Help with IC logic gate chips

[ljcox]

I agree with Steve, we need to know what we're dealing with.

BTW, the reason I don't like "geek" is because it is used a derogatory term by children against their peers who take an interest in maths, science, engineering, etc. & I suspect this is one reason why there are less children studying these courses at uni.

 

[bacteria]

I am grateful for the help you guys have offered and the welcome. What I don't want to do is be inaccurate in the information i'll ask if I can.

I might have resolved my first initial query with a manual method, will know in the next couple of days; in regards the application with the different console systems, i'm going to put that query on hold if I may; the reason being that the consoles output different voltages along the wires on each system so i'll need to compile data, and I can't do that until i've modded more console systems to know if I have a problem. If i'm lucky, as the ground is segregated on each system, the remaining 8 wires might either work in harmony with each other (as they will be off at the time) or better still, I might be lucky with using regular diodes. I've got a fair bit of work, maybe months if not certainly weeks for sure, to get to that stage of knowing. At that stage, I can compile lots of data and information and hone the issue i'll need help with. I really appreciate the offer of help ljcox and (*steve*), big thanks - i'll call on that help in due course if I may!

I will upload my video on the manual d-pad here too FYI, in the next days when made.

 

[ljcox]

If you need help with regard to the "manual method" post the circuit so we can see what you're doing.

It may be possible to do it with diodes, but you would need 180 of them.

The video will help me to understand what you're doing. As I said previously, I know virtually nothing about gaming consoles.

So when you're ready to proceed, I will tell you what measurements I want you to make so we know what we're dealing with.

 

[bacteria]

No issues with loads of diodes, or their wiring; my soldering skills are pretty good (I have steady hands so can do pretty intricate soldering work) and i'm literally soldering thousands of wires in this project anyway.

Certainly, i'll upload the video when done for the Intellivision d-pad. Also, my next post will be post #20, so I can use my forum sig - good timing for the video clip.

Thanks for the offer to help, i'll take you up on that.

 

[(*steve*)]

It would really help if you can give us a statement describing what you're doing in general terms that a non-console modder can understand (how would you explain it to your mother)

Something like "I am trying to make a device that allows me to switch my nintendo controller to by nintendo, xbox, and atari 2600".

 

[ljcox]

No issues with loads of diodes, or their wiring; my soldering skills are pretty good (I have steady hands so can do pretty intricate soldering work) and i'm literally soldering thousands of wires in this project anyway.

Certainly, i'll upload the video when done for the Intellivision d-pad. Also, my next post will be post #20, so I can use my forum sig - good timing for the video clip.

Thanks for the offer to help, i'll take you up on that.

You're welcome.

I'll need you to make some voltage and current measurements with your Multimeter before I can determine whether it can be done with diodes.

I also need to know the supply voltage of each "box". I had assumed that they were all powered from 5 Volt, but you appeared to say in one of your posts that some operate from different voltages.

It would be useful, when you're ready, if you could post a spread sheet of each "box" together with the supply voltage of each and the voltage measured at their inputs when the button is open and again when the button is closed.

It would also be useful to know the current coming out of (or into) the inputs when the button is closed & the supply current of each "box".

 

[bacteria]

As you asked to see the video, here's the link - i'm still none the wiser about the IC chips needed for this application however resolved with Zener diodes.

 

[(*steve*)]

As far as I can see, you're wire-ORing with diodes and any diode should work. 1N914's would be an example that I might use.

(whether you call it wire OR-ing or wire AND-ing depends on whether you see it as normal or inverted logic)

 

[ljcox]

As you asked to see the video, here's the link - i'm still none the wiser about the IC chips needed for this application however resolved with Zener diodes.

Thanks for the video link, it showed me what you're wanting to do.

As Steve said, I don't see why ordinary diodes did not work.

However, I suspect that the Zeners may have a lower forward voltage drop than the ordinary ones.

I can't confirm this since the data sheets of Zener diodes that I have on hand, don't give the forward characteristic.

In order to help me design a circuit for you, would you please do some voltage & current measurements?

See the attachment.

Measure the voltages first with all buttons released at the points marked A, B, C, D, E & F.

Then press the Up button and measure the voltages at A, B, C & D.

Then press the NW (north west) button and measure the voltages at all points A ~ F.

Then set your multimeter to current and (with all buttons released) connect the meter between B & Gnd.

I expect this current will be less than one mA, but start on a higher setting initially - just in case.

 

[bacteria]

My circuit works reliably as it is with each and every wire connection coming from a Zener diode. I know nothing about what diode's characteristic is vs any other, I had a few samples of diodes and experimented; the Zener ones worked whereas others seemed to block entirely. Whatever the reason, I ended up with a working circuit. I had a few sets of Zener diodes at different voltages from 3v - 12v in stock so used them all, all work just as well as each other; again, no idea if "best practice" or not but who cares if it works?

The time i'll need your offer of help will be when I put the controller connections together, and need to keep one set of controller cables separate to others; I can either do it via electronics or via these:

http://cgi.ebay.co.uk/ROTARY-CERAMI...553?pt=LH_DefaultDomain_0&hash=item335a679b81

I need 9 connections, 10 is ideal; and must be able to take up to 3 amps through them, these seem up to the job judging by the fact they are military stock and the metal is not thin.

 

[(*steve*)]

Those are 8 pole, not 9 or 10.

Do you need 3A per connection, or 3A in total?

And how does a controller need so much current?

You will need to tell us exactly what you want to do, since were were pretty much in the dark last time until you showed us that video.

 

[bacteria]

8 connections would be minimum but possible, 9 or 10 ideal as the 9th controller wire is ground which can be taken from the on/off switch. Better thinking about it to have the switch rated for 3+ amps and not the whole unit anyway. For various reasons, ground is being used for on/off per console system.

This just leaves data; 8 lines (the 9th line in each controller is ground so can take grounding from the on/off switch); so something like this would work:

http://cgi.ebay.co.uk/20PC-LOT-PC-P...877?pt=LH_DefaultDomain_0&hash=item5ade1824cd

ie, press switch, then on/off switch.

 

[ljcox]

My circuit works reliably as it is with each and every wire connection coming from a Zener diode. I know nothing about what diode's characteristic is vs any other, I had a few samples of diodes and experimented; the Zener ones worked whereas others seemed to block entirely. Whatever the reason, I ended up with a working circuit. I had a few sets of Zener diodes at different voltages from 3v - 12v in stock so used them all, all work just as well as each other; again, no idea if "best practice" or not but who cares if it works?You're missing the point, see below.

The time i'll need your offer of help will be when I put the controller connections together, and need to keep one set of controller cables separate to others; I can either do it via electronics or via these:

http://cgi.ebay.co.uk/ROTARY-CERAMI...553?pt=LH_DefaultDomain_0&hash=item335a679b81

I need 9 connections, 10 is ideal; and must be able to take up to 3 amps through them, these seem up to the job judging by the fact they are military stock and the metal is not thin.

In an earlier post, you appeared to say that you wanted to explore an IC version.

So if you do want to explore that possibility, I need to know what the console inputs need to drive them - hence my request for you to make the voltage & current measurments.

 

[(*steve*)]

That still doesn't help me.

What are you switching?

Why 2 ground wires?

Why do ground wires need to be switched at all?

Which conductor(s) carry 3A, or which in combination carry 3A?

 

[bacteria]

Yes ljcox, I did want to initially to get this working with logic chips as it would have been neat, however the simple solution is often the best one, and the simple solution was the manual method as there didn't appear to be an easy alternative.

(*steve*) - each console controller has up to 9 wires in it, one is ground, 8 are data; all 20 or so consoles will have all their controller wires going to the same connector and if they aren't separate to each other will interfere with their signals as they are all incompatible.

To turn a system on, a switch can be introduced at either the positive or negative part of a voltage; I need to keep the negative line separate for a similar reason to the above so the on/off switch will be on the negative lines. The ground for the controllers will be taken off the ground on the on/off switch, which keeps it isolated from the other systems.

3 amps, max 4 amps are for two of the console systems, most take about 1-2 amps, the on/off buttons will therefore be rated to work at that, which is easy.

The simple solution is often the best one, so those 8pdt switches seem the best solution, reliable and efficient and easy.

 

[ljcox]

Yes ljcox, I did want to initially to get this working with logic chips as it would have been neat, however the simple solution is often the best one, and the simple solution was the manual method as there didn't appear to be an easy alternative.

I agree that the simple solution is often the best one. In fact I would say that the simple solution is always the best one.

I think you can do it with 2 ICs rather than the multiple Zener diodes method.

That would be much simpler than the Zeners.

But to be sure, I need you to give me more info, ie. I need you to do the voltage and current measurements that I asked for in a previous post so I know what I'm dealing with.

How many of these units do you intend to build?

You have done your design by the "cut & try" method. Given your level of knowledge, that is fair enough.

However, when I was working as a design engineer for a large company, there were several occasions when I was called upon to diagnose and fix design problems in devices that were designed by the "cut & try" method.

I recall one case where about 70% of the devices that came off the production line did not work. When I spoke to the "designer" he said "Oh but it worked in the lab".

 

[bacteria]

This will keep all my controller cable connections separate from each other - just won a cheap bid on ebay, 20 for $26 including postage.

System will work as thus:

An 8PDT switch will be used to select the console system (the 8PDT switch will carry the 8 data lines of a console system controller), and a normal switch will select between a system being on and off. I'll have an LED showing when the 8PDT switch is "on" to keep it easy; this "on" switch will complete the voltage circuit by connecting ground to isolate that console from all the others, the ground also feeding to the audio, video and controller ground too.

Just won a pack of 20 of these on ebay for a very cheap price, they can cost a few bucks each plus postage, got 20 for $26; which is about £0.65 each! Ideal! Just enough too!!

This will resolve my other issue; cheaply too!