Adjusting the output voltage of a power supply (+0.2VDC)

[evilkitty]

i was looking around mouser's site and found a low cost 5V 1A medical grade power adapter, looked really close at the manuf picture and saw a rubycon cap; this should be a good upgrade for my thermostats RPI
then i thought if they are using rubycon caps they should be good boards

So i looked around to see what they made that may work for my main pi server and found these

• https://www.mouser.com/ProductDetail/709-EPS15-5 (5v 3a)
• https://www.mouser.com/ProductDetail/709-EPS15-12 (12v 1.25A)

these are the same size and can fit in 2 possible ways stacked, based on my measurements
I would like to adjust the 5V supply to be 5.2V to compensate for vdrop at a diode and the micro usb connector
what would i need to do to change the voltage a tad?

@sam_sam_sam Yes i know you do not like compact supplies, but i only have so much space to work with

[sam_sam_sam]

Re: Adjusting the output voltage of a power supply (+0.2VDC)

i was looking around mouser's site and found a low cost 5V 1A medical grade power adapter, looked really close at the manuf picture and saw a rubycon cap; this should be a good upgrade for my thermostats RPI
then i thought if they are using rubycon caps they should be good boards

So i looked around to see what they made that may work for my main pi server and found these[LIST][*]https://www.mouser.com/ProductDetail/709-EPS15-5 (5v 3a)[*]https://www.mouser.com/ProductDetail/709-EPS15-12 (12v 1.25A)[/LIST

@sam_sam_sam Yes i know you do not like compact supplies, but i only have so much space to work with

I like the Medical Grade power supply that is what look for first and who makes them

Now if you ever have a need for a 12 volt @ 15 amp power supply I can tell you where you can buy one and surprisingly enough it is not Medical Grade it is well made

Most time Meanwell power supply are very good By the way that not a bad price for both of them I would buy them and use them

I talking about the small USB charging power supply that plug in the wall that the USB connectors are part of the hole unit ( these power supply do not have a cords on them at all ) when you take them apart you wonder how it could do 2 amp those are the power supply I do not trust at all

[sam_sam_sam]

Re: Adjusting the output voltage of a power supply (+0.2VDC)

these are the same size and can fit in 2 possible ways stacked, based on my measurements

You can but make sure that you leave enough space for cooling for both power supply ( without a fan ) if you do not have enough space then you have to use a fan to cool both of them

[sam_sam_sam]

Re: Adjusting the output voltage of a power supply (+0.2VDC)

I would like to adjust the 5V supply to be 5.2V to compensate for vdrop at a diode and the micro usb connector
what would i need to do to change the voltage a tad?

You can but the best way to me to do this is use one those USB voltage and current meters with your load hook up and adjust the voltage to 5.00 volt

Now if you do this for a iPad or tablets you have to do this a little different you have your IPad on and using it

When you hit 1.95 amps stop adjusting the pot


When doing this make sure that your charge indicator does not show 100% more like 95% or less

Now for iPhone and other smart phone you do the same thing except that you only adjust the the amperage to .95 amps to 1.00 amps

One note for all of the device the USB connectors must use all four pins or this will not work it be set to 500 millamps max

The best thing to do if you want the best results is buy the smart USB chargers and hack them
buy removing carefully removing the USB connector board with the resistor network or the
IC chip that handles the negotiating what type of device you have

Here is an example of one of them

https://www.amazon.com/Port-Travel-C...CQTMC60MNZED63

The photo at the bottom of this post is the power supply that I do not like

[evilkitty]

Re: Adjusting the output voltage of a power supply (+0.2VDC)

I was looking at the spec sheet, andi saw Voltage Adj range 4.75 ~ 5.5V
is that what SVR1 is for?

I do have a fan in this case, but it only turns on when either the cpu is a little warm or the room temp is abnormally cooler than the case temp
the internal temp is very unlikely to exceed 30C

[sam_sam_sam]

Re: Adjusting the output voltage of a power supply (+0.2VDC)

I was looking at the spec sheet, andi saw Voltage Adj range 4.75 ~ 5.5V
is that what SVR1 is for?

Yes that what that is for but be careful on lower end of that range ( 4.75 ) it might go lower than that but might not be stable do not leave that way for very long it just keep restarting over and over again

I do have a fan in this case, but it only turns on when either the cpu is a little warm or the room temp is abnormally cooler than the case temp
the internal temp is very unlikely to exceed 30C

I would at a minimum check the temperature on the heat sink if has any with a temperature sensor to see how warm it gets after 4 hours of running with the load that you are going to use on it most of the time

Then I would also check with the most likely highest load that you would ever want to use for a couple of hours and see how much warmer it gets and will tell you if you need to have fans on those power supply or not and go from there

Because these power supply are a little compact you should keep an eye on them until you how warm they can get and this is mainly because of the caps on the board heat kills