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Main => Main Forum => Topic started by: marioxb on August 14, 2013, 09:11:34 am

Title: How do relay switches work and how do I know what I need?
Post by: marioxb on August 14, 2013, 09:11:34 am
I want my control panel config to change for certain boards with a 6 in 1 JAMMA switcher. Some games (Tekken, SF) want the first 2-3 buttons on the top row. Others (Neo Geo, 2-3 button only games) work better on the bottom row. What I want to happen, for example is when I press button 1, JAMMA wires 1, 2 and 3 go to CP buttons A, B and C. When I press button 2, JAMMA wires 1, 2 and 3 go to CP buttons D, E and F. Something like that.

I hear talk of relay switches, but I don't know exactly what they are. How do I know what type I need? How many 'things' can be switched at once? I was thinking an AV switchbox would work (y'know, those things where you press a button to switch to having your PS2/ Xbox/ GameCube/ whatever to your TV?)..

I tried some google searches, but wasn't really sure what to look for. Is it a relay switch or something else I'm looking for?
Title: Re: How do relay switches work and how do I know what I need?
Post by: PL1 on August 14, 2013, 10:11:36 am
A relay (http://en.wikipedia.org/wiki/Relay) is an electronically-controlled switch.

(http://upload.wikimedia.org/wikipedia/commons/thumb/6/67/Relay_symbols.svg/200px-Relay_symbols.svg.png)

When power is applied to the coil (curly part and vertical line on the left), it generates an electromagntic field that pulls the switch arm(s) -- dotted line indicates that those arms will all be pulled by that coil.

Relays are described by the number of switch arms (poles) and the number of output contacts (throws).

To switch 6 buttons between two possible arrangements, you would need one of the following:
1. A six pole double throw (6PDT) relay similar to this (http://www.alliedelec.com/search/productdetail.aspx?SKU=70184970) (NOTE: haven't checked specs/coil power consumption)
2. Two 3PDT relays
3. Three DPDT (sometimes called 2PDT) relays

If you don't mind manually switching configurations, you can use this (http://www.alliedelec.com/search/productdetail.aspx?SKU=70155993) switch or something like it.
(Data sheet (http://www.alliedelec.com/images/products/datasheets/bm/TYCO-ELECTRONICS/70155993.pdf) shows pinout for connections)

(http://www.alliedelec.com/images/products/Small/70155993.jpg)


Scott
Title: Re: How do relay switches work and how do I know what I need?
Post by: marioxb on August 14, 2013, 10:44:52 am
OK. I'm understanding a bit better. Now it should be OK for the ground wires to be connected all the time, correct? Also, what's the difference or dis/advantage of a relay vs a regular switch? I used to mod people's GameCubes with I think SPST switches to switch between Japanese and US regions. Pretty sure the switches weren't electronically controlled?
Title: Re: How do relay switches work and how do I know what I need?
Post by: PL1 on August 14, 2013, 12:02:45 pm
Now it should be OK for the ground wires to be connected all the time, correct?
Right.  You'll just be changing which button connects to which wire.

Buttons --> relay/switch --> 6in1 harness --> 6in1 board -->  game boards

Also, what's the difference or dis/advantage of a relay vs a regular switch?
Relay advantages:
- Automated switching based on game selected

Relay disadvantages:
- Higher cost
- More effort to research/design the circuit
- More complicated wiring
- Have to tap game board voltage to energize the relay for games that use the non-default button configuration (only works if the 6in1 only powers the board currently in use)

Switch advantages:
- Lower cost
- Simple to wire

Switch disadvantages:
- Manual switchng
- Switch placement/mounting


Scott
Title: Re: How do relay switches work and how do I know what I need?
Post by: marioxb on August 14, 2013, 01:01:13 pm
Thanks again, Scott. Yeah the 6 in 1 (from jammaboards.com I think) supposedly powers only the selected board. I don't have it yet and only currently have 1 board (Tekken 2). Just looking at pinouts and planning ahead. I also plan on having a J-PAC as one of the 6 boards.
Title: Re: How do relay switches work and how do I know what I need?
Post by: paigeoliver on August 14, 2013, 02:29:47 pm
It would probably be a lot easier just to rig up a few adapters to change the pinouts of your oddball boards to match the most common config rather than trying to rig up a bunch of relays and such.

In the past I have even done a little jiggery pokery (trace cutting and jumper wires) on the boards themselves to make boards with funny button configs (or pinouts that vary by only a few wires) play nice in my cabinets.