 Microprocessor (PIC16F873)
I used PIC16F873 by consideration of the communication functions to send data to the display unit from the console unit and the number of the input-output ports.
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4-16 decoder (74HC154)
This is the IC which decodes the binary code of 4 bits.
16 conditions are indicated by 4 bits.74HC154 makes the output which corresponds to input's 4 bits an L level.
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RS-232 Drivers/Receivers
(ADM232AAN)
This is ADM232AAN of the ANALOG DEVICES Inc.. In this IC, 2 circuits of driver and 2 circuits of receiver are housed.
This IC has the DC-DC converter to make the voltage of +10V and -10V from +5V. So, the voltage of the RS-232C (about ±9V) can be made only with +5V power.
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Voltage regulator (LM2940-5)
This is the IC to make +5V with +12V power. This regulator is low dropout type. When the output current of the regulator is 1A, the voltage drop of the regulator is 0.5V. The maximum input voltage of this IC is 26V and the maximum output current is upto 1A.
You can use 7805 instead of this IC. I attempted to use LM2940 this time.
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IC socket
PIC16F873 is the IC with 28 pins of the slim type. When the slim type 28 pin socket can not be gotten, you can use two sockets of 14 pins. I did like this to the circuit this time. |
PNP type transistor (2SA1015)
This transistor is used to control the device which was selected by PIC. This transistor is PNP type.
When the port of PIC becomes L level (0), the transistor becomes ON condition and an LED is lit up.
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Resonator
 This is the oscillation device to make the clock of PIC. A ceramic vibrator and capacitors are incorporated.
The clock frequency this time is 4 MHz. It is possible to make do the operation of PIC16F873 with the a maximum of 20MHz clock.
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Resistor
As for the resistor, all 1/6W are used. |
Multilayer ceramic capacitor
These capacitors are used for the DC-DC converter of RS-232 Drivers/Receivers and the high frequency bypass capacitor of the power circuit.
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Electrolytic capacitor
This capacitor is used to maintain the stable operation of LM2940. At least 22µF capacitor must be put to the side of the LM2940 output.
This capacitor is 33µF with 16WV. |
Printed board
Universal printed boards with 30 x 24 halls are used. The height of the parts (Button switchs, LEDs and so on) which are mounted on the printed board is different. The printed board to have cut in the needed size for each height to be able to be adjusted is used.
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Button switch
These are the switchs of the button formula which are used for the category selecting, the number input, the sending, the clearing and so on. The transparent plastic cover is put and can indicate the name of the button. |
7 segment LED
The input number can be confirmed by these 7 segment LEDs.
These are NARG105 which is made by the STANLEY Inc.. The red and green number can be displayed. This time, only red is used. |
LED for the category display
These are the LEDs which display a selected category. In the display unit, a category is displayed as the letter by the combination of the LEDs. However, in the console unit, the LED which corresponds to the category is lit up. |
DSUB connector
This is the connector of the DSUB 9 pin which connects the cable which links a console unit and a display unit. The female connector should be used because a power is supplied from the console unit.
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Case
 TS-2 which is made by the TAKACHI Inc. is used.
For operation's easily, a surface panel is inclined.
The size has 200-mm width, 150-mm depth, 35-mm height in front, the 70-mm height of the back. |
Wiring terminal
This is the terminal to connect wires for the power unit and the DSUB connector. |
Power switch
This is the power switch with LED. The ON state of the power switch can be confirmed by the LED. |
Power unit of +12V
This is the power unit to make DC 12V from AC 100V. This is LCA10S-12 which is made by the COSEL Inc. in Japan. The output is 12V and MAX 0.9A can be output.
This specification is enough for the equipment this time. |
Fuse
I am using a 1A fuse for the safety.
It isn't indispensable because a fuse is mounted on the power unit which was used this time. |
AC code
This is a 700 W-type AC code. |
Lug terminal
This is a lug terminal to fix an AC cord. |
AC code protector
This is the plastic protector for an AC cord to be prevented from being damaged by the aluminum case. |
Code binder
 This is the tape to tie an AC code.
It is the tape which is used for the sewing.
The tapes with the loop-shape thread and with the end turned plastic needle are used in the combination.
What is the name of this in English ? |
Switching diode ( 1S1588 )
This diode is used to prevent extraordinary electric current's flowing through IC2 when more than one switch is pushed at the same time. |
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