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What project are you most proud of?

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DerStrom8

Super Moderator
Hello, everyone!

I'm just curious about you guys' favorite projects. What project, whether finished or still in progress, are you most proud of? Pictures are appreciated!

Der Strom

P.S. Here's your chance to brag :D
 
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Reloadron

Well-Known Member
Most Helpful Member
Do work related projects count? I don't do as many home projects lately. :)

Ron
 

DerStrom8

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KeepItSimpleStupid

Well-Known Member
Most Helpful Member
A 4-terminal/2-terminal, selectable, current to voltage converter with 4 ranges not including auto-range for 100 mA, 10 mA, 1 mA and 0.1 mA full scale. Biasable from -10 to +10 Volts. Suppression up to +-50 mA if bias is between -5 and 5. Used two IEEE 488 system meters, one quad D/A converter and a digital I/O port. Programmed in LabView. It also had a over-range indication that blinked for 1 sec, when the output exceeded 10 V or -10 V. The over-range indicator used a bi-color LED.

Did the boards using a DOS based Easytrax and developed, etched and exposed them. It fit into a 2 RU rack and had at least 6 or 7 power supplies in the unit. The meters took up 2RU and the D/A digital took up 1 RU.

This was a Front-end to a DSP based Lock-in amplifier, an SRS-830 http://www.thinksrs.com/products/SR810830.htm

I had no help.
 

AGCB

Member
I built this all metal airplane from scratch, made every part! 100 HP Continental engine, 100 MPH cruse speed. Took 11 years to complete. The second of three planes I built.
 

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KeepItSimpleStupid

Well-Known Member
Most Helpful Member
The other project was a Direct Digital Process Control System built in the 80's way before the PC using a PDP 11/23+ and a 10 MB disk drive using RT11. It toot two of us 8 months to program the system entirely in FORTRAN (It was my very first FORTRAN program) that did simultaneous PID control of V, I and P with shorted thermocouple detection using energy limits for 7 heaters (evaporation sources).

I wrote a scripting language and the entire system could be recipie based.

I created a "device driver" model with FORTRAN that had entry points for config, display, etc. It had logging capabilities as well.
 

Reloadron

Well-Known Member
Most Helpful Member
This is part of one of my current projects. Till recently all my work was US Navy Nuclear Propulsion Systems where you work in a building sans windows and a camera gets you shot. A few years ago we embarked on a new commercial nuclear reactor project that involves the development of small reactor systems for power generation. Think mini-reactor. While Navy Systems are highly classified the commercial stuff is more open.

We are developing stepper motors for rod control. You are looking at a motor that will run in an 800 plus degree F environment under extreme pressure. The M-Power class reactor is a pretty much self contained system. The CRDM (Control Rod Drive Mechanism) is the only moving part in the core of a nuclear reactor. These mechanisms are tested in large vessels called Auto Claves. The vessels themselves have about a 24 inch ID with a three inch wall thickness so when cold about a 30 inch OD. They range between 30 to 40 feet tall. The claves are filled with grade A deionized water of special chemistry, same as the reactor.

We use electric heater elements custom manufactured. The heaters are bands (think clam shell). Each half of an element is 3 KW 240 VAC. So each band is 6 KW and on the pictured clave there are 72 bands top to bottom. All in all at full power driven by 3 phase 480 VAC about 432,watts of heaters. Yeah, that is my ugly self in the first image followed by a few of the heater bands. The tape seen is just there for holding at the time. The wire is all AWG 10 rated for a 1,000 degree F environment. The backsides of the heaters reach about 700 F during heat up and the front sides clamped to the clave exceed 1,000 F. Not seen are the backside thermocouples that measure surface temps on the back sides. I use 12 so one every 6 bands. When you heat a ten ton plus 316 SS vessel you want it to be uniform. When the internal water temperature is 600 F the clave grows a few inches. The pictured heaters represent about $42,000 USD that is sans controllers and SCR panels.

Beyond temperatures we measure various pressures and flow rates as well as other parameters. Also attached is my first data acquisition and clave control panel. The pictured unit is the first of three new ones. Everything from the IO is few to a computer system that manages clave control. Additionally and not pictured are three 500 AMP 480 VAC SCR panels that drive the heaters. The heaters are covered by large aluminum panels. They are sectioned. There is also miles of plumbing with countless valves and sensors. All of that just to control the clave environment.

This says nothing of the data acquisition systems that constantly monitor and run the actual mechanism in the clave.

The first test mechanism will go in the clave by the end of this year. It will run 24/7 for 5 years, cycling over and over again under every condition imaginable. I will be retired before it comes out after initial test. :)

This will be my last major project so what the hell I will go out with a bang (maybe a poor choice of words there).

Ron
 

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Roff

Well-Known Member
You guys probably know that I am now retired. Back in the mid-70s, I worked for Consolidated Video Systems in Mountain View, CA . We invented the digital timebase corrector for video tape recorders. I had been hired to do A/D and D/A converter design, along with other miscellaneous analog circuit design tasks.
My crowning achievement was the ADC for the CVS 520. It was a 9 bit ADC, sampling at 14.3 megasamples/sec. It was autoaligning, for the most part. It only had 6 pots, and the alignment techs loved it.
You might say that's a lot of parts for an A/D. You can buy a comparable one today on a chip for a few bucks. When I designed this, there was a total of one A/D IC available. It was made by TRW, was in a 64 pin DIP, cost $600 (!), dissipated 7 watts, and required that you epoxy a heat sink on it and blow forced air over it. My board was considerably bigger, and probably drew more power, but it was only $180 out the door, including testing and alignment. It had no exotic parts in it. Differential gain and phase were outstanding, and, due to the autoalignment, it didn't drift out of alignment.

I bought this used CVS 520 on Ebay in a fit of nostalgia several years ago for about $100. They had sold for $15k originally.

Oh, I should mention: No simulation, and all schematics were drawn by hand, on a drafting table.
 

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BrownOut

Banned
Those are some pretty amazing projects. The airplane is awesome! There was also a CNC machine, but looks like it was removed???? A CNC machine is definitely on my list of things to do.

My projects are like my children; there is no 'favorite.' I have the same affection for all of them. So, instead of bragging on my favorite, I'm gonna brag on my latest. I needed a way to keep my boat cockpit cool on the hot dog days of summer. I considered an A/C system, but that would only work in the cabin, and I wouldn't be able to enjoy the outdoors. So, I build a 'redneck' boat canopy, and added a couple systems to help cool things down. I actually wrote this up last year, with pics and all. But the first version was too heavy, not sturdy enough and had to be completely removed to configure the boat for sailing. So, for the last 3 weeks I've worked furiously to cut the weight and create a canopy that would retract for sailing. Then, I added a 12V distribution system for cooling fans, lights and a water misting system. Shown below is a picture of the canopy frame only, and not the canvas, fans, misters and distribution system. The frame is bent and welded 16ga tube of various diameters. Look closely at the very top rail, it telescopes out to the full 9 feet of the cockpit for cruising, and back in for sailing. I finished the whole thing just in time for the 4th weekend; building the wiring harness right up to the time we began to load the car.

Maybe next time I try to get pics of the complete system.

PS: I was confused about the CNC machine. It was actually shown on this thread
 

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MISSION CAT

New Member
You guys probably know that I am now retired. Back in the mid-70s, I worked for Consolidated Video Systems in Mountain View, CA . We invented the digital timebase corrector for video tape recorders. I had been hired to do A/D and D/A converter design, along with other miscellaneous analog circuit design tasks.
My crowning achievement was the ADC for the CVS 520. It was a 9 bit ADC, sampling at 14.3 megasamples/sec. It was autoaligning, for the most part. It only had 6 pots, and the alignment techs loved it.
You might say that's a lot of parts for an A/D. You can buy a comparable one today on a chip for a few bucks. When I designed this, there was a total of one A/D IC available. It was made by TRW, was in a 64 pin DIP, cost $600 (!), dissipated 7 watts, and required that you epoxy a heat sink on it and blow forced air over it. My board was considerably bigger, and probably drew more power, but it was only $180 out the door, including testing and alignment. It had no exotic parts in it. Differential gain and phase were outstanding, and, due to the autoalignment, it didn't drift out of alignment.

I bought this used CVS 520 on Ebay in a fit of nostalgia several years ago for about $100. They had sold for $15k originally.

Oh, I should mention: No simulation, and all schematics were drawn by hand, on a drafting table.
Ron -

I just lifted the Sync Tip Clamp from a copy of the 520 service manual, breadboarded it and it worked fine - input offset was 3mV. This will be used in an alternator current-meter I am building. The clamp attacks amplitude increases within one 100Hz cycle or about 10msec and releases in 300msec.

I also used the frequency-locked loop from either the 520 or 504 in the F-14 Heads-Up Display for the Navy version of the fighter. This design was accepted and used in the display although the engineers at Kaiser Aerospace never understood it, and in fact there was controversy with some engineers in favor of the 520 design and some against.

I remember that the 520 was awarded an Emmy by the broadcasting industry - this machine stood alone. I frequently refer to the analog circuits in the 520 as the best I can get. It is worthy of a book on advanced analog circuit design.

Mission cat
 

Roff

Well-Known Member
Ron -

I just lifted the Sync Tip Clamp from a copy of the 520 service manual, breadboarded it and it worked fine - input offset was 3mV. This will be used in an alternator current-meter I am building. The clamp attacks amplitude increases within one 100Hz cycle or about 10msec and releases in 300msec.

I also used the frequency-locked loop from either the 520 or 504 in the F-14 Heads-Up Display for the Navy version of the fighter. This design was accepted and used in the display although the engineers at Kaiser Aerospace never understood it, and in fact there was controversy with some engineers in favor of the 520 design and some against.

I remember that the 520 was awarded an Emmy by the broadcasting industry - this machine stood alone. I frequently refer to the analog circuits in the 520 as the best I can get. It is worthy of a book on advanced analog circuit design.

Mission cat
Thanks for the kind words. I also designed the sync tip clamp and the PLL in the 520.
I don't recall CVS receiving more than one Emmy, and it was in 1974, the same year the 504 was introduced, and before the introduction of the 520. I also designed a lot of the analog circuitry in the 504, including the A/D converter.
 

tcmtech

Banned
Most Helpful Member
Out of the many odd devices and things I have created over the years I do have to say my home built boiler system with full digital control is probably the highest on my list for being my greatest personal money and time saver and home built device with most running hours on it.
Going on nearly 9 years now its saved me around $30,000+ in fuel costs for the roughly $3500 I put into building it and installing it plus maintenance over the years.

This winter its getting updated to a full used oil injection burner system that will replace the main door as a simple plug and play drop in unit. I will just have to lift the solid fuels draft door off and drop the oil burner unit on and plug it into the PLR unit and it will be fully automatic!
A 2 minute changeover at most. :D
 
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