Supra Mains Block MD06-EU/SP MK3

After some problems with HDMI dropouts between my Projector and Receiver i decided to try a "proper" mains filter and surge arrest and a new HDMI cable from supra. Seeing that the HDMI cable alone solved my issues i was curious to see what was in the power strip.

Supra MD06-EU/SP MK3 power strip.

For some reason the manufacturer web page is not showing like it used to so here is the cached one:
http://webcache.googleusercontent.com/search?q=cache:7api80Fi4hsJ:www.jenving.se/products/view/mains-block-md06-eu-sp-mk3-3024000030+&cd=7&hl=no&ct=clnk&gl=no

According to the manufacturer it have

• a non intrusive filter (NIF) that does not slow down dynamics :-)
• 3 way protection (Live Neutral and Earth)
• Dampen noise from from cell phones, dimmers etc

Curious as to what was inside i opened it up :-)

End cap and IEC socket removed. 

Surge protection circuit board

The EMI filter consist of a single turn common mode choke around live and neutral between each outlet.

Ferrite cores in heat shrink tubing between each outlet

As commented in Supra the socket closest to the IEC inlet terminal does not have a filter. When removing the heat shrink on the MOV a thermal fuse reveled itself. 

After what i can see the schematic is like this....i might be wrong.

Comments on the circuit design

• There is a 10A ceramic fuse in the inlet IEC receptacle on Live, none on Neutral. With schuko there is no lock or indication of what is live and neutral. So the fuse might be on the Neutral line.
• The filter consist of a single turn common mode choke between the outlet sockets. There is no other filtering element in the design, Not a single capacitor. Differential noise cannot be filtered by this design. Maybe that's why its marketed as a NIF (Non Intrusive Filter).
• The surge protection is a clamping design built using MOV (metal oxide varistors) in parallel with the main current flow. The clamping deceives are protected against overload using 5A 115C thermal fuses in the same heat shrink as the MOV its protecting. 
• The Gas filled spark gap conducts if PE deviates more than 470V from the lines during lightning stirkes.
• A bit surprised to see the LEDs directly in series with resistors across 230V mains. I doubt that normal LEDs have a reverse voltage of that much but the ones used might have a proper avalance spec. A normal diode in antiparalell would not hurt. I really doubt that this design will survive a 2.5kV test voltage after the surge protection fuse is over heated.
• How can a gaping hole of 43x5cm in the faraday cage block any EMC? Its more like a tin foil hat than a faraday cage.
• I really like the looks workmanship and the mechanical quality so i will definitely keep it in my system :-)

Samsung Laptop with Synaptics touchpad in Windows 10

I have struggeled with the synaptics touchpad in my Samsung SF311 laptop since I installed Windows 10 on it. Samsung seems to abandon old hardware with no updated drivers to show for. 

The drivers from synaptics website did show a old style scroll icon as mouse pointer when attempting a scroll but Edge and Explorer windows would not respond.

Having read some attempts that seemed to work on HP laptops with Lenovo drivers I tried to install the Lenovo drivers on my Samsung SF311. The Lenovo drivers works, scrolling and everything! The only culprit now is that it is scrolling the "wrong" direction (up is down and down is up). But this is probably done on purpose to "drag" the page, not a wheel. It actually starts to feel normal.

The drivers I used:
http://support.lenovo.com/us/en/downloads/ds032247
They probably also work on SF411 and SF511 as I guess they share touchpad.

Update: It is possible to reverse direction of scrolling.
Start->Type "Mouse & Touchpad settings"
Device Settings->settings

Raspberry PI camera as telecine sensor for digitizing super 8mm?

I found this describing how to modify the camera on the raspberry pi
http://www.raspberrypi.org/archives/4279

I figured it might be a candidate for camera for transferrig Super 8mm to HD and decided to try how good the macro was.

I tried the rubber-eraser trick mentioned mentioned on the site and saw i could easely unscrew the lens with my fingers. It was not that hard. about 2 turn out and the lens come loose.

I ran this command on the pi using putty to grab an image:
raspistill -o kodak.jpg
There is a small preview window on the display on the pi that made it easy to find focus distace of approx 2-3cm.

Transferred the image to my computer using WinSCP and checked out the result:

The image quality seems good enough but seems like i only will get 814x 524 of video resolution out of this. Not enought for now so more drastic measures are needed to get the lens further out to make it fill more of the sensor.

I tried reversing the lens but then was not able to focus even with the film toutching the lens.

Then i tried to jam a bit of tape in the hole to make the lens stay longer out in the fixture

This is the result:



Paint tells me it possible to get 1080p height from one Super 8mm frame height. Exactly what I am after. Never mind the white balance. The red LED from the camera module is causing weird lighting. That will need to be covered or removed. But this looks promising.

HT Projector ground loop isolator

Once I got a projector (Epson EH-TW3200) connected to my surround amplifier I had a problem with hum in the speakers, and some nasty flickers because of bad HDMI signal quality. While connecting the HDMI between the surround amplifier and the projector I noticed a small spark when the metal on the HDMI cable connector came in contact with the metal on the receiver.

The setup with hum:

Projector (Epson EH-TW3200): Grounded
15M HDMI Cable
Surround amp: Not grounded (double isolated)
Media PC: Grounded
Sub: Grounded

I live in a pretty new house with 400V TN (terra neutral) grid. This is common in europe, but not so common in historically in norway.

I tried a small hack with tape on the safety ground on the wall power plug to the projector. Then the problems with flicker and hum went away. But I dont like having disconnected ground for safety reasons so i thought up this ground isolator:

It is pretty ugly, but it will connect the ground during a failure and trigger the earthfault circuit braker in my house. It is basically the same as a Zink Saver used for boats, but they have much more powerful diodes.



Disclaimer, this is most likely a bad idea and will probably kill you and your stereo, but if done correctly it should be better than to disconnect the safety ground completely.

What causes the groundloop in the first place?

The Surround amp/ Sub and PC is sharing the same wall outlet. 

The projetor have another wall outlet with another route to the house star ground point.

The chassi ground of the surround amp and the projector is connected together causing a triangle loop. When there is a potential difference of say 50mV between the ground in the two sockets there will flow current in the screen of the HDMI. I assume the resistance in the HDMI screen to be 0.1 Ohm. Then there will be 50mV/0.1Ohm = 500mA current flowing in the HDMI screen and into the surround receiver and adding noise to all analog logic referenced to this ground (like my Sub)

Adding the isolator the grounds must be more than 1-1.2V appart before there can be flowing any current in the HDMI cable. This will cover most noise and fields the groundloop can be subjected to.

Mounting a micro switch in the Eumig Mark 610D for synced telecine.

This is just a small followup of this post: http://oysteineliassen.blogspot.no/2012/09/diy-synced-telecine-with-eumig-mark.html

Someone on vimeo asked where I mounted the micro switch inside the 610D projector. 

Here are some pictures :-)

First off, i kept the big ALU part that locks the gear mechanism. It is held at fixed position (6 fps) with some pressure from the steel plate in the top of the first picture. I just rotate this plate to press inn the big alu gear part.

The mounting bracket for the switch is made of some black metal piece i did not need joned to strip of aluminium by a M3 screw and nut and then bent into position. Some double sided tape on the sidewall of the micro switch is securing it to the aluminium.

 The aluminium is bent into position so that the actuator of the micro switch is touching the metal flap that i noticed was "coming out" at each frame advance.

As for the reliability i managed to transfer 2 reels of 100 meters  and about 12 reels of 15 meters without breakdown of the micro switch.

Hope this is of some use to someone. 

XFX GeForce 9300 Mainboard Hdmi LPCM Channel mapping

Just wanted to mention a channel mapping issue i had while i was uprgading my XBMCbuntu 12 box with a XFX Geforce 9300 mainboard.

I always set XBMC to resample audio and sync video to soundcard, that way i get flickerfree movies.
This means i need to use LPCM for sound to my surround. And here is where the problem started.

My center channel was moved to Rear Right. :-(

While xbmc is running but movie is stopped i can do the following from an putty SSH session.

xbmc@KANON:~$ speaker-test -D hdmi -c 6

I hear that the mainboard clearly mapped the channels wrong.

While it is playing this

>  0 - Front Left
>  4 - Center
>  1 - Front Right
>  3 - Rear Right
>  2 - Rear Left
>  5 - LFE
i hear the real order as:

Front Left
Rear Left
Front Right
LFE
Center
Rear Right


Editing the alsa userconfig with
xbmc@KANON:~$ nano .asoundrc

and put the following in the empty file:
pcm.hdmi-remap{
        type route
        slave.pcm hdmi
        ttable.0.0 1
        ttable.1.1 1
        ttable.2.4 1
        ttable.3.5 1
        ttable.4.2 1
        ttable.5.3 1
}


testrun:
xbmc@KANON:~$ speaker-test -D hdmi-remap -c 6
works butiful :-)

Rebooted XBMC machine and now i have a new device in the audiosettings:

After a quic test in a movie i finally have my center in the center speaker :-)

IR encoder from a ball mouse

I was a bit curious to see how an old mouse worked to be able to use the phototransistors in there for other DIY purposes. This video is shot with an old sony DV camcorder and shows how the IR shadows penetrate the receiver phototransistors.

Here is the video:

The quaderature signal output from the two phototransistors is then something like this:

A: __|--|__|--|__|- 
B: _|--|__|--|__|--



The direction of rotation is determined by the phase difference of the pulses. This would then be the other direction:

A: _|--|__|--|__|--
B: __|--|__|--|__|- 

 Hope this is useful for someone, i have used the phototransistors for this energymeter interface.