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The out put is going to be pos no matter what but if the base pin is zero volts , can a cap diode network be utilised from zero volts pin up to meet HV pos?....creating a centre tap Thanx
Registered Member #30
Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706
Yes, it's going to be hard to get negative output from a modern flyback because of the built-in diodes. Probably easiest to get an old-style one with an external diode, you can just turn the diode around.
Registered Member #834
Joined: Tue Jun 12 2007, 10:57PM
Location: Brazil
Posts: 644
If you don't want too high voltage you can ground the positive terminal and get the output at the normal ground pin. If you are not using the other pins, the normal primary coil, for example, this will work up to the point where the ground pin sparks to the core (hopefully not inside the assembly). If one terminal of all the coils (not all!) are connected to the ground pin, there will be no sparking to the other pins. The ground pins of the potentiometers and capacitor, if present, shall be connected to the ground pin too.
Registered Member #543
Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992
Antonio wrote ...
If you don't want too high voltage you can ground the positive terminal and get the output at the normal ground pin. If you are not using the other pins, the normal primary coil, for example, this will work up to the point where the ground pin sparks to the core (hopefully not inside the assembly). If one terminal of all the coils (not all!) are connected to the ground pin, there will be no sparking to the other pins. The ground pins of the potentiometers and capacitor, if present, shall be connected to the ground pin too.
I considered making this suggestion, but didn't because some (but not all) LOPTs have the HV- pin grounded to a tab on the core, which will become quite conductive at 20kV.
Hi ,The coil is modern LOPT ,the freq = 15khz 1/2 wave input , I figure thats 25 x 25 x 25 for the sweep . I read a post about ionisers using the base pin for neg ion out put instead ,something to do with the feel good factor ?? who knows.. and got to thinking if it was possible to earth the pos and generate neg 1/2 the same way an Aerial does by using the earth as a mirror image but then your in the area of wave length and conductor length : to correct freq. Once that was established would you then have 2 x Voltage ? It comes back to the internal diodes blocking oscillation . I thought that because theres 1/2 wave input theres room between pulses to do some trick ..that I obviously dont know ,any suggestions ? or am I dreaming ? Shouldnt HV pos attract neg electrons after all e.s machines pull electrons from earth , the machine itself is a kind of polariser/separator.
Registered Member #543
Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992
paris wrote ...
Hi ,The coil is modern LOPT ,the freq = 15khz 1/2 wave input , I figure thats 25 x 25 x 25 for the sweep . I read a post about ionisers using the base pin for neg ion out put instead ,something to do with the feel good factor ?? who knows.. and got to thinking if it was possible to earth the pos and generate neg 1/2 the same way an Aerial does by using the earth as a mirror image but then your in the area of wave length and conductor length : to correct freq. Once that was established would you then have 2 x Voltage ? It comes back to the internal diodes blocking oscillation . I thought that because theres 1/2 wave input theres room between pulses to do some trick ..that I obviously dont know ,any suggestions ? or am I dreaming ? Shouldnt HV pos attract neg electrons after all e.s machines pull electrons from earth , the machine itself is a kind of polariser/separator.
Why not spend some time in finding out how a LOPT actually works in normal CRT use before dreaming of ways to make it do something different?
It often happens that when organising our knowledge about about a particular device, that answers emerge as the picture is clarified.
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Is there any tricks on FBT neg output??.....or no
