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Supply Controller (continued)

R

Robert Baer

Jan 1, 1970
0
For schematic of my "controller" see http://www.oil4lessllc.org/Misc/ .
Some responders in the past indicated that the source had to be
pulled down to ground for the dratted IR2118 to work properly.
Note in my case i need the output to be adjustable from somewhere
near ground (50V will do) to somewhere near supply (120V), and that
voltage have little ripple (say under 10% or 10V - whichever is
reasonable for supply to bottom of flyback in TV.
As shown, i do not get an adjustable voltage, and it is fairly low.

Clues please to get this to work (or an alternate that is cheeep.
Thanks.
 
   For schematic of my "controller" seehttp://www.oil4lessllc.org/Misc/.
   Some responders in the past indicated that the source had to be
pulled down to ground for the dratted IR2118 to work properly.
   Note in my case i need the output to be adjustable from somewhere
near ground (50V will do) to somewhere near supply (120V), and that
voltage have little ripple (say under 10% or 10V - whichever is
reasonable for supply to bottom of flyback in TV.
   As shown, i do not get an adjustable voltage, and it is fairly low..

   Clues please to get this to work (or an alternate that is cheeep.
   Thanks.

what are you trying to do, could you make a simple schematic?

-Lasse
 
   Please READ the first line..

That is for you "controller", I mean a schematic of the system, the
supplies,
the load etc.

when you say bottom of flyback, I'm imagining you need a supply that
can sink
current?

-Lasse
 
R

Robert Baer

Jan 1, 1970
0
Robert said:
For schematic of my "controller" see http://www.oil4lessllc.org/Misc/ .
Some responders in the past indicated that the source had to be pulled
down to ground for the dratted IR2118 to work properly.
Note in my case i need the output to be adjustable from somewhere near
ground (50V will do) to somewhere near supply (120V), and that voltage
have little ripple (say under 10% or 10V - whichever is reasonable for
supply to bottom of flyback in TV.
As shown, i do not get an adjustable voltage, and it is fairly low.

Clues please to get this to work (or an alternate that is cheeep.
Thanks.
Full manual for the TV set, and extracted schematic, with selected
info now added to http://www.oil4lessllc.org/Misc/ .
I have added a pulse transformer..the IR2118 is now driving its
primary, and a 1K added from Vs (pin 6) to ground lets it work nicely.
Still do not get adjustable range desired.
The pulse transformer used is the Murata 78601/2C (500uH) and does
not "transmit" the full width of the pulse:

|---\ <--full 12V
| \
| | v--rather small level
| |-----|
-----| |------ 0V

<--5uSec--> Pulse transformer loading is the FET gate

Would a 10,000uH pulse transformer work better?
 
T

Tim Williams

Jan 1, 1970
0
More inductance isn't the problem; you need one with a higher V.us flux
rating.

In that particular series, they use Ferroxcube 3F3 cores, so a higher
inductance will be consistent with higher flux, not just a higher
permeability core.

Tim
 
R

Robert Baer

Jan 1, 1970
0
Tim said:
More inductance isn't the problem; you need one with a higher V.us flux
rating.

In that particular series, they use Ferroxcube 3F3 cores, so a higher
inductance will be consistent with higher flux, not just a higher
permeability core.

Tim
Thanks.
 
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