Today we’ll be taking a look at the IBM Server Redundant Power System (2006) board which was taken out of an IBM server, its purpose is to combine both power supplies into one and know when a power supply goes offline/online. The date code is 2006/46th week.
I was able to take both power supplies from the server which were rated at 12V at 69A which gives 828 watts which is unusual to have that much amps on the 12V rail and I would like to use each one independently of this RPS board which we’ll also look at.
It’s a nice looking board and there are two sub-boards for the power supplies, all that’s being carried over is 12V on the thick red wires and some control lines too. We’ve got a little sub-board soldered on the main board too with two chips, some capacitors and an inductor, likely to be a SMPS. Another component that stands out is the TO220 part tipped horizontally to keep it low profile, usually you don’t see the metal part in the air like that. They’ve got a Infineon 04N03LA N power transistor and current sense resistor for the 5x 12V rails to regulate how much current each rail receives.
1. Microchip Microcontroller
The main chip with what I’m assuming is the programming pins near by.
PIC16LF747
2. Philips Quad Input NAND Gate
74HC00D
3. ON Semi Quad Input NAND Schmitt Trigger
14093
4. ST Quad Voltage Comparators
LM339
5. ST 1Kbit I2C EEPROM
24C01
When I powered up the power supply with the RPS board it started up so it’s just a matter of finding the correct control lines to switch on the power supply.
I started by cutting one line at a time and re-connecting them if the power supply turned off, eventually I was left with 3 lines. After playing around with it for a little bit, one line seemed to change to ground a few seconds after another line was connected. I measured the current of the resulting line and it drew about 15mA, connected a 390 Ohm resistor (what I had laying around) to ground and it worked.
I’ve cut all the control lines and so we’ve now done away with the RPS board.
https://www.youtube.com/watch?v=fp_Uy48G1Wo
I also sourced some 12V 4.8A fans (41Y9027) from this server too and they provide pretty decent air flow!
