PSX-PC Megatap Interface Help

[dee]

I'm about to try to construct a megatap & want to use the power circuit described here http://www.stndev.btinternet.co.uk/megatap.htm

My problem is I know absolutely nothing about electronics (but this is as good a time as any to learn) and am having trouble deciding what components I should actually be getting.

If anyone could help I'd be very grateful.

I'm getting the components from here www.rswww.com and have found the regulator but I'm not sure about the resistors and capacitors (would be v. helpful if someone could specify part numbers but any general advice would be good).

In rswww's catalogue there are a huge range of resistors and capacitors. The resistors all seem to have power ratings - what power rating would resistors in this circuit need? Also I can't seem to find any 360ohm resistors as shown in the circuit (just 330 and 390).

As to capacitors is this part number the right one to be using "221-8528" (you can find it using the advanced search on rswww.com - sorry I can't give a direct link, the site uses sessions and any link I give you would be dead within 10 mins).


Also have 2 more questions if your still reading .

The circuit shown doesn't specify the input voltage or power requirements - I'm assuming its 9V DC could someone confirm this and tell me what power rating the transformer will require?

Finally, I have a 25W soldering iron - will this be ok to construct said circuit or do I need to get a lower power one (am worried about damaging the components) ?

Cheers for any answers,
dave

[Dave_K.]

I'm about to try to construct a megatap & want to use the power circuit described here http://www.stndev.btinternet.co.uk/megatap.htm

My problem is I know absolutely nothing about electronics (but this is as good a time as any to learn) and am having trouble deciding what components I should actually be getting.

If anyone could help I'd be very grateful.

I'm getting the components from here www.rswww.com and have found the regulator but I'm not sure about the resistors and capacitors (would be v. helpful if someone could specify part numbers but any general advice would be good).

In rswww's catalogue there are a huge range of resistors and capacitors. The resistors all seem to have power ratings - what power rating would resistors in this circuit need? Also I can't seem to find any 360ohm resistors as shown in the circuit (just 330 and 390).

As to capacitors is this part number the right one to be using "221-8528" (you can find it using the advanced search on rswww.com - sorry I can't give a direct link, the site uses sessions and any link I give you would be dead within 10 mins).


Also have 2 more questions if your still reading .

The circuit shown doesn't specify the input voltage or power requirements - I'm assuming its 9V DC could someone confirm this and tell me what power rating the transformer will require?

Finally, I have a 25W soldering iron - will this be ok to construct said circuit or do I need to get a lower power one (am worried about damaging the components) ?

Cheers for any answers,
dave

The size of the resisters are specified on the schematic (360, 470, 820, and 1.8K ohms)...I'm sure 1/4 or 1/2 wattage is sufficent (at you local radio shack).  The capacitor is specified in the text as 22uf...but he then says he didn't have room for it??  Check the documentation on the rectifiers, I bet they are used for common 9v dc wall adapters.   I believe radio shack also has a dc input jack.

-Dave

[KeithD]

What I did was search the net for simple 5V regulated power supply schematics. Here is one: http://www.hut.fi/Misc/Electronics/circuits/psu_5v.html

The 7805 is the IC I am using, connected to the 12V from my PC power supply. The rest of the components came from Radio Shack. Resistors and caps from RS have their values printed on the packaging, and there might even be a little schematic on the back of the 7805 packaging similar to the one on the link i stuck in above..

I built it using one of those solderless experimenter's boards, along with the Megatap, so I could test it before soldering anything. After everything worked, I soldered and point-to-point wired the supply onto a breadboard from Radio Shack. The breadboard I used was one that came in a small kit-box. It fits neatly into the inside of the angle formed by the 2 legs of the Megatap.

The way mine is set up, the Megatap is connected to the PC through a rather short cable, and the PSX pads inside my CP have the cables unmodified. The Megatap is velcroed to the side of my PC case. While this does leave the Megatap in the open so that I can connect my PSX Dual Shock controllers to the PC for PC games, what I wish I would have done, and may well do in the future, is put the Megatap inside the control panel so that I don't have so many wires coming out of the CP. The only issues this will leave are getting power to the Megatap, and figuring out how to get access for the standard controllers. The power problem could be solved using an extra wall wart, and plugging it into the CP. If a gnarly enough wall wart is used, it could also power disco lights, and neon inside the CP.

Hope that helps.

K

[dee]

Thanks for the replies.

I've actually got my megatap up and running now. After a bit of practice the soldering turned out to be quite easy.

What I did way buy a dual entry db25 hood. The cable enters the normal entry point and I super glued a 2.1mm power jack socket into the side entry point. I happened to have 2 dead wall warts lying about so I cut the wire off of one and joined it to one of the 12V connectors inside the computer (the circuit linked above actually takes 12V in). It comes out through a fan screw hole in the back of my case and plugs into the db hood.

I managed to fit the voltage regulator circuit into the multitap case (I cut the pins of the regulators, resistors and capacitor down to around 2mm and just soldered them all together so the whole circuit is composed of 2 blocks measuring 30mmx10mmx5mm - basically the size of the regulators).

My remaining problem is that I could only find 250mA multicore cable for my parallel to multitap run and I'm not sure whether this will take the load of 4 dual shock pads. What I've done for the minute is fused this run with a quick blow 250mA fuse and used 500mA wire for the power lines inside the multitap. I've only actually got a single dual shock atm but when I eventually get a few more if the fuse does blow I'll have another hunt round for slightly higher guage multicore cable and rewire where necessary (the problem with getting this stuff is that I'm actually in Belfast, UK, and our equivalent of radio shack, maplins, is a bit rubbish. I ended up buying from rs components as linked - they seem to stock everything you would ever need and quite a lot besides, but they are geared towards the trade rather than individuals and I'd have had to $40 worth of cable just to get the 1m I needed - hence ended up buying the lightweight stuff from maplins).