5/200=25mA, must be near the real IC consumptions? Should be OK for an off circuit PSUs only test though. Blowing heavily means a heavy return current is formed in that configuration. Why is it a no no to use more transformers? Space saving issue? Use a fuse on the blowing side to avoid restoration work during tests.
Hello Salas and all,
I plan to build some 1,2R positive reg for 5V out/500ma load (using advertise of post #3720) and have some questions:
For transformer in which range should i oversize the current capacity: 2x, 1,5x or 1x regulator total draw in ma.? My target would be 600ma total for regulator (100ma in the reg/ 500ma for load).
For 5V out i've seen a post (#3250) where Salas advertise to change Q8 from 2n5457 to 2sk170bl. I suppose this is noise related choice is it right?
IIRc it was just after 1,2R release so is it still something recommended for this low Vout and if yes which idss range for this one.
Thanks.
I plan to build some 1,2R positive reg for 5V out/500ma load (using advertise of post #3720) and have some questions:
For transformer in which range should i oversize the current capacity: 2x, 1,5x or 1x regulator total draw in ma.? My target would be 600ma total for regulator (100ma in the reg/ 500ma for load).
For 5V out i've seen a post (#3250) where Salas advertise to change Q8 from 2n5457 to 2sk170bl. I suppose this is noise related choice is it right?
IIRc it was just after 1,2R release so is it still something recommended for this low Vout and if yes which idss range for this one.
Thanks.
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2x-3x is ample Tx overspec.
600mA CCS is logical target.
Its a voltage margin related recommendation in low out regs. Its a less pinch off part. BL 6-8mA.
You can use a couple of red leds, a 100R in line with them and no trimmer, just g&s to sense gnd for the jfet where the trimmer was, since you know its fixed 5V. Instead of a Ref several kOhm resistor that is. Try a good electrolytic 220uF across the leds+100R system. Should be a stable and good noise 5Vout for digital like that.
600mA CCS is logical target.
Its a voltage margin related recommendation in low out regs. Its a less pinch off part. BL 6-8mA.
You can use a couple of red leds, a 100R in line with them and no trimmer, just g&s to sense gnd for the jfet where the trimmer was, since you know its fixed 5V. Instead of a Ref several kOhm resistor that is. Try a good electrolytic 220uF across the leds+100R system. Should be a stable and good noise 5Vout for digital like that.
Thank you for answers Salas!
And please excuse me using 'advertise' in my previous post instead of 'advice', i'll never mean you're promoting some commercial products... should have been daydreaming when i wrote this post.
I'm not concerned about noise about 5457/SK170 it was just curiosity. I'll try the original schem and probably trying around with your advice when i got it working.
Regards.
And please excuse me using 'advertise' in my previous post instead of 'advice', i'll never mean you're promoting some commercial products... should have been daydreaming when i wrote this post.
I'm not concerned about noise about 5457/SK170 it was just curiosity. I'll try the original schem and probably trying around with your advice when i got it working.
Regards.
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Guys, I could not find this via the search function, altough it may have been discussed before.
I am using 9 (nine!) Salas shunts in a dac and as you can imagine the box is getting pretty crowded. I was wondering if a mini version has ever been done using smd parts. Difficult part is probably heat dissipation...
Thanks
I am using 9 (nine!) Salas shunts in a dac and as you can imagine the box is getting pretty crowded. I was wondering if a mini version has ever been done using smd parts. Difficult part is probably heat dissipation...
Thanks
This heatsink can be enough for the new reg SSR1.1 BiB shunt regulator?
529801B02500G Aavid Thermalloy Heatsinks
529801B02500G Aavid Thermalloy Heatsinks
0.5A=CCS? P=V*I. What will be the Vin, the Vout? What will be the load consumption? Define all those, then read the V1.1 Bib guide section 6:
"6.Sinking.
Q101,201,301 is the CCS Mosfet. Q106,206,306 is the shunt element. Q101 will dissipate the (DCin-DCout) * CCS current setting. Q106 will dissipate DCout * (CCS-LoadCurrent). From those Wattage products the sinking needs can be projected. If you will use a common sink 2C/W for 10W total dissipation, its temperature will rise +20 degrees C from ambient for instance. In most situations for up to 200mA settings and medium DCouts, sinking on metal enclosure floor or sides proves much tolerable. The power semis can be set upright for side sinking or underneath for parallel sinking as in the picture. For low CCS setting and DCout, individual clip on sinks can do. Check the above P=I*V conditions in your application thoroughly before any working attempts!''
Sink the above info down well, then choose sinks.
"6.Sinking.
Q101,201,301 is the CCS Mosfet. Q106,206,306 is the shunt element. Q101 will dissipate the (DCin-DCout) * CCS current setting. Q106 will dissipate DCout * (CCS-LoadCurrent). From those Wattage products the sinking needs can be projected. If you will use a common sink 2C/W for 10W total dissipation, its temperature will rise +20 degrees C from ambient for instance. In most situations for up to 200mA settings and medium DCouts, sinking on metal enclosure floor or sides proves much tolerable. The power semis can be set upright for side sinking or underneath for parallel sinking as in the picture. For low CCS setting and DCout, individual clip on sinks can do. Check the above P=I*V conditions in your application thoroughly before any working attempts!''
Sink the above info down well, then choose sinks.
I prefer...
MSRF diodes from ON Semi. These are medium speed, super soft recovery diodes and seem to be the most quiet diodes I can find. They are designed with soft recovery being the highest priority, rather than super fast switching (still pretty fast though). I have never understood why people always want the super fast diodes for 50/60 hz AC power supplies, a lot of these super fast diodes have more noise. I use these for line level stuff: the MSRF 860G is a 600V 8A TO-220 style. They also have a nice surface mount version of these (I think those ones are 4 A).
MSRF diodes from ON Semi. These are medium speed, super soft recovery diodes and seem to be the most quiet diodes I can find. They are designed with soft recovery being the highest priority, rather than super fast switching (still pretty fast though). I have never understood why people always want the super fast diodes for 50/60 hz AC power supplies, a lot of these super fast diodes have more noise. I use these for line level stuff: the MSRF 860G is a 600V 8A TO-220 style. They also have a nice surface mount version of these (I think those ones are 4 A).
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