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Post by stanleyb on Jan 8, 2020 9:07:02 GMT
In order to avoid confusion with the Dorado used with the DACs, and the R&D of the Pi Dorado, I have started a separate thread for the 5V Dorado.
Below is a picture of the prototype. I am using some USB to DC plug adapter leads in order to connect it up at the output end. But what I am trying to find is just one lead, instead of having to connect two up together. But so far no luck i finding a manufacturer of the lead that I need.
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Post by stanleyb on Jan 8, 2020 9:11:28 GMT
The unit relies on being charged up by the original Pi 5V power supply. I have used a Pi 5V power supply that I got to power the unit up so that I can show that there is 5V coming out at the other end.
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Post by MartinT on Jan 8, 2020 9:19:47 GMT
This looks good, Stan, and could bring inexpensive supercap goodness to a lot of Pi/Asus users.
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Post by stanleyb on Jan 8, 2020 9:20:10 GMT
I added a RF filter in the Dorado II. There is also a modification option that would allow it to work with a SMPS. But that SMPS mod is not activated in the Dorado II since everyone uses a linear power supply. It is however in the 5V version. That's because just about every Pi PSU is a SMPS.
The following picture is of the waveform of the 5V SMPS that I used. The thick horizontal line is a reference 0V input. The waveform is the fluctuating voltage and noise of the 5V power supply that is coming into the DoradoPi. As you can see, the average SMPS is quite noisy. The one I am using for demonstration is actually quite good. I have seen far worse.
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Post by stanleyb on Jan 8, 2020 9:22:34 GMT
In comparison, this is a picture at the output of the DoradoPi after it has been through the filter network. Top trace is the DoradoPi output. Bottom trace is the reference voltage output.
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Post by stanleyb on Jan 8, 2020 9:24:21 GMT
The two things still to complete are:
1. Finding that lead
2. Working out the components value so that the red LED turns blue when the DoradoPi is charged.
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Post by stanleyb on Jan 8, 2020 9:29:57 GMT
This looks good, Stan, and could bring inexpensive supercap goodness to a lot of Pi/Asus users. The thing is that I don't have a Pi set up running. So I have no idea if it works without any interruptions etc. The other thing is its theoretical upper limit of 2A. I am going to have ask around to see who is competent enough and have the time to try this thing out for me an maybe a spare Pi that they got. Hopefully someone else will read this thread and offer a solution. |
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Post by MartinT on Jan 8, 2020 9:34:33 GMT
Ah ok, the 2A limit would eliminate the Asus Tinker Board S, a good sounding competitor to the Pi. It requires about 2.5A on boot-up before settling to about 0.9A when running.
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Post by stanleyb on Jan 8, 2020 9:50:19 GMT
The current rating can be increased if I swap over two parts. But the higher current rating versions of those then interfere with the existing height of the case. A new case etc would then be the only option. I am trying to keep cost down by sharing certain parts across different products.
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alp
Rank: Trio
Posts: 160
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Post by alp on Jan 8, 2020 22:04:44 GMT
This looks good, Stan, and could bring inexpensive supercap goodness to a lot of Pi/Asus users. The thing is that I don't have a Pi set up running. So I have no idea if it works without any interruptions etc. The other thing is its theoretical upper limit of 2A. I am going to have ask around to see who is competent enough and have the time to try this thing out for me an maybe a spare Pi that they got. Hopefully someone else will read this thread and offer a solution. Hi Stan, I have a RPI3 with an Audiophonics DAC HAT on it if you would like to borrow that to try. It is set-up with Picoreplayer so should work with LMS if you still use that. The RPI4 takes more current but seems to run happily from a 2A output from a battery. Send me a PM or e-mail and I can post it to you. |
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Post by stanleyb on Jan 10, 2020 9:25:21 GMT
OK  |
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