555 start stop - flip flop

240

04:27:03

The circuit works in real life, pin 6 starts the led, pin 2 stops the led.
For a working version of the circuit refer to a design by BillyT http://everycircuit.com/circuit/6267963526610944 
BillyT commented that in real life stray capacitance can make the circuit work. Stray capacitance can be found in the wire between parts of the circuit & or the circuit board / breadboard the circuit is built on, even the humidity in the air can affect the performance. To see a working circuit look at YouTube (Julian Ilett) Julian's Logic: 555 Logic Functions Julian Ilett 12,080 views

published 8 years ago

jpoulin0901

8 years ago

It has nothing to do with stray capacitance. The reason it doesn't work in the sim is because you're letting your inputs float. A 555 with trigger and threshold tied together forms a Schmitt trigger, which is naturally a bistable device. Connect 2 and 6 then add a 10k resistor across each of your switches. No caps required.

yra

8 years ago

Thanks for the input, in the text it said works in real world, this is for a beginner to play with as it turns on and off a led. A 555 chip is one of the most useful chips and cheep if you destroy one as we all have. Thanks for the input maybe someone else can do what you mentioned and feel great about fixing the circuit problem in EC. Or they can visit YouTube and see the real circuit operating. To address the capacitance issue lots of people in this hobby don't know why anti static practice is important, as so many things around us have a capacitor affect and build charge, with out a great humidifier you can fry a chip or device taking it out of the package if you're not grounded or discharged properly before handling.

yra

8 years ago

Please look at YouTube the gentleman explained why this works in much detail.

yra

8 years ago

I really appreciate all the help some of you really smart people have offered, this is one of the rear times ec will not sim a working circuit. So I put it out for the people new to the hobby too test and see not everything is black & white.

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