| Author |
Message |
tse
Joined: 03 May 2006
Posts: 1014
Location: Sweatbucket, Fl.
|
| Posted: Wed Jul 06, 2011 12:24 am Post subject: |
|
|
| dvh99 wrote: | if i am going to try them they better be worth every penny  , they do not come cheap scott.
i doubt if they would have let you put such expensive fets on the hdm.
did the hdm modules fail often of overheating in warm environments or high resolution setups?
when running 1080p for a long period the heatsink gets too hot to touch. |
I hope that I haven't given the impression that I had any hand in designing the Marquee HDM. I did not. I did design the Ampro horizontal deflection circuits and we would have been very happy to have the Cree parts back then. We used three 1100V mosfets with 1 ohm on resistance in parallel. The Cree part with its 0.16 ohm on resistance would have been an improvement at about the same price.
When VDC bought the Marquee line it was noted that there were some failures of the power supply section on the HDM. I changed the heatsink on the mosfet and added a little snubber to slow the voltage rise time when the switch turns off and the problems went away.
The HDM has been pretty relliable.
Scott
_________________
"Were we directed from Washington when to sow and when to reap, we would soon want bread."
Thomas Jefferson
|
|
| Back to top |
|
 |
dvh99
Joined: 25 Dec 2009
Posts: 2158
Location: nederland
|
| Posted: Wed Jul 06, 2011 5:44 am Post subject: |
|
|
i stand corrected.
you used 3 fets just to get the on resistance low enough, is it THAT critical?
i will order 3 of those cmf10120d n channel - enhancement fets at digikey. (newark has them too).
digikey shipping costs are free above 100usd and besides that, the price is half of what they cost here.
now to get myself a digital thermometer to show the difference after ie: 1hr running the pj in the regular 161-165mhz range, 1080p.
_________________
1 answer always poses multiple questions.
marquee 9500ultra HD10L moome hdmi1.3 v3+ some mods.
|
|
| Back to top |
|
|
dvh99
Joined: 25 Dec 2009
Posts: 2158
Location: nederland
|
| Posted: Wed Jul 06, 2011 4:34 pm Post subject: |
|
|
ordered the parts, updates will follow.
at digikey.
_________________
1 answer always poses multiple questions.
marquee 9500ultra HD10L moome hdmi1.3 v3+ some mods.
|
|
| Back to top |
|
|
Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
|
| Posted: Wed Jul 06, 2011 7:55 pm Post subject: |
|
|
Just remember to turn off the heater voltage P14.
I wonder how the scope waves would look when you bring the probe close to the Coil wires.
They are nice sine waves that get larger in amplitude the closer the wires you get. I bet it might be a good way to test those new fet's wave pattern compared to stock.
Any way to test them out with a scope Scott before hooking up P14?
Athanasios
_________________
Don't blame your underwear for your crooked ass~ unknown Greek philosopher
"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan
One Smart Dog!!!
Marquee High Performance Bellows now shipping!!
Marquee Modifications and Performance Enhancement
Marquee C-element and Bellow removal
|
|
| Back to top |
|
|
Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
|
| Posted: Wed Jul 06, 2011 7:55 pm Post subject: |
|
|
| Nashou66 wrote: | Just remember to turn off the heater voltage P14.
I wonder how the scope waves would look when you bring the probe close to the Coil wires.
They are nice sine waves that get larger in amplitude the closer to the wires you get. I bet it might be a good way to test those new fet's wave pattern compared to stock.
Any way to test them out with a scope Scott before hooking up P14?
Athanasios |
_________________
Don't blame your underwear for your crooked ass~ unknown Greek philosopher
"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan
One Smart Dog!!!
Marquee High Performance Bellows now shipping!!
Marquee Modifications and Performance Enhancement
Marquee C-element and Bellow removal
|
|
| Back to top |
|
|
dvh99
Joined: 25 Dec 2009
Posts: 2158
Location: nederland
|
| Posted: Thu Jul 07, 2011 3:33 am Post subject: |
|
|
what values would be best for r1 and r219 at fet q5.
yes, i will pull p14 first.
_________________
1 answer always poses multiple questions.
marquee 9500ultra HD10L moome hdmi1.3 v3+ some mods.
|
|
| Back to top |
|
|
tse
Joined: 03 May 2006
Posts: 1014
Location: Sweatbucket, Fl.
|
| Posted: Thu Jul 07, 2011 7:13 pm Post subject: |
|
|
| dvh99 wrote: | i stand corrected.
you used 3 fets just to get the on resistance low enough, is it THAT critical?
i will order 3 of those cmf10120d n channel - enhancement fets at digikey. (newark has them too).
digikey shipping costs are free above 100usd and besides that, the price is half of what they cost here.
now to get myself a digital thermometer to show the difference after ie: 1hr running the pj in the regular 161-165mhz range, 1080p. |
The on resistance directly effects horizontal linearity. It causes the raster to compress toward the end of the line. Higher sweep rates show less of this than lower rates.
The attached waveform is about what is at Q3-drain with 1080p input. You can pick-up the waveform just by holding a scope probe near the deflection yoke or wires.
The resistor values can stay the same.
Scott
| Description: |
|
| Filesize: |
8.45 KB |
| Viewed: |
8957 Time(s) |
|
_________________
"Were we directed from Washington when to sow and when to reap, we would soon want bread."
Thomas Jefferson
|
|
| Back to top |
|
|
Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
|
|
| Back to top |
|
|
dvh99
Joined: 25 Dec 2009
Posts: 2158
Location: nederland
|
| Posted: Fri Jul 08, 2011 6:38 am Post subject: |
|
|
fets arrived in rotterdam , cannot wait to put them in.
_________________
1 answer always poses multiple questions.
marquee 9500ultra HD10L moome hdmi1.3 v3+ some mods.
|
|
| Back to top |
|
|
Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
|
|
| Back to top |
|
|
dvh99
Joined: 25 Dec 2009
Posts: 2158
Location: nederland
|
| Posted: Fri Jul 08, 2011 7:31 pm Post subject: |
|
|
haha sorry, they arrived from the usa in rotterdam (i do not live in rotterdam it is just that they arrived in holland).
now they went to köln in germany??????
so ups has to sent them back again to holland from germany, defies all logic... lol.
_________________
1 answer always poses multiple questions.
marquee 9500ultra HD10L moome hdmi1.3 v3+ some mods.
|
|
| Back to top |
|
|
Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
|
| Posted: Fri Jul 08, 2011 7:34 pm Post subject: |
|
|
| dvh99 wrote: | haha sorry, they arrived from the usa in rotterdam (i do not live in rotterdam it is just that they arrived in holland).
now they went to köln in germany??????
so ups has to sent them back again to holland from germany, defies all logic... lol. |
Ahhh, I forgot your not in Rotterdam! I should have looked in my Address book.
I figured you had enough time to put them in if in fact they were delivered.
Hope they work Dennis.
Athanasios
_________________
Don't blame your underwear for your crooked ass~ unknown Greek philosopher
"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan
One Smart Dog!!!
Marquee High Performance Bellows now shipping!!
Marquee Modifications and Performance Enhancement
Marquee C-element and Bellow removal
|
|
| Back to top |
|
|
dvh99
Joined: 25 Dec 2009
Posts: 2158
Location: nederland
|
| Posted: Sat Jul 09, 2011 2:08 am Post subject: |
|
|
if they do will you get some too?
if you keep running the blend there isn`t really the need for it i guess.
if i play several hours with my ps3 at 720p it gets warm but certainly not hot.
_________________
1 answer always poses multiple questions.
marquee 9500ultra HD10L moome hdmi1.3 v3+ some mods.
|
|
| Back to top |
|
|
dvh99
Joined: 25 Dec 2009
Posts: 2158
Location: nederland
|
| Posted: Mon Jul 11, 2011 7:28 pm Post subject: |
|
|
tried them but they do not work as a drop in replacement.
the image is much less wide (say 60 percent of the original) then shrinks a bit and then oscillates.
the hdm needs modification, need to find out what....
to be continued.
_________________
1 answer always poses multiple questions.
marquee 9500ultra HD10L moome hdmi1.3 v3+ some mods.
|
|
| Back to top |
|
|
tse
Joined: 03 May 2006
Posts: 1014
Location: Sweatbucket, Fl.
|
| Posted: Mon Jul 11, 2011 8:43 pm Post subject: |
|
|
The data sheet says they may not be a drop in replacement. These parts require a higher drive voltage than standard mosfets. The drive voltage, on the HDM, is determined by the rail voltage going to the mosfet driver chip. It is nominally +15V but some of that gets lost in the looping through the yoke connectors and diodes in the "core" circuit.
The +15V indicated on the attachment loops through the core circuit and ends at the driver as the DRV-SUPPLY. The drive voltage can be increased by detaching the +15V and inserting a higher voltage.
EDIT: The driver max voltage is 20V but what is really bad is the gate turn off device (GTO) clamps the drive to 12.5V max. That is definately bad. Specs for the parts can be found at:
http://www.datasheetarchive.com/
Some modifications to the drive circuit look to be necessary.
I recommend disconnecting P-14 and remove the shorting plug on P1 (on HDM, near heatsink) to keep the operating voltage from the output circuit. That way you can view the mosfet drive and verify that it is good without endangering the new fets.
Scott
| Description: |
|
| Filesize: |
25.88 KB |
| Viewed: |
8808 Time(s) |
|
| Description: |
|
| Filesize: |
38.85 KB |
| Viewed: |
8809 Time(s) |
|
_________________
"Were we directed from Washington when to sow and when to reap, we would soon want bread."
Thomas Jefferson
|
|
| Back to top |
|
|
dvh99
Joined: 25 Dec 2009
Posts: 2158
Location: nederland
|
| Posted: Tue Jul 12, 2011 5:08 am Post subject: |
|
|
pin 23 and pin 24 of the conv amp is +24V.
scott, do you think it is safe to get that voltage?
wait there is a +24V too on the hdm
obviously the mdc has to go but i haven`t figured out what to replace the part with.
p1 has been removed.
_________________
1 answer always poses multiple questions.
marquee 9500ultra HD10L moome hdmi1.3 v3+ some mods.
|
|
| Back to top |
|
|
dvh99
Joined: 25 Dec 2009
Posts: 2158
Location: nederland
|
|
| Back to top |
|
|
dvh99
Joined: 25 Dec 2009
Posts: 2158
Location: nederland
|
| Posted: Tue Jul 12, 2011 7:01 am Post subject: |
|
|
is it possible in the circuit to mimick the mdc1000a part with a 2n3904 and 2n3906 transistor plus 2 schottky diodes and a suitable zener?
15k for the resistors in the circuit?
i really want those cree fets to work.
_________________
1 answer always poses multiple questions.
marquee 9500ultra HD10L moome hdmi1.3 v3+ some mods.
|
|
| Back to top |
|
|
tse
Joined: 03 May 2006
Posts: 1014
Location: Sweatbucket, Fl.
|
| Posted: Tue Jul 12, 2011 1:36 pm Post subject: |
|
|
The Cree part is in some ways easier to drive than the original mosfets. The Ciss of the Cree part is only 928pF. The original ART60015 has Ciss = 7500pF and the APT8030 has Ciss = 6600pF. The GTO might not even be necessary because the low capacitance will dischage for turn off with less drive energy. The PNP turn off circuit in Fig 13 should be fine if some sort of faster turn off is needed.
The driver chip, MC34151, is rated for +20V max rail. You could use something like IXDD609PI if you want to use the +24V.
Scott
_________________
"Were we directed from Washington when to sow and when to reap, we would soon want bread."
Thomas Jefferson
|
|
| Back to top |
|
|
dvh99
Joined: 25 Dec 2009
Posts: 2158
Location: nederland
|
| Posted: Tue Jul 12, 2011 6:31 pm Post subject: |
|
|
yes i was wondering about that as well scott, but was afraid that without the turn off device the benefit of the cree with the low capacitance would be lost.
the driver you mentioned is not for sale at farnell.
will look for an alternative.
thanks again.
_________________
1 answer always poses multiple questions.
marquee 9500ultra HD10L moome hdmi1.3 v3+ some mods.
|
|
| Back to top |
|
|
|
|
