how to make a DVA adapter for multimeter

[bktheking]

Re: how to make a DVA adapter for multimeter

will a peak reading digital meter do the same thing? I think? I already have one of those.

As long as it does voltage you should be good to go.

 

[F_R]

Re: how to make a DVA adapter for multimeter

As long as it does voltage you should be good to go.

Yes, that is the whole purpose of the adapter--to store the voltage pulses so you can measure the peak value. An ordinary voltmeter cannot read and measure the pulses because they are too fast and separated by relitively long periods of no voltage. The capacitor stores a whole bunch of pulses till it is charged up to the peak voltage. Then you read the (peak) voltage stored in the capacitor. Very simple if you understand how capacitors work, otherwise a head scratcher.

 

[huntxtrm]

Re: how to make a DVA adapter for multimeter

went to neighbor hood radioshack. the closest cap they have is 23uf at 250 wvdc. Close enough? you say my digital with data hold will work without one of these, correct? I still gonna build it, already have all the parts except cap.

 

[bktheking]

Re: how to make a DVA adapter for multimeter

went to neighbor hood radioshack. the closest cap they have is 23uf at 250 wvdc. Close enough? you say my digital with data hold will work without one of these, correct? I still gonna build it, already have all the parts except cap.

23 will work but it needs to be 400VDC. If you can get 47UF in 400V get 2 and wire them in series, it will 1/2 the capacitance so you get 23.5 uF.

 

[F_R]

Re: how to make a DVA adapter for multimeter

23 will work but it needs to be 400VDC. If you can get 47UF in 400V get 2 and wire them in series, it will 1/2 the capacitance so you get 23.5 uF.

250 V is too low in theory because you will be applying around 300V or more to it. It might work awhile if you are lucky, but it is teetering on the edge. Like driving a ten ton truck across a bridge rated for 9.5 tons. Might make it if you hold your breath. On the other hand, a cap rated for 600V is better yet.

 

[bktheking]

Re: how to make a DVA adapter for multimeter

250 V is too low in theory because you will be applying around 300V or more to it. It might work awhile if you are lucky, but it is teetering on the edge. Like driving a ten ton truck across a bridge rated for 9.5 tons. Might make it if you hold your breath. On the other hand, a cap rated for 600V is better yet.

True, that's why is said 400 minimum, aren't watching the SB F_R?

New Orleans won the toss!!

 

[F_R]

Re: how to make a DVA adapter for multimeter

True, that's why is said 400 minimum, aren't watching the SB F_R?

New Orleans won the toss!!

Wrote the last before it started. Half time now. Later.

 

[bktheking]

Re: how to make a DVA adapter for multimeter

Wrote the last before it started. Half time now. Later.

I called that convert, I had a debate here at home, I knew it was good for 2- it was a good catch.


Good for New Orleans!

 

[huntxtrm]

Re: how to make a DVA adapter for multimeter

been lookin for a 23uf 400wvdc cap on the internet, can't locate one. any ideas where to buy one?

 

[huntxtrm]

Re: how to make a DVA adapter for multimeter

and by the way New Orleans Wins! Awesome!

 

[huntxtrm]

Re: how to make a DVA adapter for multimeter

Ok, looking back into the post and parts list, says 22 micro farad 400 wvdc cap, is that the a 22 uf of 22muf cap? I aint that good with electronics, is that whats tripping me up?

 

[bktheking]

Re: how to make a DVA adapter for multimeter

Edit

 

[ezeke]

Re: how to make a DVA adapter for multimeter

Parts Express lists: http://www.parts-express.com/pe/sho... &FTR=020-1462&CFID=23010686&CFTOKEN=45516235

This is the part that Bill Rogers used in the original.

 

[huntxtrm]

Re: how to make a DVA adapter for multimeter

make sense now, thanks for learnin me something. tried the link you gave they seem to sell in quantities only, but now I know what I'm lookin for. Thanks

 

[bktheking]

Re: how to make a DVA adapter for multimeter

Parts Express lists: http://www.parts-express.com/pe/sho... &FTR=020-1462&CFID=23010686&CFTOKEN=45516235

This is the part that Bill Rogers used in the original.

So it's 2.2 and not 22, wonder if it will have an effect on measurements, I thought it said 22, then again the one I read was printed out at work and the "." wasn't legible.

 

[ezeke]

Re: how to make a DVA adapter for multimeter

make sense now, thanks for learnin me something. tried the link you gave they seem to sell in quantities only, but now I know what I'm lookin for. Thanks

No, they sell small orders - just add to cart and check out. Shipping will be high.

 

[bktheking]

Re: how to make a DVA adapter for multimeter

No, they sell small orders - just add to cart and check out. Shipping will be high.

22 would be too large, i'll have to rewire mine with 2.2, thanks for pointing that out Ezeke.

 

[F_R]

Re: how to make a DVA adapter for multimeter

22 would be too large, i'll have to rewire mine with 2.2, thanks for pointing that out Ezeke.

Aha! I thought there was something strange about wanting a 22mfd there. That's why I questioned it. A 22 would hold a lot of "juice" at 300V. Knock you out of your BVD's if you touch it.

 

[bktheking]

Re: how to make a DVA adapter for multimeter

Yup, you were right F_R- not just the shock but the timing as well, too large a cap would increase the time it took for the voltage to change.
I am going to redo the diagram tonight so it reflects the proper cap, the change to the one I built should take minutes, cut the old caps out and solder in the new.

 

[Vic.S]

Re: how to make a DVA adapter for multimeter

Glad that's been revised to 2?2 μf instead of 22 μf. Like FR I thought it was rather large.

Still seems large at 2?2 μf. Seriously wondering if it should be ?22 μf.