L-Adapter

[Salas]

Hi everyone,

Still trying to read through all fifty pages of this thread...

I ought to be able to power my RPi through the 5VDC connector on the HiFiBerry DAC+ Pro, correct?

Datasheet DAC+ Pro | HiFiBerry

Is there any reason to not use a two pin header connector? I have some with beefy wire from a few past Pi projects.

Thanks!

Looks like it should work, states connected in parallel, although I don't have personal experience with the HiFiBerry. Shoot a message to the HiFiBerry people just to make sure there's no hidden trap or limitation.

 

[jameshillj]

Hi Salas,
I have an idea to power my F6 amp at 2 x 1.7A/rail - by using the recent lt4320 fet bridge on the inputs (replacing the side diodes) and a bit of 'stuffing around, I can use 1 brd for +24v rail and the other brd for the -24 rail but each transistors will need to get rid of perhaps 25W per rail so locating the bigger heatsink is a problem

Is it possible to use longer wires (maybe 60mm) to mount the TO-247 pass transistor off board on a bigger heatsink without losing circuit performance?

 

[Salas]

Maybe not a no go because it initially worked on a breadboard with wires but for the printed board itself I never tried or seen extensions. The whole PCB can alternatively be mounted against a large heat-sink. Horizontally.

 

[jameshillj]

Thanks for the very quick reply

I have seen the "Smooth Like Butta" boards with quite long leads and surprisingly, it doesn't appear to create any problems but I'll try for the "pcb to heatsink" direct connection as designed first and maybe play around with variations later on.

The current Cap multiplier drops about 3 volts across the pass transistor so the L-Adapter is only about twice that (curiously, about the same as the AMB Sigma 22 regulator) - it'll be interesting to see what difference it makes ...

 

[Salas]

To make dual polarity with L-Adapter it takes stacking two for creating a virtual ground center point as you would do with batteries because only positive PCB type is available.

 

[jameshillj]

Ah right, forgot that - saves me 'stuffing' around with altering one of the boards for the -ve rail altho it's quite possible, apart from heatsink mounts for the diodes.

Thanks again - stay safe

 

[Salas]

Such a scheme demands an independent Tx secondary and an independent bridge feeding each L-A board. But you already have those things in mind I suppose.

Regards

 

[jameshillj]

Yeah, pretty okay for the right secondary voltage transformers to feed that fancy fet bridge and choice of caps, just need to get up off my A** and build it!

I have become really lazy with this Cov-19 confinement.

 

[jameshillj]

… sorry, for each rail, 1 x L-A brd, 1sec winding and 1 fet bridge.

 

[shattered_dream]

Stupid question : Can I use some wires to connect the NJW0302G ? I´m asking cause I want to mount this transistor at a big heatsink which will be mounted only a few cenimeters away from the board. Will be approximately 5cm of wire.

 

[Salas]

Possibly. See #503.

 

[LaserGecko]

Does anyone have a link to in stock, affordable enclosures for one of these boards built with the standard BOM?

A few extra inches for the toroidal transformer would be great, too.

 

[DRONE7]

snip
Is it possible to use longer wires (maybe 60mm) to mount the TO-247 pass transistor off board on a bigger heatsink without losing circuit performance?

As Salas says devices can be mounted horizontally with insulation to a single large heatsink...I placed mine from below, marked, drilled and mounted then soldered them as the final step.

I am only using a single board for a 19.5v supply for a Thinclient and it runs fine.

https://www.diyaudio.com/forums/attachments/power-supplies/787911d1571127106-adapter-set-jpg

 

[Salas]

Very good ventilation there in your link

 

[carsten.witt]

Hi Salas,
I there an alternative LED BAR Graph possible?
Digikey no in stock and Mouser takes 18€ shipping for one part, thanks. :-(

 

[Salas]

I don't know of an equivalent. RS & Farnell have it right now. You may use 3mm individual Leds if in hurry and you don't mind the looks. Also this shop from Netherlands has ten left right now on eBay for a logical shipping charge: DC-10EWA Dutch shop A shop from Lithuania has last three in logical terms also, maybe from a newer batch: DC-10EWA Lithuanian shop

 

[carsten.witt]

Hello Salas,
thanks for the link ... voelkner.de has them also with "cheap" shipping costs ans in new.

 

[Salas]

Nice then. Such parts can't be faked, only badly stored. Buy from where its most convenient and trustworthy for you right now.

 

[jimk04]

Carsten I have one here waiting for my 3rd L Ad build but not needed yet. I can send you it if needed.

 

[euro21]

TME has in stock:
DC-10EWA KINGBRIGHT ELECTRONIC - Display: LED | bargraph; red; 2.2/5.6mcd; 25.4x10.16mm | TME - Electronic components