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how can I create a positive logic pulse from a steady high input?

Skidood

Aug 24, 2015
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Aug 24, 2015
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Analog, the oscillator and input LEDs worked. The 220R on the LEDs needs to be 1/2W.
The value of C1 ended up needing to be left at 1 uF, otherwise, when using the 0.1 uF, if the power is cycled while one of the alarm inputs is being held high, sometimes/frequently the FF would not start out in the right state (flopped instead of flipped) The set and reset inputs are too close in terms of how quickly they approach Vcc upon power-up.....
The charge rate of C3 upon power-up plays a role, when its changed to 0.01 uF, no problem.
Even at 0.1 uF, it still gave me that issue.
What was the purpose of it?
 
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AnalogKid

Jun 10, 2015
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if the power is cycled while one of the alarm inputs is being held high, sometimes/frequently the FF would not start out in the right state (flopped instead of flipped)
What was the purpose of it? C3

I added C3 as a power-on reset, specifically to keep the system from beeping if it powered up with one or more inputs disconnected. Whether that is a "feature" or a "bug" is up to you. As for the cap value, it's whatever works. I put in 5:1 over the Set cap as a starting point.

ak
 

Skidood

Aug 24, 2015
35
Joined
Aug 24, 2015
Messages
35
I sincerely want to thank you very much for your help on this project. I liked the input LED trick, I get how it works but never would have come up with that strategy. Same goes for the Schmitt oscillator...words are not sufficient to express my gratitude, man....and a great taste in music too...BTW I also played drums for a bit...bought a used 5-piece kit around 10 years ago, and for about 2 years learned how hard it is to multi-task....if you are ever in the Toronto area, message me, I will show you a good time. ;) :rolleyes:
I think Alex Lifeson still owns a bar here.
 
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