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Messages - dadler

#1
So since schottky's have higher reverse leakage, I tried two 1n5817 (only handles 20V reverse, I don't have any 1n5819 on hand) in the same configuration.

They start out around 130 Mohm and then ramp up slowly over time. But really slowly... It took about 3 minutes to ramp up to 1 Gohm. After 5 minutes it still hasn't gone over range and is floating around 1.2Gohm, and then dropped back down to 1.16 Gohm and floats around. Probably temperare dependent, my AC just kicked on. Of course we aren't really measuring resistance here, but leakage current.

Not sure this is useful but it was fun to measure  :P



#2
Hmm- then the leakage/capacitance will be dependent on the frequency. Those quoted capacitance values are at 1Mhz according to the Fairchild datasheet.

I assume this is an audio circuit with standard audio frequencies?

The nice thing about resistors is that they are pretty much linear / frequency independent (well, at the low end). You could try some diodes and see what happens?  :P Might make for some interesting learning either way.
#3
@100Hz I read 167 Mohm and @ 1kHz I read 103.6 Mohm impedance, but this is more by virtue of internal capacitance than actual "resistance".

These values will be really affected by the frequency and reverse voltage. The rated junction capacitance of the 1n4002 is 15pF @ 1MHz. I cannot measure that high of a frequency with this DE-5000.

Anyways, I imagine your use case was DC so not sure any of this is useful  :P
#4
Yeah-the results are the same with only one diode, as long as you get the polarity correct. The dual diodes just makes the (attempted) resistance non-polarized.

DCA Pro doesn't even know what to do with the dual diode, and of course with a single diode it behaves just like the spec sheet.
#5
The test current for this mode is ~.5uA. I imagine the junction capacitance charges and then the current goes down so low that it's way over range.

I have a Peak DCA Pro that can do curve tracing, maybe I will see what it shows (not sure if the data will be useful).
#6
I have a Keysight 34465A.

Unfortunately the closest I have is 1n4002.

I measured the resistance across the cathodes with the anodes tied together.

I get a reading for the first two seconds or so, and then it creeps up and goes over range. Here's a picture:

#7
Xicons @ Mouser seem to have doubled in price again, to $10/200. Geez I thought $5/200 was expensive.

http://www.mouser.com/ProductDetail/Xicon/270-10K-RC/?qs=sGAEpiMZZMu61qfTUdNhG%2fNICg4NOtz5D3ChGIwXeqI%3d
#8
Not exactly the same, but I use these curved nose pliers all the time when populating PCBs: http://www.amazon.com/gp/product/B004UN8V7W/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Cheap enough to be throw away and made in the USA. Not as nice as the high end brands but still good stuff.
#9
Quote from: pickdropper on March 15, 2015, 08:31:41 PM
Quote from: dadler on March 15, 2015, 07:22:11 PM
Erem 530E10 PCB cutter

Only one pair left at a good price:

http://www.ebay.com/itm/one-pair-Anti-shock-PCB-Cutters-Erem-530E10-UP7B-/231241549857?pt=LH_DefaultDomain_0&hash=item35d7120821

I have a pair of these.  Useful things and that is a good price.
Yeah Amazon wanted $80+. There were two left when I found the auction last night, so I bought one (probably should have bought both! Hehe).
#11
They still have Panasonic ECQ-V's.
#12
Open Discussion / Re: Good soft-touch momentary switches
February 01, 2015, 09:01:06 PM
I was thinking of going with these, even though the quality is low:

http://www.ebay.com/itm/10-SPST-Momentary-SoftTouch-Push-Button-Stomp-Foot-Pedal-Switch-FREE-SHIPPING-/380837505085?pt=LH_DefaultDomain_0&hash=item58abaf283d

Anyone have any experience with these in particular?

They appear identical to the R13-85A1-05 I have a few of in hand. Then if I can find higher quality switches, I'll just swap them out. They are cheap enough.

The other option I was considering, is these: http://www.ebay.com/itm/10-6-pin-DPDT-Guitar-Effects-Pedal-Stomp-Foot-Metal-Switch-Momentary-12MM-M6P-OO-/380805097429?pt=Guitar_Accessories&hash=item58a9c0a7d5

And board mounting them, somehow. They are smaller and more versatile, but the quality is questionable. I have been working on a circuit similar to the 1776 finish line bypass, but with the switch board mounted as well. I might just pull the trigger and hope they don't suck that bad.
#13
Quote from: selfdestroyer on December 18, 2014, 08:36:31 PM
I am super happy with mine also. I love a good tool, for sure. I want to pick up a pair of needle nose next.

Cody

I am pretty happy with my Xcelites, for pliers at least. Not as nice as the Erems, but still made in the USA and high quality. I think Apex tool group owns all thse brands now, Xcelite, Erem, Weller, Crescent, Wiss, etc. Although most of the sub-brands seem to be relatively autonomous and have maintained quality for the most part.

Anyways, for electronics pliers I have the following, which I use all the time:

http://www.amazon.com/gp/product/B004UN8R1W/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

http://www.amazon.com/gp/product/B004UN9THI/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

http://www.amazon.com/gp/product/B004UN8V7W/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

http://www.amazon.com/gp/product/B004UN9TY6/ref=oh_aui_detailpage_o07_s02?ie=UTF8&psc=1

http://www.amazon.com/gp/product/B004UNFE9U/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1

http://www.amazon.com/gp/product/B004UN8UNW/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

http://www.amazon.com/gp/product/B004UNG83G/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
#14
Open Discussion / Re: Great one note solos
December 20, 2014, 03:24:54 AM


Around 0:30
#15
Open Discussion / Re: Well, there goes another $600
December 20, 2014, 03:19:45 AM
Quote from: madbean on December 20, 2014, 01:22:07 AM
There is an indicator below the trigger on the handle. It will blink red when it has reached operating temperatures.

Doh-! Not sure how I missed that. Thanks, and thanks for the recommendation/review of the FR-300.

Along that vein--Do you have a hot air rework station that you use for smd stuff?