21-11-2018, 08:18 PM
Thanks Jeffrey.
Now here's a thing, Up to now I have used a 4uf in this particular set and thought and checked I was around the 300ma mark. I agree that the value should be nearer 5.5uf and even today all looked fine with a current of 309ma with heaters looking correct. not dull or overly bright. For the life of me I must have mistyped in Paul's calculator but with the cap marked 4uf the current was OK. So I disconnected the cap and checked it, and it was wrong as was the other two I have here that are unused. These are Italian caps bought from CPC so this explains the anomaly, no wonder my my head couldn't get round the problem. It is well over a year since I got the caps and I have also passed on at least one as well.
So yes I have made an error on the calcs but I have been unlucky with caps that are most likely wrongly marked from new, what a PITA. At least we agree that the surge with a cap will be less, I've done a good few sets with capacitor droppers and have had total reliability. Oh well you live and learn and now I shall make sure I check these caps, I have to say that I did come across this with my last job with start/run caps not at the value that is stated, I just thought my employer was buying cheap rubbish.
Now here's a thing, Up to now I have used a 4uf in this particular set and thought and checked I was around the 300ma mark. I agree that the value should be nearer 5.5uf and even today all looked fine with a current of 309ma with heaters looking correct. not dull or overly bright. For the life of me I must have mistyped in Paul's calculator but with the cap marked 4uf the current was OK. So I disconnected the cap and checked it, and it was wrong as was the other two I have here that are unused. These are Italian caps bought from CPC so this explains the anomaly, no wonder my my head couldn't get round the problem. It is well over a year since I got the caps and I have also passed on at least one as well.
So yes I have made an error on the calcs but I have been unlucky with caps that are most likely wrongly marked from new, what a PITA. At least we agree that the surge with a cap will be less, I've done a good few sets with capacitor droppers and have had total reliability. Oh well you live and learn and now I shall make sure I check these caps, I have to say that I did come across this with my last job with start/run caps not at the value that is stated, I just thought my employer was buying cheap rubbish.
