Comments for marek's microsite

Comment on PID Anbaubox für eine Gaggia Baby ’77 by Marek Lewandowski

Marek Lewandowski — Wed, 25 Jan 2012 17:01:44 +0000

So, Gala,
wenn man den Umbau nicht macht, muss man “Temperatursurfen”, die Temperatur wandert auf und ab mit dem Originalthermostat. Inwiefern es sich auf den Geschmack auswirkt, hängt vom Kaffee ab.

Der Umbau hat um die 50€ gekostet, es ist schwer genau zu berechnen. Ich habe einige Teile einfach in der Schublade gehabt und einiges wiederum teuer eingekauft (z.B. Gehäuse vom Conrad).

Zeitlich war es ein ruhiger Nachmittag bzw. Abend. Je nach dem, wie fit man mit Werkzeug umgehen kann, nicht wahr?

Gruß!
Marek

Comment on PID Anbaubox für eine Gaggia Baby ’77 by Gala

Gala — Tue, 24 Jan 2012 21:34:28 +0000

Hi Marek,
super Beschreibung. Was passiert denn, wenn man das nicht angeschaltet hat. Hat die Gaggia dann nach der Aufwärmzeit nicht eine “optimale” Temperatur, wenn man nicht Milch schäumt, sondern nur Espresso macht?
Sag mal, was hat das ganze denn in Summe gekostet?
Und wie viel Zeit hast Du investiert?

Schöne Grüße
Gala

Comment on PID Anbaubox für eine Gaggia Baby ’77 by Marek Lewandowski

Marek Lewandowski — Wed, 11 Jan 2012 06:01:34 +0000

Hi Francesco

There isn’t any visible difference between a good shot with or without PID and it’s possible to obtain a good shot either way. It’s a bit more time consuming without, as you need to temperature-surf the machine. With PID it’s always ready (or at least you can see whether it’s ready).

My machine has an adjusted OPV, but it’s the former owner that did it.

Greets,
Marek

Comment on Alinco DJ-S45CQL (der große Bruder von DJ-S45CQS) oder wie ich an eine Funke gekommen bin… by Marek Lewandowski

Marek Lewandowski — Wed, 11 Jan 2012 05:58:27 +0000

Technisch wäre es möglich, man müsste aber den Ersatzakku um so eine Nase ergänzen, wie sie der Originale hat. Diese Nase legt in der Funke ein Schalter um, der das Laden erlaubt (sonst ist die Verbindung zum Lader elektrisch unterbrochen).

Marek

Comment on Alinco DJ-S45CQL (der große Bruder von DJ-S45CQS) oder wie ich an eine Funke gekommen bin… by Volker

Volker — Wed, 11 Jan 2012 00:43:11 +0000

Wirklich ein hilfreicher Bericht. Konntest Du den “Ersatz”CRV3-Akku mit dem originalen Tisch-Ladegerät von Alinco laden?

Comment on PID Anbaubox für eine Gaggia Baby ’77 by Francesco

Francesco — Tue, 10 Jan 2012 10:44:07 +0000

-English-
Your work is awesome, perfectly and carefully integrated into the machine. I rely on the google translation, since I do not speak german. Can you add a picture of the crema obtained with the PID in a ristretto shot, and a taste opinion?
An additional question is if you also adjusted the OPV (over pressure) valve to a slighly lower control pressure (10bar?) and if you have a device/gauge to measure the pressure.
I have the same machine (color white, 1979) and plan to go for PID temperature control and adding a pressure gauge in order to fine tune the pressure as well.
Thanks!
Francesco.

Comment on Calibrating Gossen Lunasix 3 (LunaPro) by Marek Lewandowski

Marek Lewandowski — Sun, 04 Dec 2011 10:41:09 +0000

It sounds right about the placement.
The frame that holds the mirror is soft, maybe it got deformed a little when it hit the floor?

Marek

Comment on Calibrating Gossen Lunasix 3 (LunaPro) by Randy Zauhar

Randy Zauhar — Sun, 04 Dec 2011 01:42:04 +0000

Hi, this is an excellent article.

I was not trying to adjust my meter’s calibration or deal with batteries, my meter was calibrated by QLM. However, some months ago I dropped the meter and it has been sticking, intermittently.

I disassembled the meter to see if I could find the trouble. Nothing obvious, and no bad behavior while the meter was apart.

UNFORTUNATELY, while I was screwing around the half-silvered mirror popped out. I got it back in, I thought exactly right, but when I close the case the range switch wants to bind. If I pull the case apart slightly, it works smoothly.

All I did was to put the lever arm through the hole in the corner, and swing the mirror part into its slot before closing the case. I oriented it so that the clear opening replaces the silvered side when in low-light mode, I assume that is right.

Any offhand advice would be greatly appreciated!

Randy

Comment on Calibrating Gossen Lunasix 3 (LunaPro) by Lukasz

Lukasz — Wed, 16 Nov 2011 17:07:48 +0000

I thought LD6806 only takes 1µA when is not doing anything and that current draw is 0.1-0.2mA :/
Also it would be possible to install additional switch to turn whole thing off, with that we could lengthen battery life to cuple months easily.

Comment on Calibrating Gossen Lunasix 3 (LunaPro) by Marek Lewandowski

Marek Lewandowski — Wed, 16 Nov 2011 16:43:02 +0000

LD6806 draws about 100µA by just sitting there, so your spanking new SR44 battery will be drained in 2000h or about 2 months.
LD6806 needs also about 1mA current draw for proper stabilization, so you need to add dummy load to Lunasix internal circuitry.
Otherwise the idea of an LDO crossed my mind, it was just not worth it… You anyway will need to calibrate the whole business.

Comment on Calibrating Gossen Lunasix 3 (LunaPro) by Lukasz

Lukasz — Wed, 16 Nov 2011 10:47:52 +0000

Hi Mark,
I was thinking about using LD6806 low dropout voltage regulator instead of your solution.
It’s possible to achieve stable 2,8V (I require 2×1,35V for lunasix) enclosed in one small simple circuit.
What do you think about voltage 2,8 instead of 2,7? should I look for something that gives me 2,6? or use LD6806 2,5V version?

Comment on Calibrating Gossen Lunasix 3 (LunaPro) by Mark

Mark — Mon, 26 Sep 2011 11:22:01 +0000

Your article is very much appreciated. I’ve tried re-calibrating my Luna Pro using silver oxide batteries, using only the trim-pots as suggested in the excellent article at
http://www.butkus.org/chinon/batt-adapt-us.pdf
However at least on my meter the trimmers don’t have *quite* the range needed to compensate for the much higher battery voltage. Installing a diode is a sensible and cheap solution to the dilemma.

Comment on Calibrating Gossen Lunasix 3 (LunaPro) by Marek Lewandowski

Marek Lewandowski — Tue, 05 Apr 2011 04:40:00 +0000

typical value is just that – typical. ldr sensors have a wide variation, so i wouldn’t write any off if it seems to work fine. it should calibrate anyway.
i’m typing on a cellphone, excuse briefness
greets
marek

Comment on Calibrating Gossen Lunasix 3 (LunaPro) by Augie

Augie — Mon, 04 Apr 2011 00:09:38 +0000

Hi, sorry I disappeared for bit there. Here’s what I’ve done.

The switch looks fine, but I cleaned the contacts just in case. Both scales do give readings.

I’ve tested the range of resistance of each pot. Everything looks reasonable, although I have no way of really knowing. If you have any numbers that I can compare to, that may or may not be useful.

I’ve been working on your LDR calibration sheet. I have all but the lower third of the scale pretty well filled in. The gamma value is 0.4, with no reading more than 11% off. Your notes say that 0.6 – 0.99 is typical. Could 0.4 be out of the range that is possible to calibrate? Does this mean that the LDR is no good?

Augie

Comment on Calibrating Gossen Lunasix 3 (LunaPro) by Marek Lewandowski

Marek Lewandowski — Fri, 01 Apr 2011 17:17:52 +0000

Have you been succesful?

Comment on Calibrating Gossen Lunasix 3 (LunaPro) by Marek Lewandowski

Marek Lewandowski — Tue, 29 Mar 2011 18:56:29 +0000

Do you get any readings on any scale?
For a rough test: without ND in the way (on low-light scale) a reading off an average LCD monitor screen showing white should about just max out the scale (12). Reading taken 1ft from a 60W bulb should definitely exceed the range. This is for a properly working, calibrated meter.

Without ND filter in place you should be able to obtain similar reading on both scales.

Before taking on the pots I’d have a look of the wiper switch that switches scales. If its contacts are corroded (oxidized) nothing will work reliably.

Marek

Comment on Calibrating Gossen Lunasix 3 (LunaPro) by Augie

Augie — Tue, 29 Mar 2011 13:23:13 +0000

I think I understand. I guess my next step is to start checking each connection. Can you tell me how I could test the individual pots?
Thanks,
Augie

Comment on Calibrating Gossen Lunasix 3 (LunaPro) by Marek Lewandowski

Marek Lewandowski — Tue, 29 Mar 2011 06:34:31 +0000

There’s not much point in graphing the range of calibration this way, because LDR elements differ from piece to piece by a lot. If you want to approach the problem systematically, you have to take ldr variability into consideration. You will not gain much anyway, because the adjustment has to be done in very fine increments and so putting some sort of a scale on each pot will be useless. The range of adjustment is sufficient by design to accomodate the variance and normal (i.e. Not catastrophic) aging of the ldr cell. If you can’t get this meter into calibration it means some of the components have failed, i.e. pot cracked or bad contact somewhere.
Marek

Comment on Calibrating Gossen Lunasix 3 (LunaPro) by Augie

Augie — Mon, 28 Mar 2011 20:43:22 +0000

And, again. Sorry I’m taking over your blog. I see now that all extra whitespace is removed. Maybe I can get around that like this.

high range
____l____c____r
l____–___.6___.3
c___–___.3____1.6
r___–___3.3___+

low range
_____l____c____r
l____0____0____0
c____0___.6____+
r____+___+____+

Slope is down and offset is across.

Comment on Calibrating Gossen Lunasix 3 (LunaPro) by Augie

Augie — Mon, 28 Mar 2011 20:35:06 +0000

Ok, lets try that again

high range
offset
l c r
slope l – .6 .3
c – .3 1.6
r – 3.3 +

low range
offset
l c r
slope l 0 0 0
c 0 .6 +
r + + +

Comment on Calibrating Gossen Lunasix 3 (LunaPro) by Augie

Augie — Mon, 28 Mar 2011 20:30:34 +0000

With the pots ‘reset’ to center, and the filter removed, there is a 6 stop difference between the scales.

I decided to try to check the full range of possible calibrations. For each range, I set the two pots to either left, center, or right in all possible combinations. For each setting I compared readings with and without the filter. I have created a graph of my results, which will hopefully be readable. The numbers are the difference between readings. I used +/- when the readings were out of range.

high range
offset
l c r
slope l - .6 .3
c - .3 1.6
r - 3.3 +

low range
offset
l c r
slope l 0 0 0
c 0 .6 +
r + + +

Comment on Calibrating Gossen Lunasix 3 (LunaPro) by Marek Lewandowski

Marek Lewandowski — Mon, 28 Mar 2011 18:33:06 +0000

Okay, so it seems that the gauge and the ND filter are okay. I assume the meter is reading generally something, i.e. it reacts to light too.
What you need to know is that the switch not only moving the ND filter, it also changes the connections within the meter. There are actually two relatively independent meter circuits, one for highlights and one for low-light. If you misadjust them badly, they can read whatever you want on each scale.

What happens when you REMOVE the ND filter completely and take a reading for highlights/shadows? do readings differ then? They should by about 6 stops, since the meter reads the same for both scales when it’s in.
Marek

Comment on Calibrating Gossen Lunasix 3 (LunaPro) by Augie

Augie — Mon, 28 Mar 2011 13:25:40 +0000

The filter appears to be fine. I even stuck it in front of another Lunapro, which I am using as a reference, and it lowered the reading by about six stops.
The battery check was a bit high. I followed some other instructions which told me to calibrate the battery check first, so I can’t say exactly where it was. I’m using silver batteries with a diode to drop the voltage. I’ve checked the voltage when the meter is on, and it looks correct.
The problem is present in both scales. If I understand correctly, the two sets of pots are on independent circuits, so this would seem to rule out a single bad pot.
Thanks for responding so fast,
Augie

Comment on Calibrating Gossen Lunasix 3 (LunaPro) by Marek Lewandowski

Marek Lewandowski — Mon, 28 Mar 2011 06:37:29 +0000

Let’s try a little troubleshooting: can you see through the ND filter with your own eyes? It should be silverish and quite opaque, you might see a light source like the sun or a bright bulb through it, but not your desk.

NEXT THING: what does the battery check say? Does the meter provide ballpark readings on the high scale (without nd)?

Technically a bad pot could lead to funny readings, but let’s get the hardware issues off the table first.
Marek

Comment on Calibrating Gossen Lunasix 3 (LunaPro) by Augie

Augie — Mon, 28 Mar 2011 00:30:04 +0000

Hi,
I hope you can help me with this. I recently received a lunasix 3, which I am now struggling to calibrate. No matter how I adjust the pots, when I take readings with and without the nd filter, there is only a third of a stop difference. I don’t know enough about electronics to figure out what could compress the range so much, or why no adjustments make a difference.
Thanks in advance,
Augie