Search found 3449 matches

by JR.
Sun Sep 20, 2020 2:20 pm
Forum: The Peabody Lounge
Topic: home improvement turns into science fair projects?
Replies: 222
Views: 18663

Re: home improvement turns into science fair projects?

Finally getting around to finishing a project I have been chewing on for well over a year. blower1.jpg I purchased this blower for a crazy cheap price <$30 IIRC... The blower moves way too much air but I finessed that with a three speed switch using series capacitors to scrub off mains voltage. High...
by JR.
Sun Sep 20, 2020 10:03 am
Forum: Pro Audio Design
Topic: How Closely Do The Values Of Electrolytic Caps From The Same Lot Match?
Replies: 15
Views: 128

Re: How Closely Do The Values Of Electrolytic Caps From The Same Lot Match?

is it fair to assume that his resolution floor is 0.0008?

Some parts may be better?

JR
by JR.
Sat Sep 19, 2020 10:23 am
Forum: The Peabody Lounge
Topic: home improvement turns into science fair projects?
Replies: 222
Views: 18663

Re: home improvement turns into science fair projects?

I have talked about this before but I just realized that my solar franken-lamps are still working.... a good thing. :lol: Over the last few years I have made several modifications, -I cobbled together 2 solar arrays on each lamp for more voltage during cloudy days, -then I changed the value of the i...
by JR.
Sat Sep 19, 2020 8:51 am
Forum: Pro Audio Design
Topic: How Closely Do The Values Of Electrolytic Caps From The Same Lot Match?
Replies: 15
Views: 128

Re: How Closely Do The Values Of Electrolytic Caps From The Same Lot Match?

That thread about smd resistors is pretty old and I didn't even share about my drama with operating high Z SMD resistors at high voltage, another case where larger package resistors were required to meet spec. JR PS: For my outlet tester I realized off scale >500M insulation resistance @ 500V (the 1...
by JR.
Fri Sep 18, 2020 10:24 am
Forum: Pro Audio Design
Topic: How Closely Do The Values Of Electrolytic Caps From The Same Lot Match?
Replies: 15
Views: 128

Re: How Closely Do The Values Of Electrolytic Caps From The Same Lot Match?

What about the tempco? heat them with a hot air gun and report back. Speaking of temperature, that reminds me of a production problem I encountered with potentiometers. The resistive element is generally a screened on carbon ink. The tolerance of the bulk resistance is around 20% but not widely kno...
by JR.
Thu Sep 17, 2020 10:53 am
Forum: The Peabody Lounge
Topic: The Corona Virus Hoax of 2020
Replies: 266
Views: 14921

Re: The Corona Virus Hoax of 2020

Mueller's team wiped over 30 government phones before turning them in.... :oops:

JR
by JR.
Thu Sep 17, 2020 8:15 am
Forum: Pro Audio Design
Topic: How Closely Do The Values Of Electrolytic Caps From The Same Lot Match?
Replies: 15
Views: 128

Re: How Closely Do The Values Of Electrolytic Caps From The Same Lot Match?

In the 60's I was interested in 2R R ladders, so I sorted in a lot of 1K 5% resistors, they came out well matched, better than I presumed. I was told, resistors were sorted at the end of the production line, so the 5% I got were those that did not make it in the 2%. So I had those from the same of ...
by JR.
Thu Sep 17, 2020 8:12 am
Forum: Pro Audio Design
Topic: How Closely Do The Values Of Electrolytic Caps From The Same Lot Match?
Replies: 15
Views: 128

Re: How Closely Do The Values Of Electrolytic Caps From The Same Lot Match?

I just got in 50 pieces of 33uF electrolytic caps, 20%. I only measured about ten of them but found a range of 33.5uF to 34.5uF, so roughly a 3% variation, nominally just above the specified value... not too shabby for (cheap) 20% parts. I think I'll use them. :lol:

JR
by JR.
Wed Sep 16, 2020 8:51 am
Forum: Pro Audio Design
Topic: How Closely Do The Values Of Electrolytic Caps From The Same Lot Match?
Replies: 15
Views: 128

Re: How Closely Do The Values Of Electrolytic Caps From The Same Lot Match?

Not surprising from production manufacturing. Chunka-chunk automated production lines won't wary widely, while tolerances specs are are mostly important for batch to batch variation. When designing for large scale manufacturing we ASSume the worst, and sometimes get it. (I won't bore you with bad ca...
by JR.
Sat Sep 12, 2020 10:46 am
Forum: Pro Audio Design
Topic: Dielectric Absorption
Replies: 64
Views: 40300

Re: Dielectric Absorption

The one place where I think I might be able to hear it is the timing capacitor in an RMS or averaging detector sidechain. This is an old story of mine but about the only time I ever used a high DA cap on purpose was in the side chain of the CX decoder kit I did back in the 80s. Popular electronics ...