There is a claimed universal approximation. If you will try it let us know. There you are: Post #1274
Yes Sir 😀
Ready. I opened a thread.
https://www.diyaudio.com/forums/power-supplies/336685-adapter.html#post5761291
Wonderful Salas that you finished the L-Adapter...so quickly!
And for the continuous pursuit of the RPI3 strange behaviour,
I have this new observation.
Scenario 1:
RPi3 with 5V, 3.3V & 1.8V fed by linear Power Supply with 9Vac sec transformer of 50VA.
UltraBiB Reg is set to 8.0V and then feeds the 3xLT1963 regulators(the 3 individual voltages mentioned above).
It works....as long as I have only a USB cable plugged in.
When I plug in the ethernet cable, the UltraBiB Reg output volt drops down to 6.4V; then back up to 7.2V after 2 secs.
The plugged ethernet cable renders the RPi3 unusable as the music files start to disappear from the interface; wifi connection and LAN connection are lost after a moment.
Scenario 2:
I plugged in both USB cable and ethernet cable before turning it on.
Power on.
Same problem: Reg voltage drop by 2V on UltraBiB Reg then back to 7.4V.
RPi3 did not boot, red LED (power indicator) flashed, dimmed or off.
Why didn't it work earlier with only USB cable plugged in? I don't know.
My solution:
I can live without the ethernet cable plugged in since wifi connection is my priority; and Moode audio says it should not have both connected anyway.
I sometimes have wifi disconnection after a long period of inactivity and need the ethernet to shake the RPi3 up a bit or to restart.
And for the continuous pursuit of the RPI3 strange behaviour,
I have this new observation.
Scenario 1:
RPi3 with 5V, 3.3V & 1.8V fed by linear Power Supply with 9Vac sec transformer of 50VA.
UltraBiB Reg is set to 8.0V and then feeds the 3xLT1963 regulators(the 3 individual voltages mentioned above).
It works....as long as I have only a USB cable plugged in.
When I plug in the ethernet cable, the UltraBiB Reg output volt drops down to 6.4V; then back up to 7.2V after 2 secs.
The plugged ethernet cable renders the RPi3 unusable as the music files start to disappear from the interface; wifi connection and LAN connection are lost after a moment.
Scenario 2:
I plugged in both USB cable and ethernet cable before turning it on.
Power on.
Same problem: Reg voltage drop by 2V on UltraBiB Reg then back to 7.4V.
RPi3 did not boot, red LED (power indicator) flashed, dimmed or off.
Why didn't it work earlier with only USB cable plugged in? I don't know.
My solution:
I can live without the ethernet cable plugged in since wifi connection is my priority; and Moode audio says it should not have both connected anyway.
I sometimes have wifi disconnection after a long period of inactivity and need the ethernet to shake the RPi3 up a bit or to restart.
Unless by activating the Ethernet you pull enough extra current to make C1's ripple eat critical DC headroom for 8V output, because the voltage across M1 is already low and it doesn't function as CCS, the other two scenarios are: Voltage drop signifies the current limiter has kicked in or big enough oscillation happens that robes part of the DC reading to AC garbage.
- First try a 12V transformer
- Do you have an oscilloscope?
- First try a 12V transformer
- Do you have an oscilloscope?
I don’t have a 12V transformer but I will get one for my setup later.
I have a very cheap portable oscilloscope, nothing fancy but works.
I will do the experiment tonight or tomorrow.
Thanks for the explanation for all of us.
I have a very cheap portable oscilloscope, nothing fancy but works.
I will do the experiment tonight or tomorrow.
Thanks for the explanation for all of us.
Quick check for first scenario is you measure raw DC across C1 with a multimeter as things happen. How low does it go for system up and for system down connect configurations.
P.S. You can probe C1 between the Rf resistor's output pin and any ground point on an already mounted UBiB build.
I'm about to finish 5V 1.3 board. In the kit I've got 3 jfets, one about 9mA Idss and other two 4,3 and 4,7 mA. I know that for 5V, J3 are prefered to be below 7,5mA so let's J3 have the 4,3mA one. Higher Idss (9mA) jfet should go to J1 or J2?
A little questions.
i am soldering the 15v + - board
on the minus board there were green led from Tea
on the plus board there were green and red led from Tea
shall i use red or green on the plus board
best Bjarne
i am soldering the 15v + - board
on the minus board there were green led from Tea
on the plus board there were green and red led from Tea
shall i use red or green on the plus board
best Bjarne
board is op and running
have now run for more hours....drift about 0.3vdc down from 15vdc
i have no resistor to load the supply with ..so i test it without
R1 is 2 ohm
cooling is good ..easily holding on the heatsink---
will the dc voltage go up when i mount my load ??
so close to testing on my Mirand dac
have now run for more hours....drift about 0.3vdc down from 15vdc
i have no resistor to load the supply with ..so i test it without
R1 is 2 ohm
cooling is good ..easily holding on the heatsink---
will the dc voltage go up when i mount my load ??
so close to testing on my Mirand dac
It could show little less drift due to less heat from M2 because of power sharing with the load but not much. That drift is its normal thermal settling before going steady in this voltage area. Better allow for it in set up anyway.
some problem with connection
i shall use 15+ 0 -15
when i mount the 2 0 volt together the regulator goes out on the led on positive and negative board
works fine without the 2 0 volt mounted together
is there something in the wiring i have done wrong ?
i shall use 15+ 0 -15
when i mount the 2 0 volt together the regulator goes out on the led on positive and negative board
works fine without the 2 0 volt mounted together
is there something in the wiring i have done wrong ?