I decided to draw up some regulator boards and am looking for a few people to build them alongside me. They will support the two versions of the circuit found in the Maida paper, as well as the use of a single pass MOSFET. Send me a message if you're interested.
The one question I have, and maybe SY or Jack can answer is the series resistor before the regulator. The paper says this serves to limit current to 50mA in the case of a short circuit. The circuit specifies 0.5W 100R. Does this resistor act as a fuse more or less, and if not, how does the current limiting work?
On my prototype, I had to drop this to 62 ohms and used a 1W resistor in order to get the output up to 350V. If this is supposed to act as a fuse somehow, then I'm assuming I need to choose the value a bit differently.
The one question I have, and maybe SY or Jack can answer is the series resistor before the regulator. The paper says this serves to limit current to 50mA in the case of a short circuit. The circuit specifies 0.5W 100R. Does this resistor act as a fuse more or less, and if not, how does the current limiting work?
On my prototype, I had to drop this to 62 ohms and used a 1W resistor in order to get the output up to 350V. If this is supposed to act as a fuse somehow, then I'm assuming I need to choose the value a bit differently.
I'll be happy to do a build with you, especially since we're now neighbors.
I'm up in the northeast part of town, near Pflugerville.
The resistor has several functions. It does help to current limit (though shorts will kill the regulator anyway). I use a low power resistor in the usually vain hope that in an emergency, it will sacrifice itself to protect the regulator. The resistor also seems to help regulator stability.
I'm up in the northeast part of town, near Pflugerville.The resistor has several functions. It does help to current limit (though shorts will kill the regulator anyway). I use a low power resistor in the usually vain hope that in an emergency, it will sacrifice itself to protect the regulator. The resistor also seems to help regulator stability.
I've got the board done pretty much. BUT by one of the holes for each LED there is a letter , possibly a "C" for cathode. But whatever, which lead goes into the hole with the letter , the long or short?
I've been diagramming how to do the power supply on perf board, but I wouldn't mind a boardas long as it would have the option of using SY's circuit exactly.
Mark
I've been diagramming how to do the power supply on perf board, but I wouldn't mind a boardas long as it would have the option of using SY's circuit exactly.
Mark
wirewriggler:
One thing to note is that there is a ground plane, so I'm not sure how hard it would be to etch, even though all the traces are on the bottom.
variac:
I'm pretty sure this can be built to the original design, but I cannot find my copy of the article to verify.
Cost will be $15 shipped and PayPaled, partially subsidized by myself. Please let me know today if you're interested, as I'm going to place the order by COB today.
One thing to note is that there is a ground plane, so I'm not sure how hard it would be to etch, even though all the traces are on the bottom.
variac:
I'm pretty sure this can be built to the original design, but I cannot find my copy of the article to verify.
Cost will be $15 shipped and PayPaled, partially subsidized by myself. Please let me know today if you're interested, as I'm going to place the order by COB today.
At this point it's extremely likely that all my HV reg boards are sold. I'll let you guys know if they are worthy of a bigger group buy though
Now starting the ImPasse layout, just drew up the schematic and BOM and drew the appropriate patterns. If there is anything you think would be a nice to have, let me know.
SY, if you're interested in the schematic drawing, which turned out quite nicely I might add, I can e-mail it your way, provided you can assist me in recovering your e-mail address
Now starting the ImPasse layout, just drew up the schematic and BOM and drew the appropriate patterns. If there is anything you think would be a nice to have, let me know.
SY, if you're interested in the schematic drawing, which turned out quite nicely I might add, I can e-mail it your way, provided you can assist me in recovering your e-mail address
I have a couple questions as I am working on populating my boards. The value of R1 is listed on the board as 10k, and listed one SY's bom as 18k. I am using the Cinemag transformers from the group buy. Which value should I use? Do I need to play around to find out?
C1 is listed on the BOM as jumpered out. On the boards it is listed as 100nF. Which is correct? what impact will there be by jumpering or populating that part?
Thanks
C1 is listed on the BOM as jumpered out. On the boards it is listed as 100nF. Which is correct? what impact will there be by jumpering or populating that part?
Thanks
The R1/C1 combination "tunes" the output of the transformer to optimize transient response if the potentiometer is of a relatively high value. There's some disagreement as to what constitutes the "best" response- some like to have a bit of overshoot, some prefer a slight overdamping (I'm in the latter camp).
In the original build, I jumpered C1 so that the 18k resistor was directly across the 100k pot. If you use a lower value potentiometer, then C1 can be put back in. If you have an oscilloscope, then tune R1/C1 to give the best square wave response. If you don't, use 330pF as a compromise value- try taking the R1/C1 combination in and out of the circuit to see if you hear a difference- it will be very subtle, and quite frankly it will be in a region where my 54 year old ears don't work anymore.
In the original build, I jumpered C1 so that the 18k resistor was directly across the 100k pot. If you use a lower value potentiometer, then C1 can be put back in. If you have an oscilloscope, then tune R1/C1 to give the best square wave response. If you don't, use 330pF as a compromise value- try taking the R1/C1 combination in and out of the circuit to see if you hear a difference- it will be very subtle, and quite frankly it will be in a region where my 54 year old ears don't work anymore.
luvdunhill said:At this point it's extremely likely that all my HV reg boards are sold. I'll let you guys know if they are worthy of a bigger group buy though
I still have a bunch of my boards if anyone is interested:
http://www.linearaudio.nl/t-reg-2.htm
Don't know if they are worthy of the ImPasse...
Jan Didden