Here's the final post, the last hoorah. My quick showing of the systems on the ZADD (Zombie Assembled Detection Device). I don't have any photos of the build process due to my hurried assembly of the system, which i regret. I hope the final pieces appearance will help the viewer to understand the workings due to the very visible components.

The idea behind this is that in the event of a world changing disaster, like a zombie apocalypse, any average person would be able to get this glove and attach different components that they would need throughout the day/period of time they're active. The LCD screen can display an infinite number of different readings. If one were to have this attached to a wireless network they could receive all types of data from the internet/network... assuming one is still active.

The methane and CO sensors are applicable with zombies, because as everyone knows, zombies put off massive amounts of methane gas due to their constant decomposition and defecation. The CO sensor is too keep me safe from toxic amounts of CO, makes sense right.

On a more serious note, I really need to work on a more solid concept for this because it's not gonna fly as it is I feel.

Enjoy!

oh, i have those items from surplus to display too.

Stratagene RoboCycler 40 PCR Machine

Stratagene RoboCycler 40 PCR Machine, Contains 4 heat blocks that you set to the desired temperature. A robotic arm moves the samples from block to block eliminating ramp time. 40 wells /Block, Well Volumen 0.6 ml, linea temp. range up to 14 or 22 across the well block, with temp. difference of up to 2 C between adjacent wells in each row. Can test up to 12 different anealing emp. in a single experiment. Single temperatures of up to 99C for pcr cycling.

Category:

Inventory List » Biotechnology » Thermal Cyclers

Current Price:	Condition:	Age:
$2,500.00	Excellent	Current

The Roche LightCycler

utilizes a rapid air heating and cooling system to decrease run times to approximately 30-45 minutes. With a 32 sample capacity, this instrument is perfect for small projects or as a quick diagnostic tool. This instrument is located in (Building 7 room 7102)

Remarks on the Spectra Diode Labs SDL-800 (LDI-800) Laser Diode/TEC Controller

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modification for avoiding temperature oscillations: see at bottom

I got hold of one of these classic controllers. At some point I'll measure long-term stability and other factors that would be important for holography. Here are some remarks:

Here are links for manual and DIN-8 connector pinout. Thanks go to Spec and Marconi at photonlexicon.com.
The unit didn't at first seem to work - this was due to an open interlock, for which there is a little plug at the backside. Needless to say that first thing to do was to short this for good.
By changing the current sense resistor, one can modify the current range. I read somewhere that one can extend it to 1.6A max or so. The resistor in question is shown in the figure below. Normally (for 1A max) it is 1Ohm, 1%, 5W. I found my unit to be equipped by a 10Ohm resistor instead, limiting the max current to 100mA. After reinstating the 1Ohm resistor, I can go up to 1A, however the display doesn't show it right - it displays 100.0mA when the current really is1A. Obviously this had been modified by the previous owner, but I couldn't figure out what else was done - no further resistors anywhere of the board seem to have been changed, it seems an issue of programming the microprocessor; indeed, all what needs to be changed is the decimal point, and from tracing the circuit, that seems to be controlled directly by the processor.

What is very preculiar, is that there is no soft-start feature!. Insted the current is switched on (after a delay) by a relay, and so goes up in a microsecond or so. I was skeptical and checked the current carefully with a scope: indeed, there is a ca 30mA overshoot on the diode upon turn-on. This can destroy a low current diode instantaneously! Below a scope trace for a 30mA setting, there is overshoot to approx 90mA; the current limit was set to 40mA. For a 100mA setting, I found overshoot to ca 130mA, and for an1A setting, the overshoot is still in the order of 30mA. So don't use this driver if you have a diode that cannot take more than 30mA! It is a good idea to have a small series resistor (1-10Ohm) close to the diode and a cap of 100nF or so parallel to the laser diode. And a Schottky diode anti-parallel to the LD plus a 100Ohm resistor are a good investment too.
Shown here is a current overshoot to over 90mA for a laser diode setting of 30mA.
This was measured across a low-induction 1Ohm series resistor near a dummy diode.
The temperature stability is supposedly 0.1C, which corresponds to a wavelength shift of approx 0.03nm. This may not be good enough for holography applications. But it is not specified under what conditions, so some measurements are in order.
The TEC controller is uni-directional and not bi-directional - that is, it can cool only; the idea is, of course, that the cooling is balanced by the heating from the diode. This can be non-optimal for some applications, where fast response time is required.
I have tried this controller with TEC's in various different laser heads, and in every single case the temperature oscillated - apparently the feedback loop is designed to work with specific SDL laser heads. Thus, the TEC controller as-is appears not be useful for stabilizing other laser heads, and in particular is not suitable for holography applications.
I now changed the feedback circuit so that it is now stable with all my laser diode mounts. The time constant for the integrator was too short, but the following simple operation remedies this. See this part of the circuit diagram:
Simply replace R74 by 1Mohm und C33 by 4.7uF (or more; preferably MKS2 film capacitor or similar). They are easy to find as the PCB shows the component labels, they are at the center of the PCB somewhat to the front (see the blue circle in the picture above). The little modification has the following effect:

To the left: temperature swing due to oscillation in original setup. To the right: Damped response after modificaton.

Clearly now the nice gadget can be resurrected from the shelf and actually be used for something ;-)
The short-term stability seems sufficient for holography applications (x-axis is scaled by ten):