Pins don't look right. Especially pin #3. The timer should be configured like PDF page #10 here:
http://www.ti.com/lit/ds/symlink/lm555.pdf
There is a 14 pin and 8 pin version of the timer. See here also:
http://www.mycircuits9.com/2013/06/555-Timer-Pin-Configuration-Applications-Projects.html
Pins are counted counter clockwise from the index mark.
It's bedtime for me.
Hi Keep,
Hope you had a good sleep.
No, if you are an old hand with the 555 and read the data books, they will not look right- I just like to be different.
All that calculation with the two resistors to get the frquency you want while maintaining a 1:1 mark to space ratio gives me a headache.
Thinking about it I have never used the text book aproach, and I have literally built hundreds of 555 circuits: CMOS version, 556 dual and so on. Even used them as power drivers: the output stage can handle 200mA, in theory anyway.
With my approach you only need one timing resistor, which means that only one pot is required when you need a variable frequency, but not only that, if you use the discharge, open collector output with a 1K pull up, it swings rail to rail and the waveform is a lot cleaner with faster rise and fall edges: ideal for drivinf TTL. Much better than the blood-and-thunder of the Q output.
I allways feel that the 555 missed the boat by not providing an inverting output- would have made the chip much more useful.
It is still a great chip though, just beware of the huge spikes of current that the output stage whips off the supply rail as both transistors in the output sytage crosses over- not a problem with the CMOS version. Because of the current glitches I wouldn't dream of using a bipolar 555 without a 100nF cap strapped across the supply rails.
All good fun