HP 5340A Service Manual

Model 5340A
Theory of Operation
4 - 87. BCD to Decimal Decoder 1820 - 1047
4 - 88.
70 milliwatts.
The 1820
- 1047 is a low power version of the 1820 - 0214.
Power dissipation
is typically
4 - 89. Voltage Regulator 1826 - 0010
4 - 89. The outline drawing and equivalent circuit for the 1826 - 0010 are shown in Figure 4 - 38. The
regulator consists of
a current source, a voltage reference amplifier, an error amplifier, a current
limiter, and
a series pass transistor. The current source, Zener diode, and voltage reference
amplifier provide a constant 7.2 volt reference output
(Vref) for the non - inverting input of the
difference amplifier. The inverting input of the difference amplifier senses the power supply
output voltage through an external voltage divider.
An example of operation is as follows. If
the power supply output voltage decreases, the voltage at the inverting input (pin
2) also
decreases. This drives the error amplifier output to bias the series pass transistor to decrease
its
impedance. When the impedance of the series pass transistor decreases, the output voltage tends
to increase to regulate the output. The frequency compensation input prevents high frequency
oscillations.
Figure 4
- 38. Voltage Regulator 1826 - 0010
FREQUENCY
V+ COMPENSATION
TEMPERATURE
COMPENSATED
VC
SERIES PASS
TRANS
ISTO R
NON INVERT1 'OUT
VZ
V- ERROR CURRENT
AMPLIFIER LIMITER
CURRENT
LIMIT
CURRENT FREQUENCY
INVERTING
INPUT
NON INVERTING INPUT
uvo'. 3
VREF VC
V-
NOTE: PIN 5 CONNECTED TO CASE
4 - 91. Voltage Regulator 1826 - 0016
4 - 92. The 1826 - 0016 (Figure 4 - 39) is a negative regulator.
Operation
is similar to the 1826 - 0010.
4 - 93. Operational Amplifier 1826 - 0021
4 - 94. The 1826 - 0021 (Figure 4 - 40) is an operational amplifier internally connected as a unity-
gain non - inverting amplifier. Pins 1 and 8 allow for offset balancing.
, ,J
j
I'i
I
4 - 28

HP 5340A Specifications

General

Brand	HP
Model	5340A
Category	Cash Counter
Language	English