I want to use one button for set and reset. With a hex-inverter (because of falling edge), when I press the button, set works fine, but I need another button to reset the 74HC73.

Is there some possibility to make a 74HC73 reset automaticallt when I release the same button? I will upload schematic later to provide you logic.

Thank you in advance.

  • \$\begingroup\$ Why do you want to do this? \$\endgroup\$ Feb 3 at 19:26
  • \$\begingroup\$ I have logic condition on start, and when that condition is correct, it supposed on button press to activate relay. Then it will start start test next condition and if is correct then will acrivate another relay. I want to both relay stay activated while i hold button pressed and when realesd then i want to clear/reset the flip flop. Conditions are not the same and thats why i need flip-flop to remember first state so the first relay can stay activated. I done this with 2 buttons, but i want to make less buttons to press, somehow to optimize that part. \$\endgroup\$
    – n0b
    Feb 3 at 21:32

You don't need a 74HC73 to set an output when a button is pressed and reset it when it's released. Something like this will do nicely:


simulate this circuit – Schematic created using CircuitLab

  • \$\begingroup\$ Sorry for missunderstanding, with purpose i want to use 74hc73. I want flip flop remember state, cuz i have some logic with logic gates, and when the condition is good, i want with pressing the button Q goes high, but when i unpress it, then i want to reset 74hc73. \$\endgroup\$
    – n0b
    Feb 2 at 18:02
  • \$\begingroup\$ Your description still does not require anything but what I've drawn. You say you want "logic gates" but in the end you still go back to "Q is high when I press and it goes low when I unpress". There is no need for anything else. \$\endgroup\$
    – jwh20
    Feb 2 at 23:58
  • \$\begingroup\$ 74hc73 have CLK and CLR. When J is "1-HIGH" on falling edge of CLK, output Q become "1-HIGH" and of falling edge of CLR 74hc73 is cleared-reseted. With Your wiring work fine for both CLK and CLR, but need two separeted buttons. My question is, how i can combine two of them to work with just only one button "When button is pressed to do CLK and put Q to HIGH and when I released the same button to do CLR so output Q become LOW". I mean to set flip flop and to cleared it. \$\endgroup\$
    – n0b
    Feb 3 at 6:08

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