View Single Post
Old 07-13-2009, 07:52 AM
witsend witsend is offline
Gold Member
Join Date: May 2009
Posts: 1,881
Joit - is your waveform proving TinselKoala's point? Is that 555 switch wrongly presented? To me it looks like it is. In which case, I must apologise to all concerned. Clearly the Quantum article was wrong.

So, to all concerned - to everyone who built the circuit as presented in that article, and if, indeed, it is wrong, my abject apologies. I had a shrewd idea it may have been wrong because, thinking back, a university professor kindly edited the quantum paper prior to presenting it to the IET. And his first recommendation was that we omitted a detailed circuit of the 555 switch as being irrelevant to the claim. Which is why I was reluctant to endorse the Quantum article as being a correct presentation. I just wish, in retrospect, that he had pointed out the error if he had seen such. In any event, it seems that I have been entirely at fault. My own objection to it was due to the lack of the feedback diode - which was the entire subject of the exercise. I knew it was in the apparatus. It certainly was not in diagram.

I would point out though, that my reluctance to admit this prior to ascertaining the fact was due to the person who presented that diagram and assisted me in that first article. He is a good friend and he, like all of us, was 'giving' his time. I was not keen therefore to expose the problem unless I also knew it was a problem. So, if you're reading this, don't even worry. In any event, the blame was not his. I should, at least, have had the circuit vetted - considering my own inability to read such.

So. Many apologies, even to TinselKoala and anyone in the entire world who duplicated that circuit. It is wrongly presented. I am sincerely sorry that I have wasted so much of your time. And Joit - you've put the question to bed. I would be very glad to refund you for your time and trouble - if required - and if I can get the money to you with our exchange control. Just send me an account on the PM system. You've done a very good thing here.

What I do assure you all is this. The switch may have been wrongly drawn. Our own duty cycle application is NOT. I have the experimental apparatus available and it has been checked by EE's even at universities. We have also, over the years, built many different 555 switches and by different people. And there are replicated experiments by others using nothing but a functions generator. And all this prior to publication. More to the point is that the battery duration is consistent with measurements based on the duty cycle. But, in point of fact, after publication I never experimented again for a period of 7 years and I certainly never even looked at the article again. The only reason I could scan a copy for the blog when I eventually did this, was because my children kept a copy of the original publication. I was just so dejected at the entire lack of interest it seemed to generate. I had no idea that the test would really ever be duplicated.

Therefore, please take this admission as a sincere apology to all those who have tried to build the switch according to the quantum article. I see that the Quantum article was the primary reference point as the IET paper was only posted to the blog after July. It seems that Ramset and TinselKoala started their thread on OU.COM in mid June. Unfortunate. But there you are. Sorry guys - It's all I can say.

Last edited by witsend; 07-13-2009 at 08:33 AM. Reason: spelling