I don't know anything about a BA2018 preamp but you do need to find out how much current it uses. Your biggest issue with such a high input voltage will be power dissipation in Q1. With 37V in and 19V out, the power in Q1 at 200mA is (37-19)*0.2=3.6 Watts just for the crossover load. You can use a resistor to soak up some of the power from Q1 but need to factor in the total current variation, mains voltage variation etc. when you calculate the resistance value. Too much resistance will starve the regulator on current peaks if the mains is on the low side.
SR will perspire badly trying to source 200mA unless you change the pass device to a darlington.
I searched for the BA2018 preamp and in the thread the current per channel is stated to be 25mA, so 50mA for stereo. In total you should be designing for about 300mA load on the regulator.
The gain of a D44H at 300mA is about 150 at 25C. When the transistor heats up the gain goes up a bit too. This is enough gain to at least try the D44H to see if it will push the 250-300mA you need. It might work fine.
The gain of a D44H at 300mA is about 150 at 25C. When the transistor heats up the gain goes up a bit too. This is enough gain to at least try the D44H to see if it will push the 250-300mA you need. It might work fine.
Thank you. The Superreg listing page on the diyAudio store says it's good for up to 1A per rail.is this not the case?
Yes! Definitely. This is not the 'official' circuit from the diyaudio store.
So if this is a home-brew circuit and/or home-brew PCB, that could be it. Good catch.
@b4bz, can you check please?
Jan
To sum up, Given that the caps I used are 50V, and I have heatsinks that I will monitor during initial use with a temp "gun", I should be ok to attempt powering the SR with 37V, with an output of 19V with a load of ~300mA, correct?
Yes, first quickly check for correct output voltage. Then monitor the temperature of Q1. It may get hotter than you think...
Nope. Above 550mA the opamp can't provide enough drive to the pass device.
Optimal performance -- you need 5V of headroom.
(for my "Minnie Pearl" boards I am using Jan's SR boards @24V out, just a little input protection. OPA604 instead of AD825)
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Yes! My schematic is for a 40V version, I am not decided yet if a home brew or stock boards will be used.
Hello,
I have a super regulator with + 5V and would like to convert it to 3.3V.
The consumption of the iancanada fifo pi is max.200mA at 3.3V.
This is the 5V regulator.
D5 = LM4040AIZ 2.5V.
R7 = 1K.
R6 = bridge.
D2 = 2 red LED. (3.2V)
R5 = 4.99K.
R2 = 10K.
Is my calculation correct?
3.3 volts - 3.2 V = 0.1 V.
0.1 / 3.2 = 0.03125
0.03125 X 1K = 0.03125K for R6
Is my bill ok?
Hallo,
ich habe einen Superregler mit +5V laufen und würde diesen gern 3,3V umrüsten.
Der Verbrauch des iancanada fifo pi ist max. 200mA bei 3,3V.
Das ist der 5V Regler.
D5 = LM4040AIZ 2.5V.
R7 = 1K.
R6 = bridge.
D2 = 2 red LED. (3,2V)
R5 = 4.99K.
R2 = 10K.
Ist meine Rechnung richtig.
3,3 Volt – 3,2 V= 0,1 V
0,1 / 3,2 = 0,03125
0,03125 X 1K = 0,03125K für R6
Ist meine Rechnung ok.
I have a super regulator with + 5V and would like to convert it to 3.3V.
The consumption of the iancanada fifo pi is max.200mA at 3.3V.
This is the 5V regulator.
D5 = LM4040AIZ 2.5V.
R7 = 1K.
R6 = bridge.
D2 = 2 red LED. (3.2V)
R5 = 4.99K.
R2 = 10K.
Is my calculation correct?
3.3 volts - 3.2 V = 0.1 V.
0.1 / 3.2 = 0.03125
0.03125 X 1K = 0.03125K for R6
Is my bill ok?
Hallo,
ich habe einen Superregler mit +5V laufen und würde diesen gern 3,3V umrüsten.
Der Verbrauch des iancanada fifo pi ist max. 200mA bei 3,3V.
Das ist der 5V Regler.
D5 = LM4040AIZ 2.5V.
R7 = 1K.
R6 = bridge.
D2 = 2 red LED. (3,2V)
R5 = 4.99K.
R2 = 10K.
Ist meine Rechnung richtig.
3,3 Volt – 3,2 V= 0,1 V
0,1 / 3,2 = 0,03125
0,03125 X 1K = 0,03125K für R6
Ist meine Rechnung ok.