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General Chat / Re: Tickling the Dragon's Tail
« Last post by JohnnyP on Today at 04:36:21 PM »
Yes, time to dust off my copy of The Making of the Atomic Bomb.

I have always been fascinated by the bomb, wondering how people figured out it could be done.

It must have been the early '90's when I found it on the shelf at Barnes and Noble.  But, that was before the internet, when I had time to read.
@Fank1 - if I set it up like that I would get pulse-trains due to noise like I mentioned in my second question.
Test Equipment / NEW $50 multimeter shootout - 15 DMMs compared
« Last post by retiredcaps on Today at 04:31:37 PM »
Saw this new (Aug 2, 2015) and am downloading now to watch.

This person, eevblog member, 5ky, also has done some other DMM reviews in the past.
General Chat / Re: huge vending machine replaces village shop
« Last post by rx8pilot on Today at 04:30:07 PM »
There is no question that the details of making this thing profitable and have some consumer acceptance is nuts. One limit switch will shut your store down until a $150/hr technician is flown in from another city to fix it.

Lots and lots of challenges to make it work.
Axel, do you have any schematic of your fixed version? Could you maybe post it here?

Thank you, Lukas


It seems that there is so much discussion about the circuit already that all of the issues are covered. Since this circuit seems to be doomed I'm not too eager to publish my revision. (and there is not updated paper version anyway).

However, as a summary, comparing to the Electronics Lab version:
- transformer 180VA 38V
- Q3, U1 and U3 regulated to 26V
- U2 regulated to 35V
- U2 = OPA604
- removed R13, R14, Q1 circuit
- much bigger input and output caps
- Q4 as double 2N3773
- "adapter style" -solution in 5V reference. Used the original circuit and ISL21009 based voltage reference
- R7 to 20W
- small tweaks in component values, added few coupling caps to new power rails etc etc
- overheat protection capability (by separate control unit)
(proper heat dispatching must be taken care of - as probably mentioned everywhere)

I'm glad I have always been nice to noobs online about all the subjects I have helped them with over the years.
I did the calibration when trying to find the probe ratio, thinking maybe it was not properly calibrated.

The scope said to be sure there was NO SIGNAL at all, so I removed all probes and told it to start the calibration.

THEN I later find out in the manual it says you need to connect the TRIGGER OUT in the back to both the CH1 and CH2 and the EXT TRIGGER jacks, before doing the self-calibration!

Whaaat? I was having trouble comprehending this, so I went looking. Sure enough on page 13-11 of the  manual (p.237 of 266 in the .pdf) it says to do this.... while displaying the screen image of the message that says just the opposite. (Says not to connect any signal to the input channels.)

On the Rigol site, in the FAQs for the DS2000 series, I found the following:

OK thanks; that is reassuring. And also confirms I was not hallucinating! I need to go find a revised version of the manual then.
General PCB/EDA/CAD Discussions / Re: PCB/EDA software list
« Last post by wxm145 on Today at 04:24:28 PM »
 ;D, pcb sample quick turn, offer fast, payment is safe way--paypal
our website is online quick quote.
General Chat / Re: IP issue
« Last post by JohnnyP on Today at 04:21:42 PM »
We turned over the files today.  Then I asked him to google "nolo who owns the code" and read example 1.  He did a lot of arm waving and basically waived it off.

He said one of my monthly invoices had a line item for x hours of programming (I don't know if it did or not, I don't have any in my files that say that, maybe I verbalized it), so that means he paid for the software.  He said he explained that to his attorney yesterday, who said something like software for electronics is a little tricky, but he agreed with his client that he paid for it.

I know, I know.  (note to self) Just drop it, John.
I don't get the point of this thing. It is too bulky to use as a probe. With this size it should have a display and autonomous use. It is a fail IMHO.
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