Re: [motm] Power Question -- Adding+5v I did this exact thing on one of my cabinets. I already had aMOTM-900 power supply in a cabinet and bought a separate +5V supply tohandle the newer modules that need +/-15V and +5V. These two supplieshook into a MOTM-990 power distribution board.
What you describe will work fine. Just make sure you have fuseson the HOT side of the AC for each of power supplies, because they areindependent. You don't need to bolt the two chassis together, you canjust run a fat wire between them that connects to earth ground. Youalso need to hook a wire between the 0V terminals on both supplies sothat "ground" on the 5V supply is at the same potential as"ground" on the 15V supply (this is not the same as earthground).
I've posted some pictures of my power supply conversionhere:
http://www.tellun.com/motm/darmok/power/Darmok_power.html
I suppose I should draw a schematic to show how it all hookstogether.
Would someone on the list be so kind asto check my thinking? The only thing about my modular that's a realgray area for me is the power supply portion. I'm no engineer, andthe fact that the voltages involved are dangerous, coupled with thefact that I could burn out my modules, means that I cringe in terrorwhenever I need to work on the power supply.
But with the MOTM-650 around the corner,I guess it's time to start thinking about adding that +5v rail tothe cabinets.
I have the new MOTM power distributionboard on order, the one with the new 6-pin connectors (http://www.synthtech.com/images/m990large.jpg). And I have some+5v PowerOne supplies on hand. I'm thinking that I would wire one inthe following way someone please yell if I'm about to dosomething rampantly idiotic.
- The AC power comes into thecabinet.
- Split it so that it goes to both"center pins" of a front panel DPDT switch.
- From there, both the +/-15v and 5vsupplies are wired up independently, but the two chassis frames arebolted together (someone a while ago indicated that multiple powersupplies in a system should have their frames electricallyconnected).
- Run lines (12 gauge wire) to the powerdistribution board from each supply to the appropriate screw terminalson the distro board.
Thanks in advance for any life- andsystem-saving advice!
Ken Tkacs