Canon EOS 350D/Digital Rebel XT



I have only just bought this camera and have not yet done much to it;
- Repaired
Good thing to start with ;)
There was a bad contact with one of the flex cables leading to the LCD, and also the flash is defective which i really have to fix soon (NOT!!).
- De-filtered
I have removed the IR-filter, and have chosen to not replace it with a Baader filter or an optical window for max. transparancy and IR sensitivity. I might not reach focus on infinity with some lenses, but thats no biggy for me as i only use my astro camera's on telescopes.


Thats all at the moment. I have high hopes for this one, a dark frame i made looked very clean, and its pixels are of a reasonable size. Next i'll get it cooled, the construction of a coldfinger will be the same as with the 400D as these cams are mechanically built the same.

Updated: 7-10-2009
I am going to try another Amp Off version using a 3.5V regulator.
schematic
Layout
Board
Size
pic

Update 10-10-2009
I've succesfully tested this version on a 300D, so after 7 version this is the non plus ultra final version ;)
The eagle project for this version is now included in the .rar in the 300D Amp Off mods.

Update 11-10-2009

Well, the non plus ultra final version has to be modified a little for the 350D ;) more about that later. First how to connect it to the pcb.
Read the 300D amp off modification first, much of the modification is the same as with the 300D and i wont go into every detail here.
As with the 300D you need to cut 4 traces next to the connectors that lead to the sensor.
PCB
Zoomed in
top connector

bottom connector
Signals on marked positions:
A new supply voltage to sensor, connect to output of amp off circuit
B Ground
C +5V
D Amp off activation signal, connect to input of amp off circuit

Again rotate the circuit to a better position and fix it with a drop of glue, now testing can begin.
rotated

Update 13-10-2009

Hmm, old fashioned maze game anyone?
pattern
I tried 4V instead of 3.5V during the exposure, but that wasn't the any better. Then i tried to supply both sides of the sensor with the new voltage, instead of just one point on the top connector i also connected the left side of the bottom connector:
better

So, the revised connections are:
A (pins 4&5 from the left from the top AND bottom connectors to the sensor) new supply voltage to sensor, connect to output of amp off circuit,
B Ground
C +5V
D Amp off activation signal, connect to input of amp off circuit

Changes needed for the amp off circuit for the 350D

The amp off circuit as can be found in the 300D section needs a few changes, so here is a new eagle project.
The components used are all fairly common. The power fet IRLML6401 has extremely low Rdson & Vgs, and can handle upto 4A, the voltage regulator used might be obsolete, but can be replaced with virtually any other regulator in SOT-5 or SOT-6 package.