# Trimmer capacitor values!?

Discussion in 'General Electronics Chat' started by hantto, Jan 7, 2003.

1. ### hanttoMember

Joined:
Oct 25, 2002
Messages:
380
Likes:
1
Location:
Finland
I have some variable condensators and i dont't know their value! So if you know a sit where it's explained I'd apreciate it . Or if you know so tell me.

Got two yellow ones.
And one green one.

Thx!

2. ### kinjalgpActive Member

Joined:
Oct 28, 2002
Messages:
1,851
Likes:
3
Location:
INDIA/USA
Why don't you try a capacitance meter?
Or do this thing. First completely discharge the capacitor by shorting its leads. Then, connect a resistor in series with the capacitor and apply some fixed and accurate voltage to this circuit. Now measure the time taken for capacitor to fully charge to applied voltage. use this time in the formula
t = 0.693*R *C
Where,
t=Time taken to charge
R=Resistor value
Thus you can find C. Use larger value of R to get some time to turn your stopwatch on and off. This is just an approximate method because there are always some human error associated and also resistor has tolerance.

3. ### bogdanfirstNew Member

Joined:
Dec 13, 2002
Messages:
1,310
Likes:
1
Location:
Ramnicu Valcea, Romania
my guess is that it is mesured in picos, and that would mean 445(the numbers from the color code), so the value would be 4400000pF=4.4uF, but i thing i am wrong.....it couldn be that bog.....
or maybe the lines are in the oposite order?
544? 540000pF=540nF.....i dont know what to say....check it out, mesure it somehow....