Đồng hồ số SamGordon

1 Mạch nguyên lý:

Linh kiện cho mạch nguyên lý :

R1=2.2Kohm 1/4W 5% IC5-7=74HC32 [3] Q1=BD139 on Heatsink

R2......R38=470ohm 1/4W 5% IC6=74HC08 [4] SL1....SL5=7 pin connector

 

IC1-4=74HC390 [1] IC8=74HC04 [5] SL6-7=2 pin connector[separator]

IC2-3=74HC92 [2] IC9....IC13=4511 [6] or [74LS47] [7] SL8=3 pin connector

[1] 74HC390 or 74LS390= Dual 4bit Decade and Binary COUNTER [5] 74HC04 or 74LS04= Hex inverter

[2] 74HC92 or 74LS92= Decade, divide by 12 and Binary COUNTER [6] 4511= BCD to 7-segment Latch/Decoder/Driver for CC Display*

[3] 74HC32 or 74LS32= Quad 2-input OR gate [7] 74LS47= BCD to 7-segment Decoder/Driver for CA Display*

[4] 74HC08 or 74LS08= Quad 2-input AND gate CC=Common Cathode CA=Common Anode

2 Mạch hiện thị

R39-40=220ohm 1/2W 5% DIS6=20 mm Led Display Common Anode SL10.....SL4=7 pin connector

DIS1-5=20 mm Led Display Common Cathode* SL9-15=2 pin connector

3 : Cơ số thời gian A

R41-42=470ohm IC14=74HC04* IC19=74HC08*

R43-44=10Kohm IC15-16-17=74HC390* S1-2=Push Button normal open

CSL1=1MHZ Crystal IC18=74HC32*

4 : Cơ số thời gian cho B

R45=10Mohm IC20=4060 [8] CSL2=3.2768 MHZ crystal

C1-2=22pF ceramic IC21-22=4017 [9] S3-4=Push switch recrudescent

C3=22pF trimmed capacitor IC23=4013 [10]

CÒn mạch nguồn nữa các pác tự lấy nguồn đối xứng +-5V .