Re: Modern replacement power supplies for Apple ProFile hard drive?

Am Sonntag, 22. Dezember 2013 13:26:24 UTC+1 schrieb groink:

Rather than trying to replace all the caps in these power supplies, I'm
> hoping that there are more modern power supplies out there that I could use
> to replace the Apple ProFile power supplies.

But keep in mind that any NOS power supply also will have problems with these EMC capacitors. So you will have to replace them in any case.

Vintage computers are often kept as collector's items, not for daily use. In that case you want to keep the machine as original as possible, including the original PSU. But if performance has priority, of course the Profile PSU can be replaced by almost any other switchmode power supply that provides the required voltages. An AT or ATX PC supply would be a possible choice (though the quality and durability of modern ATX supplies is much worse than these vintage ASTEC units).  

> The power supply supplies +5VDC and +/-12VDC. There are two power
> connectors: one connects to the hard disk drive, and the other connects to
> the controller board. Reading the service manual, the power cable that
> connects to the controller board is used so that the controller board can
> detect loss of power, so that it minimize data loss that might have been
> still stored in the controller board's memory.
>

There is a "power good" signal generated by the PSU supervisor circuit which starts up the controller board. In case your new module does not provide such a power-on reset, you will have to add a RC network to ensure startup (e.g. 2.2µF to GND and 47k to VDD).

Patrick

-- 
-- 
-----
You received this message because you are a member of the LisaList group.
The group FAQ is at http://lowendmac.com/lists/lisa.html
To post to this group, send email to lisalist_at_email.domain.hidden
To leave this group, send email to lisalist+unsubscribe_at_email.domain.hidden
For more options, visit this group at http://groups.google.com/group/lisalist
--- 
You received this message because you are subscribed to the Google Groups "LisaList" group.
To unsubscribe from this group and stop receiving emails from it, send an email to lisalist+unsubscribe_at_googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.



text/html attachment: alternate version of message