Regulated PSU Help..

[jleaman]

Id like to know if there is any one that has a regulated psu schematic out there for my amp. The amp has voltage rails of 45V+ 0 45V- I was told that having a steady accurate psu for my power amps would be a little better as im learning to work on psu's.. i was also told that the regulated psu is basically like a power amp feeding a power amp. is this true.. the amps are small and are really fast clean simple amps.. my so called favorite blue amp's.. Can any one help me ? the psu so far has a 500va Toroidal transformer but i will be buying another to make these mono block's.. thanks


J'

[jleaman]

similar to this..

http://www.aussieamplifiers.com/regulated.htm

but not so high of voltage rail's..

[jackinnj]

if you must regulate -- the easiest way of doing it for high power and high voltage positive and negative is with the LM317HV and LM337HV regulators PLUS an outboard pass transistor -- National gives an example on their site for the LM317HV -- you can also use the lower voltage versions of these regulators and lift the "ADJ" terminal off the ground with a zener diode.

this isn't the most elegant solution, but it will work.

[moamps]

Originally posted by JasonL
similar to this..
http://www.aussieamplifiers.com/regulated.htm
but not so high of voltage rail's..

Hi,
Change Z1 and Z2 from 12 to 9.1V/1W to get output voltage around 40V from original schematic.

Regards
Milan

[jleaman]

Originally posted by moamps

Hi,
Change Z1 and Z2 from 12 to 9.1V/1W to get output voltage around 40V from original schematic.

Regards
Milan

Thanks moamps,

Ill look into this.. maybe get a friend to help me design the board since he is good at them : O ) any thing else i can do before laying out a board. ?

[moamps]

Originally posted by JasonL
...any thing else i can do before laying out a board..

Few ideas...

Use output transistors with high beta at high output current.
Input voltage must be ca 10V higher than output (55 in, 45 out) without load.
Downsize R1 and R17 (4k7) to ca 3k3 or so. (same zener current at smaller Vin (from 80 to 55).

Regards
Milan

[jleaman]

oohhh ok.. i was goiing to keep the original psu and use this infront.. but that is ok i canget new tranny's..

Now ami still useing filtering cap's Before or after this regulated psu ? I think it would be after Am i correct ?

[moamps]

Originally posted by JasonL
[B]oohhh ok.. i was goiing to keep the original psu and use this infront.. but that is ok i canget new tranny's..

Start off by using the existing psu. Set the output voltage to around 35V. If this sounds better to you then it may be worthwhile investing into some new trannies with higher secondary voltages.

Now ami still useing filtering cap's Before or after this regulated psu ? I think it would be after Am i correct ?

No. Use the caps BEFORE the regulated psu. Solder two small caps (100-470uF) directly onto the amp's pcb.

Regards
Milan

[jleaman]

The Original PSU sounds great but i want to tinker and if i build one for one channel and see if there is a difrence or not...

[jackinnj]

Originally posted by moamps


Few ideas...

Use output transistors with high beta at high output current.
Input voltage must be ca 10V higher than output (55 in, 45 out) without load.
Downsize R1 and R17 (4k7) to ca 3k3 or so. (same zener current at smaller Vin (from 80 to 55).

Regards
Milan

Power Darlingtons