Electronics 7 Segment Displays

Transcription

1 Electronics 7 Segment Displays Wilfrid Laurier University April 6, 2011

2 7 Segment Displays

3 Here is a 7 segment display.

4 Here is a 7 segment display.

5 Here is a 7 segment display. It is made up of at least 7 separate LEDs.

6 Here is a 7 segment display. It is made up of at least 7 separate LEDs. (There are actually 8 in this case if you count the decimal point.)

7 The seven segments are labelled a to g.

8 The seven segments are labelled a to g.

9 The seven segments are labelled a to g.

10 The seven segments are labelled a to g.

11 The seven segments are labelled a to g.

12 The seven segments are labelled a to g.

13 The seven segments are labelled a to g.

14 The seven segments are labelled a to g.

15 The seven segments are labelled a to g.

16 The seven segments are labelled a to g. There is also usually a right decimal point.

17 The seven segments are labelled a to g. There is also usually a right decimal point. There may also be a left decimal point.

18 Internally it looks like this.

19 Internally it looks like this.

20 Internally it looks like this. The LEDs will all be tied together at one end.

21 If the anodes are all tied together, it looks like this.

22 If the anodes are all tied together, it looks like this.

23 If the anodes are all tied together, it looks like this. This is called a common anode display.

24 If the cathodes are all tied together, it looks like this.

25 If the cathodes are all tied together, it looks like this.

26 If the cathodes are all tied together, it looks like this. This is called a common cathode display.

27 Remember that any LED needs a resistor to limit current.

28 Remember that any LED needs a resistor to limit current.

29 Remember that any LED needs a resistor to limit current. The resistor can come either before or after the LED.

30 For a common anode display, you can connect to each cathode through a resistor.

31 For a common anode display, you can connect to each cathode through a resistor.

32 For a common anode display, you can connect to each cathode through a resistor. Note that you can t use a resistor array because the resistors don t have a common connection at either end!

33 For a common cathode display, you can connect to each anode through a resistor.

34 For a common cathode display, you can connect to each anode through a resistor.

35 For a common cathode display, you can connect to each anode through a resistor. Note that you can t use a resistor array because the resistors don t have a common connection at either end!

36 Instead of using several resistors, you could use a single resistor on the common pin.

37 Instead of using several resistors, you could use a single resistor on the common pin. The only drawback to this is that you might see the display get dimmer as more segments are lit.

38 For a common anode display, it looks like this.

39 For a common anode display, it looks like this.

40 For a common cathode display, it looks like this.

41 For a common cathode display, it looks like this.