Does anyone know what this Pro-Line component is and what it's for?

[MaximRecoil]

 

It completes the common ground circuit, but why is it there as opposed to just a jumper/trace? And what is it specifically; i.e., what type of component is it and what's its value?

 

I converted an NES controller to a 7800 controller recently, and none of the instructions I found online include that component (they only include the two 620 ohm resistors). Instead, they simply call for a jumper wire to complete the ground.

 

I converted the NES controller according to instructions I'd found, and it worked as it should, for both 2-button and 1-button 7800 games, as well as 2600 games (on both a 7800 console and a 2600 console). However, I noticed tonight while playing Missile Command on my 2600 console, that every so often a single button press would fire off 2 shots in rapid succession.

 

I began to wonder if perhaps that component on the Pro-Line's PCB is performing an anti-bounce function. So I took the NES-to-7800 controller apart; removed the jumper wire that was completing the ground; removed that mystery component from the Pro-Line's PCB; and soldered it into the NES-to-7800 controller's PCB in place of the jumper wire.

 

So far I haven't had any more instances of 2 shots per button press; it is working perfectly; 1 shot per button press just as it should. I would like to know what that component is though so I can buy some to use if I convert more NES controllers to 7800 controllers.

Edited April 8, 2012 by MaximRecoil

[+Mitch]

It's a ferrite bead.

 

Mitch

[Prodos8]

It's a ferrite bead.

 

Mitch

 

Yep, ferrite bead inductor. It only serves as a jumper though. I've converted stuff to work as 7800 two button sticks and omitted that part entirely without any issues.

[MaximRecoil]

Thanks. What purpose would a ferrite bead serve here? If they only needed a jumper it would have been cheaper to just use a jumper, or design the PCB with a trace connecting those two points in the first place. What were they trying to accomplish by placing a ferrite bead there? Does it do anything at all that could be considered beneficial to the joystick operation or to anything else?

[+bcombee]

Ferrite beads are usually used to reduce RF interference. Perhaps they were having a problem with RF frequencies being radiated over the joystick cable on some units.

[Rex Dart]

Maybe it's to allow better operation with extension cables?

[MaximRecoil]

I don't suppose anyone has any of these ferrite beads from a Pro-Line laying around do they? I looked on Mouser and Digikey but there but there are tons of them, with various "Impedance @ Frequency" and DC resistance values; so I'd like to just get one from a Pro-Line that's perhaps already been gutted for its cord or whatever.

[Underball]

I believe that's a Sux Capacitor.

[Enig]

I believe that's a Sux Capacitor.

 

But will it help it run at 1.21 Jiggawhats?