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- Dave and Chris discuss the after-Easter candy/chocolate sales. And many other cultural differences.
- Injection molding plastics is an art and a necessary skill for high run products. Have you ever worked on molds?
- Chris has a new podcast about general engineering topics. This will free his brain to talk more circuits on The Amp Hour!
- Dave likes the new OSHW RC controller by Gizmo For You. Design files can be found at OS-RC.com.
- Kent Lundberg is still working through Jim Williams’ app notes. There is a great “best-of” page that points out the key ones to read.
- Though it’s still just a rumor, the DARPA grand challenge that could be forthcoming sounds awesome. Robots to save people…then conquer them all?
- Is there any use still for Germanium Diodes? Interesting uses in an old Sylvania manual. Have they been supplanted by Schottkey and other low drop variants? Or does an application still exist that requires them?
- Jack Ganssle calls out a similarly awesome old book for playing with BJT circuits. Lots of great applications for trying out analog circuits.
- Do you go to expensive conferences on your company’s dollar? Would you go to the forthcoming Hardware Innovation Workshop for $775?
- Conferences are good for networking, if nothing else. Chris recommends, “Never Eat Alone” by Keith Ferrazzi, a book on how to do just that.
- Chris used CircuitLab to share a SPICE-like circuit with a friend to illustrate a point. If you want to see the Low Pass Filter Chris entered into the program, see here.
- If you’re interested in sharing schematics (KiCAD only right now) in a more interactive way than PDFs, Circuit Bee is an option.
- Chris was trying to illustrate Bode Plots for the friend. Pronounced “Boh-Dee”, according to his (impressive!) wikipedia page.
- If you’re interested in analog filtering, specifically Sallen Key Filters, check out this app note from TI.
- We have a winner from last week’s contest, Lorin Tauss! Though it was not requisite, the chip he suggested was great and was this week’s CotW!
- Chip of the Week
- The AD8555 by Analog Devices is a zero-drift, digitally programmable sensor signal amplifier. You can tweak offsets with a DAC and clamp at a specified input voltage. Pretty cool!
- Switch mode power supplies (SMPS) are a topic most younger engineers (Chris included) take a while to get accustomed to (especially when starting with a linear regulator or similar). There was a great application note by Microchip about the basics of SMPS and the different topologies that are available.
- Dave has talked about the differences (and similarities!) between SMPS and Linear Regulators before on EEVblog:
[tube]http://www.youtube.com/watch?v=cM7t1Mpu7s4[/tube]
Thanks to Patrick Nouhailler for the Easter candy picture!
Hey Chris,
If you are in the valley on 14th, you should check out the Electronics Flea Market:
http://www.electronicsfleamarket.com/
Its kind of a ham swap meet and there’s a lot of other stuff there too. Its quite the fun event to see. It takes place in Cupertino and starts early Saturday morning.
Moulds cost $10k plus to make, depending on the complexity and just how many parts it consists of.
Cheaper ones are vacuum form moulds, where you start with a heated sheet blown or sucked into a form.
The engineering shop I use makes them, as well as car part moulds and jigs. To form steel sheet you use a mould that most likely is spark eroded from a massive block of tool steel, and some of these will only last a few thousand pressings before you refinish them. Your cooldrink cans are made with tooling that only lasts about a day of production before it wears too much and needs reworking.
For something electronics related fictive reading, poems and other.. Try some Stanislaw Lem (The cyberiada) .. He made plenty good and funny stuff, the earlier was written on Polish and translated, some later in English.
http://en.wikipedia.org/wiki/Stanis%C5%82aw_Lem
Good to hear about the new podcast Chris, I look forward to future episodes.
Chris
You inform us all about your new podcast an the reasons for it, then spend the next 10 mins talking about injection moulding??? Did I miss something? Lol. Had a quick listen sounds interesting…but don’t stretch yourself too thin, ‘er indoors may get the hump and cut down on playtime. 😉
You should check “Product status” for chip of the week! AD8555 is not recommended for new designs 🙁
I suggest this for the chip of the week:
LT3477 – 3A, DC/DC Converter with Dual Rail-to-Rail Current Sense.
It has 3 control loops (2xI, 1xU) and voltage control loop is very flexible
You can buy Germanium diodes in Amazon!
http://www.amazon.com/AmplifiedParts-1N34A-Germanium-Diode/dp/B004XNSJQM
As I understand, but don’t quote me for this, is that germanium diodes are excellent for RF detection, such as in receivers, cell phones, etc. The thing is that they are embedded in devices and not as standalone parts.
CH!
and BTW, check this!
http://youtu.be/CNJVhzOjWgU
I see now why those fluke 87 on Dave’s dedicated eevblog episode roasted with a cell phone call!
CH!
I have the classic RF probe with a Ge diode. I don’t know if a Ge diode is required. According to this guy and his measurements http://www.cliftonlaboratories.com/diodes_for_rf_probes.htm a Schottky is good, but not as good as a Ge diode for an RF probe.
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There are a few similar booklets on the web page where the 40 diodes book came from http://n4trb.com/AmateurRadio/SemiconductorHistory/SemiconductorDocuments.htm Although Sylvania seems to reuse the same circuit in multiple booklets.
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Reading the booklet titles I find it interesting that a semiconductor manufacturer at that time was actively addressing “Home Hobbyists, Experimenter and Model Maker”. Today most manufacturers are to arrogant to even acknowledge the existence of hobbyists.
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Here is another collector of such historic books http://www.tubebooks.org/technical_books_online.htm#General%20Electrical%20Engineering%20Books Some are still worth reading.
Germanium diodes, in analog audio overdrive/distortion effects.
http://au.element14.com/microsemi/1n34a/diode-germanium/dp/1651088?Ntt=1N34A
Germanium stuff is hard to find on Disti sites, but there is plenty of SiGe stuff on Digikey.
http://search.digikey.com/scripts/DkSearch/dksus.dll?vendor=0&keywords=sige&stock=1
OSHW RC is opensource in name only, they didnt post ANY files, all they do is try to get you to preorder $500 Android phone as an interface.
Unless by open source he means posting Wiki with “Module Replacement & Installation Tutorials”
+ they sell radio modules with no certs, there was a post on hackaday about them and someone pointed to a message by the author of that project claiming he doesnt need any certs because nobody does them, and then messages from people linking to ALL the RC manufacturers pages full of certs.
So he claims to be Open source while not providing anything and sells radio modules with no certificates.
About the injection molding (Warning, you might get an orgasm watching his creations) :
http://lcamtuf.coredump.cx/rstory/
http://lcamtuf.coredump.cx/guerrilla_cnc1.shtml
Guerrilla guide to CNC machining, moldmaking, and resin casting by an IT security software hacker.
OSHW RC told me they haven’t put the files up yet because they are huge, and haven’t determined the best way to do it yet. But they will be going up.
Try searching for SiGe devices instead, used for high frequency very fast devices – think of a front end amplifier for a 300GHz device.