Build Your Own Arcade Controls Forum

Main => Monitor/Video Forum => Topic started by: Sonny_Jim_Pin on June 05, 2022, 05:46:41 am

Title: Manual deguassing ciruits
Post by: Sonny_Jim_Pin on June 05, 2022, 05:46:41 am
The chassis my cabinet has at the moment has no degaussing circuitry, I've got the wiring around the tube and nothing else.  I've tried using a handheld degausser but I've still got spots on the screen.

Is it possible to create a 'manual' degausser separate from the chassis?  Any ideas what components it uses?

Title: Re: Manual deguassing ciruits
Post by: Zebidee on June 05, 2022, 02:53:57 pm
"Manual degausser" functions in original arcade cabs are mostly very simple. It consists of a button (appropriately AC voltage rated) with a spring inside, so that the circuit is only closed while the button remains pressed. Nothing more complicated than that.

Note that degaussing coils suck a lot of power and get hot fast, so should be operated for no more than a few (2-3) seconds, and not operated repeatedly over a short time (let it cool down). If you want to run with a manual degauss function, probably also a good idea to think about putting a fuse (and a line filter) on the AC input to your cab.

For TVs that degauss automatically on power-up, they typically switch off power to the coil using a thermistor (or some other temperature-controlled method).

Title: Re: Manual deguassing ciruits
Post by: Malenko on June 05, 2022, 04:26:27 pm
if you have a PC CRT, put it face to face with your arcade monitor and hit the degauss button.
Title: Re: Manual deguassing ciruits
Post by: Sonny_Jim_Pin on June 05, 2022, 10:01:35 pm
"Manual degausser" functions in original arcade cabs are mostly very simple. It consists of a button (appropriately AC voltage rated) with a spring inside, so that the circuit is only closed while the button remains pressed. Nothing more complicated than that.
That's what I figured after looking at a few chassis schematics.  I did read somewhere that a capacitor is required to provide some sort of 'ringing', but I'll give it a go with an appropriately rated momentary button.

Thanks!

EDIT:  Wired up a quick degauss test using a relay to switch the 110V to the degaussing coil.  It looks like I need a suitable PTC for it to 'decay' properly, got one on order, will update when it turns up