Is there any way to diy measure capacitance?

[pseudolobster]

So surface mount capacitors... they're really useful but are never labeled.

Using a multimeter, a stopwatch, a ball of twine, two matchsticks, and a rubber band is there any way to macguyver together some way of identifying blank caps?

 

[Bionic-Badger]

Yes you can, but you need to have an oscillator signal source.  Basically what happens is you construct a signal filter using a resistor and capacitor, and measure the attentuation of that filter at certain frequencies.  Using the resistor value and filter response, you can work out the value of the capacitor. It works with inductors too.

It's a bit easier if you use a sound-card to both source the signals and measure the input.  I once saw a program that did this for you automatically, but I can't find it.

 

[laserguys]

You can pickup a capacitor checking Multi Meter on eBay for less than $16.00 delivered. And you end up this a full function DMM to boot.

Here are two I found real quick. The first one seems a bit better.

Sorry I don't have enough posts to insert a link.

httX//cgi.ebay.ca/Multi-Function-Digital-Multimeter-Capacitance-Tester-DC_W0QQitemZ290246782712QQihZ019QQcategoryZ42291QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

httX://cgi.ebay.ca/Slim-Multi-Meter-Function-Digital-Capacitance-Tester-DC_W0QQitemZ300243483915QQihZ020QQcategoryZ42291QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Just fix the "httX"

Hope this helps.

 

[laserguys]

Sorry, forget the 2nd one it has no cap checking.
This one is the better one at $15.98 delivered.

http://cgi.ebay.ca/Multi-Function-D...ryZ42291QQssPageNameZWDVWQQrdZ1QQcmdZViewItem