Readout Electronics: ±5V 500mA Quad Preamplifier Power Supply

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This is part of my readout electronics system. This is a fairly simple ±5V 500mA preamplifier power supply I designed originally with Hamamatsu PMT preamplifiers in mind, but I ended up not getting one of those. So now I’m using it for my own preamplifier modules. The circuit is a fairly standard LM317 and LM337 one with stability improvements by adding a capacitor (and associated diode) to the programming pin. See the data sheets for any LM317 or LM337 for the circuit.

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Stabilized Linear 2,5A 12V Power Supply

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The other day I built this power supply out of components I had lying around. In particular I had this enclosure sitting on the shelf for years now and wanted to finally put it to use and also a toroidal transformer I also had sitting in the shelf. Unfortunately I didn’t take any pictures while building it only after the fact. Here is the schematic, fairly standard and self-explanatory, it uses a 2N3055 transistor and a Zener diode.

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Upgrading CISCO IOS

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I imported this from my old website from way back in time as I just needed it as a reference for myself again. Warning! Everything here is on your own risk. If you don’t know what you are doing DON’T. This is a small step-by-step guide on updating IOS annotated from a script(1) transcript I took from a while back. In my case I’m upgrading IOS 12.1(20)EA1a to IOS 12.1(22)EA14, the latter of which is the last version supporting the Catalyst 2950 series.

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Quick Reference of Gauss Quadrature Forms

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The following is from my notes I did a while back, whilst evaluating different numerical quadrature methods. Quite a lot of numerical quadrature in software used seems to be Gauss-Kronrod, in particular derived from QUADPACK. Any thoughts or corrections? Drop me a mail. Gaussian Quadrature Gaussian quadrature approximates integrals in the form of: $$ \int^{b}_{a}f(x)\ dx $$ For some range \(a\) to \(b\) inclusive or exclusive depending upon the type. With a sum in the form of: $$ \int^b_af(x)\ dx\approx\sum_{i=1}^nw_if(x_i) $$ Where \(w_i\) is some weight and the node \(x_i\) being the root of an orthogonal polynomial.

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МБС-10 (MBS-10, MBC-10) Stereomicroscope

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My MBS-10 with MFU phototube and LED ring light On this I share some information about the popular Russian/Soviet MBS-10 stereomicroscope. I got mine a while back and I’m quite satisfied with it. I’m going to update this page if I have any new information worth sharing. If anyone has any additional information worth adding here, drop me a mail. Versions As far as I could find out there are at least two versions of the MBS-10 with different accessories depending upon the manufacturing date.

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Microscope Illuminator ЛОМО ОИ-19 (LOMO OI-19)

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I got this microscope illuminator a while back and wanted to share some things about it. Mine came as is, without power supply nor any filters. It did however come with the tungsten lightbulb, which is nice since those things alone are expensive to get. Optical design The optical design consists of a convexconcave and a biconvex lens, followed by a diaphragm and an optional filter. According to the instruction manual the aperture is 0,67.

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DIN Rail ESP8266 Dual-Relay

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The other day I’ve built myself an ESP8266 WiFi dual-relay for standard DIN rails. Electronics Bottom PCB The bottom PCB is fairly simple, input goes through a polyfuse and a bridge rectifier such that I can power it both from 8VAC-12VAC or 12VDC. And then just a 7805 with protection diodes and a heatsink. At 12V the 7805 dissipates around 0.6W of power which doesn’t sound much, but it gets hot.

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Leitz REDYX Fuse Addition

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I have an old Leitz REDYX variable AC transformer for 6V and 8V tungsten microscopy lamps. Unfortunately it does not contain a fuse, so in other words if the transformer has an isolation failure it will start smoldering until the main circuit breaker for the room trips. So I figured to improve the safety I should add a fuse. In this case I’ve only fused the primary side, it might be a good idea however to fuse the secondary sides as well.

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Apple PowerBook 170

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So I recently rescued an Apple PowerBook 170 from ca. 1991. I couldn’t find the power supply, but fortunately the power connector is just a standard DC jack requiring 7.5V - so I removed the (probably broken and internally leaking) NiCd battery. So I took a DC jack, hooked it up to my lab supply …and bingo! Started up right away! However the mouse ball didn’t worked initially, turns out it was dirty.

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