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Model 7158 low Current
Scanner Card
Instruction Manual
Contains Operating and Servicing Information
Model 7158 Low Current Scanner Card
Instruction Manual
0 1987, Keithley Instruments, Inc.
Test Instrumentation Group
All rights reserved.
Cleveland, Ohio, U.S.A.
June 1990, Second Printing
Document Number: 7158-901-01 Rev. B
SAFETY PRECAUTIONS
The following safety precautions should be observed before using this
product and any associated instrumentation. Although 6ome instruments
and accessories would normally be used with non-hazardous voltages,
there are situations where hazardous conditions may be present.
This product is intended for use by qualified personnel who recognize
shock hazards and are familiar with the safety precautions required to
avoid possible injury. Read the operating information carefully before us-
ing the product.
Exercise extreme caution when a shock hazard is present. Lethal voltage
may be present on cable connector jacks or test fixtures. The American
National Standards Institute (ANSI) states that a shock hazard exists
when voltage levels greater than 30V RMS, 42.4V peak, or 60VDC are
present. A good safety practice is to expect that hazardous voltage is
present in any unknown circuit before measuring.
Before operating an instrument, make sure the line cord is connected to a
properly grounded power receptacle. Inspect the connecting cables, test
leads, and jumpers for possible wear, cracks, or breaks before each we.
For maximum safety, do not touch the product, test cables, or any other
instruments while power is applied to the circuit under test. ALWAYS re-
move power from the entire test system and discharge any capacitors be-
fore: connecting or disconnecting cables or jumpers, installing or
removing switching cards, or making internal changes, such as installing
or removing jumpers.
Do not touch any object that could provide a current path to the common
side of the circuit under test or power line (earth) ground. Always make
measurements with dry hands while standing on a dry, insulated surface
capable of withstanding the voltage being measured.
Do not exceed the maximum signal levels of the instruments and awes-
series, as defined in the specifications and operating information, and as
shown on the instrument or test fixture rear panel, or switching card.
Do not connect switching cards directly to unlimited power circuits. They
are intended to be used with impedance limited sources. NEVER connect
switching cards directly to AC main. When connecting sources to switch-
ing cards, install protective devices to limit fault current and voltage to
the card.
When fuses are used in a product, replace with same type and rating for
continued protection against fire hazard.
Chassis connections must only be used as shield connections for measur-
ing circuits, NOT as safety earth ground connections.
If you are using a test fixture, keep the lid closed while power is applied
to the device under test. Safe operation requires the use of a lid interlock.
If a @ screw is present on the test fixture, connect it to safety earth
ground using #18 AWG or larger wire.
The f symbol on an instrument or accessory indicates that 1OOOVor
more may be present on the terminals. Refer to the product manual for de-
tailed operating information.
Instrumentation and accessories should not be connected to humans
Maintenance should be performed by qualified service personnel. Before
performing any maintenance, disconnect the line cord and all test cables.
SPECIFICATIONS
MODEL 7158 LOW CURRENT SCANNER CARD
CHANNBLS PER CARD: 10
CONTACT CONFIGURATION: Single pole. When a channel is open, sign81 HI is con-
nected to signal LO. Signal LO is common for ail 10 channels and aulput.
CONNIXTOR TYPE; BNC
RELAY DRIVE CURRENT: lOOmA per card typical.
MAXIMUM SIGNAL LEVEL; lOOmA, 3OV, peak (resistive load)
368 BANDWImHz lM& typical.
CONTACT LIFE: 10' closures (cold switching); 10' closures (at maximum signal level)
CONTACT RESISTANCE: CONTACT POTBNTIALr <20,&V
ACTUATION TIME: OPPSET CURReNT: <10'"A (<3 x 10-laA typical)
COMMON MODR VOLTAGE: 3OV peak
GENRRAL
ENVIRONMENT,
Operating: 8' to 50