Internal power supply and PSU mod

Discuss Yocto construction and related issues

Re: Internal power supply and PSU mod

Postby hofmann25 » Oct 15th, '16, 06:49

Altitude wrote:
hofmann25 wrote:Also what is the benefit of changing the PSU into a full wave bridge/Full wave Rectifier (removing D1&2)?

Does this turn the PSU into DC?


Both set ups take an low voltage AC and convert it to DC. The difference between half and full wave rectified supplies is that the full wave has better ripple characteristics but requires a transformer secondary with a center tap. Those are generally only seen in internal transformers, external AC-AC bricks dont have a center tap.


Thanks Altitude, always so eloquent ;)

Ok so knocked up 2 options (Using the NAVA PSU [if these posts need to be moved to the NAVA Hardware thread a moderator could do it. I don't know how, Either way it'll work on both right?]). :geek:

The probably have mistakes :oops: so correct me if I am wrong. Also I'm a little unsure of where the top diode junction connects to in the loop breaker (You can see in my 2nd image I've questioned myself). One end to J8 GND and the other to the Chassis?

And maybe there are two people who have tried one of each?

So the first option is better because it has 'better ripple characteristics'?

Full Wave Bridge & Loop Breaker?
Image

Full Wave Rectifier & Loop Breaker ?
Image

jeroenbvo wrote this but I'm still not 100% :idea: on it. And which one of my diagrams it refers to :oops:

-The rectification efficiency of full-wave rectifier is double of that of a half-wave rectifier.
-The ripple voltage is low and of higher frequency in case of full-wave rectifier so simple filtering circuit is required.
-Higher output voltage, higher output power and higher Transformer Utilization Factor (TUF) in case of a full-wave rectifier.
-In a full-wave rectifier, there is no problem due to dc saturation of the core because the dc current in the two halves of the two halves of the transformer secondary flow in opposite directions.


Thanks :)
User avatar
hofmann25
 
Posts: 272
Joined: Jan 26th, '16, 21:30

Re: Internal power supply and PSU mod

Postby jeroenbvo » Oct 21st, '16, 22:02

hofmann25 wrote:
jeroenbvo wrote:
I have also connected the chassis ground to the PSU using a loop breaker intended to prevent earth/ ground loops to prevent hum when systems are interconnected.




What 2 diodes did you use for the ground loop breaker jeroenbvo? :)

1N4004's or 1n5818 or other schottky diodes?

The reason I ask is because at the top you mention 1N4004's and on your blog you say the 1N5***'s http://imgur.com/a/IeBch#3

Will this mod work for the Nava?



To complete the existing half wave bridge rectifier, I've added two additional 1N4004's to make it a full bridge rectifier.

The 1N5*** are used in the ground loop breaker.

Your second image shows the way I did it. And yes this will work for the Nava too!
User avatar
jeroenbvo
 
Posts: 134
Joined: May 6th, '14, 15:58

Re: Internal power supply and PSU mod

Postby hofmann25 » Oct 21st, '16, 23:21

Thanks jeroenbvo ;)
User avatar
hofmann25
 
Posts: 272
Joined: Jan 26th, '16, 21:30

Re: Internal power supply and PSU mod

Postby hofmann25 » Oct 22nd, '16, 04:28

Ok now I'm afraid to hook this up to 240v! :oops:

I have one of these http://80.93.56.75/pdf/0/5/5/2/1/05521864.pdf http://catalog.triadmagnetics.com/item/power-transformers/toroidal-mount-world-series-power-transformers/vpt30-1670
I'm afraid I'll blow up the house/kill myself :?

I wanna run 2x 15V 15VAC. And a center tap for earth.

What are the input connections?

Image

Image

Image

Input1: Series - BLUE and BROWN, Jumper GRAY to VIOLET
Parallel - BLUE and BROWN, Jumper BLUE to VIOLET, GRAY to BROWN
Output1:: Series - BLACK and YELLOW, Jumper RED to ORANGE
Parallel - BLACK and YELLOW, Jumper BLACK to ORANGE, RED to YELLOW

I don't get this. Is it INPUT: Blue = Negative, Brown = Positive & Just solder BLUE to VIOLET, GRAY to BROWN? What is earth?

OUTPUT: Black = Negative, Yellow = 1x15v? The rest I'm confused...

Can you help me with the exact connections?
User avatar
hofmann25
 
Posts: 272
Joined: Jan 26th, '16, 21:30

Re: Internal power supply and PSU mod

Postby jeroenbvo » Oct 22nd, '16, 11:29

Hi,

Looking at the data sheet you want following, (I see you live in Australia, so 230V is the voltage, series will be the connection method):
Primary side

1) Connect Gray and Violet to each other and insulate the joint. You don't need it further on.
2) Blue and Brown will go to your 230V input. It doesn't matter here which one goes where. But I see the colour coding is the same as in Europe so just connect Blue to Blue and Brown to Brown.

Secondary

This one you want in series as well, so you connect;
1) Red to Orange, and this joint is now your 0V center tap which will be connected to the point between C90 and C91
2) Black for example goes to D109
3) Then Yellow will go to the center of your two added 1N4004's.

Earth from 230V side goes straight to chassis. And that point is also where you hook up one side of the ground loop breaker.

Image

Thats it.

Hope this helps

Jeroen
User avatar
jeroenbvo
 
Posts: 134
Joined: May 6th, '14, 15:58

Re: Internal power supply and PSU mod

Postby hofmann25 » Oct 22nd, '16, 11:43

Thanks so much for the swift reply! :)

Primary;
"Blue and Brown will go to your 230V input. It doesn't matter here which one goes where. But I see the colour coding is the same as in Europe so just connect Blue to Blue and Brown to Brown."

Blue is negative and Brown is positive?

Secondary;
Red/Orange 0v
Black negative
Yellow 15v.

Sorry for so any questions but 240v hurts! :shock:

:oops:

EDIT: also is the switch before or after the transformer?
User avatar
hofmann25
 
Posts: 272
Joined: Jan 26th, '16, 21:30

Re: Internal power supply and PSU mod

Postby jeroenbvo » Oct 22nd, '16, 13:11

hofmann25 wrote:Thanks so much for the swift reply! :)

Primary;
"Blue and Brown will go to your 230V input. It doesn't matter here which one goes where. But I see the colour coding is the same as in Europe so just connect Blue to Blue and Brown to Brown."

Blue is negative and Brown is positive?

Secondary;
Red/Orange 0v
Black negative
Yellow 15v.

Sorry for so any questions but 240v hurts! :shock:

:oops:

EDIT: also is the switch before or after the transformer?


With AC there is no such thing as positive and negative. In most modern house installations the standard is (L) Live - Brown and (N) Neutral - Blue.
For the transformer it doesn't really matter in fact as it is still AC.

If the switch is rated for 240V, you can put it before the transformer on the (L) Brown wire.

With regards to the secondary.
Yes, the Red/Orange will be your 0V center tap.
Both Black and Yellow will have 15V AC

Remember we are still at the transformer before rectifying, so until there all is AC. (Which doesn't have + or -)

Hope it helps.

Test Tip: Just wire the transformer up out of the case and not connected to the Yocto. Insulate all 240V connections. Plug it in and with a multimeter (Set for AC) measure between Red/Orange and Black, you should have more or less 15V AC. Measure between Red/Orange and Yellow and again you will have more or less 15V AC.

240V AC is indeed not to joke with, however if you take care and insulate all connections, there is no problem.
Worst thing that can happen is you blow a fuse in your house, release some magic smoke and maybe get a little zapp. Happened a lot to me when I was young and still experimenting, still the usual anecdote for my mother to tell at birthday parties, after I screwed something up and left the house in darkness.. :mrgreen:

Have a look at his videos, although he is crazy, you can learn a lot from him and he's still alive, however don't try this at home haha!

User avatar
jeroenbvo
 
Posts: 134
Joined: May 6th, '14, 15:58

Re: Internal power supply and PSU mod

Postby hofmann25 » Oct 23rd, '16, 08:38

jeroenbvo you da man.

Thanks so much for your help man. A true legend! 8-)

I'm getting a run through on a Yocto before I try the Nava...

Ok, so got the Primary all connected.
But I'm getting 18.20V AC. Is that too high? :o
Will I need to put a resistor in-between connections (Between secondary winding and PSU) or change some components in the PSU?
EDIT I believe after alot of research that the NAVA/YOCTO PSU can deal with this 18.2VAC but I am yet to test it.

Image

Now secondary (Once I sort this 18.20V AC).

- Red/Orange (0V) goes to the GND pad, where the sleeve of the connector was?
"the twisted centertap goes to ground" I'm confused here :oops: http://imgur.com/a/IeBch#4
OR (Between C5 & C 7 on YOCTO) (Between C 90 & C91 on NAVA) are these now the NEW connections for GND? This is my 1st main question. Do you have a photo of this connection?

- Yellow (15v) to the twisted diodes I have installed full wave bridge.

- Black (15v) to the 15v Pad where the Center pin of the connector was?

Image

Earth on my IEC socket goes to the chassis & my Ground Loop Breaker which connects to the GND plate on the main PSU Cable (See below image)?

Image

Lookin good! ;)

EDIT: please enjoy this video ;) and thanks for the previous video. :lol:
User avatar
hofmann25
 
Posts: 272
Joined: Jan 26th, '16, 21:30

Re: Internal power supply and PSU mod

Postby jeroenbvo » Oct 24th, '16, 08:38

So the 18.2 volt is what you measure when there is no load attached. This is perfectly normal, no need for resistors.

Indeed the 0V centertap goes between C5 and C7 on the Yocto! (I'm into my Nava for the moment, so hence the mistake)

Your pictures show the correct connections. Here is a detail of where I put the 2 additional 1N4004's

Image
User avatar
jeroenbvo
 
Posts: 134
Joined: May 6th, '14, 15:58

Re: Internal power supply and PSU mod

Postby hofmann25 » Oct 24th, '16, 23:08

All sorted!

Tested the PSU not connected to the main board. 5/15/0V!

Will post photos when I get a glue gun for the biggg ass resistor! ;)

Thanks jeroenbvo 8-)
User avatar
hofmann25
 
Posts: 272
Joined: Jan 26th, '16, 21:30

PreviousNext

Return to Yocto v1.0 Hardware

Who is online

Users browsing this forum: No registered users and 4 guests