seconds and then
switched on again.

The +5V and +48V are current limited and will self rec over whe n any short ci rcuit is
removed.

2 Introduction

MAINS VOLTAGE SELECTION

Special attention should be paid to the fo llowing infor m atio n:

Do not change the voltage setting without first
turning the unit off and unplugging the mains lead.

This unit is capable of operating over a range of mains voltages by means of a
4-position mains input fuse carrier. It is important to ensure that the correct voltage
setting is selected for the level of local mains voltage supply, for safe, uninterrupted
operation of the unit. Voltage selection is achieved by positioning the fuse carrier so
that the required voltage appears next to the arro w which is moulded in the conne ctor.
In this way the unit is set up for operation at one of the following ranges of mains
supply:

NOMINAL VOLTAGE OPERATING VOLTAGE RANGE

(+10/-15%)

Vrms AC Vrms AC

230 196 - 253
115 98 - 126
100 85 - 110
85 73 - 93

To remove the fuse use a small screwdriver to prise the fuse carrier from its location
in the connector.

To avoid risk of fire use the correct value fuse, as
indicated on the unit.

REPLACING MAINS FUSE

Switch the ON/OFF switch to the OFF position. Remove the mains lead from the
connector. Use a small screwdriver to prise th e fuse carrier from its location i n the
connector. Check the fuse and replace if necessary; also check that the voltage
selection is correct for the mains supply level be fore switc hin g the unit ON agai n.

In the event of repeated failure of t he mains fuse co nsult the Sound craft dealer from
where the unit was purchased.

This unit contains no user serviceable parts. Refer
all servicing to a qualified service engineer, through
the appropriate Soundcraft dealer.

Introduction 3

Warranty

1

Soundcraft
End User
Dealer

purchased the Equipment, provided such a pe rs on is a utho ri se d fo r th is purpos e by
Soundcraft or its accredited Distributor.

Equipment

2 If within the period of twelve months from the date of delivery of the Equipment
to the End User it shall prove defective by reaso n only of faul ty ma terials and/or
workmanship to such an extent that the effectiveness and/or usability thereof is
materially affected the Equipment or the defe c tiv e c omp onent should be returned
to the Dealer or to Soundcraft and subject to the following conditions the Dealer or
Soundcraft will repair or replace the defective com pon en ts. Any com pone nt s
replaced will become the property of Soundcraft.

3 Any Equipment or component returned will be at the risk of the End User whilst
in transit (both to and from the Dealer or Soundcraft) and postage must be prep ai d.

4 This warranty shall only be available if:

a) the Equipment has been properly installed in accordance with instructions

contained in Soundcraft’s manual; and

is a trading division of Harman International Industrie s Lt d.

means the person who first puts the equipment into regular operati on.

means the person other than Soundcraft (if any) from whom the End User

means the equipment supplied with this ma nua l.

b) the End User has notified Soundcraft or the Dealer within 14 da ys of the defe ct

appearing; and

c) no persons other than authorised representatives of Soundcraft or the Dealer
have effected any replacement of parts maintenan ce ad justme nt s or repa irs to the
Equipment; and

d) the End User has used the Equipment only for such purposes as Soundc ra ft
recommends, with only such operating supplies as mee t Sou ndc raft’s spec i fica t ions
and otherwise in all respects in accordance So undc ra ft ’s rec omm e nda ti ons.

5 Defects arising as a result of the following ar e not cov ere d by thi s Wa rra nty:
faulty or negligent handling, chemical or ele c tro-c hem ic a l or electrical influences,
accidental damage, Acts of God, neglect, deficiency in electrical power,
air-conditioning or humidity control.

6. The benefit of this Warranty may not be assign ed by the End Us er.

7. End Users who are consumers should note their rights under this Warrant y are in
addition to and do not affect any other rights to which they may be en tit le d ag ai nst
the seller of the Equipment.

4 Introduction