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Topic: T flip flop (Read 805 times) previous topic - next topic

neema_t

Hello,

At the moment I'm building a sub-circuit of a larger project. It's an LED status display consisting of 8 LEDs, one is a power indicator which is easy, two are momentary and only turn on when a button is pressed which are also easy. The other five have to latch on or off.

Of those five, three are easy, they're turned on and off by DPDT toggle switches which are normally open but have momentary closed positions either side of the middle position, so I've used S-R latches made from NAND gates for them. However, the last two are controlled by DPST toggles with just an off and momentary on position. I've so far determined that a T flip flop is most likely what I need. If I were to have T held high and use the switch as the clock input, would this suit my needs?

Thanks!

elandd2011

with your explanation you are right
so make a test and tell us

westfw

Quote
If I were to have T held high and use the switch as the clock input, would this suit my needs?

Beware contact "bounce" in the switch.  You'll probably need a separate debounce circuit and toggle circuit...

MarkT

No, switch-bounce would make that very unreliable (expect zero to hundreds of bounces per operation).  I presume you don't have a microcontroller handling this or you could do everything in software?

You need to add debouncing circuit before the flip-flop clock input - an R/C low-pass filter and a schmidt-trigger gate would do (if the flip-flop has schmidt-trigger clock input, that would be ideal).
[ I won't respond to messages, use the forum please ]

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