2 replies to this topic

[sirwoogie]

I did my best with forum searches and Google searches, but still a bit confused and hope someone can chime in.

 

I'm slowly gathering parts for my cab, and have been investigating how my power supply setup should be. I'm going to be using q pinscape controller with the expansion boards (no chime). I'm going to eventually have the full gamut of DOF toys and multiple audio setup (ROM 2.1 and playfield with four exciters). Obviously I'm going to need the PC supply, but also some decent 24V, 12V, and 5V.

 

Shout-out to MJR for his excellent build guide. It really consolidated the information so I didn't have to hunt and peck. Got me going a lot faster!

 

Question #1

I plan to use 10 Siemens contactors (24V), but the audio amps will also be 24V. The amps are TPA3116D2 board variety: the 2x50W + 1x100W (@ 24V 4ohm) for backglass/sub, and then two 2x50W for the exciters (similar to the Poor Man DOF recommended setup). Question is for the power supply, should I get a single power supply to cover all 24V needs, or separate them: 1 for DOF, 1 for audio? Or should I use PC bricks for the audio instead? Since the Chinese power supplies are so cheap to get at high wattages, it's an economic way to get watts.  I want to overbuild, but not approach ludicrous speed.

 

Question #2

If using an ATX for the 12V and 5V, and have a large array of toys, what is the best way to get the most amps from that ATX to the pinscape board? If I use one set of wires from the 4-pin molex, it's my understanding they're only good for about 10A from each of those rails on that wire. How do I ensure I get enough to the power board for all items? Most of the ATX supplies nowadays are the pluggable variety, so you can just pop the casing and twist all the wires together internally and run a single large wire out. Do I just take multiple molex-based main wires and twist them together and insert into the power board?

 

Or, should I go with another set of higher amperage Chinese supplies dedicated for 12V and 5V and run to the pinscape expansion that way?

 

Thanks!

 

[DDH69]

I would use a separate correctly rated PSU for each voltage required.  That way you are not second guessing what a PC PSU might provide, balance between 12V and 5V, etc.  In addition, I would use two 24V PSUs, one for audio and the other for contactors.  Without some extra circuitry the sudden load of the contactors is likely to cause some sound issues.  This also applies to LED strips if your audio was 12V, the switching nature of the load can cause buzz in audio if you use a single PSU.

[sirwoogie]

Thanks for the insight. I was leaning towards the PS per major function anyway, but was smirking "that's 5 power supplies!" I've also heard that issue on the switching power supplies and the hiss/dips in audio you get on these large burst draws if on the same supply along with the grounding loops.