48v on Brent Averill Lunchbox

Is anyone famliliar with these lunchboxes? I have one and just found out it's the PSU without 48v.

Up until now, I have only had eq's in it. I now have some pre's and was wondering if 48v is easy enough to add in myself, or if it's better left up to BAE.

It looks like the price difference on the new units is about 70.00 USD for the addition of 48v, but I don't know what they would charge to add 48v into my unit.

Any thoughts?

If anyone has the schemo on this unit, could you please post a pic so this may be discussed further?

thanks

I looked inside my BA power supply because I heard something moving around in there. I found it was a standard L shape open frame power supply (I forget if it was international or Power one, something like that) and the 48V circuitry was just added on, floating inside the case. Probibally a voltage doubler.

take your DMM and see how much voltage your getting on the secondary of the transformer. If your getting 20VAC - 30VAC then just add 48V circuitry like in SSLtechs kps-1 power supply.

Wow, that PSU looks pretty delicious... I've got a project for racking 8 strips of an old MIDAS Board (PRO4A strips). It needs -/+16v and 48v for phantom, would this PSU work for me? Thanks in advance!

Do you mean kevs PS or BA? If you mean the BA then yes it should work fine, but it's expensive. You may think about International or Power one instead.

I'm actually selling a power supply PCB based off kev's schematic from my website. 78xx and 79xx regulators don't come in 16V though, it would have to be either 15V or 18V. The IC's can probably handle the 18V (check the documentation), but you may put some stress on LED's.

I don't know how much current the MIDAS strips will draw, but my PCB's should be able to handle the job. Amperage in a power supply is limited in three places; the transformer, the bridge rectifier (or diodes) and the regulators.

I used the big square 3A-6A bridge rectifiers. The regulators are 78xx and 79xx series in a T0-220 package. The highest I've seen these go is 2A, and that should be more than you will need. Just make sure you mount the regulators to the case for heat dissipation.

Brent uses a voltage convertor to step up to 48v.
It's the same one, I believe, for the N and A supplies, but there are five diodes in series (from the pos. sup. rail to convertor pos. in) with the A model for a little V drop.

He might sell just the part...I don't know.

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