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Need help with a circuit design

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blackbeen

New Member
Hello,

I've made the Digital Up/Down Selector with 74hc193 and 74hc154 for 16 switching output for variable power supplay
push up/down key but output 74hc154 random swithing for example jumping output 74154 from 1 to 3 or 6 or 16 switching
power supply 7805 and capacitance 100uf and 100nf and input used gate 4584 but yet problem.

Please help me another circuit without 74hc193 and no use microcontroler ic simple circuit.

Thanks you!
 

eTech

Active Member
Hello,

I've made the Digital Up/Down Selector with 74hc193 and 74hc154 for 16 switching output for variable power supplay
push up/down key but output 74hc154 random swithing for example jumping output 74154 from 1 to 3 or 6 or 16 switching
power supply 7805 and capacitance 100uf and 100nf and input used gate 4584 but yet problem.

Please help me another circuit without 74hc193 and no use microcontroler ic simple circuit.

Thanks you!
Post your schematic..
 

rjenkinsgb

Well-Known Member
Most Helpful Member
I'd guess you need a debounce circuit on the switches to give a "clean" signal to the logic inputs.

A mechanical switch can open and close many times in a fraction of a second as the contacts make., causing multiple inputs to fast logic.
You need something to give a single signal from a switch change.
It also needs the input signal to change quickly between low and high levels, unless the next input is a schmitt trigger.
 

tomizett

Active Member
Agree with the above - de-bouncing would certainly be the place to start.
 
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