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Help pls..

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carlandrewg

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Hi! I need a 100nF 63V, 330nF 63V and a 15nF 63V Polyester capacitors. The problem is that it its not available in my country. What can I replace it with? One more question, Can i charge a 9V NiCad battery using a universal charger used for cellular phones? Thank You very much. Help would be appreciated.
 
As you don't have your location filed in, how are we supposed to know what country you supposedly can't get the capacitors in?.

As to what you can use to replace them, it depends entirely on the circuit they are used in.

And no, you can't use your cellphone charger.
 
Thanks Nigel. Btw, I'm from the Philippines. I'm going to use it for this circuit.The ones labeled C2,C3,C4,C5 and C6 are the polyester capacitors.C2____________100nF 63V Polyester Capacitor
C3,C4_________330nF 63V Polyester Capacitors
C5,C6__________15nF 63V Polyester Capacitors.**broken link removed**
 
Please post the schematic so we can see if they're are any suitable subsitutions.
 
hi,
Polyesters are a stable capacitor over a wide temperature range.
Looking at your cct, some of the caps are used in pulse/osc timing and I would infer that stabilty is important.
What type of capacitors are you able to get locally ?.

If I understand your question regarding battery charging, the batteries
in mobiles are usually around 3.6v, I would not expect a standard mobile charger to be able to charge a 9v NiCd battery.

Regards
EricG
 
Polyester capacitors in the Orient are called, "Green Caps" but I have seen reddish ones. Some people call them, "Mylar Caps".
100nF ones are marked 104, 330nF ones are marked 334 and 15nF ones are marked 152. J is 5% and K is 10% tolerance.

A "9V" Ni-Cad or Ni-MH rechargable battery is actually 7.2V because they contain six AAAA 1.2V cells. They are about 8.4V fully charged right out of the charger, then the voltage quickly drops to 7.2V.
 

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carlandrewg said:
I'm going to use it for this circuit.
Just curious; what is that circuit used for? The inductor (L1), and the way it is driven by two oscillators (IC2C&D) has me puzzled.

audioguru said:
A "9V" Ni-Cad or Ni-MH rechargable battery is actually 7.2V because they contain six AAAA 1.2V cells. They are about 8.4V fully charged right out of the charger, then the voltage quickly drops to 7.2V.
I've often wondered why they don't put another cell in those 9V nicads so that the nominal voltage is 8.6V rather than 7.2V.... Surely, a fully charged voltage of around 10V wouldn't be a problem....
 
Six AAAA cells fit into a rectangular 9V housing. Seven won't fit.
Have you seen how skinny are those little AAAA cells? There is nearly nothing in them.
The capacity of the "9V" Ni-MH cells are up to 175mAh today. A little more than nothing.
 
So it is OK for me to use mylar caps? I'm confused back then because polyester caps have voltage ratings while in our country, mylar caps doesn't have any voltage ratings. Thanks Guys.
 
mylar caps doesn't have any voltage ratings
Most unmarked caps are 50V.... But as long as the caps voltage rating is greater than your battery voltage (1.50x battery voltage), they will be fine. 63V is overkill and anything over 25V should be fine as the IC won't take much more than 15V if it is a 4000 series CMOS.
 
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