Hi, it probably will work but it is playing with fire. The dangerous moment is when switching it on. Because of the quite large cap at the output it could be that the voltage over the 317 exceeds the max. values by a large margin. Maybe TL783 is a better choice.
I remember Elektor using a 400 V max. rated reg but unfortunately I don't remember the typenumber. That one was also a 3 pin reg.
I found a few regs using parts that are rated for such high voltages.
http://www.linearaudio.nl/t-reg-2.htm
Will the Maida circuit drop 400V to 250V?
Thought you might know the most you can drop across it?
Hello All,Hi,
Has anyone used this regulator? I am refering to the HT side!
I am thinking of using a LM317T device in place of the LM317K because of low current requirements!
Does anyone see any problems with this?
Thank's for any input!
Regards
M. Gregg
With THAT much voltage drop you could use a valve rather than a transistor!Will the Maida circuit drop 400V to 250V?
Thought you might know the most you can drop across it?
Hi, it probably will work but it is playing with fire. The dangerous moment is when switching it on. Because of the quite large cap at the output it could be that the voltage over the 317 exceeds the max. values by a large margin.
The reg you show IS a Maida regulator. Very reliable, works well. Not the very best as far as noise, but for applications where the signal circuit has reasonable supply rejection and/or line-level or higher signal, it's more than good enough. I wouldn't use it, for example, to supply a cascode phono input stage, but I use them pretty much anywhere else.
If you need to drop a lot of volts, put a resistor in series with the input to absorb some of the excess power.
Sorry, I can't remember which is the TO3 and which is the TO220.![]()
In any case, I've used both interchangeably, depending on what I have on hand, but never actually found a need for the TO3 device in tube circuits- the voltage drop across it is something like 15V, so even at pretty hard use (say, the 200mA of stereo 6L6 or EL34 output stages), we're talking about 2-3 watts, which is well within the TO220 device's limits (use a heat sink!). The pass transistor is the critical bit for higher power operation; a MOSFET or Darlington can be a better choice as the currents go up, because of base current issues.
The reg you show IS a Maida regulator. Very reliable, works well. Not the very best as far as noise, but for applications where the signal circuit has reasonable supply rejection and/or line-level or higher signal, it's more than good enough. I wouldn't use it, for example, to supply a cascode phono input stage, but I use them pretty much anywhere else.
If you need to drop a lot of volts, put a resistor in series with the input to absorb some of the excess power.
Hello M Gregg and All,
If you are supplying a Aikido consider using John Broskie’s PS-1 regulator. PS-1 Solid-State Regulator Kit
Over several iterations of power supplies in The Audio Amateur Walt Jung and others pointed out the issue of noise with the LM 317. Yes it was noise increasing with each octave of frequency.
DT
All just for fun!