Hi all,

I have to create a power supply distribution ckt for my project. I have a 16.54V 4.5 A laptop charger that I am gonna use as Input power supply.

I need to power Atmega328 chip used as a custom Arduino with 5V 1A, SMD ws2812 LEDs with 5v 1A and Raspberry PI 3 B + with 5.1V 2.2 A or 2A.

So I am thinking of using LM7805 for 5V 1A for both above devices and LM338 for raspberry PI. will this be fine? or there is a better way to do this. Please share your valuable Ideas.
If you have to create this ckt simple way without transformer just with a voltage regulator IC's what will you use or how would you create?

 

Hello,

Why don't you use fixed switching regulators?
Then you won't wast so much power.
Recom has a series for 1 A that are very easy to use:
https://www.digikey.com/en/product-highlight/r/recom-power/r78-series

For higher powers they also have a nice serie, even upto 6A:
https://www.digikey.com/products/en...word=RPM&sv=0&pv7=2&sf=0&FV=fffc03b1,ffe0039a

Bertus

 

Hello,

Why don't you use fixed switching regulators?
Then you won't wast so much power.
Recom has a series for 1 A that are very easy to use:
https://www.digikey.com/en/product-highlight/r/recom-power/r78-series

For higher powers they also have a nice serie, even upto 6A:
https://www.digikey.com/products/en/power-supplies-board-mount/dc-dc-converters/922?k=RPM&k=&pkeyword=RPM&sv=0&pv7=2&sf=0&FV=fffc03b1,ffe0039a

Bertus

Is there the problem of Power dissipation with this regulator like that of in LM78xx series? Like I am seeing Installation an application page in the datasheet of R-78E-1.0 It just needs one input cap and cap at the output. Input Voltage Range is from 8-24 Voltage and I have 16 V with 4.5 A so is there will be additional components or something? or any problem? No heatsink no resistor burn etc. And 2A and 3A version are available in DIP(Not SMD)?

For 5V 1A this one: https://www.digikey.com/product-detail/en/recom-power/R-78E5.0-1.0/945-2201-ND/4930585

In above one Installation and Application circuit I have to build right?

For 5V 2A : https://www.mouser.in/ProductDetail/RECOM-Power/RPM50-20?qs=qSfuJ%2Bfl/d5ZoJchXFXdTg==

In above one I have to build that "Remote Sense" one right? with Rdown = 311kOhms and Rup = 375 Ohms.

For 5V 3A: https://www.mouser.in/datasheet/2/468/RPM-3.0-1398189.pdf

In above one I have to build "Remote Sense" one right? with Rdown = 311kOhms and Rup = 375K Ohms.

I don't know about RW1 value what should I take.

And does both Rdown and Rup necessary?

If not then I will order it now. And test it.

 

Hello,

You can use the 1A version for the custom Arduino and a second one for the leds.
The datasheet says that the caps are optional.
The raspberry takes more, so tink of one of the higher current modules.

Bertus

 

Do not use linear regulator such as LM7805. It has to dissipate 12W and will get very hot.

 

Hello,

You can use the 1A version for the custom Arduino and a second one for the leds.
The datasheet says that the caps are optional.
The raspberry takes more, so tink of one of the higher current modules.

Bertus

I have edited my response above please review it. Thanks.

 

Use a switching regulator like bertus suggested.

 

Use a switching regulator like bertus suggested.

Yes, I am gonna use that but in the above response, I have edited and added my queries. Please see that and guide me.

 

Anyone, please solve my query.

 

Hello,

It is better to have some capacity left and not push the modules.
If you can afford it, I would buy two 3 A modules.
One for the Arduino and leds, the other for the Raspberry.

Bertus

 

Hello,

It is better to have some capacity left and not push the modules.
If you can afford it, I would buy two 3 A modules.
One for the Arduino and leds, the other for the Raspberry.

Bertus

Ok, but could you please answer my remaining questions

I have to build "Remote Sense" one right? with Rdown = 311k Ohms and Rup = 375K Ohms and RW1 but what is the value of RW1?

And does both Rdown and Rup necessary?

And 2A and 3A versions available in DIP?

 

Answer Please.

 

Hello,

Why don't you use fixed switching regulators?
Then you won't wast so much power.
Recom has a series for 1 A that are very easy to use:
https://www.digikey.com/en/product-highlight/r/recom-power/r78-series

For higher powers they also have a nice serie, even upto 6A:
https://www.digikey.com/products/en/power-supplies-board-mount/dc-dc-converters/922?k=RPM&k=&pkeyword=RPM&sv=0&pv7=2&sf=0&FV=fffc03b1,ffe0039a

Bertus

Is there any other alternatives for this?

 

ebay has some nice step-down switching regulators good for about 2A. There is a LED display, voltage and/or current limit.

There is also available 7805 plug in replacement switching regulators.

Don't use a linear regulator. The input should be about 9 VDC max for a tru 7805. The 3 V minimum and a 1v margin.

remember people live in different time zones and cannot answer right away. Don;t be impatient.