Phantom PCB

I just finished a layout for a basic +48V phantom PSU that I have built on tag strips in the past. Nothing magic, just 50V ac input to four diodes, 4700uF 100V smoothing, TL783 reg with holes for heatsink, output setting resistors and output cap plus half a dozen mounting holes. Size 4 inches by 2.2 inches.

I am going to have some made and wondered if anyone else was interested in one before I place the order. Cost will of course depend on how many I order but at 20-off it is looking like 8 GBP delivered and for 100-off about half that.

Cheers

Ian

I could use a couple

Bump.

Yes, I'll be in for a couple as well ! or a couple of couples 

The above plus a few PMs means  we are close to 20-off already so I'll order at  least that many. I'll wait another week just in case there are any late comers.

Cheers

Ian

I can use about 4-6.

I am in for 2ea.

Bill W.

interested...

two at least.

I could use at least five.

2-4 for me (must check with something first).

Looks like we are up to 30 now.

Just so you know what you will be getting I have attached a link to a pic of the layout. Note although there are only tracks on one side this is a double sided PCB. This means there are pads on both sides for each component with through plated holes between. I always do this because I find the components solder much better.

http://www.ianbell.ukfsn.org/data/phantompcb.jpg

Cheers

Ian

I may be up for a few... some ideas:
move the AC in pads further apart, with nice big holes
pads for charge pump caps if one wants to use 36volts or so shared w/ bipolar rails & or doubler for 24 v
alternate pads for use of RC-2 and RS-2 Bridge Rectifiers
pads for 0.1uF cap parallel with V-set resistor
pads for second cap on output
protection diode from input to output of reg
NO ground contact near mounting holes (only 4 required)
I think you can do this on the same size board, & no additional cost

nielsk said:

I may be up for a few... some ideas:
move the AC in pads further apart, with nice big holes

Click to expand...

They are 5mm apart now which is plenty for 50VAC and the pads accept a standard 0.2 pitch connector if you want to ease assembly.

pads for charge pump caps if one wants to use 36volts or so shared w/ bipolar rails & or doubler for 24 v
alternate pads for use of RC-2 and RS-2 Bridge Rectifiers

Click to expand...

Voltage doubling is an unnecessary complication with very poor regulation IMHO. The present layout will allow commonplace 1N4000 and 1N5000 series diodes to be used. I never use bridges.

pads for 0.1uF cap parallel with V-set resistor

Click to expand...

I normally include the 100nF snubber so I will add this. Not sure what you mean by a V-set resistor.

pads for second cap on output

Click to expand...

What for? The Texas data sheet makes no specific recommendations about output caps other than to show a single one in some of the application circuits. I have found 10uF is necessary to eliminate output noise. Are you thinking of something like a 100nF film as well?

protection diode from input to output of reg

Click to expand...

I have never found that to be necessary with this circuit but I guess someone is bound to connect it to loads of C so I''ll add diode pads.

NO ground contact near mounting holes (only 4 required)

Click to expand...

What do you define as near?? A 4 by 2 PCB is long and skinny and I am not happy with losing the centre mounting holes.

I think you can do this on the same size board, & no additional cost.

Click to expand...

I think so too.

Cheers

Ian

I have modified the layout to include an input snubber capacitor and a protection diode. I have also included some component values on the silk screen. Pic attached:

http://www.ianbell.ukfsn.org/data/phantompcbV2.jpg

Cheers

Ian

OK, looks like there are no more takers so I'll place the order for 30-off on Monday.

Cheers

Ian

Hi Ian,
Just seen your thread.
If not too late I would be in for Two PCB's.
Thanks !
Guy

guy_4 said:

Hi Ian,
Just seen your thread.
If not too late I would be in for Two PCB's.
Thanks !
Guy

Click to expand...

No, you are not too late. I have been watching another thread about adding decoupling to the TL783 adjust pin so I have made a couple of last minute tweaks to the layout and I plan to place the order tomorrow. Here's a pic of the latest layout.



Cheers

Ian

Order placed. I'll let you all know when they arrive.

Cheers

Ian

looks great! if you end up with spares or do another run, I could use half a dozen to modify old mic-pre.s cheers.

envelope said:

looks great! if you end up with spares or do another run, I could use half a dozen to modify old mic-pre.s cheers.

Click to expand...

No problem. I'll let you know what's left over after this run and if there is enough interest I can always get more made.

Cheers

Ian

Just read this thread and it looks like I am too late. Count me in for 4/6 if you do a second run please.

Probably a stupid question, but I recollect the regulation requires a minimum load of 15ma - so I assume this is taken into account with your output loading ??