Pick And Place At Home

June 9, 2011 by Mike Nathan 13 Comments

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[Erv’] wrote in to share a manual pick and place he recently constructed. He builds a lot of circuits using SMD parts, and after looking at commercial pick and place systems, he decided it would be far cheaper to build his own. Using some components he had sitting around the house, along with a few store-bought pieces, he put the pick and place together for about $50, which is pretty cheap when you think about it.

The base is made from wood he had left over from another project, which has a sliding rail and a movable arm rest built into it. A rotating TV stand is used to hold workpieces, allowing PCBs to be repositioned at will while parts are being laid out. A square furniture leg is used as a support arm, holding the pick and place vacuum pen in place at the end of a small accordion hinge. As in most DIY pick and place installations, a small aquarium pump has been used to provide the suction needed to pick up SMD parts.

It’s a great build with plenty of useful features, and comes in far cheaper than any commercial system you’ll find out there.

Designing And Building A Bench Supply

June 8, 2011 by Mike Szczys 13 Comments

[Scott’s] been digging around the back issues of the Internet to find this project. He blew the dust off and sent us a link to an article that traverses the design and build process of a bench power supply.

[Guido Socher] does an excellent job of presenting his bench supply project. So many others show of the final product, but he has gone out of his way to make sure we understand the design principles that went into it. He starts off by talking about the simplest possible supply design: a transistor and Zener diode which generates a reference voltage. He goes on to discuss the problems with this simplified circuit and how to address them, covering the gotchas that pop up at each step in the process.

Once he designed the circuit and laid out some boards he began building an enclosure. We love his tip about using a stick pin and an unpopulated through-hole PCB to mark button locations on the front bezel of the case. The final design is shown above, and includes a laptop brick to translate mains power into a 24V 3A DC feed for his custom circuitry.

Building A One-ton Linear Servo

June 7, 2011 by Mike Nathan 13 Comments

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A while back, [Windell] from Evil Mad Scientist Laboratories wrote up an article for Make Magazine detailing how he built a one-ton, servo-controlled scissor jack for under $100. He dropped us a line to let us know that the project details have been released for free at Make Projects, so we stopped by to take a look.

The project starts out by pulling apart an electronic scissor jack to get access to the solder pads for the up and down buttons. Once wires are added there, a servo is the next victim. [Windell] recommends using an old servo with a busted motor, but you can use a good one just the same. The servo’s pots are replaced with 10 turn pots, and then wired up to a controller board, to which the jack is also connected. Then, to provide feedback to the servo, a string is looped around the top of the jack, which is used to turn the pots added in the previous step.

[Windell] says that the setup works quite well, though we imagine the duty cycle might be a bit short before adjustments are required. Regardless, it’s a quick way to get a heavy load lifted with servo precision.

The Complete AVR Programmer That Fits In Your Pocket

June 6, 2011 by Nick Schulze 13 Comments

We have seen a few very nice and polished AVR based projects from [Manekinen] over the last few years. Now he has just finished his latest project, the µProg, a super tiny complete AVR programmer with a bunch of features. The µProg completely eliminates the need for a computer to program your embedded AVR chips.

The programmer fits entirely behind an LPH7779 graphics display, and accepts any FAT16/32 formatted microSD cards. Some features include, reading, writing or verifying flash, eeprom, fusebits and lockbits, it also shows amusing animations after every operation. The device is controlled with the use of 4 tactile buttons and operates on a couple of CR2032 batteries.

For an amazingly detailed write up including pictures, eagle files and firmware check out his website. The video embedded after the break has a nice demonstration of the µProg in action, showing off a few of the features and animations. You should also check out his PSU monitor and a spectrum analyser

Continue reading “The Complete AVR Programmer That Fits In Your Pocket” →

How To Make A Hand Drill Out Of A Pencil Sharpener

June 5, 2011 by Jeremy Cook 27 Comments

Necessity is the mother of invention, or so they say. [Jason] was in such a situation where he needed to install some safety railing at his grandmother’s house. He didn’t have the necessary tools available, like a drill, so he fashioned one himself out of a pencil sharpener and some fittings and wire that he was able to find.

Although crude, and probably not what one would choose to use if an actual drill was available, this “drill-pencil-sharpener” actually does a pretty decent job of cutting through plywood as seen in the video after the break. Continue reading “How To Make A Hand Drill Out Of A Pencil Sharpener” →

Putting The Flex Back Into The RDS 80 Soldering Station

June 5, 2011 by Mike Nathan 16 Comments

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[Markus] was looking to upgrade his soldering station, and having had good luck with Ersa in the past, opted to purchase one of their new stations, the RDS 80.

Once he got the iron home however, he was very disappointed to see that while his previous Ersa model used a silicone cable to connect the iron to the base station, his new iron used a stiff, non heat-resistant PVC cable instead. He found plenty of people complaining about the same issue online, but no one seemed to have a fix, so he set off to figure it out for himself.

He thought that he could disassemble the iron and change the wiring out once it was apart, but it seemed that there was no way of doing so without destroying it. Instead he chopped the wire off at the end of the soldering iron, replacing it with a new silicone cable. He did the same thing at the base station end, since he was forced to reuse the proprietary 4-pin plug Ersa decided to use there.

His modifications worked out nicely, and he is now happily soldering away.

If you happen to have one of these soldering stations, be sure to swing by his site to get a closer look at how he swapped out the cable.

DIY High Voltage Electric Field Detector

June 3, 2011 by Mike Nathan 23 Comments

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Who needs a Fluke high voltage detector when you’ve got one of these things?

Actually, we still recommend a professional high voltage detector for serious work, but you’ve got to like this electric field detector that [Alessandro] recently put together.

The detector works by using a JFET to detect the high impedance electric fields that are generated by high voltage lines. The JFET amplifies the signal while dropping the impedance in order to drive a pair of NPN transistors which are used as a threshold amplifier. Once the voltage hits 3V, an LED is lit, indicating the presence of high voltage near the detector’s probe. A wire-wrapped resistor does double-duty serving as the probe while providing a high impedance path to ground, ensuring that stray charge does not accumulate on the JFET’s gate, causing false readings.

It’s a neat project, and something that can be constructed in no time, making it perfect for beginner electronics classes.

Keep reading to see a quick video of the HV detector in action.

Continue reading “DIY High Voltage Electric Field Detector” →