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#48251 - 02/06/05 05:29 PM Meters
JCooper Offline
Member
Registered: 12/30/02
Posts: 228
Loc: Kendall Park, NJ USA
Does anybody here know of a good analog meter that can do peak to peak readings? Or a digital that can do the same. My father said the old Simpson 260 can do it but I can't seem to find anything on the Simpson site to support that, or any of their meters that can do it. It is a pain to have to drag out my scope when I need a peak to peak level, and a portable scope is a bit out of my price range right now, but when I have $3k around you can bet I will be ordering a nice color Fluke one. Thanks.

Jim
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#48252 - 02/06/05 06:24 PM Re: Meters
winnie Offline
Member
Registered: 09/15/03
Posts: 649
Loc: boston, ma
What about a simple diode/capacitor circuit followed by a DC meter?

-Jon
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#48253 - 02/07/05 08:12 PM Re: Meters
JCooper Offline
Member
Registered: 12/30/02
Posts: 228
Loc: Kendall Park, NJ USA
Well I am willing to give it a shot, how would I go about finding a schematic?
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#48254 - 02/07/05 08:34 PM Re: Meters
Dave55 Offline
Member
Registered: 05/08/04
Posts: 697
Loc: Crystal Lake, Illinois, USA
At the risk of seeming dense I'll assume you mean voltage (peak to peak). The Fluke 337 Clamp Meter has a button to push after reading voltage that gives the min./max.. It's a digital reading, not a scope.

Dave
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#48255 - 02/08/05 01:38 PM Re: Meters
wa2ise Offline
Member
Registered: 11/29/02
Posts: 782
Loc: Oradell NJ USA
Quote:
Well I am willing to give it a shot, how would I go about finding a schematic?


It's fairly simple, miminum would be two parts, the diode and a cap. The cathode of the diode (usually marked with a band) connects to the + voltage input of the DC voltmeter. The anode of the diode goes to the voltage being measured. The cap goes between the + and the common of the DC voltmeter. The common of the voltmeter also goes to the ground (or other end of the voltage being measured). Now to select the diode and cap: What is the highest voltage you will ever want to measure, or will be present in the area of where you will be poking around? You want the diode to not blow up. Minimum voltage rating "peak inverse voltage" needs to be at least 2.8 times the RMS (assuming a sine wave) voltage of the AC voltage you will measure. The cap should charge up to drive the meter but not hold it too long once you remove the probe from the voltage your measuring. Say 1/10 second. If the DC voltmeter has a load of about 5 megohms, the cap would be 0.1uF to 0.02uF. Its voltage rating should be higher than 1.4 times the highest RMS voltage you will ever measure. I'm thinking out loud here and haven't tried it, but this should work. Try measuring some voltages of known peak to peak voltage to test this out first.
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#48256 - 02/09/05 05:27 PM Re: Meters
Bjarney Offline
Moderator
Registered: 04/10/02
Posts: 2527
Loc: West-Southern Inner-Northeast ...
 
Older Fluke 8024s and early-to-late 80-series meters have various peak-hold capabilities. Please give us a little detail on your application so we can better advise you. It’s all timing—what is yours in particular?
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#48257 - 02/09/05 06:11 PM Re: Meters
adamb Offline
Member
Registered: 06/02/04
Posts: 25
Loc: Corinna, Maine, US
i had to build a diode/cap multi-meter for class if you want to pm me I will see if I can send you the plans

"see if i can send you the plans cause i'm puter dislexic"
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#48258 - 02/09/05 06:56 PM Re: Meters
JCooper Offline
Member
Registered: 12/30/02
Posts: 228
Loc: Kendall Park, NJ USA
I am mostly looking to measure video levels and some data voltages, I didn't want to get something specialized that only does video levels I was hoping to find an analog meter that would do video levels and still be a normal meter.
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