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By openschemes, on November 1st, 2011% 6,321 views
Howdy folks!
Welcome to another edition of Openschemes’ teardown and review series. Sadly, our normally venomous and sarcastic reviewers have been impressed into saying mostly nice things about the device in hand, although it could be that they’re extremely susceptible to the pew pew goodness of low-cost laser shows!
The device under investigation will be the CASA CTL-BM RGV Laser Show. This is a 3-beam laser projector with Red, Green, and Blu-Ray Violet lasers. It’s legal status for commercial use is doubtful at best, and the safety aspects are extremely suspect due to the use of DPSS green and Blu-Ray Violet lasers. But it looks freaking fantastic and is quite a treat to poke around inside one. The cost is about $200 USD, available on ebay and other web sellers. That money comes directly from the ad revenue of these pages, so we thank our users for disabling Adblock on these pages, and hope the ads are relevant and interesting enough that they are not annoying. We’d like to hear your feedback on the subject in The Forum – Ad Thread.
Today, we will disassemble and analyze the construction and operation of the CTL-BM in hopes of bringing new knowledge to those users that want to build their own RGB (or RGV) laser show. It’s such a cool application, and such a serious undertaking, that it really helps to see just what makes those commercial models tick. If for no better reason than to prove to you that it is within the capability of the homebrewer. We hope that you gain some knowledge, sprout some new ideas, and get inspired to go out and make something fantastic. Please leave us your comments, especially if you’re starting a project of your own! You can discuss this project on The Forum – Lasershow thread.
The projector is an RGV model, meaning that it combines 3 separate laser beams (Red, Green, Violet) to produce various colors. This color palette includes the highly desirable “white”, although since the blue beam is actually violet it is not a true white and is referred to as “silver” by the manufacturer. But it still looks pretty white, especially when scanning around and switching between colors. This device is intended to be a small standalone laser show for parties or dance clubs, and seems that it would work well for smaller venues, especially with the use of a fog machine to make the beams visible. As previously mentioned, the device is probably not legal for and is certainly not FDA approved for commercial use in the US, so don’t take our positive comments as incentive to use this device for anything other than your own personal enjoyment at home.
The CTL-BM contains X-Y stepper motor drivers so it can control the direction of the beam over about a +/-45 degree angle in both the horizontal and vertical directions. It includes pre-programmed projection patterns and has a small microphone to sync the display to whatever music is playing. The manufacturer states 100 patterns and 500 laser effects in all. This include both static patterns such as a steady circle or square, or dynamic patterns such as an expanding circle or wiggling sine wave. Plenty of stuff stored in there, and it’s great that it’s able to run in automatic mode, synced to the music in the room, or via DMX control. Good stuff!
Let’s take a look at a classic laser show effect, the “tunnel”. This pic is from the manufacturer’s ad for the device.
Manufacturer’s Representation of the Device – It’s fairly accurate, too.
Oooh, you’re salivating now. What the device is doing in the above pic is tracing a circle with the XY scanning stage, and blinking on and off the three colored beams as it steps through various index positions on the route. By shooting a red and green beam, you get yellow. By shooting a red and violet, you get magenta. All three gives you the whitish beams you see just to the left of the 6 o’clock position. Repeat this over and over at a fast speed and you get an outwardly radiating fan of beams. Vary the start position of the on/off blink sequence but keep the XY positioning sequence the same, and you can make the fan rotate left and right in the classic laser tunnel fashion.
We’ll investigate the position sequencing later when we get into the guts of the box.
You can find many videos of this and other devices in action online, but the one we like best is from Amonstar, a seller of a rebranded CASA device. The demo vid shows some killer color-changing fans around 0:25 and an overall fairly good demo of the unit. A few too many spinny circles, and you miss out on the neato random-shooting space invaders mode, but still good. Check out Amonstar’s page and video here.
It looks like they either found a song that the device had extreme sensitivity to, or built themselves a DMX routine to actuate it very close to in time with the music. The track in question is “How Old R U”, by Master Blaster. Sampling an old Italian disco song about reminiscing where an old flame may be these days, Master Blaster’s version succeeds in sounding both campy and somewhat skeevy at the same time. Classic! But the gravelly bass warble interleaved with a big fat kick drum makes for a fine piece of dance club history. Watch the totally 90′s music video: Youtube – Master Blaster – How Old R U.
Here’s the dirt on the device:
CASA CTL-BM Specifications:
- Total Output Power: 270mW
- RED: 100mW, 650nm diode laser
- GREEN: 70mW, 532nm DPSS laser
- VIOLET: 100mW, 405nm (Blu-Ray) diode laser
- DMX, Auto, Sound-Activated Operation modes (Latched on startup)
- 100 patterns, 500 laser effects
- 9 Channel DMX Control (Yes, it works with Freestyler)
And without further ado, let’s go ahead and crack this thing open!
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By openschemes, on November 1st, 2011%
By openschemes, on November 11th, 2010% 20,425 views
WARNING: This circuit analysis deals with high-voltage, high-current induction heater power stages. Touching one of the HV nodes (600V @ 30A) of these types of circuits would probably be instantly lethal. We take no liability for your actions, so if you don’t know what you’re doing – stay away!
Hello Fellow ‘Schemers,
Today we’re looking into the guts of an induction cooktop. For those of you not familiar with induction cooking, the theory is as follows:
By running a big current through a coil, you can induce an incredibly massive current in a ferromagnetic (say, steel) pot sitting on top of that coil. Since the steel is very conductive, there is essentially no voltage built up across the metal but plenty of current still flows. This heats the pot through resistive heating and eddy losses, transforming the pot itself into the heating surface. Cool stuff. Want to heat a pan? Apply power directly to the atoms of the pan through electromagnetic tomfoolery. Go check out Induction Heating at Wikipedia for a more complete description.
Induction heating has become a meandering side interest here at oschemes, due to our desire to build a sweet induction forge for a metalsmithing buddy. The web has a nice selection of induction heating (IH) projects, including
- Neon John’s Open-Source IH. Pretty fantastic, and he has a kit or prebuilt devices for instant gratification
- Richie Burnett’s IH Discussion and Projects. IH 101 and 102 all in one page. Brilliant description, beautiful theory and plenty of sims and scope shots to illustrate the details. Plus killer glowing metal pics to show that he ain’t screwin around.
- Uzzors2k PLL Based IH. A self-tuning masterpiece. Really great stuff for when you’re ready to expand your mind to orthogonal V/I phase control.
All of those pages have additional links to even more information, so enjoy! We’ve built a couple self-biased Royer Oscillators at a hundred or so watts, and have gotten metal hot enough to burn ourselves. Ow! Dammit, it works! But never any orange-glowing slag or anything else deliciously lethal – that’s next.
So as a starting point for our own designs, we always like to see what’s going on in the industry. Sure the Bosch’s and the Westinghouses of the world can build some cool stuff, but what about the minimalistic approach? High power, low cost! For that, we decided to take a look into a low-priced induction cooktop available around the web. Ours was purchased from Amazon for $70, the Max Burton Model 6000 1800W induction cooktop.
Fig 1 – Yum, Looks like lemon and corpse soup!
As an appliance… Well there’s a reason this model’s on the sale rack. The switching noise (high pitched whine) is earsplitting for those of you that can hear it, and is modulated by the position of the pan. In other words, if you were to wiggle your pancakes or stirfry pan around the noise will cycle from inaudible to teeth-grating and back. Have fun seeking the perfect pan position where the noise is tolerable! It seems to get better after warming up, but it is never silent.
There’s also a weird startup noise that sounds like the device is ramping the frequency (phase?) back and forth to try to check the resonance. This seems like a legitimate technique to us and probably a necessity with jerky customers moving their pancake pans around. But please, designers – continually seek resonance, don’t sweep it 4 or 5 times and then have to resweep whenever the pan moves or is lifted. Ugly!
All bitching aside, this piece of crap can certainly deliver power to a load. It will boil a small pool of water almost instantly (err, after the 3 seconds required to find resonance) and can even heat thin copper such as PCB traces if you trick it by having a pan partially on the coil area. That’s interesting because non-ferrous metals are usually hard to heat at the 20kHz frequency this thing seems to run at, but fun nonetheless. Not sure if it could deliver enough power to reflow a PCB but there’s probably risk of blowing up your components from induced currents, so that kooky idea will have to live on the shelf a while
Let’s look a little further, shall we?
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By openschemes, on November 11th, 2010%
By openschemes, on March 23rd, 2010% 11,370 views
In order to do some advanced hax0ring of the SPMP8k, we bought a logic analyzer. It’s called the LogicCube by a Taiwanese company, ZeroPlus. We’ve already gone and hacked it front to back, top to bottom, side to side and more. But we’ll get to all that in due time.
Fig 1 – Photo of the Zeroplus Logic Cube
It’s a good product, and we recommend you buy one if you’re in the market for a USB logic analyzer. Or perhaps if you’re just in the market for a nice new toy to hack!
The device scores high marks on our chart for:
- Dependability - You plug it in, and it does what it says it’s going to. No screwing around with dodgy drivers and flaky hardware. These guys really do seem to use their own hardware, and it shows. FEBE? For engineers, by engineers?
- Reliability - It always does what it says it’s going to do. It doesn’t miss edges or do other stupid stuff. Ever, as far as we can tell and that’s a big plus for us.
- Portability - It’s nice that the whole setup: Cube, USB cable, fancy colored wires, and some minigrabbers all fit nicely in a ziplock bag. Keeps it fresh, as well.
- Capability - Depending on how much money you’re willing to spend, you can get a device with 16 or 32 channels, and memory ranging from 32k to 2MB. That’s a lotta sampling! But since these guys aren’t stupid, they added some pretty awesome triggering and compression that gives you tons of sampling with very little memory. Also, the plug-in protocol analyzers are fantastic. We hate counting I2C clocks and writing hex characters by hand, so having the software do all the work is great.
- Hackability - Due to economies of scale naturally found in manufacturing, the board we got (smallest mem, lowest channels) was able to be upgraded to a pretty awesome box for just about $10. Oh, that and a shitload of work. But that stuff’s considered fun over here.
Teardown & Functional Description
Teardown is dead freakin easy. Remove the 4 rubber feet on the bottom/back to reveal 4 totally goofy sheet-metal looking screws. The only part of the device that was oddly low-quality was these screws. Not a big deal, but when you open and close the box about a thousand times, you think how ugly they are about a thousand times. Guess it stuck.
Fig 2 – Back of the LAP-C Showing the 4 Case Screws.
LAP-C is what they call it, so that’s what we’ll be calling it too. Guess it’s the lower-end of what ZeroPlus manufactures, but it’s fine for us. Blows SUMP clean out of the water, and trust us – we love SUMP! But you get what you pay for, really.
One thing you’ll notice is that we’re blurring out the device’s serial number. Why? Well when we went googling, we found that all the serial numbers were always blurred out. It occurred to us that the image of a serial number must be considered pornographic in Taiwan, so we decided to blur ours in order to show respect.
Sure, the protocol licensing is tied to the serial number among other things, but unless we showed our serial number AND our license key, AND you changed your device’s serial number to ours – we can see no way that the public viewing of a serial number could in any way affect ZP. But still blurred – and hence, they must either be highly offensive or highly arousing and in either case are not suitable for public viewing.
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By openschemes, on March 23rd, 2010%
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