I'm new here. Hello. I hope to soon build my first arduino (s3v3) so that I can learn more and more about electronics and make some pretty lights to go with the things I make mostly from wood. In parallel, I'm trying to create one of Dr Le Hung's LCFesR meters - http://members.upc.hu/lethanh.hung/LCFESRmero/en/index.htm and I'm stuck working out how to match a component - a 13.3nF 250V polyester cap.
I'm getting my bits from bitsbox (I've yet to find another uk stockist as charming, useful and just good as they are), hopefully, and wonder if anyone can advise (or advise against) trying to match this value using a series. It seems to me that i'll need 3 caps of 100V to get a necessary voltage ceiling:
47 > 22 > 100 = 13.033nF
...is as close as my tiny mind has got. My feeling is that there's a lot of values there, 3 different tolerences, much room for error. That, and the feeling is that I have a lot of reading to do.
My abilities in electronics amount to soldering (I've made up PCB's for some MP3 kiosks, optimised some amp circuits in my digital audio equipment, tinned wires and that kinda thing) generally following the good guidance of other folk. I hope someone can kindly tell me something.
You need a 5.1nF and 8.2nF polyester capacitor in parallel, both of the requisite tolerance and voltage (or better). Capacitance in parallel adds, 5.1+8.2 = 13.3
[ edit: other more obvious combinations are possible! ]
Is it about the 10..15nF capacitor in the circuit diagram ???
•Some critical electric parts can be any value within their range: capacitor from 10 nF to 15 nF, inductor from 1 uH to 2.2 uH can be used (software will handle these values)
I just saw this strange 13.3 nF value in that mailto : link
And I'm not sure if this "250V" is a real requirement, too.
michael_x:
Is it about the 10..15nF capacitor in the circuit diagram ???
•Some critical electric parts can be any value within their range: capacitor from 10 nF to 15 nF, inductor from 1 uH to 2.2 uH can be used (software will handle these values)
I just saw this strange 13.3 nF value in that mailto : link
And I'm not sure if this "250V" is a real requirement, too.
I'm not sure either, 'still working on that. The reference to the parts is from the component detail:
13.3 nF, 0.5%, 250V, RM 7.5 mm, polystyrene
2.1 nF, film, 1%, 250 V, RM 7.5 mm, polystyrene
I'm learning anyway. Ah yeah the schematic has it listed as you've said too, for C3 ('<2%'). Well, I can can go and fumble with something else now. Cheers
