555 Clock Help

301

03:04:04

I have been following Ben Eater on YouTube with his 8-Bit computer build https://www.youtube.com/user/eaterbc
and the first stage of the build involves using three 555 timer IC's for the clock. The first is in astable mode the second in monostable and third in bistable. The third 555 is used to select between the first two stages. Each 555 has a LED at the output in  order to show that it is functioning. As soon as I place a LED on pin 3 of any of the 555's i get 'CANNOT FIND SOLUTION'. I have tried different timings etc but still get the same result. I would like to have the LED's in as they are indicators for what mode the clock is in. Any help much appreciatted.

published 8 years ago

zeeman2000

8 years ago

Also meant to mention the LED's were fine until the logic circuit was added

BillyT

8 years ago

2.4v led voltage 100 ohm resistor.

zeeman2000

8 years ago

you solved it. thanks

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