Hacked Gadgets Forum

September 22, 2013

Mercury Arc Rectifier

at 2:16 pm. Filed under Vintage Electronics

 Mercury Arc Rectifier_2


This is an interesting look into old school rectifiers. Mercury Arc Rectifier have now been replaced with solid state bridge rectifiers which are inexpensive and reliable. I wonder how many of these Mercury Arc Rectifiers are still in operation, it seems that lots of this old stuff will be kept in use until it fails.

“Operation of the rectifier relies on an electrical arc discharge between electrodes in a sealed envelope containing mercury vapor. A pool of liquid mercury acts as a self-renewing cathode that does not deteriorate with time. The mercury emits electrons freely, whereas the carbon anodes emit very few electrons even when heated, so the current of electrons can only pass through the tube in one direction, from cathode to anode, which allows the tube to rectify alternating current.

Once an arc is formed, electrons are emitted from the surface of the pool, causing ionization of mercury vapor along the path towards the anodes. The mercury ions are attracted towards the cathode, and the resulting ionic bombardment of the pool maintains the temperature of the emission spot, so long as a current of a few amperes continues.”




Mercury Arc Rectifier

September 19, 2013

Heavy Lifting Copters

at 11:39 pm. Filed under Funny Hacks, Insane Equipment, What Were They Thinking


Hobby King had a great plan to get people building big lifting copters. They call it the Beer Lift but water is used as a substitute although I am sure an equal weight of beer is weighting behind the scenes for enjoying after the competition. The last video isn’t a heavy lift but make sure you watch what happens at 2:20, that is some good flying!





September 18, 2013

$200 MakiBOX 3D Printer

at 2:21 am. Filed under Cool Gadgets, Electronic Hacks

 MakiBOX 3D Printer_1840


Who would have thought that we would see a $200 printer this early! Looks like the MakiBOX by Jonathan Buford is currently the cheapest 3D printer around (please correct me in the comments if there is something cheaper). Now that Makerbot has gone through some drastic changes and is no longer open source are we going to see lots of low cost entry level machines fill the void? The current MakiBOX uses a 0.4mm nozzle can print 0.1mm layers. You can see lots of their previous pre-production versions on their Youtube site. Looks like there has been lots of refining over the months but just like any new machine there is sure to be some more fine tuning needed by the builder. Tweaking the printer to work just right might be half of the build fun though.


MakiBOX 3D Printer_1845


MakiBOX 3D Printer


September 16, 2013

Where will 3D Printing Take us?

at 1:40 pm. Filed under Insane Equipment


If you look at a modern construction site these days you don’t generally see very many craftsmen carving intricate details into the buildings, what you see are pre-manufactured sections being assembled. With the revolution that is happening with 3D printing I think it is just a matter of time when many custom details are once again built onsite. Not by skilled craftsmen but by precision universal machines. I can envision a day when a large concrete printer will be assembled onsite and print the walls of your new house leaving voids where your windows and doors will go. For cold climates the same printer could be equipped with a method of printing insulating material while it is printing the structural walls. Smaller printers could print items that need more precision from plastics. Gone will be the day where new developments have 2 or 3 styles of houses one after another, the house printer can make every house unique. I look forward to seeing domes and round corners instead of the rectangular cookie cutter houses that are built today.



September 14, 2013

High Voltage Transformer Autopsy

at 6:17 pm. Filed under Electronic Hacks


Ever want to see what is inside a huge High Voltage Transformer? The Geek Group got one donated and took it apart for everyone to have a peek. The transformer is an old medical XRAY transformer, there is a huge safety disconnect contactor under the top cover and the entire case is filled with mineral oil for high voltage isolation.  They spread it out over 3 videos and some of it is a bit slow. The first video doesn’t show much other than using a fork lift to lift the top out, the second video around the 8:40 mark shows the transformer being lifted out of the can. Video 3 goes over much of the guts of the huge transformer. At 4:50 in video 3 you can see a huge stack of series capacitors that was housed in the metal box on the side. Interesting how the paper holds up after many years of being submerged in oil.



September 13, 2013

Complimentary Subscription to The Scientist Magazine

at 2:22 pm. Filed under Educational



We have a special limited time offer. Thanks to The Scientist Magazine for offering our readers a chance to subscribe to this cool magazine for free. It is a limited time offer so if you are reading this when the offer has ended and would like to purchase the magazine you can go here to buy it. Hacked Gadgets does receive a small payment for each subscription to any of our Free Magazine Subscriptions so we appreciate the support from all who subscribe to the free magazines that we offer.

Click Here to Subscribe for Free

“The Scientist is the magazine for life science professionals. For 20 years they have informed and entertained life scientists everywhere. Their target audience is active researchers that are interested in maintaining a broad view of the life sciences by reading articles that are current, concise, accurate and entertaining.”

Hacked Stamps.com Scale Displays Weight

at 2:09 pm. Filed under DIY Hacks, Electronic Hacks

Hacked Stamps.com Scale Displays Weight


Stamps.com seems to be promoting their service in all corners of the web these days. Their scales are a big part of how their service works to allow you to print your own stamps at home. Only thing is the fully functional scale they provide is only good if it is connected to a computer since there is no display on it (looks like the new scales do have displays on them). Oleg had one of these scales and wanted to use it while it wasn’t plugged into the computer. Using an Arduino and a HD44780 LCD he can now see the weight that the scale is reading.

Via: Hack a Day

“For this project I used the following:

  1. An Arduino board. Standard size board, such as UNO, Duemilanove or Leonardo, will work
  2. USB Host Shield
  3. Toshiba HD44780-compatible LCD display, in 16×1 or 16×2 configuration. If you’re planning to use this sketch for something else, like data logging, the display is optional – all output from the scale is repeated to the serial port
  4. Stamps.com 5lb digital scale. Scales are standard HID devices with usage table 0x8d, therefore, scales from other brands may work as well with no or minimal modifications to the code
  5. USB Host library



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