LM317 tracking pre-regulator and current regulator

Four 10mF/25V caps added. B540 replaced with Schottky PBYR1025 in TO220 to save space - a bit hot. Vripple = 0.7mV rms @ 9.2 ohm load

bu7upu9a.jpg
 
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what is your voltage drop across the regs? The LM317 performs best with at least 5V in to out difference :) if you don't have 10V to drop then make the voltage drop on the second one higher, making sure to at least have more than the drop out voltage on the first one :) (unless of course it doesn't matter in this configuration which I have not tried).

Tony.
 
Voltage drop across current reg is 3.5V+1.24V across 1.22 ohm resistor+6.1V across filament equals 12.84V. So there is roughly 6V drop across TPR.
I must use heatsinks with lower C/W, I think. They are quite hot. I can touch it, but not too long. I guess they are about 50-60 C. I will try to measure temperature tomorrow.
 
Measured or shall I say estimated* temperature of heatsinks of all regs - they are 65 to 75 deg C hot in open air. I guess regs themselves has higher temp. I will measure when the board is inserted into the enclosure.
Schottky diodes are mounted without heatsinks and the temperature is about 40 deg C.
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* I used temperature sensor form the kitchen oven while my beloved wife was away :D
 
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Tracking pre regulator LM317, LM337 with highly denoiser.
See WEB link below.
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Using 3-pin regulators off-piste: part 4
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See attached ZIP files.
PCAD2006 binary files.
Gerber files for China and Taiwan.
Dimension 100x100 mm.
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You may use LM317HV, LM337HV .
VD7, VD12 is a LED with 2.8 ... 3.2 Volts across.
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