I am glad I keep this link as favorite 
I don't time to start this yet but got all the parts need. kodabmx, any chance you do a summary on fist page of your first post? Such as does it work with rectifier tube or just diodes only, and what kind of diodes that compatible, chokes, ground problem, etc...
Now come to the rc snubber, saw the pic but not sure how to apply if it happens to mine. May be calico88 can explain more detail how to so others can follow.
I don't time to start this yet but got all the parts need. kodabmx, any chance you do a summary on fist page of your first post? Such as does it work with rectifier tube or just diodes only, and what kind of diodes that compatible, chokes, ground problem, etc...Now come to the rc snubber, saw the pic but not sure how to apply if it happens to mine. May be calico88 can explain more detail how to so others can follow.
This thread needs more switchers. Switchers are easy peasy (Flybacks) once you get it, but that applies to everything in life i guess.
I just recently finished a prototype for a 6-12V or 12-24V to -60V 100mA flyback. For bias purposes. Ripple in the audio range is non-existent. and there is only some Megahurtz ripple that i keep out with some 1206SMD beads. Works really well actually.
And a 10-14V in Flyback to 450V 100mA for well guess the purpose. Im gonna use two cores to go from 24VDC to 450VDC 200mA next..
Next up is a Buck from 24VDC to 6.3 8A guess the purpose..
I just recently finished a prototype for a 6-12V or 12-24V to -60V 100mA flyback. For bias purposes. Ripple in the audio range is non-existent. and there is only some Megahurtz ripple that i keep out with some 1206SMD beads. Works really well actually.
And a 10-14V in Flyback to 450V 100mA for well guess the purpose. Im gonna use two cores to go from 24VDC to 450VDC 200mA next..
Next up is a Buck from 24VDC to 6.3 8A guess the purpose..
Attachments
Do you mind posting the schematic for the 10-14v to 450v flyback converter?
Or if not, a verbal description of the design blocks?
Having a lot of problems with my own prototypes, feels like I'm missing something.
Also, where does one source reliable flyback transformers for this purpose?
Thank you.
Or if not, a verbal description of the design blocks?
Having a lot of problems with my own prototypes, feels like I'm missing something.
Also, where does one source reliable flyback transformers for this purpose?
Thank you.
TI-EF25-1068 FERYSTER - Transformer: impulse | power supply; 45W; Works with: UC3843 | TME - Electronic components
Data from Ferryster.
Lprim 10.89 µH ±10%
Ratio 1:10
Ipeak 15.8 A
Isat >18 A
fosc 70 kHz (UC3843, DCM)
Rsc 0.075 Ω (Ipeak = 13.33 A), 0.068 Ω (14.7 A) 5 W
I use IRFP240/UC3843 for my proto nice slow fet, no need to go to LT1243 for the better fall times, just use a 6K/W cooler for the fet. Less garbage in means less garbage out on the secondary. Not that you cannot get somewhat higher efficiency, but most of your dissipation comes from the 1V current sense resistor. I used a TO220 resistor for that, but theres no reason you cannot get away with three 0.22R 2W metal oxides in parallel to get to 82 or 68mOhm
Next thing on my list is to take two of these cores, and put the primaries in series, and the secondary in parallel.
CNY64 has horrible current transfer ratio, a 4N25 will work better. But i wanted to be able to stack this supply on top of something else, into the KV range.
This is the Fet i plan on using for the improved version. There is no need to have both a slow fall time FET and a slow fall time output on the UC3843
AOT296L ALPHA & OMEGA SEMICONDUCTOR - Transistor: N-MOSFET | unipolar; 100V; 50A; 54W; TO220 | TME - Electronic components
If you want better regulation than whit a zener stack, TL431 is the way to go.
Data from Ferryster.
Lprim 10.89 µH ±10%
Ratio 1:10
Ipeak 15.8 A
Isat >18 A
fosc 70 kHz (UC3843, DCM)
Rsc 0.075 Ω (Ipeak = 13.33 A), 0.068 Ω (14.7 A) 5 W
I use IRFP240/UC3843 for my proto nice slow fet, no need to go to LT1243 for the better fall times, just use a 6K/W cooler for the fet. Less garbage in means less garbage out on the secondary. Not that you cannot get somewhat higher efficiency, but most of your dissipation comes from the 1V current sense resistor. I used a TO220 resistor for that, but theres no reason you cannot get away with three 0.22R 2W metal oxides in parallel to get to 82 or 68mOhm
Next thing on my list is to take two of these cores, and put the primaries in series, and the secondary in parallel.
CNY64 has horrible current transfer ratio, a 4N25 will work better. But i wanted to be able to stack this supply on top of something else, into the KV range.
This is the Fet i plan on using for the improved version. There is no need to have both a slow fall time FET and a slow fall time output on the UC3843
AOT296L ALPHA & OMEGA SEMICONDUCTOR - Transistor: N-MOSFET | unipolar; 100V; 50A; 54W; TO220 | TME - Electronic components
If you want better regulation than whit a zener stack, TL431 is the way to go.
Attachments
Last edited:
I've been using prebuilt modules.
I'd try this if I was going to design instead though: 12V To 255V 300V EC42/EC4045 Horizontal High Frequency Transformer Inverter Booster|AC/DC Adapters| - AliExpress
I'd try this if I was going to design instead though: 12V To 255V 300V EC42/EC4045 Horizontal High Frequency Transformer Inverter Booster|AC/DC Adapters| - AliExpress
I've recently built a small EL84 SE amp using this module and my experience has been quite good. Voltage is stable at about 80mA current draw. i had some "flapping" noise (not very loud even on high efficiency speakers) but found that re-arranging the heater wiring to keep it away from signal wire resolved this, now it's dead quiet.