Hi, i am currently undertaking a project and part of it involves a flashing LED. Just looking for any ideas to alternate an LED between flashing at a rate of 1 per sec and then faster up to it being continuously on. I was thinking a variable resistor would do the job? Any help would be great! .

 

How about this...

You probably should break the resistor up between a variable and a fixed value, the fixed value will set your max freq.

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For what it's worth, I've built the above circuit (with one LED going to ground) with just one variable resistor.

 

If you do not have a 555 but do have some caps, transistors, and resistors you can do something like at the following site:

http://www.technologystudent.com/elec1/dual1.htm


OR

http://ourworld.compuserve.com/homepages/Bill_Bowden/page10.htm#15flash.gif

OR

http://pigeonsnest.co.uk/stuff/picprog/single-cell-led-flasher-two-year-battery-life.html

 

Yea, put the minimum resistance safe for a 555 (about 1K is definately safe) in series with your pots.. Otherwise you'll end up frying the 555 each time you dial too low..

 

Actually, not. It hits a max and can't go any faster.

Have you had some bad experiences?