| Main > Main Forum |
| Q-bert controls software asjustment ? |
| << < (11/17) > >> |
| Level42:
Hey SirPoonga, That posting was in response of 2600's posting, not yours. I'm in your league normaly, not the designer :) ! Those differences were copied from the diagram of John from John's Retro Arcade this site: http://www.johnsretroarcade.com/hardware_knocker.asp Read this page, it has a LOT of interesting info, like a patcher to give new versions of MAME the knocker triggering ability (don't know if it still works though !) As John mentions on his site, this is actualy part of the original Q*bert diagram ! Hence the cap and the fuse placing. I think it'll work fine without the cap. Must be some filtering or something, not really sure. The fuse is placed behind the coil of the knocker (looking from the 30V supply) in John's design and on the other side in Brad's design. It really doesn't matter, since the current is exactly the same on both sides so if it gets too high, the fuse will blow and disconnect it from the 30V from either side. John also brings forward another important thing: the LED could be turned on for a longer period of time if the PC is in normal "PC" mode and you hit the caps lock. This will continuesly power the knocker and that's not a good thing to do. He included a switch to simply turn off the knocker alltogether. Crude but efficient. |
| SirPoonga:
--- Quote from: Level42 on June 19, 2006, 02:23:45 pm ---That posting was in response of 2600's posting, not yours. --- End quote --- Yep, I know :) --- Quote ---John also brings forward another important thing: the LED could be turned on for a longer period of time if the PC is in normal "PC" mode and you hit the caps lock. This will continuesly power the knocker and that's not a good thing to do. He included a switch to simply turn off the knocker alltogether. Crude but efficient. --- End quote --- Which is why I suggest using the LEDWiz ;) Don't want the LEDWiz for only a qbert knocker, use powermame or a frontend with controls.dat *sneaks a plug*. |
| 2600:
John's Retrocade tried to copy Q*bert Schematic, but I think he might of just misread the schematic slightly. At least that's what it looks like. The knocker circuit spans multiple pages and if you put it all together it goes left to right 30V ->fuse-> knocker-> Main board. The fuse and knocker are on one page, the 30V is on another. The .1 uF cap is for filtering, debouncing. Why the QMAME's circuit doesn't have it I dunno. It's not "required" just a better circuit design to include it. --- Quote ---1. Can you explain me why you think there is a risk of blowing up the darlington ? 2. Can you explain me why the opto isn't hooked up correctly and how should it be hooked up in your view ? --- End quote --- 1. Your putting 30V onto the Base pin of the transistor. Please, don't try to back that up with, I'm using a 33000000 Ohm resistor, that's just ugly. 2. You should pull the emitter of the opto down with a resistor. When the circuit is off the Base pin of the Darlington should be 0 Volts not left floating. Additions: 1. I'd put the fuse on the high side of the knocker. 2. The resistor on the driving side of the optoisolator should be spec'd when you pick the optoisolator, otherwise it's just an arbitrary number. |
| juggle50:
Well, my knocker came today. I got it, the 30 volt power supply and I don't have a clue what to do. Should I give the relay a shot with the ledwiz or sit on it for a bit? |
| Level42:
Sure as long as that relay can work on 5 volts and use very little current you could try it, what relay are you intending to use ? |
| Navigation |
| Message Index |
| Next page |
| Previous page |