Seven Segment Display Help!

[Dougal]

Can someone please help me? I want to put a common anode display in the
circuit displayed by the link below. Can you tell me what changes I need to
make.

I am desperate for a solution!

http://www.tep.org.uk/upload/112%20circuits/Word/circ54.doc

 

[grahamk]

Dougal wrote:

Can someone please help me? I want to put a common anode display in
the circuit displayed by the link below. Can you tell me what changes
I need to make.

I am desperate for a solution!

http://www.tep.org.uk/upload/112%20circuits/Word/circ54.doc

Reverse the power supply and reverse all the diodes.
The common cathode becomes the common anode.

--
My most up-to-date website is
Beginners and Intermediate Electronics
http://homepage.ntlworld.com/g.knott/index.htm

 

[petrus bitbyter]

"Dougal" <anon@anon.com> schreef in bericht
news:4065b152$0$22999$cc9e4d1f@news.dial.pipex.com...

Can someone please help me? I want to put a common anode display in the
circuit displayed by the link below. Can you tell me what changes I need
to
make.

I am desperate for a solution!

http://www.tep.org.uk/upload/112%20circuits/Word/circ54.doc

Don't you understand how this circuit works? To explain very shortly,
current from the plus of the battery flows to the switch and to the cathodes
of all the diodes the switch is pointing to. From that point each of the
diodes get its part of the total current which flows through the diode, the
resistor and the LED segment of the seven segment display that has to light.

Guess you know that diodes - including LEDs - conduct current in one
direction only. So if you change to a common cathode display you reverse the
direction of the LEDs. You will have to reverse your battery and your diodes
as well to keep the circuit functioning.

petrus


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