Keywords: lock ring modulator circuit diagram
Author: Lin De Yao
This production is under single-chip control, and the television channel output by the double-locking phase ring adjacent frequency modulator is incremented or decremented by the reset switch, and the double-lock phase ring neighbor frequency modulation described based on the previous period (09th). Based on the design and production of the device, in the MC145152AP, MC12022 phase-locked, digital encoding is digitally encoded on the vibration frequency of the television channel (38MHz to the image carrier frequency of the channel), according to the information obtained by the coding rule. Conduct C language programming. After the simulation test passes the program, the program is burned in the AT89C52 single-chip microcomputer chip, and the production of the circuit is switched through two reset switches, and the relevant data is displayed on the LCD liquid crystal display. First, the microcontroller control circuit principle The microcontroller control circuit is shown below. SW3 is a reset switch. When the reset switch SW3 is pressed, the circuit is reset, the single chip is in the starting state (1Ch); pressing the reset switch SW1 or SW2, double lock The television channel output from the phase ring neighboring frequency modulator is summarized or decreased.
All of this information is transmitted by the system software, and the CK1 socket is output to the CK1 socket with the CK1 socket, the CK1 socket and the previous stage (09th), the CK1 socket, and the first stage (09th) MCL45152AP. The corresponding port is connected, forcing the dual-lock phase ring neighboring modulator to switch between the television channel according to people, and display the number of channels and vibration frequencies currently set on the LCD liquid crystal display.
Digital Code Information and LCD LCD Display The number of preset channels and the local vibration frequency correspondence relationship list are shown in the table below.
Number of channels
DN9 ~ DN0 (MCL45152)
DA5 ~ DN0 (MCL45152)
Shock frequency (MHz)
1ch
000010101L 000010101L 000010101L 000010101L
111000
87.75
2ch
000010111L 000010111L 0000101111L 0000101111L
111000
95.75
3ch
110011
111000
103.25
4ch
111001
101000
115.75
5ch
111101
101000
123.25
6ch
1100111
1000
206.25
7ch
1101011
1000
214.25
8ch
1100101
1000
222.25
9ch
1101111
1000
230-25
10ch
0001L10111
1000
238.25
11ch
1111011
1000
246.25
12ch
1111111
1000
254.25
Second, the design procedure
1. The program flowchart of the program flowchart Double-phase ring neighbor frequency modulator system is shown below.
Third, software system debugging When the system is normal, the initial state LCD displays CH1-87.25MFLZ; pressing the reset switch SW1 or SW2, channel and frequency to do corresponding increase or decrease. If the LCD LCD screen is displayed abnormal when running the system, the LCD display subroutine is mainly checked if the LCD display subroutine is incorrect; if the code output is incorrect, check if the checkpoint program is wrong; if there is no change when the reset button is pressed, the problem may appear Interrupt subroutine, check if interrupt initialization or subroutine is incorrect. Fourth, the printed board design skill This circuit is a digital circuit. It is combined with the high-frequency electronic circuit. In the correct case of the schematic, it is necessary to produce its success or failure. The key is how to typeset, because high frequency circuit It contains very rich harmonic ingredients, these harmonic ingredients drifted with the wire board, the power supply is busy, interferes with the normal digital signal, so this signal is taken through the typography, and it eliminates it in the germination state. Therefore, the following principles must be followed when typography:
(1) The layout of components should be reasonable, and the small signal components are pushed forward, and the last level is in the end; if the above layout is met, it is necessary to consider the beautiful, neat, such a product. . (2) Part of the circuit negative (ground) power supply, the printed board is taken from a large-scale coated to further eliminate the source of the random fluctuation. The typesetting trails and physical maps of the circuit PCB are shown in the figure (omitted), shown below (omitted).
V. Meristale list This control system is shown in the following table.
Serial number
Device name
Specification model
Principle number
quantity
1
Resistor
RT14-4.7K
R2, R3
2
2
Resistor
RT14-10K
R1, R4, R5
3
3
Potentiometer
WH125-0.5W-10K
Rp1
1
4
Exclusion
A103J
R01 ~ R08
1
5
Miniature reset switch
Be
SW1, SW2, SW3
3
6
led
2EF101A
VD1
1
Seduce
Crystal
11.0952MHz
Y1
1
8
Porcelain capacitor
CC1-63V 12P
C2, C3
2
9
Electrolytic capacitor
CD11-16V a 10UF
C1
1
10
socket
16-core socket
CK1
1
11
Integrated block
AT89C52 (or STC89C52)
IC
1
12
LCD Monitor
LCD1602
YC
1
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