What are u working on right now (electronics related and with picture please)?

[tszaboo]

My running projects:
http://nandblog.com/running-projects/
Some of them even have pictures uploaded in the menu.

[Skimask]

D.A.V.E. - Dave the Autonomous Vehicle Experiment

Neighbor was going to throw this truck in the garbage a few days ago.  Kids outgrew it, battery was shot, switches are shot, but the motors, gears, steering, etc. are all still ok.
I snagged it.  A friend and I are going to rework it, add a handful of sensors, GPS, ultrasonic, IR, LASER range finders (if I can find something in a reasonable $$$ range), cameras, WIFI, bluetooth, XBee, R/C, whatever else we can think of to throw at it, as long as it's not too crazy expensive (e.g. GPS-RTK is likely more than I want to spend on it).  And I'm taking ideas!
Just getting started on it.  Haven't even figured out which MOSFETs I want to use in the H-bridge...

[smashedProton]

An instructional function generator kit (0.1Hz - 5MHz, sine square and tri, AM, FM, sweep, digital frequency/amplitude readout) with an accompanying instruction "manual" providing in-depth lessons and explanations of the circuit operation, from resistors to long-tailed pairs and Gilbert cells, targeted at beginning analog electronics enthusiasts.

Here's a Jim-style prototype of the comparator which forms the main oscillator. It's very much inspired by the discrete comparator used in the HP 3312A (mostly, it's just been simplified a slight bit). Works a treat up to 16 MHz! And the ringing is just from my atrocious probing setup - I forgot about W2AEW's awesome probe socket trick until afterwards

(Also, I have a handful of other projects languishing on the vast back burner)

Send me your final manual and stuff and I will review it for you.  I'm a beginning analog enthusiast 

[c4757p]

I'm posting as I go, over here.

[KJDS]

I've just got this high power RF amp functional

[smashedProton]

I just got my ham license and my first radio!

[AF6LJ]

I have a couple of projects in the works, an SDR transceiver kit that has been stalled for a while, other issues in life seem to have gotten in the way, including Oscar's rehabilitation, but Oscar is more important right now.You can meet Oscar here.  http://forums.qrz.com/showthread.php?372651-SB-220-Find
Here are a few pictures....

As you can see Oscar came to me a bit modified, but gently built.


The thread I posted a link to above has background information and a decent discussion on the work being done.
Included in that thread are many more pictures along with a few of other people's projects.

[alank2]

One thing I've got going is a project where I am converting the output from a iteadstudio gps shield (neo 6m) to the GPS stream that my Lucent RFTG needs so it will discipline itself.  The second part of this project is a pid controller for the fan beneath the rftg, it varies the speed to try to keep the LPRO rubidium module inside at consistent temperature.  It is a mess right now as you can see, but it has been running for almost 30 days this way.  I've developed a pcb that I need to order that cleans things up a bit and I'm going to put an enclosure under the RFTG that hold everything and also blow air upwards to cool it.

[alank2]

I've spent much more time lately on the reflow oven I've been working on.

The oven is just a $40 oven from Walmart with convection. It has what look to me like quartz style heating rods, two on top 450W each and two on bottom 300W each. 1500W total. I love the door on it, it clamps the K thermocouple wire gently and holds it into place without putting any stress on it. Door stays open real easily and is soft to open and close (no board jerking).

Easy to open up and rewire. I used some TGGT 250 deg C wire (not sure if I had to) for as much as I could and am using some 14/4 service cord between the oven and the SSR box. Why it is so thick looking for 14 gauge I don't know. Green = chassis ground, White = neutral, Hot = heater element, Black = fan and front oven light.

The SSR box is aluminum and like the oven chassis also grounded. It has mains (120 VAC) coming into it and it uses two SSR's to switch the heat and fan/light wires going into the oven. The heating SSR is on a heat sink and I drilled some holes in the top and bottom of the aluminum box to let airflow cool it. The fan SSR is just mounted to the inside side of the box. I am using 1/8" minijack 3 conductor to connect the SSR box to the control board (sleeve=ground, tip=heat, ring=fan/light). This was the first time I machined aluminum on my CNC and it is much tougher than plastic especially with my weak Harbor Freight 1/4HP router. I messed it up slightly as you see in the picture, but it is functional.

The control board right now is on a dip adapter I got from this guy a few months ago. Real nice guy who was kind enough to give me some reflow tips as well:

http://www.mattairtech.com/index.php/development-boards/atmega32u2-usb-development-board-arduino-compatible.html

And the max6675 on a dip adapter from eBay.

In the end I am going to make a board in Eagle that has the atmega32u2 and the max6675 and supporting components only. I'm should be able to make it very tiny almost enough to make it a cable inline type deal where one end is usb to the PC and the other end goes to the SSR control box.

The AVR is already running the PID algorithm, but not the reflow algorithm at this point, but with plenty of flash left I am toying with the idea of giving the AVR a very simple interface where you can select a reflow profile and run through. Not sure about that though.

Next up is some PC software development...

[84GKSIG]

Probably got too many unfinished projects going on at the same time to be honest but here goes...



to the right is a hybrid low voltage tube/mosfet amplifier which runs on 12 volts pulls just over an amp, this prototype was originally going to be a headphone amplifier but impressed with how silent and low noise it turned out to be I then started using it as a preamp for my stereo amplifier which it sits on top of in that image.
its case started off as a faulty external hard drive enclosure 

the hybrid amplifier sits on top of a stereo amplifier which I built around a chip known as the LM3886, circuit is designed by my self with some guidance from the data sheet and about 5 months worth of good old experimenting with component values to get it to the point it's at today.
came up with about 5 different circuits but now finally have one ive settled with.


here's bad quality shot of the guts before installing the heat sinks and shielded input cable. ( still on the to do list as well as build another 3 of these and a couple more tube preamps and a DAC for the surround sound system!

[delmadord]

Here is one really bad quality photo of my "digitally controlled temperature regulator for old iron" for chemistry and lamination process in PCB manufacturing. Maybe even for solder reflow, I want to try it. It uses ATtiny44, 74HC595, rotary encoder and a 7-segment display. Mostly parts from my drawers. The iron was in my grandmother basement, lying around, so I took advantage of it. I started just few days ago, so it is only on breadboard (also I ned this to actually make PCB for it )

[JeanF]

Here is my ATMEL AVRISPmkII ghettoblaster :  O0 




The hardware is from a pair of small amplified speakers, a Edifier MP300+ kit. I didn't like the fact that it was a 3-piece kit with bulky cables between the speakers and I wanted an all-in-one solution.

There were also some feature that I wanted to change. The speakers don't have any power switch, but the board boots by default in a low-power mode (the TDA7377 is on standby) and you have to click on one of the volume buttons to power on the output stage. This is rather nice, but I wanted to use the speakers as alarm clock speakers (using the alarm clock from a phone or an ipod) so if there is a short mains cut in the middle on the night, they will boot in standby mode when power comes back, so not good to wake up. I made a small "dead bug style" board with a small PICAXE (I can't program in C yet) ; one of the audio input channels is hooked to an ADC pin via a AC-coupled opamp set to a gain of 100. The PICaxe detects when the audio signal is coming, and pulls high the standby pin of the TDA7377. When the song ends it's back in standby mode.

There was also a SPI volume control chip that I removed because the main microcontroller (AT89C2051) used to reset the volume at its medium level at each startup, and since there is a volume control on the music playing device, this redundancy was, in my case, useless.

All that, I guess, probably could have been done by reprogramming the AT89C2051 but I don't have any skills with that family so why bother...  O0

[delmadord]

Here is my ATMEL AVRISPmkII ghettoblaster :  O0 

I love the carboard case That caution sign looks like it should be there by design

[SLJ]

Working on this vintage Non Linear Systems digital voltmeter form the 1950s.  This "edge lit" display was the first type of digital display.  Each digit was an engraved Lucite plate lit by a small lamp. The display was selected by a resistor dividing network and stepper relays.



Video of display and relays working:

Display Teardown: NLS 481 Digital Voltmeter Display



Edit:  Lucite plates not Lexan.

[PA0PBZ]

Each digit was an engraved Lexan plate lit by a small lamp. The display was selected by a resistor dividing network and stepper relays.

Oh man, that sound! Only suitable for measuring very stable voltages I'd say 

[SLJ]

Each digit was an engraved Lexan plate lit by a small lamp. The display was selected by a resistor dividing network and stepper relays.

Oh man, that sound! Only suitable for measuring very stable voltages I'd say 

Fortunately there is a sensitivity control on the front panel otherwise the last digit constantly wanders unless the source being measured is rock steady.

[84GKSIG]

that thing looks amazing and i want one! was that arcing on the board near the tubes??

[chickenHeadKnob]

Each digit was an engraved Lexan plate lit by a small lamp. The display was selected by a resistor dividing network and stepper relays.

Oh man, that sound! Only suitable for measuring very stable voltages I'd say 

The noise that thing makes has a very sinister quality, not pleasant  at all, and it clashes with the front panel esthetic. If you have a laboratory cat or dog I would imagine they would get freaked out by the sound.

[Stonent]

Each digit was an engraved Lexan plate lit by a small lamp. The display was selected by a resistor dividing network and stepper relays.

Oh man, that sound! Only suitable for measuring very stable voltages I'd say 

My father had a 1981 Nissan/Datsun 280Z (called Fairlady Z in some other countries) and some of the lights on the dash worked that way. I don't know of it used relays but it did use stacked engraved plastic with various symbols.

[rexxar]

I'm trying to convince my boss to let me teach an electronics class for kids, so I put together a demo board with some projects we'd be working on.

[SLJ]

that thing looks amazing and i want one! was that arcing on the board near the tubes??

That's a reflection off a couple of neon lamps on the circuit board that fire on and off when the relays are in motion.

[jancumps]

without words (because it's not going as smooth as I expected):

[rexxar]

Working on this vintage Non Linear Systems digital voltmeter form the 1950s.  This "edge lit" display was the first type of digital display.  Each digit was an engraved Lexan plate lit by a small lamp. The display was selected by a resistor dividing network and stepper relays.

Holy hell, that's impressive.

I suddenly want one.

[WarSim]

Here is one really bad quality photo of my "digitally controlled temperature regulator for old iron" for chemistry and lamination process in PCB manufacturing. Maybe even for solder reflow, I want to try it. It uses ATtiny44, 74HC595, rotary encoder and a 7-segment display. Mostly parts from my drawers. The iron was in my grandmother basement, lying around, so I took advantage of it. I started just few days ago, so it is only on breadboard (also I ned this to actually make PCB for it )

I like this project the best, because he is making this project in order to make a project.  I just think it is great that people still get the development chain. 
It's like patching together a 3D printer to print the missing parts of the 3D printer your are making them on. 

Only project in the last year coming close to this is several electronic loads to test the multi-output power supply I needed for another project. 
All the others are just items I couldn't find to buy or prove something could be done. 

[mtdoc]

I like this project the best, because he is making this project in order to make a project.  I just think it is great that people still get the development chain. 
It's like patching together a 3D printer to print the missing parts of the 3D printer your are making them on. 
 

Reminds me of.....

"In making the handle
 Of an axe
 By cutting wood with an axe
 The model is indeed near at hand."
   
 Lu Ji's Wen Fu, fourth century  A.D