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Home Brew Analog Computer System
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GK:
Very nice. That one might like look impressive rotated in 3D projection.

Just out of curiosity, have you tried to derive an electrical analogue for any of the systems from Sprott's book represented by the equations in jerk form (chapter 3.5)? He has a few example circuits in chapter 10, but this isn't something I've started at yet.

I like your trig function generator, but I think you've cheated a bit with the EPROM  ;D. I'm sticking with the traditional analogue methods for my function generators, but will be resorting to digital for my programmable/variable analogue time delay unit, for simulating transport lag. 
GK:

--- Quote from: netdudeuk on February 01, 2015, 02:43:45 pm ---Looks amazing.  It wouldn't even matter if it didn't work  :)

--- End quote ---


The power supply worked first time, well after I fixed the improperly wired transformers  ::). There are 4 regulated rails: +/-110V and +/-15V. The two vertically mounted toroidal transformers are 55V+55V secondary types with the secondary windings connected in series to give me 110V+110V (+/-155V rectified DC) for the high voltage rails. I accidentally wired them out of phase the first time around so the voltages summed to zero.

After fixing that issue and testing/calibrating the power supply I started testing the integrators by wiring them up to the regulated supply rails one by one. The "outboard" transformer shown in the picture is a 18V+18V secondary type for the +/-15V regulated rails. This one doesn't have a high enough VA rating to power all 10 integrators and is just wired in for testing purposes. I don't have the correct transformer for installation yet.

Anyway, for testing purposes I knocked up a quick test circuit (as shown in the pic) on the breadboard. Basically it's a couple of threshold comparators (LM311's) and a flip-flop (1/2 4013) and a BC560 acting as a level-shifter, wired to make a (when wired to the integrator under test) a 200Vp-p triangle wave generator.

This whole thing will look two hundred times neater when finished and all the wiring is neatly bunched up and cable tied.



BTW, does anyone have long term experience with those soft, rubbery-like, self-adhesive thermal insulator pads? I had these hand so I used them for the TO-264 power transistors (+/-110V rails series-pass) mounted on the heat sink, but they appear rather marginal to me. I think I'll replace them with reliable mica and good old thermal paste.

T3sl4co1l:
110V?  What for?  3/2 power functions from toobz?! ;D

Sil-pads are only good for the thermal resistance they claim (if even that..), so, typical on a TO-247 is 50W tops, maybe up to 100W with a water cooled sink.  So the 264's will be slightly better, but not by too much.  I shouldn't think that's a problem unless you need amperes from those supplies...

Tim
GK:
This is a 100V computer.

I'm not concerned with heat transfer, but electrical isolation. These double-sided adhesive pads are as soft as bubblegum.

T3sl4co1l:
Is that the almost jelly-like kind, then?

Those aren't intended for use with screw clamping force.  You need the stiffer rubber kinds for that.

The soft stuff is fantastic for filling space, like if you need better conduction between a PCB and mounting plate.  It works even if you've got a bunch of 0603 and 1206 parts on the backside.

Might also look into a "full pack" style transistor in that size.  Kind of late as you've already bought and installed them, and such variants aren't always available, but... just something to keep in mind.

Tim
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