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Review: Elenco CS-440 capacitor box

Started by John Larkin October 23, 2016
I'm tuning a bunch of control loops on breadboards so I figured a
capacitor box would be handy. Amazon had the Elenco so I got one.

It was intermittent so I opened it up to see why. Amazing garbage.

https://dl.dropboxusercontent.com/u/53724080/Gear/Elenco/Elenco_CS-440_1.JPG

https://dl.dropboxusercontent.com/u/53724080/Gear/Elenco/Elenco_CS-440_2.JPG

https://dl.dropboxusercontent.com/u/53724080/Gear/Elenco/Elenco_CS-440_3.JPG

https://dl.dropboxusercontent.com/u/53724080/Gear/Elenco/Elenco_CS-440_4.JPG

https://dl.dropboxusercontent.com/u/53724080/Gear/Elenco/Elenco_CS-440_5.JPG

Note the reference designators in that last pic!



-- 

John Larkin         Highland Technology, Inc

lunatic fringe electronics 

On Saturday, October 22, 2016 at 8:39:44 PM UTC-7, John Larkin wrote:
> I'm tuning a bunch of control loops on breadboards so I figured a > capacitor box would be handy. Amazon had the Elenco so I got one.
Amusingly-pointless exercise: build a box that uses a fast high-voltage ADC and DAC to emulate any two-wire component of any value, in the same undemanding conditions where you would use a cheap substitution box like this one. -- john, KE5FX
Den søndag den 23. oktober 2016 kl. 05.39.44 UTC+2 skrev John Larkin:
> I'm tuning a bunch of control loops on breadboards so I figured a > capacitor box would be handy. Amazon had the Elenco so I got one. > > It was intermittent so I opened it up to see why. Amazing garbage. > > https://dl.dropboxusercontent.com/u/53724080/Gear/Elenco/Elenco_CS-440_1.JPG > > https://dl.dropboxusercontent.com/u/53724080/Gear/Elenco/Elenco_CS-440_2.JPG > > https://dl.dropboxusercontent.com/u/53724080/Gear/Elenco/Elenco_CS-440_3.JPG > > https://dl.dropboxusercontent.com/u/53724080/Gear/Elenco/Elenco_CS-440_4.JPG > > https://dl.dropboxusercontent.com/u/53724080/Gear/Elenco/Elenco_CS-440_5.JPG
sure it is not a diy kit someone returned assembled? :P
> > Note the reference designators in that last pic!
I guess they use the same PCB for a resistor box -Lasse
On Sat, 22 Oct 2016 22:43:06 -0700 (PDT), "John Miles, KE5FX"
<jmiles@gmail.com> wrote:

>On Saturday, October 22, 2016 at 8:39:44 PM UTC-7, John Larkin wrote: >> I'm tuning a bunch of control loops on breadboards so I figured a >> capacitor box would be handy. Amazon had the Elenco so I got one. > >Amusingly-pointless exercise: build a box that uses a fast >high-voltage ADC and DAC to emulate any two-wire component of >any value, in the same undemanding conditions where you would >use a cheap substitution box like this one. > >-- john, KE5FX
We make resistor simulators, and that's plenty hard enough. -- John Larkin Highland Technology, Inc lunatic fringe electronics
On Sat, 22 Oct 2016 20:39:35 -0700, John Larkin
<jjlarkin@highlandtechnology.com> wrote:

>I'm tuning a bunch of control loops on breadboards so I figured a >capacitor box would be handy. Amazon had the Elenco so I got one. > >It was intermittent so I opened it up to see why. Amazing garbage.
Elenco makes toys, educational kits, and test equipment: <http://www.elenco.com> <http://www.elenco.com/product/toy> I can't determine which classification the CS440 falls into. If you're having difficulties, the documentation at: <http://www.elenco.com/admin_data/pdffiles/cs440.pdf> suggests: "If you are a student, and any parts are missing or damaged, please see instructor or bookstore." Ah, I think I found the problem. See page 3: "Use only rosin core solder of 63/37 alloy." Looking at the dull solder connections in your photo, it appears that someone has used RoHS solder. The documentation also has a troubleshooting section, which consists primarily of mechanical and soldering defects. It would appear that troubleshooting bad soldering is common and part of the OOB (out of box) experience. The schematic on Pg 6, shows that all the capacitors have resistor reference designators. It would seem that the PCB was originally designed as a resistance substitution box. I think you could have done better by purchasing something that was not a "toy". -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
On Sun, 23 Oct 2016 09:00:14 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:

>On Sat, 22 Oct 2016 20:39:35 -0700, John Larkin ><jjlarkin@highlandtechnology.com> wrote: > >>I'm tuning a bunch of control loops on breadboards so I figured a >>capacitor box would be handy. Amazon had the Elenco so I got one. >> >>It was intermittent so I opened it up to see why. Amazing garbage. > >Elenco makes toys, educational kits, and test equipment: ><http://www.elenco.com> ><http://www.elenco.com/product/toy> >I can't determine which classification the CS440 falls into. > >If you're having difficulties, the documentation at: ><http://www.elenco.com/admin_data/pdffiles/cs440.pdf> >suggests: > "If you are a student, and any parts are missing or damaged, > please see instructor or bookstore." > >Ah, I think I found the problem. See page 3: > "Use only rosin core solder of 63/37 alloy." >Looking at the dull solder connections in your photo, it appears that >someone has used RoHS solder. > >The documentation also has a troubleshooting section, which consists >primarily of mechanical and soldering defects. It would appear that >troubleshooting bad soldering is common and part of the OOB (out of >box) experience. > >The schematic on Pg 6, shows that all the capacitors have resistor >reference designators. It would seem that the PCB was originally >designed as a resistance substitution box. > >I think you could have done better by purchasing something that was >not a "toy".
Usually Amazon sells decent stuff. What benefit is it to Elenco to sell trash? It takes no more effort to do it right. I also got their resistance box, the one with rows of slide switches, and it seems fine. It's very accurate. Can anyone recommend a reasonably priced small c-box? I'm tuning voltage regulators, switchers and homebrew LDOs mostly. I don't have trustworth Spice models for everything. -- John Larkin Highland Technology, Inc lunatic fringe electronics
On Sat, 22 Oct 2016 22:43:06 -0700 (PDT), "John Miles, KE5FX"
<jmiles@gmail.com> wrote:

>On Saturday, October 22, 2016 at 8:39:44 PM UTC-7, John Larkin wrote: >> I'm tuning a bunch of control loops on breadboards so I figured a >> capacitor box would be handy. Amazon had the Elenco so I got one. > >Amusingly-pointless exercise: build a box that uses a fast >high-voltage ADC and DAC to emulate any two-wire component of >any value, in the same undemanding conditions where you would >use a cheap substitution box like this one. > >-- john, KE5FX
Not so advanced, but a little USB box, full of small relays and resistors and caps, maybe even some inductors, would be cool. Some topological cleverness could keep the parasitics down. Then a PC program could interface to an oscilloscope, be given some performance rules, and could optimize things. I sometimes get "lost in space" doing manual tuning. OK, separate small R and C boxes for versatility. The minimal PC program would just have sliders, or solution-space scanners, so I can tune by hand or semi-automatically, and look at the scope until I see what I like. A 2D slider would be cool for adjusting, say, a series RC that compensates a switcher. This would run maybe 1000x faster than Spice, and would be a lot more realistic. I really want that. -- John Larkin Highland Technology, Inc lunatic fringe electronics
John Larkin wrote...
> >>> I figured a capacitor box would be handy. >>> Amazon had the Elenco so I got one. >>> >>> It was intermittent so I opened it up to see why. >>> Amazing garbage.
It looks to me like the PCB does not have plated- through holes, leading to inferior soldering.
> Usually Amazon sells decent stuff.
I can attest that they sell piles of counterfeit products, labeled as if they're the real thing. Most of these are imported from the Pacific rim, and put up on Amazon as "Other Sellers". However, in this case the seller is Elenco, and it's a Prime item. So it's genuine crap. -- Thanks, - Win
On Sun, 23 Oct 2016 10:01:11 -0700, John Larkin
<jjlarkin@highlandtechnology.com> wrote:

>On Sun, 23 Oct 2016 09:00:14 -0700, Jeff Liebermann <jeffl@cruzio.com> >wrote:
>>Elenco makes toys, educational kits, and test equipment: >><http://www.elenco.com> >><http://www.elenco.com/product/toy> >><http://www.elenco.com/admin_data/pdffiles/cs440.pdf>
>Usually Amazon sells decent stuff.
Agreed, but the Amazon name is no guarantee of quality. Caveat Emptor.
>What benefit is it to Elenco to sell trash? It takes no more effort to >do it right.
Well, since Elenco makes kits and educational products, I can image a situation where a skool might buy a few kits, have their students build them, and sell the results on eBay or Amazon. The proceeds from the sales would fund the next round of kit purchases. Of course, I have no proof this is what happens, but if true, it does help explain the general lack of soldering quality.
>I also got their resistance box, the one with rows of slide switches, >and it seems fine. It's very accurate.
Probably a better class of student kit builders.
>Can anyone recommend a reasonably priced small c-box? I'm tuning >voltage regulators, switchers and homebrew LDOs mostly. I don't have >trustworth Spice models for everything.
I made my own using a 10 position thumbwheel switch and some carefully selected capacitors. No packaging, just a switch and a tangle of caps. You could do the same with a 10 position rotary switch. I did some Googling and found these: <https://www.amazon.com/Electronics-Salon-9999uF-Step-1uF-Programmable-Capacitor/dp/B00UT03HO2/> <https://www.amazon.com/Electronics-Salon-9999nF-Step-1nF-Programmable-Capacitor/dp/B00USZV56K/> <https://www.amazon.com/Electronics-Salon-1000uH-Standard-Programmable-Inductor/dp/B00UT07B9E/> I'm not sure how long the dip switches will last. Manual: <http://www.audiowind.com/pdf/E-101.pdf> This looks nice but costs more: <https://www.tindie.com/products/redrocketlabs/capacitor-decadesubstitution-box-/> eBay perhaps: <http://www.ebay.com/sch/i.html?_nkw=capacitor+substitution+box> Or maybe just buy an Elenco CS-440 kit, and build it yourself with better soldering technique? -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
On Sunday, October 23, 2016 at 12:00:18 PM UTC-4, Jeff Liebermann wrote:
> On Sat, 22 Oct 2016 20:39:35 -0700, John Larkin > <jjlarkin@highlandtechnology.com> wrote: > > >I'm tuning a bunch of control loops on breadboards so I figured a > >capacitor box would be handy. Amazon had the Elenco so I got one. > > > >It was intermittent so I opened it up to see why. Amazing garbage. > > Elenco makes toys, educational kits, and test equipment: > <http://www.elenco.com> > <http://www.elenco.com/product/toy> > I can't determine which classification the CS440 falls into.
It says right there in black and white: The assembled "instrument" is the CS-440 and the corresponding "kit" is K-38.
> > If you're having difficulties, the documentation at: > <http://www.elenco.com/admin_data/pdffiles/cs440.pdf> > suggests: > "If you are a student, and any parts are missing or damaged, > please see instructor or bookstore." > > Ah, I think I found the problem. See page 3: > "Use only rosin core solder of 63/37 alloy." > Looking at the dull solder connections in your photo, it appears that > someone has used RoHS solder. > > The documentation also has a troubleshooting section, which consists > primarily of mechanical and soldering defects. It would appear that > troubleshooting bad soldering is common and part of the OOB (out of > box) experience. > > The schematic on Pg 6, shows that all the capacitors have resistor > reference designators. It would seem that the PCB was originally > designed as a resistance substitution box. > > I think you could have done better by purchasing something that was > not a "toy".
It's not bad for an educational kit. Looks like that company is frozen in the 1970s or something, kinda pathetic offering.
> > > -- > Jeff Liebermann jeffl@cruzio.com > 150 Felker St #D http://www.LearnByDestroying.com > Santa Cruz CA 95060 http://802.11junk.com > Skype: JeffLiebermann AE6KS 831-336-2558