If you start with a 33r or 30r resistor and measure the CCS current from it's Vdrop, you can add as many more similar resistors until you reach the CCS current you require.
As each extra resistor is added you will find that the Vdrop changes slightly. This is due to the Vgs of the FET increasing with each increase in Id.
eg.
with one 30r fitted you may measure 1950mVdrop indicating 65mA
with two fitted it may be ~1930 indicating 64mA through each for a total of 128mA
for three, maybe 1920 showing a total of 192mA.
If you want exactly 200mA then you require an extra 8mA.
This would need a fourth resistor whose value would be ~1920/0.008 ~=240r
As each extra resistor is added you will find that the Vdrop changes slightly. This is due to the Vgs of the FET increasing with each increase in Id.
eg.
with one 30r fitted you may measure 1950mVdrop indicating 65mA
with two fitted it may be ~1930 indicating 64mA through each for a total of 128mA
for three, maybe 1920 showing a total of 192mA.
If you want exactly 200mA then you require an extra 8mA.
This would need a fourth resistor whose value would be ~1920/0.008 ~=240r
Hi!
First of all thanks for the perfect boards and the work on the regs, too!
A few have been working in my buffalo for a longer time now, and now I'm going to complete a BA-3b build. This is why I have read many hours about star grounding and about preventing ground loop issues.
My questions is, what is the best practice on wiring the SSLV with a (pre)amplifier, in my case the BA-3.
a) As the SSLV uses remote sensing, the (twisted) cables should meet as close to the terminal of the BA-3 board as possible.
b) If it was an unregulated supply, I would set here a star ground, and wire it to the earth connector (seperated with a bridge rectifier || 10R || 100nf). Can I do the same with SSLV--BA3?
Is this the best way to get "perfect" ground, would this be a best practice?
Thank you for your help!
Best regards,
Matthias
First of all thanks for the perfect boards and the work on the regs, too!
A few have been working in my buffalo for a longer time now, and now I'm going to complete a BA-3b build. This is why I have read many hours about star grounding and about preventing ground loop issues.
My questions is, what is the best practice on wiring the SSLV with a (pre)amplifier, in my case the BA-3.
a) As the SSLV uses remote sensing, the (twisted) cables should meet as close to the terminal of the BA-3 board as possible.
b) If it was an unregulated supply, I would set here a star ground, and wire it to the earth connector (seperated with a bridge rectifier || 10R || 100nf). Can I do the same with SSLV--BA3?
Is this the best way to get "perfect" ground, would this be a best practice?
Thank you for your help!
Best regards,
Matthias
There was a nice member posting here nicknamed ''backbones'' who has experience on BA-2 & BA-3 regarding SSLV1.1, maybe he can give you specifics if he will read your questions.
In general:
a) Correct
b) SSLV can be earthed centrally from the (-) pin of its smoothing capacitor (C105). Being a double rectifier symmetric system in your case, it can be tempting to try use it floating. Which is what you do with your bridge lifted plan (excluding fault condition) anyway.
In general:
a) Correct
b) SSLV can be earthed centrally from the (-) pin of its smoothing capacitor (C105). Being a double rectifier symmetric system in your case, it can be tempting to try use it floating. Which is what you do with your bridge lifted plan (excluding fault condition) anyway.
Thank you Salas!
Hm, I think I'll try to "audio-ground" it shortly before it goes into the preamp. What pros and cons do you see for floating vs. grounding?
PS:
The buffalo had a floating supply all the time, but now I know. And how I'll do it if I place it in its new case. Here I see that I've learned a lot but by far not enough!
Hm, I think I'll try to "audio-ground" it shortly before it goes into the preamp. What pros and cons do you see for floating vs. grounding?
PS:
The buffalo had a floating supply all the time, but now I know. And how I'll do it if I place it in its new case. Here I see that I've learned a lot but by far not enough!
Build it up in stages without a chassis. Keep the "mains" end well insulated for safety.
Get it all working with just a Main Audio Ground. At this stage there is no Safety Earth and no connection to PE.
Connect to the Power amp. And get that working properly.
Second to final.
Add in temporary "chassis" and make the PE connection and then the MAG to SE connection.
finally.
If it is still operating properly then you can work out how to package it with identical electrical connections.
There is no point in assembling inside a chassis and trying to experiment with grounding inside that chassis with the added complication of the PE & SE connections.
Get it all working with just a Main Audio Ground. At this stage there is no Safety Earth and no connection to PE.
Connect to the Power amp. And get that working properly.
Second to final.
Add in temporary "chassis" and make the PE connection and then the MAG to SE connection.
finally.
If it is still operating properly then you can work out how to package it with identical electrical connections.
There is no point in assembling inside a chassis and trying to experiment with grounding inside that chassis with the added complication of the PE & SE connections.
Hi Matthias,
Just seen your post. I have the SSLV powering the BA-2 and the BA-3 and in both cases I have followed Nelson's power supply circuit to the letter. The main C-R-C power supply ground is taken as the star ground and this supplies the power boards. This star ground is connected to the chassis and the mains earth via the CL60 that Nelson has in his circuit diagram.
I have then connected the ground of the SSLV to this same star ground point (as well as the ground of the front end of course).
If you don't connect the SSLV ground to the star ground you will get a hum as I did when experimenting with the BA-2 (I didn't bother with the BA-3).
Hope this helps. If you are using the BA-2 front end with the SSLV then remove the noise filters consisting of the 1000uF cap (remove) and the attached resistor (short the latter don't remove it).
Best wishes,
Chris
Yes the story is that I forgot that I have on hand these superb Auricap 10uF 200V without use so I installed and WOW is incredible always these caps sounds very good adding more bass, mids & clear trebles, the sound is full and more 3D, the bass is more marked but not boomy, the voices have more body so more natural & the highs are simply superb very clear but not crystal or metallic, Auricaps are specials I have the same subjective results using them in the signal way like in PSU or in the regs.
The reg. is powering a TP Legato without output caps.
The reg. is powering a TP Legato without output caps.
Shunt resistor voltage
Hi,
I have my shunt regulator running with 3 leds for the CCS. As I lower the CCS resistor value to increase the current, I notice that the voltage across the CCS resistor drops to a lower value as expected. I currently have 1.1 volts across the CCS resistor and want to increase the current. Is there a problem if the voltage across the CCS resistor drops to a lower value? I know that I can add another led to increase the voltage but I would rather not because it will increase the CCS resistors dissipation. Any advice on how to proceed is greatly appreciated.
Also, I am not sure on which wires to twist together. Is it the 2 force and the 2 shunt, or the positive force/shunt and negative force/shunt?
Hi,
I have my shunt regulator running with 3 leds for the CCS. As I lower the CCS resistor value to increase the current, I notice that the voltage across the CCS resistor drops to a lower value as expected. I currently have 1.1 volts across the CCS resistor and want to increase the current. Is there a problem if the voltage across the CCS resistor drops to a lower value? I know that I can add another led to increase the voltage but I would rather not because it will increase the CCS resistors dissipation. Any advice on how to proceed is greatly appreciated.
Also, I am not sure on which wires to twist together. Is it the 2 force and the 2 shunt, or the positive force/shunt and negative force/shunt?
For digital as Vref I use lytic as per Salas advice in the manual BiB.
Arcotronics MKP 10uF 63V
No problem, that is what's expected as with more current the Mosfet's VGS climbs nearer to the LEDS. You can proceed with small value 2W set resistors that will keep dissipation low, until Ohm's law shows you got your target. Up to 0.5A its feasible, higher is 4 LEDS territory. If you got some livelier Vf greens they can help for a bit more margin also.