Perfect 360 joystick voltage?

[Wadeduck]

I have a pair of Perfect 360 optical joystics (thanks to AmericanDemon) and I wanted to know what the voltage tolerance on these are.  I have a wall wart that is putting out 7v, is that close enough or do I have to use a voltage rectifier to bring that down to 5v.   I know they are rated at 5v but usually things are tolerant of a little over voltage but I want to be sure not to burn them up.  Any help here is appreciated as this will be my first real control panel.

[mrbones]

I have the same sticks in my cab and I used 5V from my PC power supply. Just grab it from one of the plugs used for a hard drive. I don't know about the voltage tolerance, but I'd be a little hesitant to plug 7V into a pricey joystick like that.

[Wadeduck]

I would do that but this is going to be just a control panel not in a cabinet.   I will not have access to the PC power supply unless I steal from USB port.

[MonMotha]

IIRC, P360s use C/HC series logic, which is specified to be tolerant up to 6V and are only recommended for use up to 5.5V.  7V could cause damage.

Most wall warts do tend to run high with no/low load.  You can try finding one rated for 4-4.5V or adding an artifical load, aka big'ol resistor.  A 100 ohm 1W resistor (or two 220 ohm 1/2W in parallel, purchasable at Radio Shack) should bring the wart down nearer to 5V.

There are some nicer wall warts out there that don't run high like that.  These are the "regulated" kind.  Some are based on a 60Hz transformer followed by a linear regulator while others are switching type.  Either should run much closer to the voltage on the sticker.

Another option would be to use your own voltage regulator.  A 7805 and a couple caps should work, especially at low currents like those needed to run a P360, but they always need a few volts of overhead, so you may need something like a 7V rated wall wart.

Stealing from USB should be fine in this application.  Include a 100mA fuse and a series diode on the VBUS line (1N4001-1N4004 or similar is fine).  VBUS is specified to not exceed 6V ever, so you should be good.

[Wadeduck]

Mrbones thanks for the info.
              I think I will end up going the USB route.  What should I do with the D+ and D- wires in the USB cable?   I think I have an old USB header I could mount in the controller and just use the wires that should go to the motherboard and pull power from them.  Then just connect the header to the PC  with a standard cable.

              Who would have thought that after 14 years I would be dusting off my EET associates again on an arcade project.

[MonMotha]

Don't connect D+ or D- to anything.  The PC won't think you have anything plugged in at all.  Just make sure you don't draw more than 100mA.  That's the maxmimum allowed by an unenumerated device.  Hence the 100mA fuse.

The series diode is to prevent bad stuff like feeding power back into the PC's USB port, which would happen if the line came loose and touched or was otherwise inadvertently raised above the PC's 5V VBUS rail.  Just install it with the anode on VBUS and then power your stuff off the cathode, using the GND line in the cable as the power return.  You can get by without it, but 10 cents now potentially saves you a couple hundred bucks (new motherboard) if something bad happens.

[Wadeduck]

Thank for all the great info MonMotha.  I will go out and get a few diodes and fuses over the holidays.  I will try to post a few pictures once I get this all hooked up.