- This topic has 7 replies, 4 voices, and was last updated 12 months ago by sumire.
05/08/2022 at 19:41 #1712rickmcinnisParticipant
Thought i would ask this here since it may be of interest to others.
I am wondering if this regulator’s output voltage can be raised?
It is lower, at 15 volts, than what is allowed by the battery supply and both are lower than the 18 volts that has been mentioned on the old lamented threads at the other forum as being better than 15 volts.
Wondering why 15 volts was chosen. Using just one rail for the clock.
Is there a way to raise it simply?
In addition, I would prefer to have transformer and rectifiers close together and neither close to the circuit. I presume it would be simple to bypass the rectifiers on the board and take the DC voltage direct to the capacitors – if nothing else wiring directly to the capacitors. In addition I have lots of suitable chokes around and would use one in the supply.
What voltage does the raw supply need to present the 15 volts version?
05/08/2022 at 23:51 #1714The Well AudioParticipant
There is no phase noise difference when powering the DRIXO oscillator with 15 or 18V.
We have measured the phase noise with the TWRPS-UGL at 15V, with the TWRPS-pp at 15V and 18V, with the TWRPS-LBS-M battery at 16V5. Always the plots overlapped.
The TWRPS-UGL is designed to output 15V. In order to get 18V one or more zener diodes should be replaced. Not recommended.
15V was chosen because the phase noise of the DRIXO is exactly the same in respect to power it with 18V.
Bypassing the rectifiers is enough simple, then one can provide DC directly to the board.
The the raw supply has to be 18 to 20 VAC.
Suitable transformer is the Bel Signal DP-241-6-20 Mouser part
20/01/2023 at 17:49 #2056jan.hoParticipant
is the aforementioned Transformer with 1.5A output so 30W good for only one TWRPS-UGL or can be shared for two?
20/01/2023 at 17:50 #2058The Well AudioParticipant
You can share it for two UGL.
16/02/2023 at 10:54 #2117sumireParticipant
My mistake shorted the output of TWRPS-UGL-SF.
Both LEDs are red, but the output voltage has risen to +24v.
I think Q3 is definitely broken, but there may be other broken parts.
Please let me know the model number of the part that is considered to have a possibility of failure, and if you have any advice, please.
Is it possible to provide a parts list for the additional (Semi-finished board)? .
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16/02/2023 at 11:05 #2120The Well AudioParticipant
Maybe the output bjt is broken, you can start replacing it, Q3 part BCP53-16T1G.
If it does not work you can replace Q1 part FQT7N10LTF, then Q4 part LND150K1-G and finally U1 part OPA140AIDR.
You can find the BOM to build the UGL semi fnished board here https://www.thewellaudio.com/wp-content/uploads/TWRPS-UGL-semi-finished-board-BOM.zip
17/02/2023 at 02:36 #2124sumireParticipant
I’ll get the parts and give it a try.
It seems that it is difficult to obtain other than Q3.
10/03/2023 at 01:21 #2261sumireParticipant
It took some time to obtain the parts, but the output was restored by replacing the Q3.
thank you for your support
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