Table Of Contents - Philips PM2521 Service Manual

03
CONTENTS
Page
1.
CIRCUIT DESCRIPTION
1
1.1.
General
1
1
.2.
Survey
of
main
sections
1
1.2.1.
Analog
section
1
1
.2.2.
Control section 6
1
.2.3.
Display section 6
1.3.
Functional description 6
1.3.1.
General 6
1.3.2.
Analog
section (standard measurements) 7
1.
3.2.1.
Direct voltage
measurements
7
1.3. 2. 2.
Alternating voltage
measurements
8
1
.3.2.3.
Direct current
measurements
9
1.3. 2.4.
Alternating current
measurements 9
1.3. 2. 5.
Resistance
measurements 10
1.3. 2.
6.
Diode measurements
11
1.3.2.
7.
Temperature measurements
11
1
.3.3.
Analog
section
(extended measurements) 12
1. 3.3.1.
Frequency measurements 12
1.3.3.
2.
Time
measurements
13
1.
3.3.3. Trigger
measurements 13
1.3.4.
Analog
section (multifunction
circuits)
14
1.
3.4.1.
R.M.S. convertor 14
1.3.4.
2.
Impedance
convertor
14
1.3.4.
3.
Active
filter
15
1.
3.4.4.
Analog-to-Digital convertor 15
1.3.5.
Control
section
17
1.3. 5.1.
Microprocessor
8035
17
1.3.5.
2.
Interrupt controller
21
1.3.5.
3.
Counter
22
1.
3.5.4.
Analog
control
22
1.3.5.
5.
ROM's
and Address/Data decoding 23
1.3.6.
Display section
23
1.4.
Detailed
circuit description
26
1.4.1.
Measuring sequence
26
1.4. 1.1. Initialisation
27
1.4. 1.2.
Internal test
and
adjust routine
28
1.4. 1.3.
Set
up
routine 31
1.4. 1.4.
Measurement
routine 31
1.4. 1.5.
Calculation routine
32
1.4. 1.6.
Display
output
routine
32
1
.4.2.
Analog
section (standard
measurements) 33
1. 4.2.1.
Direct voltage
measurements 33
1
.4.2.2.
Alternating voltage
measurements 34
1
.4.2.3.
Direct current
measurements 35
1.4. 2.4.
Alternating current
measurements 36
1
.4.2.5.
Resistance
measurements 37
1.4. 2.
6.
Diode measurements 38
1.4. 2. 7.
Temperature measurements 38