Operating Introduction:
1. When INPUT port hasn't input voltage, that is when A-B/C-D both disconnect, VIN is connected, CD4511 2-pin, 4-pin are low level;
   since IC1 the fourth pin is blanking input control port; when BI=0,no matter what other input ports' state are, its output port A-G are all 0; and 7 segment digital tube are all off and not display number.

2. When INPUT port inputs low level which is lower than 0.47V, that is short circuit INPUT C-D port,
   VT1 cut off,  and its collector output high level;IC1 BCD code input DCBA=0100, after decoding,
   IC1 output port B/C/F/E is high level, and others are low level. So digital tube display "L" representing logic low level.

3. INPUT port input 3.13-5V high level, that is short circuit INPUT A-B port, VT1 is connected;
   its base and collector are both high level, IC1 BCD code input DCBA=0110; after decoding, IC1 output port A/C/D/E/F/G output high level; and others are low level;digital tube display "H" representing logic high level.

Packing List:

Finished Product Picture:

Circuit Picture:

Tested by ICStation's Outstanding Partner bzoli5706:

The digital tube display "L" indicates logic Low level.

The digital tube display "H" indicates logic High level.

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