Finishing The Schematic


#1

Originally published at: https://contextualelectronics.com/topic/finishing-the-schematic/

Here are some of the links used in these videos: http://www.555-timer-circuits.com/flashing-led.html https://en.wikipedia.org/wiki/555_timer_IC http://www.nxp.com/docs/en/data-sheet/ICM7555.pdf


#2

In the video, pin 5 (ctrl voltage) of the 555 timer is connected to ground. But in the reference schematic it’s left unconnected. Does this matter?


#3

It does! You found the secret error that is rectified in the last video. It’s ok if you end up connecting it, you’ll need to bodge it like I do.


#4

Does this mean that you should keep the ground connected to pin 5 ?? or don’t ?


#5

If you want to follow along exactly…then yes. If you want it to work right off the bat…then no :slight_smile:

This was a mistake I made in the video recording process but didn’t realize until I had the board in hand. I used it as an opportunity to showcase how to fix a mistake with solder. You can choose whether or not you’d like to follow all of the same steps.


#6

Thanks for your reply @ChrisGammell