[TCML] Measuring capacitance

[Brandon Hendershot]

Thanks David, that helped a lot. I'll be getting one shortly.

On Nov 29, 2009, at 5:32 AM, "David Rieben" <drieben at comcast.net> wrote:

> Brandon,
>
> There's really no direct way to convert "Ohms to Farads" from the ohm
> scale of a standard multimeter. With the old-style analog  
> multimeter, you
> could place your meter in one of the ohmic resistance ranges and place
> the test leads across the terminals of the test capacitor. The  
> needle indi-
> cator would slowly move from a low resistance reading toward an  
> infinite
> resistance reading, I believe?, because the resistance function of  
> the multi-
> meter checked for resistance by applying a small voltage to the test  
> resis-
> tance through it. This small voltage would also enter the test  
> capacitor and
> chagre it up, which would cause the scale deflection.The larger the  
> capaci-
> tor, the slower this deflection would occur. However, I don't know  
> if this
> method would work with a modern DMM.? Anyway, all that this method
> of testing could really determine was if the capacitor in question  
> was good
> or bad.
>
> Capacitive measuring meters (usually LC meters, which can measure both
> capacitnace and inductance) are just about always available on eBay  
> for a
> reasonable price (dirt cheap if you don't mind China made). I have a  
> chea-
> py Chinese made (eBay special) LC meter that actually works quite well
> and gives pretty accurate capacitive measurements. Certainly  
> adequate for
> my hobby level use. Think it cost me < $20, IIRC.
>
> http://cgi.ebay.com/3-1-2-2nF-200uF-2mH-20H-LCD-Inductor-Capacitor-LC-Meter_W0QQitemZ250538945643QQcmdZViewItemQQptZBI_Electrical_Equipment_Tools?hash=item3a5548ec6b
>
> http://cgi.ebay.com/3-1-2-LCD-LC-capacitance-inductor-Capacitor-Meter-mH-F_W0QQitemZ260512061626QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3ca7ba98ba
>
> David Rieben
>
>
> ----- Original Message ----- From: "Brandon Hendershot" <mrbrandman at cox.net 
> >
> To: "Tesla Coil Mailing List" <tesla at pupman.com>
> Sent: Thursday, November 26, 2009 1:32 PM
> Subject: [TCML] Measuring capacitance
>
>
>> I'm looking to make a new tank cap this Christmas and I'd like  
>> some  help from a meter to measure the farad rating to aid wiring  
>> the in a  mixture of series and parallel. The only thing I can  
>> think of that  would measure farads is an ohmmeter. Do they make a  
>> farad meter? If  not, how do you convert ohms to farads?
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