Sharing an idea for a portable feature. EDIT: It worked!

[GonzoMPM-1]

So I got bitten by the bug.

My first project is a table top Ms Pacman using the Jakks TV device.

Its designed and the case is done and painted. What's left is cutting a polycarbonate overlay for the control panel and bezel, printing and applying decals, clear coating it and wiring the insides.

I used an Intex XBOX screen.

And had an idea.

You know the little 5 pin plug that's in the XBOX screens?

I'm using it (attached to the Jakk's original a/v cable) as audio / video out.

But, what I'm going to do is (since its mono) use the extra two pins to automatically power off the XBOX screen whenever the external cable is plugged in.

Here's how:

The two extra pins are "shorted" together in the cable, but not in the device side plug.

In the device, I'll use a P-channel FET. Power from the 7.5v voltage regulator will go to "source", the gate will be wired BOTH to ground through a 10k pulldown resister AND to one of the extra pins on the device side connector, and the "DRAIN" pin will then go to the XBOX screen's power lead.

The other extra pin in the device side connector will be wired to the hot lead from the power regulator.

In this manner, when the cable is not plugged in, the gate will be at ground state and power will flow through the FET from SOURCE to DRAIN.

But when the external cable is plugged in, it will short the two extra pins, taking power to the GATE pin, which in this type of FET when energized will STOP power flowing from SOURCE to DRAIN.

This way, there will be no need for a switch for internal/external power, and I'll save power when displaying output to a TV.

Just a kind of elegant trick I figured out, and thought I'd share.

Thanks for the site and I'll be sure to post pictures when it's all done. (Its a gift for a friend, so I'll have to make another one for me later).


EDIT FOR UPDATE:

It did work! I used an International Rectifier MOSFET, part no. IRF9540N, and the original plug that's built into the XBOX version of the PS1 screen.

You plug in the cable and the internal sound and video shuts off automatically, right as the signal then is picked up by the Television.

Pretty nifty.

Schematic to follow.

[tom61]

Sounds interesting. It also sounds like you know what you're doing as well. Post pictures when you're done.

[gannon]

Hmm...so that screen doesn't have the a/v 1/8" (or smaller) jack? Seems those when available are designed to bypass the lcd. But yeah, using the extra pins to control power would be fine, either via a transistor or an NC relay

[Bibin]

as long as you've got a Jakks, do a quick test for me. Turn it on, then while it is at the first screen, wiggle the joystick like nuts and wham buttons 1 and 2. If done properly, a hardware test and sound test should come up. In the sound test, the sounds for the original (non ms) pacman will show up.

Anyone know why this happens?

[GonzoMPM-1]

Hmm...so that screen doesn't have the a/v 1/8" (or smaller) jack? Seems those when available are designed to bypass the lcd. But yeah, using the extra pins to control power would be fine, either via a transistor or an NC relay

The XBOX version doesn't have a video out. But even if it did, what I'm trying to accomplish is to power down the entire X-BOX screen, audio, video, whatever, when plugged into external A/V.

I got a few of the FETs I selected (International Rectifier IRF9540N) so next week when I've got some time finally, I'll be in a position to rock and roll on this.

Thanks for your comments!

[GonzoMPM-1]

as long as you've got a Jakks, do a quick test for me. Turn it on, then while it is at the first screen, wiggle the joystick like nuts and wham buttons 1 and 2. If done properly, a hardware test and sound test should come up. In the sound test, the sounds for the original (non ms) pacman will show up.

Anyone know why this happens?

Tried it, and did get the diagnostic to come up. Mine had MSPacman sounds. Maybe you've got an earlier revision?

[GonzoMPM-1]

Here's a schematic: