I know almost nothing about PS design but this looks like it might work for the CD player tube output that I want to build to replace the IC op amps. It will be a SRPP circuit using two 6N2P-EV or 7308 tubes (one for each channel).
Will you be selling these PCBs once you finalize your design?
Thanks.
Will you be selling these PCBs once you finalize your design?
Thanks.
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Thanks. I am having issues downloading and opening gerber files. Window keeps blocking me saying the files are "not frequently used and therefore untrustworthy" Maybe I need to try turning off Windows Defender. It is not my primary antivirus program anyway and thought it was disabled.
As I said, I know almost nothing about designing power supplies and have spent the last 3 weeks reading tutorials. I was leaning toward trying to use an LR8N3-G chip because it seems to have have capability to handle higher voltages than any other chip I have read specs for. Please bear with me here.
I can't figure out how you are able to use an LM317 chip to regulate voltages like 200VDC . Does it just regulate a lower voltage and then the voltage is increased using a voltage multiplier after the chip?
As I said, I know almost nothing about designing power supplies and have spent the last 3 weeks reading tutorials. I was leaning toward trying to use an LR8N3-G chip because it seems to have have capability to handle higher voltages than any other chip I have read specs for. Please bear with me here.
I can't figure out how you are able to use an LM317 chip to regulate voltages like 200VDC . Does it just regulate a lower voltage and then the voltage is increased using a voltage multiplier after the chip?
It's a maida style regulator. https://www.ti.com/lit/an/snoa648/snoa648.pdf
The zip files are just the gerbers and a BOM, nothing special about them, you can upload the gerbers directly to your PCB house of choice, I like JLCPCB.
The zip files are just the gerbers and a BOM, nothing special about them, you can upload the gerbers directly to your PCB house of choice, I like JLCPCB.
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Thanks. I will see if I can upload the files directly for a quote.
I had never heard of Maida regulators until a few days ago. I read a couple of articles and still don't understand how they work. I have a lot to learn. I'll Google more articles about them in the morning.
Thanks again.
I had never heard of Maida regulators until a few days ago. I read a couple of articles and still don't understand how they work. I have a lot to learn. I'll Google more articles about them in the morning.
Thanks again.
I've designed and made a 3080 based HV maida and other supplies, a couple of notes on the schematic:
1. don't rely on the internal mosfet diode, so a diode across the series-pass HV mosfet is a good thing.
2. I'd add a diode across the mosfet gate and source to protect the gate.
@audioexcel - the maida works by the series pass mosfet making a bubble (and handling the main load) for the voltage regulator to sit in;
a) On turn on the HV mosfet has the full HV voltage across it.
b) The HV mosfet then slowly lifts up the output voltage, but leaving a few volts between input and output when it sits at full voltage. That voltage "bubble" remains all the time and it's this that the voltage regulator sees (rather than the full voltage).
c) The voltage regulator is floating so it doesn't see the full voltage but instead sees the floor voltage of the bubble to the top HV voltage. It then continues to regulate as normal, as if it was a 2V or 15V (depending on regulator). It's even possible to use high precision LDOs in this same way by only having a couple of volts of bubble..
d) Heatsinks - if left floating and metal screws used you may end up with a LIVE HV heatsink. Caution on the heatsinks (and this should be in the metal case). If nylon or non-conducting screws are used and the insulation works at the high voltage then you could simply ground the HV heatsink for safety. Any short to the grounded HS will blow the regulator mosfet and the fuse.
Now there's a few fun points:
1. the KEY attribute to select the series pass mosfet is the safe operating area (SOA). On startup the mosfet gets hit by the full voltage and many mosfets nowadays cannot cope with a long DC HV applied (outside of their SOA DC zone) for current draw at full voltage. The modern mosfets are developed for SMPS pulse works so don't need to cope with the hard DC start. This is why it is a pain in the behind (and lots of blown mosfets later) to find any replacement should that mosfet be unavailable.
2. the voltage regulator incoming ripple must really be within the bubble range or the regulator has to rely on the series regulator todo the work. I use my maida after a first stage simple passive filter - I think the schematic has this aready.
3. Power down - if there are caps after the maida then you can get the scenario where the HV exists but the first cap bleeds off - this is why you MUST have diodes across the maida to protect against reverse current (as often people put the HV bleed resistor on the first passive filter cap..
4. Power down on complex multiple FLOATING power supplies (ie for circlotron) - you want a diode to prevent reverse polarity on the output (protects any electrolytics and the regulator).
Hope that helps answer some things about the maida.
1. don't rely on the internal mosfet diode, so a diode across the series-pass HV mosfet is a good thing.
2. I'd add a diode across the mosfet gate and source to protect the gate.
@audioexcel - the maida works by the series pass mosfet making a bubble (and handling the main load) for the voltage regulator to sit in;
a) On turn on the HV mosfet has the full HV voltage across it.
b) The HV mosfet then slowly lifts up the output voltage, but leaving a few volts between input and output when it sits at full voltage. That voltage "bubble" remains all the time and it's this that the voltage regulator sees (rather than the full voltage).
c) The voltage regulator is floating so it doesn't see the full voltage but instead sees the floor voltage of the bubble to the top HV voltage. It then continues to regulate as normal, as if it was a 2V or 15V (depending on regulator). It's even possible to use high precision LDOs in this same way by only having a couple of volts of bubble..
d) Heatsinks - if left floating and metal screws used you may end up with a LIVE HV heatsink. Caution on the heatsinks (and this should be in the metal case). If nylon or non-conducting screws are used and the insulation works at the high voltage then you could simply ground the HV heatsink for safety. Any short to the grounded HS will blow the regulator mosfet and the fuse.
Now there's a few fun points:
1. the KEY attribute to select the series pass mosfet is the safe operating area (SOA). On startup the mosfet gets hit by the full voltage and many mosfets nowadays cannot cope with a long DC HV applied (outside of their SOA DC zone) for current draw at full voltage. The modern mosfets are developed for SMPS pulse works so don't need to cope with the hard DC start. This is why it is a pain in the behind (and lots of blown mosfets later) to find any replacement should that mosfet be unavailable.
2. the voltage regulator incoming ripple must really be within the bubble range or the regulator has to rely on the series regulator todo the work. I use my maida after a first stage simple passive filter - I think the schematic has this aready.
3. Power down - if there are caps after the maida then you can get the scenario where the HV exists but the first cap bleeds off - this is why you MUST have diodes across the maida to protect against reverse current (as often people put the HV bleed resistor on the first passive filter cap..
4. Power down on complex multiple FLOATING power supplies (ie for circlotron) - you want a diode to prevent reverse polarity on the output (protects any electrolytics and the regulator).
Hope that helps answer some things about the maida.
Just seeing this post. Was any credit given to the original designer of this board -> ME?
Go to eBay and look for boards made by HVFORLESS (my eBay handle).
Not trying to be snarky, but I gave credit for ideas I used in my board. And I like some of the improvements, especially the timer. I've used a separate timer board from Pete Millet in the past when needed.
Go to eBay and look for boards made by HVFORLESS (my eBay handle).
Not trying to be snarky, but I gave credit for ideas I used in my board. And I like some of the improvements, especially the timer. I've used a separate timer board from Pete Millet in the past when needed.
Originally - yes. It probably got inadvertantly edited out over time through changes to the circuit and notes. Happy to delete the post if it upsets you.
If it's really that concerning to you, things began here, and your ebay username was most certainly mentioned - https://www.diyaudio.com/community/...8-etc-mu-follower-or-srpp.388295/post-7096217
It's all good. I was just surprised when a potential buyer on eBay asked me if he should buy my board or this one.
I've had people suggest improvements and sometimes work them into new revisions. Seems easier for the community here rather than starting over with a new project. A lot of time went into developing that board. I did take a break from eBay for a year, but a search for HVFORLESS on this site makes it easy to find me.
Looking at the schematic, this PS uses a center tapped transformer. How would I connect a dual output transformer such as this one?
https://www.antekinc.com/as-1t175-100va-175v-transformer/
https://www.antekinc.com/as-1t175-100va-175v-transformer/
@audioxcel - Your transformer isn't center tapped. The instructions in the link below apply to your Antek.
https://www.circuitbread.com/tutorials/how-to-wire-a-transformer-series-versus-parallel
https://www.circuitbread.com/tutorials/how-to-wire-a-transformer-series-versus-parallel
I understand that my transformer isn't center tapped which is why I asked how to connect it to the PS PCB. I should have been more specific.
I don't want to double the voltage from the transformer into the PS so I suppose I would have to use a parallel configuration.
If I join the two white wires of the secondaries together and the two tellow wires together i will have a parallel connection. I could then connect the joined white wires to to pin 1 of J8 and the two joined yellow wires to pin 3 of J8. BUT... that leaves no wire to connect to pin 2 of J8. This is my dilemma. What do I connect to pin 2 of J8?
https://www.antekinc.com/as-1t175-100va-175v-transformer/
I don't want to double the voltage from the transformer into the PS so I suppose I would have to use a parallel configuration.
If I join the two white wires of the secondaries together and the two tellow wires together i will have a parallel connection. I could then connect the joined white wires to to pin 1 of J8 and the two joined yellow wires to pin 3 of J8. BUT... that leaves no wire to connect to pin 2 of J8. This is my dilemma. What do I connect to pin 2 of J8?
https://www.antekinc.com/as-1t175-100va-175v-transformer/
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Black together and reds together on the primary connected to your incoming power (black is +). On the secondary B+, white together and yellows together go into AC1 and AC2. For the secondary heaters, blues together and greens together go into HT1 and HT2.