Supertex developed a nice little (TO-92) regulator which will "do" 1.2 to 450 V -- the LR8N3 -- it's stated purpose seems to be controlling the high voltage on the front-end of an off-line switching power supply. Of course it is also applicable as a regulator to control the base of a pass transistor.
http://www.supertex.com/pdf/datasheets/LR8.pdf
www.mouser.com is their distributor in the U.S.
http://www.supertex.com/pdf/datasheets/LR8.pdf
www.mouser.com is their distributor in the U.S.
just saw this thread.
quasi
silicon chip used this idea for there ULD amp power supply +- 55v
Used 317/37's and trimpots for adjusting.
psu works well very versatile.
jackinnj
the LR8N3 looks interesting.
i need a 300v and 600v voltage lines for a valve amp.
been using zeners, because haven't found high voltage reg.
until now, thanks, food for thought.
300v rail easy to work out but 600v?
? could reference off the 300v or bypass like this thread.
any suggestions???
quasi
silicon chip used this idea for there ULD amp power supply +- 55v
Used 317/37's and trimpots for adjusting.
psu works well very versatile.
jackinnj
the LR8N3 looks interesting.
i need a 300v and 600v voltage lines for a valve amp.
been using zeners, because haven't found high voltage reg.
until now, thanks, food for thought.
300v rail easy to work out but 600v?
? could reference off the 300v or bypass like this thread.
any suggestions???
quasi
3*150v 1*130v zeners with 20% tolerance made to total of 594v, close enough
farnel has zeners up to 270v
did have it working, then when putting in case, redesigned psu pcb,
not stable since
probably done somthing wrong
got sidetracked till i saw these regs.
astouffer
preamp?
built this fair while ago
http://headwize.com/projects/showfile.php?file=gilmore_prj.htm
allan
3*150v 1*130v zeners with 20% tolerance made to total of 594v, close enough
farnel has zeners up to 270v
did have it working, then when putting in case, redesigned psu pcb,
not stable since
probably done somthing wrong
got sidetracked till i saw these regs.
astouffer
preamp?
built this fair while ago
http://headwize.com/projects/showfile.php?file=gilmore_prj.htm
allan
oops sorry
just reread my post
Not your circuit but the one in the link using zeners and bu508's
this one
http://headwize.com/images/gilmore4.gif
allan
ps silicon chips circuit i can mail if you want?
just reread my post
Not your circuit but the one in the link using zeners and bu508's
this one
http://headwize.com/images/gilmore4.gif
allan
ps silicon chips circuit i can mail if you want?
awpagan said:
you can use a pair of big Hexfets -- one as an inverting amplifier to drive the gate of the second -- the basic circuit is described in H&H -- here's a link to a version I used at one time (it is scaled to 400V but can be built for 600V) -- it used a voltage doubler and inverting amplifier scheme:
http://www.tech-diy.com/MCTracer_no_pix_files/B+SupplyIR_FET.jpg
I think that such high voltages as 600V are easier to regulate by means of a flyback converter, or a flyback pre-converter outputing something quite close to the desired output voltage and then a linear regulator that won't be required to whitstand high voltages or dissipations. Current limiting may be performed also in the flyback, making things even simpler.
jackinnj and Eva, thank guys.
I already have the transforner ~700 centre tapped
don't need to voltage double, and switchmode in audio
first time i've seen a "Supertex developed a nice little (TO-92) regulator which will "do" 1.2 to 450 V -- the LR8N3"
easy enough to reg 300v
but if it like the "317's" i was thinking about base "reference" to the 300v line to get the 600v
does the LR8N3 only handle ~430v or voltage drop.
same as the 317's handle ~40v drop.
buy raising the "ground" voltage to say 30v adjust could be up to 70v
allan
ps if you get what i mean
I already have the transforner ~700 centre tapped
don't need to voltage double, and switchmode in audio
first time i've seen a "Supertex developed a nice little (TO-92) regulator which will "do" 1.2 to 450 V -- the LR8N3"
easy enough to reg 300v
but if it like the "317's" i was thinking about base "reference" to the 300v line to get the 600v
does the LR8N3 only handle ~430v or voltage drop.
same as the 317's handle ~40v drop.
buy raising the "ground" voltage to say 30v adjust could be up to 70v
allan
ps if you get what i mean
You can raise the ground if you want, it works. But a lot of problems will arise during overload conditions. Also, you should make some room for line fluctuations, for example, your target output voltage should be obtainable with mains input voltages from 180V to 250V AC (80 to 130V or something like that) if you want your equipment to be smart enough to work almost everywhere. This may be a bit challenging for a linear 600V regulator, and if you want to use a standard LM317 or similar you will have to fit a pre-regulator to protect it against overvoltage.
The point of the schematic which I showed wasnt' the voltage doubler -- it was the inverting amplifier regulating via an opamp error amp. instead of a DAC (a variable reference) use a high quality, low noise reference.
Eva's points are well taken -- an LM317 is only going to regulate a small portion of the possible variation in input voltage.
Sorensen makes regulated HV supplies using (I believe) forward technology, synchronous rectification, current mode control. These things are designed by teams of engineers at Raytheon -- not for the faint of heart.
Eva's points are well taken -- an LM317 is only going to regulate a small portion of the possible variation in input voltage.
Sorensen makes regulated HV supplies using (I believe) forward technology, synchronous rectification, current mode control. These things are designed by teams of engineers at Raytheon -- not for the faint of heart.
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