Pasco Scientific SF-9584A User manual

©1996 PASCO scientific $5.00
012-06263A
10/96
LOWVOLTAGEAC/DC
POWERSUPPLY
Instruction Manual
for the PASCO scientific
Model SF-9584A
better
teach science
ways to
Phone [phone] • FAX [phone] • email: [e-mail]
10101 Foothills Blvd. • P.O. Box 619011 • Roseville, CA 95678-9011 USA
¨

LOW VOLTAGE AC/DC POWER SUPPLY
¨
6A
10 A
12 V 24 V
0 – 24 V
DC
AC
2
4
6
VA
2-24 V
6AMAX
RESET
ON
VOLTAGEADJUST
SF-9584A
–
OFF
8
10 12 14 16
18
20
22
24
CURRENTADJUST
+
MAX DC CURRRENT

The lightning flash with arrowhead, within
an equilateral triangle, is intended to alert
the user of the presence of uninsulated
“dangerous voltage” within the product’s
enclosure that may be of sufficient magni-
tude to constitute a risk of electric shock
to persons.
The exclamation point within an equilat-
eral triangle is intended to alert the user
of the presence of important operating
and maintenance (servicing) instruc-
tions in the literature accompanying the
appliance.
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION
TO PREVENT THE RISK OF ELECTRIC SHOCK, DO NOT
REMOVE COVER ON UNIT. NO USER SERVICEABLE
PARTS INSIDE. REFER SERVICING TO QUALIFIED
SERVICE PERSONNEL.

i
012-06263A Low Voltage AC/DC Power Supply
Table of Contents
Section Page
Copyright,Warranty,andEquipmentReturn ......................................................ii
Introduction .......................................................................................................1
Operation ....................................................................................................... 1 - 2
EquipmentSpecifications...................................................................................3
SchematicsandPartsLists ............................................................................. 5 - 12
TechnicalSupport ................................................................................... Back Cover

ii
Low Voltage AC/DC Power Supply 012-06263A
Equipment Return
Should the product have to be returned to PASCO
scientific, for whatever reason, notify PASCO scientific
by letter or phone BEFORE returning the product. Upon
notification, the return authorization and shipping instruc-
tions will be promptly issued.
ä NOTE: NO EQUIPMENT WILL BE
ACCEPTED FOR RETURN WITHOUT AN
AUTHORIZATION.
When returning equipment for repair, the units must
be packed properly. Carriers will not accept responsi-
bility for damage caused by improper packing. To be
certain the unit will not be damaged in shipment,
observe the following rules:
➀The carton must be strong enough for the item
shipped.
➁Make certain there is at least two inches of packing
material between any point on the apparatus and the
inside walls of the carton.
➂Make certain that the packing material can not
shift in the box, or become compressed, thus letting
the instrument come in contact with the edge of the
box.
Address: PASCO scientific
10101 Foothills Blvd.
P.O. Box 619011
Roseville, CA 95678-9011
Phone: [phone]
FAX: [phone]
email: [email protected]
Copyright Notice
The PASCO scientific 012-06263A manual is copy-
righted and all rights reserved. However, permission
is granted to non-profit educational institutions for
reproduction of any part of the Low Voltage AC/DC
Power Supply manual providing the reproductions are
used only for their laboratories and are not sold for
profit. Reproduction under any other circumstances,
without the written consent of PASCO scientific, is
prohibited.
LimitedWarranty
PASCO scientific warrants the product to be free from
defects in materials and workmanship for a period of one
year from the date of shipment to the customer. PASCO
will repair or replace, at its option, any part of the product
which is deemed to be defective in material or workman-
ship. The warranty does not cover damage to the
product caused by abuse or improper use. Determina-
tion of whether a product failure is the result of a
manufacturing defect or improper use by the customer
shall be made solely by PASCO scientific. Responsi-
bility for the return of equipment for warranty repair
belongs to the customer. Equipment must be properly
packed to prevent damage and shipped postage or
freight prepaid. (Damage caused by improper packing
of the equipment for return shipment will not be
covered by the warranty.) Shipping costs for returning
the equipment, after repair, will be paid by PASCO
scientific.
Copyright, Warranty and Equipment Return
Please—Feel free to duplicate this manual
subject to the copyright restrictions below.
Credits
Author: Hans Frederiksen
Editor: Sunny Bishop

012-06263A Low Voltage AC/DC Power Supply
1
The PASCO scientific Model SF-9584A Low Voltage
AC/DC Power Supply provides two outputs: a regulated
DC output and an unregulated AC output. The DC out-
put can be delivered in two modes: constant voltage
mode and constant current mode.
Introduction
Operation
DC Output Operation:
➀Flip the power ON/OFF switch to OFF.
➁Plug the power cord into a grounded outlet of the ap-
propriate voltage :
Model SF-9584A, 115 V AC (78–130 V AC), 60 Hz
or
Model SF-9584A-230, 230 V AC (200 –242 V AC),
50 Hz.
➂Connect the 0–24 V DC OUTPUT terminals of the
power supply to the circuit. (Connecting wires are not
provided with the power supply.)
➃Rotate the DC VOLTAGE ADJUST knob and the DC
CURRENT ADJUST knob fully counterclockwise.
➄Flip the power ON/OFF switch to ON. The switch
will light to show that the power supply is on.
➅Constant Voltage Mode: Turn the DC CURRENT
ADJUST knob fully clockwise. Then adjust the DC
VOLTAGE ADJUST knob to obtain the desired out-
put voltage, as indicated on the meter. The output cur-
rent is displayed on the current meter.
➆Constant Current Mode: Turn the DC VOLTAGE
ADJUST knob fully clockwise. Adjust the DC CUR-
RENT ADJUST knob to obtain the desired output
current, as indicated on the meter. The output voltage
is displayed on the voltage meter.
Figure 1. Maximum DC Current
6A
10 A
12 V 24 V
MAX DC CURRRENT
The Low Voltage AC/DC Power Supply is intended for
supervised classroom use.
DC Output, Limitations
The DC output is regulated for both constant-voltage and
constant–current operation.
Constant Voltage mode:
The voltage is continuously variable from 0 –24 V DC.
The maximum load drawn in the range from 0–12 V DC
is 10 A. In the 12 - 24 V range, a load of 10–6 A may be
drawn as the maximum load. At 24 V, the maximum is 6
A. (See the illustration printed on the front panel, “Max.
DC Current,” or Figure 1.)
Constant Current mode:
The load may be varied from 1–10 A in the 1–12 V DC
range. At 12 V, the DC range is variable from 1–10 A.
At 24 V, the range decreases to 0–6 A. (See the illustra-
tion printed on the front panel, “Max. DC Current,” or
Figure 1.) A digital meter allows monitoring of both
voltage and current for the DC output.

2
Low Voltage AC/DC Power Supply 012-06263A
ä NOTE: If at any time the power supply fails to
come on, or if it shuts down during operation due to
excessive current, check the following: If the
ON/OFF switch does not light when unit is plugged
into the appropriate power source and the switch is
turned ON, check the fuse on the back of the unit.
If it is blown, replace it only with a similarly rated
fuse (Model SF-9584A— 8A Slo-Blo fuse, Model
SF-9584A-230— 4A Slo-Blo fuse).
AC Output Operation:
➀Flip the power ON/OFF switch to OFF.
➁Plug the power cord into a grounded outlet of the ap-
propriate voltage :
Model SF-9584A, 115 V AC (78 - 130 V AC), 60 Hz
or
Model SF-9584A-230, 230 V AC (200 - 242 V AC),
50 Hz.
➂Connect the 2–24 V AC OUTPUT terminals of the
power supply to the circuit. (Connecting wires are not
provided with the power supply.)
➃Rotate the AC VOLTAGE ADJUST knob to the
2–V position.
➄Flip the power ON/OFF switch to ON. The switch
will light to show that the power supply is on.
➅Set the AC VOLTAGE ADJUST knob to the desired
setting.
AC Output Limitations
The AC output is unregulated and is adjustable in 2-V
increments from 2 to 24 V AC, with a maximum out-
put current of 6 amperes. This output is protected by
a 6-amp circuit breaker. If the maximum current out-
put is exceeded, the circuit breaker button below the
power switch will pop out. (See Figure 2.)
The circuit breaker can be reset by simply pushing the
button back in. It may be necessary to reduce the AC
output voltage or the load connected to the AC output in
order to resume operation.
Figure 2. Location of Circuit Breaker Button
AC
2
4
6
2-24 V
6A MAX
RESET
ON
OFF
8
10 12 14 16
18
20
22
24
power switch
circuit breaker
button

012-06263A Low Voltage AC/DC Power Supply
3
Specifications:
Outputs:
DC: regulated for both constant–voltage and con-
stant–current operation. Both current and voltage con-
tinuously variable over the range 0–24 V DC and 0–10
amperes maximum. Independent floating ground refer-
ence.
AC: 2 to 24 V (rms) AC, unregulated, selectable in
2–V increments, current up to 6 amperes. Output pro-
tected from overload by a 6-amp thermally-activated cir-
cuit breaker. Independent floating ground reference.
ä NOTE: Both DC and AC outputs are available
simultaneously on separate floating output terminals.
Either one of the DC output terminals can be con-
nected to either one of the AC output terminals to
form a composite signal without damage to the unit.
Equipment Specifications
Line Regulation:
Less than 1% change in DC output voltage or cur-
rent for full range change in line voltage. AC out-
put not regulated.
Load Regulations:
Better than 1% no-load to full-load on the DC out-
put voltage or current. AC output not regulated.
Ripple and Noise:
Less than 25 mV pp on DC output.
Metering:
DC voltage and DC current
Accuracy is +1% ± 2 L.S.D.
Line Voltage Requirement:
78–130 V AC, 60 Hz (model SF-9584A)
200–242 V AC, 50 Hz (model SF-9584A - 230)
Power Requirement:
DC and AC: Maximum 350 W
DC only: Maximum 175 W
AC only: Maximum 175 W
Fuse:
8 A Slo-Blo—(model SF-9584A)
4 A Slo-Blo—(model SF-9584A-230)
Size:
118 x 298 x 229 mm (H x W x D including controls)

4
Low Voltage AC/DC Power Supply 012-06263A
Notes:

012-06263A Low Voltage AC/DC Power Supply
5
Schematics and Parts Lists
ä Caution: If repairs are needed, they should be performed only by experienced personnel.
Figure 2. Schematic Overview

6
Low Voltage AC/DC Power Supply 012-06263A
Figure 3. Main Board

012-06263A Low Voltage AC/DC Power Supply
7
Parts List – Main Board
1 R201 RESISTOR 4K7 250V 0.4W 1 601074
2 R204R206 RESISTOR 10K 250V 0.4W 2 601082
3 R220-221 RESISTOR 10K 250V 0.4W 2 601083
4 R205 RESISTOR 47K 250V 0.4W 1 601099
5 R216 R219 RESISTOR 100K 250V 0.4W 2 601106
6 R211 R214 R217 RESISTOR 100R 250V 0.4W 3 6030701
7 R227 RESISTOR 150R 250V 0.4W 1 6030801
8 R228 RESISTOR 390R 250V 0.4W 1 6031051
9 R218 R223 RESISTOR 470R 250V 0.4W 2 6031101
10 R226 RESISTOR 680R 250V 0.4W 1 6031201
11 R207 R230 RESISTOR IK0 250V 0.4W 2 6031301
12 R212 RESISTOR 4K7 250V 0.4W 1 6031701
13 R213 R229 RESISTOR 10K 250V 0.4W 2 6031901
14 R222 RESISTOR 100K 250V 0.4W 1 6032501
15 R202-203 R208 RESISTOR 180K 250V 0.4W 3 6032651
16 R224 RESISTOR IM0 250V 0.4W 1 6033101
17 R210 R215 RESISTOR 0.01R 20mV 2W 2 604301
18 TR201-202 TRIMPOT HORIZ 220R 250V 0.lW 2 605935
19 TR203-205 TRIMPOT HORIZ 10K 250V 0.lW 3 605960
20 C229-234 C243-244 CERAMIC CAP 1.0nF 63V 8 611890
21 C213 C215 C235 CERAMIC CAP 10nF 63V 7 612010
C237-238 C240-241
22 C224-227 STACK FOIL CAP 100nF 400V 4 613170
23 C214 C216-223 STACK FOIL CAP 100nF 63V 11 613450
C228 C239
24 C211-212 STACK FOIL CAP 470nF 63V 2 613530
25 C207-210 C236 ELECTROLYT CAP 4.7UF 25V 5 615643
26 C201-205 ELECTROLYT CAP 100UF 63V 5 615785
27 C206 ELECTROLYT CAP 1000UF 35V 1 616003
28 D203 DIODE BYV27-200 200V 2A 1 623267
29 D205-209 DIODE lN4148 75V 0.2A 5 623300
30 D201-202 DIODE 2W04M 400V 2A 2 623665
31 D210 ZENER-DIODE BZX79-C2V7 2.7V 0.5W 1 624060
32 Q205 NPN TRANSISTOR BC547B 50V 0.lA 1 624710
33 Q203 PNP TRANSISTOR BC557B 50V 0.2A 1 624720
34 Q202 NPN TRANSISTOR BC639 100V 1.5A 1 624750
35 Q201 Nch MOSFET BUK456-60A 60V 52A 1 625690
36 Q204 Nch MOSFET BS170 60V 0.5A 1 626120
37 U204 DualOpAmp LTll12 30V 10mA 1 630211
38 U201 IC LM614 36V 0.3mA 1 631214
39 U202 VOLTAGE REGULATOR LM317 40V lA 1 632130
40 U205 VOLTAGE REGULATOR LM78L05 35V 0.1A 1 632430
41 U207 VOLTAGE REGULATOR LM7805 35V 1.5A 1 632533
42 U206 RAIL SPLITTER TLE2426CLP 40V 0.08A 1 634941
43 RE201-202 RELAY 5V M4-5H 125V/30W 1A 2 637428
44 J202-208 CONNECTOR 6.3 MM 7 641245
45 J200 3M-929 20 PIN 20 PIN 1 641321
46 J213 STOCKO MKS4 4 PIN 1 641357
Item Reference Part Name Value Qty Stock No.

8
Low Voltage AC/DC Power Supply 012-06263A
Figure 4. Display Unit

012-06263A Low Voltage AC/DC Power Supply
9
Item Reference Part Name Value Qty Stock No.
1 R101 R111 RESISTOR 330R 250V 0.4W 2 6031001
2 R107-108 RESISTOR 1K0 250V 0.4W 5 6031301
R117-118 R120
3 R103 R113 RESISTOR 6K8 250V 0.4W 2 6031801
4 R104 R114 RESISTOR 47K 250V 0.4W 2 6032301
5 R100 R102 RESISTOR 100K 250V 0.4W 8 6032501
R105-106 R110
R112 R115-116
6 P1-2 POTMETER 10K 300V 1.5W 2 608251
7 C103 C123 CERAMIC CAP 100pF 63V 2 611770
8 C112 C132 CERAMIC CAP 1.0nF 63V 2 611890
9 C109-110 CERAMIC CAP 10nF 63V 4 612010
C129-130
10 C102 C104 STACK FOILCAP 100nF 63V 12 613450
C106-10 C111
C122 C124
C126-128 C131
11 C105 C125 STACK FOIL CAP 470nF 63V 2 613530
12 C101 C121 ELECTROLYT CAP 100UF 25V 2 616440
13 D101-102 LED HLMP-1719 2V 2mA 2 622000
14 DS101-108 DISPLAY HDSP-5301 2V 20mA 8 622940
15 D103-104 DIODE 1N4148 75V 0.2A 2 623300
16 D105-106 DIODE 1N4007 700V 1A 2 623390
17 U102 U104 VOLTAGE REF. LM385 20mA 2 631185
18 U101 U103 IC ICL7107 9V 2 635057
19 SW101 SWITCH LOCKING MK2 120V 250mA 1 638031
20 J102-103 HEADER 16 PIN 500V 2.5A 2 641029
21 J101 3M-929 20 PIN 20 PIN 1 641321
30 U101 U103 TULIPAN SOK 40 PIN 2 635539
Parts List – Display Unit

10
Low Voltage AC/DC Power Supply 012-06263A
Figure 5. Switch-Mode Regulator

012-06263A Low Voltage AC/DC Power Supply
11
Item Reference Part Name Value Qty Stock No.
1 R3 RESISTOR 2K2 250V 0.4W 1 601066
2 Rl-2 RESISTOR 10K 250V 0.4W 2 601083
3 R14 RESISTOR 0R 250V 0.4W 1 6020901
4 R10 R12 RESISTOR 10R 250V 0.4W 2 6030101
5 R9 RESISTOR 100R 250V 0.4W 1 6030701
6 R8 RESISTOR 470R 250V 0.4W 1 6031101
7 R5 RESISTOR 3K3 250V 0.4W 1 6031601
8 R7 RESISTOR 4K7 250V 0.4W 1 6031701
9 R4 R13 RESISTOR 47K 250V 0.4W 2 6032301
10 R6 RESISTOR IK0 500V 1.6W 1 603810
11 Rll RESISTOR 0.01R 20mV 2W 1 604301
12 CI2 C14 C19 CERAMIC CAP 1.0nF 63V 3 611890
13 Cll CERAMIC CAP 4.7nF 63V 1 611970
14 C7-8 C13 CERAMIC CAP 10nF 63V 3 612010
15 C17-18 STACK FOIL CAP 100nF 400V 2 613170
16 C2-4 C15 STACK FOIL CAP 470nF 63V 4 613530
17 C9-10 ELECTROLYT CAP 2.2UF 63V 2 615622
18 C5-6 C16 ELECTROLYT CAP 100UF 63V 3 615785
19 Cl ELECTROLYT CAP 6800UF 63V 1 616102
20 Dl DIODE BYV27-200 200V 2A 1 623267
21 D2 ULTRA FAST DIODE BYV79-100 100V 14A 1 623268
22 D4-7 DIODE lN4007 700V lA 4 623390
23 D10 DIODE BRIDGE PBU802 100V 8A 1 623685
24 D9 ZENER-DIODE BZV85-C15 15V 1.0W 1 624515
25 D8 ZENER-DIODE BZV85-C33 33V 1.0W 1 624533
26 Q2-3 NPN TRANSISTOR BC639 100V 1.5A 2 624750
27 Ql Pch MOSFET SMP40P06 60V 40A 1 626110
28 Ul IC LM3524 40V 1 632350
Parts List – Switch-Mode Regulator

12
Low Voltage AC/DC Power Supply 012-06263A
Figure 6. Filter Board
Parts List – Filter Board
Item Reference Part Name Value Qty Stock No.
1 H1-4 4
2 C301-303 STACK FOIL CAP 100NF 400V 3 613170

012-06263A Low Voltage AC/DC Power Supply
13
Technical Support
Feedback
If you have any comments about the product or manual,
please let us know. If you have any suggestions on alter-
nate experiments or find a problem in the manual, please
tell us. PASCO appreciates any customer feedback.
Your input helps us evaluate and improve our product.
To Reach PASCO
For technical support, call us at 1-800-772-8700 (toll-free
within the U.S.) or [phone].
fax: [phone]
e-mail: [email protected]
web: www.pasco.com
Contacting Technical Support
Before you call the PASCO Technical Support staff, it
would be helpful to prepare the following information:
➤ If your problem is computer/software related, note:
Title and revision date of software;
Type of computer (make, model, speed);
Type of external cables/peripherals.
➤ If your problem is with the PASCO apparatus, note:
Title and model number (usually listed on the label);
Approximate age of apparatus;
A detailed description of the problem/sequence of
events. (In case you can’t call PASCO right away,
you won’t lose valuable data.);
If possible, have the apparatus within reach when
calling to facilitate description of individual parts.
➤ If your problem relates to the instruction manual, note:
Part number and revision (listed by month and year
on the front cover);
Have the manual at hand to discuss your questions.

Instruction Sheet
for the PASCO
Model CI-6552A
POWER AMPLIFIER II
012-05783A
2/95
$1.00
Phone [phone] • FAX [phone] • email: [e-mail]
10101 Foothills Blvd. • P.O. Box 619011 • Roseville, CA 95678-9011 USA
better
teach physics
ways to
POWERAMPLIFIER II
CI-6552A
CAUTION!
CI-6552A
POWER AMPLIFIER II
ON
CAUTION!
SIGNAL OUTPUT
0to ±10 V
1 A MAX
WHEN LIGHT IS ON
WAVEFORM IS DISTORTED.
DECREASEAMPLITUDE!
© 1995 PASCO scientific
This instruction edited by Robert Morrison
Introduction
The PASCO CI-6552A Power Amplifier II is an acces-
sory to the PASCO Signal Interfaces, Series 6500 and
Mac65. It amplifies the output of the computer, allowing
it to be used as a controlled DC power source or an AC
function generator.
With the Power Amplifier II plugged into one of the ana-
log channels of the Signal Interface, the appropriate soft-
ware (Power Amplifier for DOS, Power Amplifier for
APPLE II, or Science Workshop) can be used to generate
the following types of waves (up to ±10V peak at 1A, up
to 5,000 Hz):
• sine,
• square,
• triangle, and
• sawtooth.
This means the computer can now be used as an AC sig-
nal generator to power external circuits while it monitors
its own output current as well as other inputs. The Science
Workshop software can also generate a DC output.
Filter Select Switch
The CI-6552A Power Amplifier II has a filter select
switch which is preset for use with the CI-6560 Signal
Interface II (Mac65). The bandwidth at that switch posi-
tion is about 100KHz, limited by the power amplifier’s
feedback compensation section and the load. When using
the Power Amplifier II with the CI-6510 Signal Interface
(Series 6500), the bandwidth needs to be limited to
1.5KHz. To change the switch position push the filter se-
lect switch in the back panel slot to the left, as shown in
the illustration below.
Switch position
for CI-6510
Signal Interface
Switch position
for CI-6560
Signal Interface II

2
Power Amplifier II 012-05783A
Using Power Amplifier II
To install the Power Amplifier II, plug in its power cord
and plug the DIN plug into Channel A, B, or C of the ap-
propriate PASCO Signal Interface box (CI-6510 or
CI-6560).
➤NOTE: Using Power Amplifier II with Series
6500, the Power Amplifier program is calibrated for
channel C. The Power Amplifier II can also be
plugged into Channel A or B but these channels are
not automatically calibrated to read the current as is
Channel C.
To use the output of the Power Amplifier II, connect the
load to the banana jacks on the front of the Power Ampli-
fier II. There is a power switch on the back left hand cor-
ner of the Power Amplifier II.
➤WARNING! Do not turn on the power switch
until a program (either Power Amplifier, Data
Monitor or Science Workshop) has been run and the
desired output voltage has been selected.
When the computer is in DOS, the Power Amplifier
will output 10 Volts if the power switch is on and
this could overload a circuit that might be con-
nected to it. The software controls this voltage:
The Data Monitor Program sets the default voltage
to zero and the Power Amplifier Program sets the
default AC peak voltage to 5 Volts.
When the Power Amplifier II is operating, a green power
indicator light on the front panel of the Power Amplifier
II will be lit. There is also a red current overload light
which comes on whenever the maximum current of 1 A is
exceeded. If this warning light is on, the waveform is dis-
torted and you should reduce the output voltage.
Limited Warranty
PASCO scientific warrants this product to be free from
defects in materials and workmanship for a period of one
year from the date of shipment to the customer. PASCO
will repair or replace, at its option, any part of the product
which is deemed to be defective in material or workman-
ship. This warranty does not cover damage to the product
caused by abuse or improper use. Determination of
whether a product failure is the result of a manufacturing
defect or improper use by the customer shall be made
solely by PASCO scientific. Responsibility for the return
of equipment for warranty repair belongs to the customer.
Equipment must be properly packed to prevent damage
and shipped postage or freight prepaid. (Damage caused
by improper packing of the equipment for return ship-
ment will not be covered by the warranty.) Shipping costs
for returning the equipment, after repair, will be paid by
PASCO scientific.
Equipment Return
Should this product have to be returned to PASCO scien-
tific, for whatever reason, notify PASCO scientific by let-
ter or telephone BEFORE returning the product. Upon
notification, the return authorization and shipping instruc-
tions will be promptly issued.
➤NOTE: NO EQUIPMENT WILL BE AC-
CEPTED FOR RETURN WITHOUT AN AU-
THORIZATION.
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION:
TO PREVENT THE RISK OF ELECTRIC SHOCK, DO
NOT REMOVE COVER ON UNIT. NO USER SERVICE-
ABLE PARTS INSIDE. REFER SERVICING TO QUALI-
FIED SERVICE PERSONNEL.
Thelightningflashwitharrowhead,within
anequilateraltriangle, isintendedto alert
the user of the presence of uninsulated
“dangerous voltage” within the product’s
enclosurethatmaybeofsufficientmagni-
tudetoconstituteariskofelectricshockto
persons.
The exclamation point within an equi-
lateral triangle is intended to alert the
userof thepresence of important oper-
ating and maintenance (servicing) in-
structions in the literature accompany-
ing the appliance.