Decoding a JK Flip Flop

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Deathshead

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can i decode a jk flip flop w/ a BCD to 7 segment display? I need it to display segments "b" and C" , or the number one. How can i do this or do i need 2 ff's
 
BCD-7seg or 7seg?

Your question is a bit confusing. Are you using a BCD - 7 Segment decoder/driver chip in front of the display, or are you trying to interface directly to a 7 segment display? If it's the later case, use the Q/ output to drive both the "b" and "c" segments for a common-anode display (use the Q output for common-cathode displays). Put a 270/330 current-limiting resistor in series with the output (lower values are ok if you're always driving the same two segments from one output). Btw, half-digit ("b" & "c" segments only) displays are available cheap on the surplus market.
 
Hi Deathshead,

If you just want the flip-flop to display a 'one'
or nothing, then yes, you can just drive the two
segments from the flip-flop.

If the seven segment has other things to do also
then use a couple of diodes from the flip-flop
to the two segments, to prevent any back-feed.

If you want to display both a zero or a one,
then you would need to use a few diodes to feed
the appropriate segments, and use both sides of
the flip-flop, one side for zero, other for one.

Regards, John
 
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