Lucifer22334
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Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 5:38 am

Hi all,

I was going through the setup of Raspberry Pi 3 b+ and found that it needs 5V and at least 2A to work that's fine. But I need to know that what is the Maximum Current Supply to Raspberry Pi with keeping in mind it won't damage it and how much current will I get from GPIO from this Maximum current Supply to Raspberry Pi 3b+.

Thanks.

drgeoff
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Re: Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 6:18 am

Th RPi will not take more current than it needs. You could use a 5 volt 20 Amp supply and not cause damage to the RPi though there are other reasons why that might not be advisable.

You question about how much current from the GPIO is unclear. The GPIO header has many pins. Some of those are logic outputs from the Broadcom chip and you should not take more than 16 mA from each of those subject to a total of 50 mA. There are also 3.3 and 5 volt power rails on some pins which can be used to power other circuitry you connect.

ejolson
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Re: Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 6:19 am

Lucifer22334 wrote:
Thu Apr 18, 2019 5:38 am
Hi all,

I was going through the setup of Raspberry Pi 3 b+ and found that it needs 5V and at least 2A to work that's fine. But I need to know that what is the Maximum Current Supply to Raspberry Pi with keeping in mind it won't damage it and how much current will I get from GPIO from this Maximum current Supply to Raspberry Pi 3b+.

Thanks.
Since the data lines are 3V and deliver almost no current, you presumably want to know how much current you can safely draw from the 5V power pins on the GPIO connector.

Unfortunately I don't know. I think the micro USB socket delivering power to the Pi is rated for 2.5A. I suspect 0.5A could be drawn from the 5V pins, but am not sure. Anyone else have a better answer?

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rpdom
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Re: Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 6:31 am

ejolson wrote:
Thu Apr 18, 2019 6:19 am
Unfortunately I don't know. I think the micro USB socket delivering power to the Pi is rated for 2.5A. I suspect 0.5A could be drawn from the 5V pins, but am not sure. Anyone else have a better answer?
The fuse on the Pi 3B+ is rated at about 2.5A, so that is the maximum current that the Pi can take.

In theory, the USB connectors can supply up to 1.2A total between them. If the USB isn't being used, I suspect the same current can be taken from the 5V supply pins on the GPIO connector.
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Lucifer22334
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Re: Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 6:37 am

Hi,


Ok so, I can Provide 5V and 2.5 A max to Raspberry Pi, right?And I wanted to Know about How Much current I can Draw from 5V and 3.3V?
And Can we Ask for a Custom designed Raspberry Pi?

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rpdom
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Re: Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 6:46 am

Lucifer22334 wrote:
Thu Apr 18, 2019 6:37 am
Hi,


Ok so, I can Provide 5V and 2.5 A max to Raspberry Pi, right?And I wanted to Know about How Much current I can Draw from 5V and 3.3V?
And Can we Ask for a Custom designed Raspberry Pi?
From the 5V I would say you can draw up to 1.2A.
From the 3.3V I would say a maximum of 50 to 100mA.

Yes, you can ask for a custom Pi. Element 14 make them. You just need to order at least 5000 of them.
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Lucifer22334
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Re: Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 6:58 am

rpdom wrote:
Thu Apr 18, 2019 6:46 am
Lucifer22334 wrote:
Thu Apr 18, 2019 6:37 am
Hi,


Ok so, I can Provide 5V and 2.5 A max to Raspberry Pi, right?And I wanted to Know about How Much current I can Draw from 5V and 3.3V?
And Can we Ask for a Custom designed Raspberry Pi?
From the 5V I would say you can draw up to 1.2A.
From the 3.3V I would say a maximum of 50 to 100mA.

Yes, you can ask for a custom Pi. Element 14 make them. You just need to order at least 5000 of them.
Ok, I think this is good, and that's too much order need. Can' t they just Provide a custom rasp as Sample or Experiment. I just need Like 2-3 right now for Experiment with my product.

drgeoff
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Re: Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 7:09 am

Lucifer22334 wrote:
Thu Apr 18, 2019 6:58 am
Ok, I think this is good, and that's too much order need. Can' t they just Provide a custom rasp as Sample or Experiment. I just need Like 2-3 right now for Experiment with my product.
I expect Element14 will be quite happy to send you only 3 custom designed and manufactured RPis provided you pay for 5000 of them.

Lucifer22334
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Re: Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 7:34 am

drgeoff wrote:
Thu Apr 18, 2019 7:09 am
Lucifer22334 wrote:
Thu Apr 18, 2019 6:58 am
Ok, I think this is good, and that's too much order need. Can' t they just Provide a custom rasp as Sample or Experiment. I just need Like 2-3 right now for Experiment with my product.
I expect Element14 will be quite happy to send you only 3 custom designed and manufactured RPis provided you pay for 5000 of them.
LoL. :lol: :lol:

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Imperf3kt
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Re: Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 7:41 am

For an actual explanation, part of the reason you must order such a large amount is because it is only financially viable for them to sell you at least that many. They need to pay their staff to redesign this custom Pi for you and that costs a lot of money, which gets siphoned from the relatively miniscule profits of one Pi. So a few thousand need to be sold to make that money back.

The other reason is because they make one batch at a time and a batch of two or three Pi is ironically, more expensive to produce than a few thousand Pi.
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Lucifer22334
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Re: Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 7:46 am

Imperf3kt wrote:
Thu Apr 18, 2019 7:41 am
For an actual explanation, part of the reason you must order such a large amount is because it is only financially viable for them to sell you at least that many. They need to pay their staff to redesign this custom Pi for you and that costs a lot of money, which gets siphoned from the relatively miniscule profits of one Pi. So a few thousand need to be sold to make that money back.

The other reason is because they make one batch at a time and a batch of two or three Pi is ironically, more expensive to produce than a few thousand Pi.
Yeah, I thought So.

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HawaiianPi
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Re: Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 10:06 am

The recommended power supply for the Raspberry Pi 3B/3B+ is 5V at up to 2.5A, and the official Raspberry Pi Universal Power Supply is an affordable PSU that is a proven performer.

You can use a power supply with a higher current rating, but the polyfuse in the Pi 3B/3B+ will limit current to 2.6A, so you won't gain much with a 3A+ power supply. Don't confuse a phone charger with a power supply. Many phone chargers won't maintain a stable 5V under load (no matter what they are rated for). An alternative to powering the Pi with micro USB is to power it through the GPIO expansion header 5V and Ground pins. However, doing that bypasses the polyfuse protection.

The Pi3B(+) itself will draw up to 1.3A when pushed hard, and the USB ports can output up to 1.2A, with no per-port limits (all 1.2A can come out of a single USB port if no others are in use). GPIO accessories may use power, reducing available power to the SoC and USB.

If your "project" requires more power than the Pi can deliver, it will need to be self-powered.
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Lucifer22334
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Re: Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 10:13 am

HawaiianPi wrote:
Thu Apr 18, 2019 10:06 am
The recommended power supply for the Raspberry Pi 3B/3B+ is 5V at up to 2.5A, and the official Raspberry Pi Universal Power Supply is an affordable PSU that is a proven performer.

You can use a power supply with a higher current rating, but the polyfuse in the Pi 3B/3B+ will limit current to 2.6A, so you won't gain much with a 3A+ power supply. Don't confuse a phone charger with a power supply. Many phone chargers won't maintain a stable 5V under load (no matter what they are rated for). An alternative to powering the Pi with micro USB is to power it through the GPIO expansion header 5V and Ground pins. However, doing that bypasses the polyfuse protection.

The Pi3B(+) itself will draw up to 1.3A when pushed hard, and the USB ports can output up to 1.2A, with no per-port limits (all 1.2A can come out of a single USB port if no others are in use). GPIO accessories may use power, reducing available power to the SoC and USB.

If your "project" requires more power than the Pi can deliver, it will need to be self-powered.
Thank you for your Information. I am searching for a 5.1or 5.3V- 3A circuit Diagram for stable Power Supply to Raspberry Pi but getting mostly for 2A. Any suggestions regarding this?

hippy
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Re: Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 10:40 am

Lucifer22334 wrote:
Thu Apr 18, 2019 10:13 am
I am searching for a 5.1or 5.3V- 3A circuit Diagram for stable Power Supply to Raspberry Pi but getting mostly for 2A. Any suggestions regarding this?
For experimenting with your product I would suggest just buying a 5V supply module which can have its outputs adjusted upwards to what you desire, for example -

https://www.makerlab-electronics.com/pr ... supply-50w

For actual product use it's probably best to talk to a commercial PSU designer or manufacturer who would be well placed to deliver you the best solution. Stontronics, part of the Stadium Group, manufactures the official Pi PSU. Might be worth contacting them -

http://www.stadiumgroupltd.com/connecti ... berry-pi-3

scotty101
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Re: Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 10:42 am

Perhaps you can explain a bit about your project and why you need more current from the 5V and 3.3v supplies?

You can certainly use a separate power supply to power any extra components that require more current. I've used a few motor/amplifier HATs/pHATs which take a wide range input voltage, convert that to 5v to power the pi and any drive the motor/amp circuitry.
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Lucifer22334
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Re: Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 10:56 am

scotty101 wrote:
Thu Apr 18, 2019 10:42 am
Perhaps you can explain a bit about your project and why you need more current from the 5V and 3.3v supplies?

You can certainly use a separate power supply to power any extra components that require more current. I've used a few motor/amplifier HATs/pHATs which take a wide range input voltage, convert that to 5v to power the pi and any drive the motor/amp circuitry.
I am Going to connect an Arduino nano Custom board with IR Arrays. And I am Going to add RFID reader and SMD LED Lights. SO need more current.

scotty101
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Re: Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 11:05 am

Lucifer22334 wrote:
Thu Apr 18, 2019 10:56 am
scotty101 wrote:
Thu Apr 18, 2019 10:42 am
Perhaps you can explain a bit about your project and why you need more current from the 5V and 3.3v supplies?

You can certainly use a separate power supply to power any extra components that require more current. I've used a few motor/amplifier HATs/pHATs which take a wide range input voltage, convert that to 5v to power the pi and any drive the motor/amp circuitry.
I am Going to connect an Arduino nano Custom board with IR Arrays. And I am Going to add RFID reader and SMD LED Lights. SO need more current.
So buy an off-the-shelf DC 5v Power Supply. Split the power supply between the Pi and the Arduino/peripherals. You shouldn't rely on pulling all the current you need directly from the Pi's 5v/3.3v supplies. There are plenty of 15W 5V PSU's available on RS/Element14/ebay/other and another poster has already shared a link to a 50W PSU.
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Lucifer22334
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Re: Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 11:08 am

scotty101 wrote:
Thu Apr 18, 2019 11:05 am
Lucifer22334 wrote:
Thu Apr 18, 2019 10:56 am
scotty101 wrote:
Thu Apr 18, 2019 10:42 am
Perhaps you can explain a bit about your project and why you need more current from the 5V and 3.3v supplies?

You can certainly use a separate power supply to power any extra components that require more current. I've used a few motor/amplifier HATs/pHATs which take a wide range input voltage, convert that to 5v to power the pi and any drive the motor/amp circuitry.
I am Going to connect an Arduino nano Custom board with IR Arrays. And I am Going to add RFID reader and SMD LED Lights. SO need more current.
So buy an off-the-shelf DC 5v Power Supply. Split the power supply between the Pi and the Arduino/peripherals. You shouldn't rely on pulling all the current you need directly from the Pi's 5v/3.3v supplies. There are plenty of 15W 5V PSU's available on RS/Element14/ebay/other and another poster has already shared a link to a 50W PSU.
I am Gonna use Raspi and Arduino nano as master(Raspi)-Slave(Arduino). it is the demand for my Product. So can't Supply External power.

scotty101
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Re: Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 11:10 am

Then you might be out of luck. The Pi's internal power supplies and protection circuits will only provide so much current.
If you need more, you have to use an external supply.
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Lucifer22334
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Re: Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 11:18 am

scotty101 wrote:
Thu Apr 18, 2019 11:10 am
Then you might be out of luck. The Pi's internal power supplies and protection circuits will only provide so much current.
If you need more, you have to use an external supply.
yeah, That's why I was Trying to Learn how to build 5.1V or 5.3V - 3A circuit. I can Try if this work or not.

hippy
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Re: Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 12:08 pm

Lucifer22334 wrote:
Thu Apr 18, 2019 11:08 am
I am Gonna use Raspi and Arduino nano as master(Raspi)-Slave(Arduino). it is the demand for my Product. So can't Supply External power.
It's not clear what you mean by that. You can do what you want with a single external power supply -

Code: Select all

                       ___________________________
                      |                           |
                      |  .-----.----------. 5V    |
                      |  |     |          |       |
    _    .-----.      |  |  .-----.  .---------.  |
L -| |---| 10A |----> >--'  | RPi |==| Arduino |  |
N -|_|---| PSU |----> >--.  `-----'  `---------'  |
         `-----'      |  |     |          |       |
                      |  `-----^----------' 0V    |
                      |___________________________|
And you can move the PSU into the product's enclosure -

Code: Select all

            ______________________________________
           |                                      |
           |             .-----.----------. 5V    |
           |             |     |          |       |
    _      |   .-----.   |  .-----.  .---------.  |
L -| |---> >---| 10A |---'  | RPi |==| Arduino |  |
N -|_|---> >---| PSU |---.  `-----'  `---------'  |
           |   `-----'   |     |          |       |
           |             `-----^----------' 0V    |
           |______________________________________|

What you can't do is take the Arduino 5V from the Pi's GPIO 5V output pin if the amount of current your Arduino needs exceeds 1.2A less anything USB uses. The Pi is limited to only taking in 2.5A, uses up to 1.3A for itself -

Code: Select all

                               .----------. 5V 1.2A max
                               |          |
         .------.  2.5A max .-----.  .---------.
      ---| 2.5A |-----------| RPi |==| Arduino |
      ---| PSU  |--------.  `-----'  `---------'
         `------'        |     |          |
                         `-----^----------' 0V

Lucifer22334
Posts: 36
Joined: Wed Mar 06, 2019 7:36 am

Re: Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 1:16 pm

hippy wrote:
Thu Apr 18, 2019 12:08 pm
Lucifer22334 wrote:
Thu Apr 18, 2019 11:08 am
I am Gonna use Raspi and Arduino nano as master(Raspi)-Slave(Arduino). it is the demand for my Product. So can't Supply External power.
It's not clear what you mean by that. You can do what you want with a single external power supply -

Code: Select all

                       ___________________________
                      |                           |
                      |  .-----.----------. 5V    |
                      |  |     |          |       |
    _    .-----.      |  |  .-----.  .---------.  |
L -| |---| 10A |----> >--'  | RPi |==| Arduino |  |
N -|_|---| PSU |----> >--.  `-----'  `---------'  |
         `-----'      |  |     |          |       |
                      |  `-----^----------' 0V    |
                      |___________________________|
And you can move the PSU into the product's enclosure -

Code: Select all

            ______________________________________
           |                                      |
           |             .-----.----------. 5V    |
           |             |     |          |       |
    _      |   .-----.   |  .-----.  .---------.  |
L -| |---> >---| 10A |---'  | RPi |==| Arduino |  |
N -|_|---> >---| PSU |---.  `-----'  `---------'  |
           |   `-----'   |     |          |       |
           |             `-----^----------' 0V    |
           |______________________________________|

What you can't do is take the Arduino 5V from the Pi's GPIO 5V output pin if the amount of current your Arduino needs exceeds 1.2A less anything USB uses. The Pi is limited to only taking in 2.5A, uses up to 1.3A for itself -

Code: Select all

                               .----------. 5V 1.2A max
                               |          |
         .------.  2.5A max .-----.  .---------.
      ---| 2.5A |-----------| RPi |==| Arduino |
      ---| PSU  |--------.  `-----'  `---------'
         `------'        |     |          |
                         `-----^----------' 0V
So I have to use a Power Supply Like 12v and 5A or Something and divide it for both Raspi and Arduino. Like in 5V - 2.5 A. and supply them Both.

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Re: Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 1:46 pm

Lucifer22334 wrote:
Thu Apr 18, 2019 1:16 pm
So I have to use a Power Supply Like 12v and 5A or Something and divide it for both Raspi and Arduino. Like in 5V - 2.5 A. and supply them Both.
Do not try to use a 12v supply directly to a Pi. You will destroy it.

Lucifer22334
Posts: 36
Joined: Wed Mar 06, 2019 7:36 am

Re: Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 1:50 pm

W. H. Heydt wrote:
Thu Apr 18, 2019 1:46 pm
Lucifer22334 wrote:
Thu Apr 18, 2019 1:16 pm
So I have to use a Power Supply Like 12v and 5A or Something and divide it for both Raspi and Arduino. Like in 5V - 2.5 A. and supply them Both.
Do not try to use a 12v supply directly to a Pi. You will destroy it.
yeah, I know. I am going to convert it into 5v-3A. using Voltage Regulator Circuit.

alphanumeric
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Re: Max Power Supply For Raspberry Pi 3 b +

Thu Apr 18, 2019 3:39 pm

Somebody correct me if I'm wrong, but if you supply your +5V to GPIO Pin 2 or 4, you bypass the poly fuse, and its current limit. I'm not saying its a good idea to do that, but it is an option. I've done it on Pi Zero's that don't have a poly fuse anyway, and a couple of A+'s because it made feeding power to my project easier.
I have a 5V 10A switching power supply powering my breadboarding setup. The 5V goes to a protoboard that has some fuses on it, and then to where ever its needed. One feed goes to my Pi 3B+ via its Micro USB power jack, another feed goes to my 7 inch touchscreen via its Micro USB power port. It also powers and analog audio amplifier. I also made up some custom USB cables. At the Pi end its only data and ground wired up. The +5V for the device end comes from the power supply not the Pi.

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