Custom Circuit Drives A Small Round CRT Display

November 5, 2012 by Mike Szczys 31 Comments

[Svofski’s] latest hack seeks to do no more than look cool on his desk. We’d say mission accomplished. He doesn’t even need anyone around to be proud of the small round CRT display unit he put together. Just having it hum away next to him will be more than enough to keep him going when regular work gets a bit tedious.

One of the biggest challenges when working with a cathode ray tube is the supply. He compares the requirements with that of Nixie tubes, and this is quite a bit more challenging since he wants to generate the 750V from a 12V DC source. To pull it off he hand wound his own transformer. There are two secondary coils, one for the cathode heater and the other as the supply. You can see a brief clip of the unit in action after the break.

Take note of the PCB section of his writeup. He took a meandering route through several different software packages before printing the board. It started with Eagle, moved to freerouting.net, which produced a Specctra file that he converted to gEDA using a Python script.

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CRT Reborn As A Planter

August 18, 2012 by Mike Szczys 18 Comments

It does make us sad to see all the waste generated as we move from CRT monitors and televisions to flat panel offerings. Here’s a way to cut down just a bit on how much is going to waste. [Denizpa] turned a CRT monitor into a planter.

The project is very straight-forward. First remove the plastic body from the electronic guts. Next you’ll want to choose your paint colors. While you’re at the home store, pick up a sanding sponge as well. [Denizpa] used 320 grit to sand all of the outside surfaces to help ensure the paint would bond well. Once the paint dried four plastic corner brackets were screwed in place to add some interest to the bottom of the planter. It’s not quite time to plant though, there’s way too many holes in the case to just fill it up with soil. A black plastic garbage bag serves as a liner and completes the project.

No mention on what to do with the guts you removed. If you have an idea let us know in the comments section.

Building A CRT And Bathing Yourself In X-rays

July 12, 2012 by Brian Benchoff 15 Comments

For the Milan design week held last April, [Patrick Stevenson Keating] made a cathode ray tube and exhibited it in a department store.

The glass envelope of [Keating]’s tube is a very thick hand-blown piece of glass. After coating the inside of the tube with a phosphorescent lining, [Keating] installed an electrode in a rubber plug and evacuated all the air out of the tube. When 45,000 Volts is applied to the electrode, a brilliant purple glow fills the tube and illuminates the phosphor.

Since the days of our grandfathers, CRTs have usually been made out of thick leaded glass. The reasoning behind this – and why your old computer monitor weighed a ton – is that electron guns can give off a substantial amount of x-rays. This usually isn’t much of a problem for simple devices such as a Crookes tube and monochrome CRTs. Even though [Keating] doesn’t give us any indication of what is being emitted from his tube, we’re fairly confident it’s safe for short-term exposure.

Despite being a one-pixel CRT, we can imagine using the same process to make a few very interesting pieces of hardware. The Magic Eye tube found in a few exceptionally high-end radios and televisions of the 40s, 50s, and 60s could be replicated using the same processes. Alternatively, this CRT could be used as a Williams tube and serve as a few bits of RAM in a homebrew computer.

You can check out the tube in action while on display after the break, along with a very nice video showing off the construction.

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Making Instagram With An Old CRT

May 25, 2012 by Brian Benchoff 14 Comments

If you’re not familiar with Instagram, it’s a mobile app that takes pictures, applies low-fi ‘lomographic’ digital filters, and shares them on the Internet. For reasons we can’t comprehend, Instagram has been wildly successful as of late and was recently purchased by Facebook for a Billion dollars. [Martin Ström] figured he could do something much cooler than applying digital filters to a cell phone picture, so he built InstaCRT, an app that turns your pictures into grainy CRT images and satiates the geek and hipster in everyone.

From [Martin]’s project page, InstaCRT uses a small black and white CRT from an old camcorder and a Canon 7D to apply real-world analog filters to all the uploaded pictures. Once the pictures are uploaded to the MacBook Pro server, they’re displayed on the CRT and a picture is taken with the 7D. Once an Android/iOS device sends a picture to the server, it’s displayed on the CRT, the 7D snaps a picture, and the resulting ‘filtered’ picture is sent back to the mobile device.

While we’re sure a few Hackaday commentors are going to ask ‘why’, it’s still a very cool build that is the first real world digital camera filter we’ve seen. You can check out the video demo of InstaCRT after the break.

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You’ll Throw Your Back Out Playing This Analog TV Synth

May 15, 2012 by Mike Nathan 11 Comments

de-rastra

While CRT televisions fall to the wayside as more people adopt flat-panel TVs, the abundance of unused sets gives hacker/artist [Kyle Evans] an unlimited number of analog canvases on which to project his vision. He recently wrote in to share his latest creation which he dubs “de/Rastra”.

The “CRT Performance Interface” as he calls it, is an old analog television which he hacked to display signals created by moving the TV around. Fitted with an array of force sensors, accelerometers, and switches, the display is dynamically generated by the movements of whomever happens to be holding the set.

Signals are sent wirelessly from his sensor array to an Atmel 328 microcontroller with the help of a pair of XBee radios, where they are analyzed and used to generate a series of audio streams. The signals are fed into a 400W amplifier before being inserted into the CRT’s yoke, and subsequently displayed on the screen.

We’re sure [Kyle] is probably trying to express a complex metaphor about man’s futile attempts to impose his control over technology with his project, but we think it simply looks cool.

Check out [Kyle’s] work for yourself in the video below and give us your take in the comments.

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CRT Vector Graphics Arcade Game Built From An FPGA Board

March 16, 2012 by Mike Szczys 18 Comments

[Sprite_TM] wanted to challenge his VHDL skills, and there’s no more satisfying way of doing this than making something that will be playable when you’re done. He decided to try his hand at creating a vector-based CRT arcade. The distinction here is that vector-based games take control of the magnetic ring that guides the electron path toward the screen. This technique allows point-to-point graphic generation rather than the pixel-based scanning that CRT televisions use.

He had a small color CRT on hand and decided to grab a VHDL version of asteroids from the Internet to see if he could get it to work. But upon further inspection of the source he found that it had a chunk of code which rasterized the vectors for use with a scanning monitor. After removing that chunk, and giving it a spin he had enough confidence that he knew what he was doing to start implementing his own game. The choice of what title really came down to the hardware the original arcade cabinets used. He was not interested in implementing a soft-process for the math chips used in games like Star Wars and Tempest. In the end he got a version of Black Widow up and running, and even built a miniature cabinet for the thing. Check out some of the gameplay in the clip after the break.

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Installing Military Hardware In A Home Flight Simulator

March 9, 2012 by Brian Benchoff 10 Comments

The cockpit of an F-16 Fighting Falcon features a small 3-inch display that monitors and tracks hostile aircraft and missiles, friendlies, and the current target. This Radar Warning Receiver is vitally important to pilots in combat, so [Mike] decided to add one to his homebuilt F-16 simulator that runs Falcon 4.0.

The RWR displays threats as symbols that are usually generated by tens of thousands of dollars worth of military hardware. [Mike] figured a $7 PIC microcontroller would work just as well and set about designing vector graphics that would fit on a single chip.

[Mike] had the graphics displaying correctly on an oscilloscope, but that’s a far cry from the from the surplus RWR display he picked up. Although the display is a simple CRT, the original designers of the radar warning receiver thought it necessary to put the deflection amplifiers in another part of the airplane. After building a pair of 30 Watt amplifiers, [Mike] could finally display more than a single dot on the display.

After all was said and done, [Mike] has a wonderful radar warning display that fits into his F-16 cockpit perfectly. While it’s not quite a 737 in a garage, we’ve got to respect someone who takes surplus avionics and makes them work. Check out [Mike]’s display in action after the break.

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