4P2T switch -what's available

Feb 10, 2007 11 Replies

I need a 4 pole double throw switch, but all I can find are toggle switches like this:

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What other types of switches of this type (4P2T) are available, and where? I'd prefer something like a PCB solderable slide-switch in a vertical position, but I'll consider anything smart and modern looking.



4 pole switches aren't very common. What load current and voltage are you switching ?

Graham

It's just for video signals. I don't know the voltage/currents, but I'm pretty sure it can't be more than 12V and a few mA. Any low voltage switch should do.

" snipped-for-privacy@lycos.com" wrote in news: snipped-for-privacy@q2g2000cwa.googlegroups.com:

Maybe a pair of DG111 analog switches?

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I'm not sure how well they cope with video signal rates, but if you use individual switches to form SPDT pairs, two IC's will be enough, and you can control it with any SPDT toggle switch you like. You can get your alternating control levels directly from a physical toggle switch.

Lostgallifreyan wrote in news:Xns98D49BBF5F79Czoodlewurdle@140.99.99.130:

Meant DG211...

Does it have to be a physical switch 4 pole ? How about a single pole switch of your choice and some relays ?

Do you mean actual video or RF btw ?

Graham

The channel resistance may be a bit high actually or I'd have suggested that too. You could use discrete fets though.

Graham

All of this sounds very good except I wouldn't know where to start :-(

My electronics knowledge restricts itself mainly to creating working circuits out of schematics and other practical things. Not designing stuff from scratch.

The circuit I'm working on in Eagle for creating a complete PCB is the following diagram I found somewhere:

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It allows for a standard PC (VGA) monitor to be connected to an Atari ST as opposed to just the special Atari monitor itself.

If the VGA monitor is a multisync type (e.g. it can handle all of the Atari ST frequencies (*)) the switch can be used to choose colour or mono modes.

(*) Atari ST monochrome mode:

35.70 KHz horizontal 71.2 Hz vertical

Atari ST colour mode:

15.75 KHz horizontal 50/60 Hz vertical

" snipped-for-privacy@lycos.com" wrote in news: snipped-for-privacy@k78g2000cwa.googlegroups.com:

Have a look at the DG211. Looks like you might be ok with two of those. Eeyore mentioned that the on resistance might be a bit high, but as you're using a circuit that uses 62 ohm resistors in three of the four lines, it won't matter there. The 'monochrome sensor' line is probably a DC level state line, so it won't matter there either.

If you can handle soldering and veroboard, you'll not have much trouble. Just check VERY carefully before connecting to the computer's 5V supply. The Analog switch IC's are very easy to use. The most awkward bit will just be working out how you will route the connections.

Just realised, you might need a 12V supply. That Atari plug appears to provide one, which is helpful. The DG211 can work with 22V in some versions, 12V should be safe for all.

Your VGA monitor can go down to 16 kHz horizontal sync ? Which model is it ? I've never seen any that went below about 30 kHz.

André Majorel (Counterfeit: uryl@withy.com wasis@allison.com) First rule of Usenet : if we don't have an answer, it's not a good question.

Not a VGA monitor. I was referring to Multisync monitors. I used to have an NEC Multisync II which could handle all of the Atari ST's sync rates.

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