110v temperature controlled soldering station build no. 2

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Mike Doughty from PCB Smoke shared his DIY 110v temperature controlled soldering station in the project log forum:

This project is build number 2 of a 110v temperature controlled soldering station. It is a follow-up post to the project that I was working on last October.
Blog post with complete details here.
This version has a couple of improvements over the first build. This new soldering iron is a better unit and was less expensive than the first one.
A chisel tip plus a selection of other tips was available for this soldering iron instead of being limited to a conical tip only.

More details at PCB Smoke project page.

Via the forum.

Check out the video after the break.

Slider controller with auto-reverse and variable speed control

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Paulo built a DIY electronic camera slider controller based on a small PIC microcontroller. It supports auto-reverse and variable speed:

These motorized sliders share a common electronic controller design that provides speed control for the gear motor and also an auto-reverse feature using limit switches. In this article , I’ll go over the electronics and software for this slider controller and show how you can build your own.

Project info at paulorenato.com.

Check out the video after the break.

Modifying RAM SPD data

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Zak Kemble wrote a post on his blog showing how he modified the RAMs Serial Presence Detect (SPD) data:

Recently I brought some low-power Mini-ITX motherboards; a Gigabyte GA-N3050N-D3H and a Biostar N3050NH. These boards take SO-DIMM DDR3 RAM, the sort found in laptops. The boards are both pretty much the same, however the Gigabyte board lacks quite a few BIOS features and settings that the Biostar board has. One of those missing features was being able to set the RAM frequency. I wanted to run the RAM at its lowest frequency of 800MHz, but the Gigabyte board would run it at the its normal frequency of 1600MHz. Running at 800MHz reduced idle power consumption by about 0.12W on the Biostar board, a ~2% reduction… yeah ok, it’s a teeny tiny amount, but it was just a matter of flicking a switch.
To remedy this it looked like I was going to have to modify the RAMs Serial Presence Detect (SPD) data.

More details at Zak’s blog.

Using Altium for a DirtyPCBs order

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Jarrett  has written an article describing a technique of using Altium for a DirtyPCBs order:

This is a pretty rare combo: using a premium PCB package with the budget board house.
Kinda funny.
Generally these small run PCB houses provide DRU and CAM files for EAGLE design rule checking and Gerber outputs, respectively. Because I’m using Altium, I had to make it up as I went along.
It gets much easier when you understand what Gerber files are. While we’re all used to standard, unified output formats that contain all of the data we need, Gerbers are very much still a holdover from manufacturing in the 80s.
When you export these, a whole bunch of files get generated. This is intimidating, but don’t panic! They all have different extensions like GBO, GTL, etc. These are all the same type of file.

Details at Jarrett’s blog.

Via the contact form. Thanks for the tips!

Measuring SDR noise figure

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David has written an article on measuring SDR noise figure:

One number I wanted to know was the Noise Figure (NF) of the SDR. Mark has a bunch of SDRs so we got on a roll and checked out the NF on all of them.

Now there are a lot of people playing with SDRs, but very few tutorials on HowTo engineer radio systems. For example, how to answer questions like “can I send this many bit/s over X km with SDR hardware Y?” So I thought it might be useful to explain how we measured Noise Figure (NF) and present the results for a bunch of SDRs.

More details at Rowetel site.

How do I FPGA?

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TC-Engineering writes:

I’ve been thinking about building stuff with FPGA’s for a while, and usually get turned away because FPGA’s are considerably harder to implement than microcontrollers since they have no on-chip memory. It is necessary to re-program the gates every time they power up, which requires an external flash memory chip. There aren’t great references online for the DIY community, so I figured I’d post how to get this working. Not using dev boards opens a world of opportunities, so I’m a proponent of not using Arduino’s and their FPGA equivalent for too long (sure, they’re good to get started with, but don’t become dependent)
Not wanting to screw up an expensive complex board by being a first-timer at putting an FPGA into a circuit, I figured I’d build a little test board with the cheapest Spartan 6 you can get (about $10), which comes in a solderable TQFP144 package. Sadly, most high end FPGA’s are BGA and therefore quite hard to solder as a DIY project.

More details at TC-Engineering blog.

Using “Ultracapacitors” as a power conditioner and ballast for transient high-power loads (or “How to run your HF rig from D-cells” – sort of…)

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KA7OEI writes:

An advantage of Lead-Acid, NiCd, Lithium Ion and some NiMH cell types is that they have quite low internal resistance compared Alkaline cells: Even an aging lead acid battery that is near the end of its useful life may seem to be “OK” based on a load test as its internal resistance can remain comparatively low even though it may have lost most of its storage capacity!
One could ask, then, why now simply parallel Alkaline cells, with their ready availability, long life and high storage capacity with one of these other cell types and get the best of both worlds? In theory you could – if you had some sort of charge control circuitry that was capable of efficiently meting out the energy from the alkaline pack and using it to supplement the “other” storage medium (e.g. lead-acid, lithium-ion, etc.) but you cannot simply connect the two types in parallel and expect to efficiently utilize the available power capacity of both types of storage cell – this, due to the wildly different voltage and charge requirements.
Even if you do use a fairly small-ish (e.g. 7-10 amp-hour) lead-acid or lithium-ion battery pack, even though its internal resistance may be low compared to that of alkaline packs, it likely cannot source the 15-20 amp current peaks of, say, a 100 watt SSB transceiver without excess voltage drop, particularly if it isn’t brand new.

This is where the use of “Ultracapacitors” come in.

Details at KA7OEI’s blog.