Power button

[jsb666]

hey guys, just a quick question what sort of button do i need for the power and reset buttons?

[OvRiDe]

For the most part I think about the only requirement is that they are "Momentary", which means that is only switch is only connected while you are pressing it. Other then that I think the skys the limit..

[tybrenis]

For the most part I think about the only requirement is that they are "Momentary", which means that is only switch is only connected while you are pressing it. Other then that I think the skys the limit..

OvRiDe is completely correct. I have used keyswitches... keypads... you may use whatever you please.

[jsb666]

thanks for the quick replys guys. thats all i needed to know

[xmastree]

Just a thought, If you like toggle switches you could use one switch for both.
Get a momentary, spco center off switch.
Switch it one way and release to turn on, the other way and release to reset.

[DaveW]

Just remember that you might need to be fiddling around for a while with those switches to make them work right. As a guy who's written a switch de-bouncing program in PIC assembler, and has a vague understanding therefore of how the motherboard sees the switch, you really want to make it as easy as possible: no matter what sort of switch you put in, all the motherboard wants to see is a simple Push-To-Make switch.

So although you can hook up pretty much anything as a switch-hell, even a thermistor can act as a switch, if you're that bored-you might need to do a little 'studio engineering' to get it to send the correct signal.

2 incredibly popular unusual switches: Key switches, like a car ignition, and missile-style toggle switches. You have any specific switches in mind?

-Dave

[xmastree]

As a guy who's written a switch de-bouncing program in PIC assembler, and has a vague understanding therefore of how the motherboard sees the switch

Given the cheapness of the switches on some cases, I imagine there's enough hardware debouncing on the motherboard to cope with most switches.

Know what would be cool? Reed switches behind the panel, and a magnet to activate them. Similar to what's used in a burglar alarm.

[DaveW]

Given the cheapness of the switches on some cases, I imagine there's enough hardware debouncing on the motherboard to cope with most switches.

Yeah, but not something like a toggle switch, which is really what i meant. And you'd have to be careful with 'novelty' switches as well, e.g. ones that remain stuck in for a set time and slowly depress.

Know what would be cool? Reed switches behind the panel, and a magnet to activate them. Similar to what's used in a burglar alarm.

It would make for some artistic and interesting setups, but anyone who comes anywhere near my computers with any kind of magnet, permanent or otherwise, suddenly discovers how difficult it is to hold a magnet without hands.

Although, magnetic switches could make for a completely button free front panel, which would be cool.

Reminds of a story my lecturer once told me; he knew a guy who, as an experiment, built a CPU out of relays instead of transistors. It started small, then took over the walls and ceiling. Every time the room was under stress, you could all the relays tapping away...i'd really love to see a CPU like that, it would be completely fascinating.

I think this was in the days of the 6502, when the transistor count was under a million. The 6502 only had 2300 transistors, if you can imagine that many relays, all up your walls, etc...must have been merry hell if one ever broke, or jammed...

-Dave

[xmastree]

Yeah, but not something like a toggle switch, which is really what i meant.

You'd be surprised. Remember the old type AT power switches? Push on, push off which switch the mains to the PSU? I've successfully converted one of those to momentary action (by removing the bit of wire which latches it) and used it to power an AT board with a dual (AT/ATX) psu option. I just fitted an ATX PSU and wired the switch to the header as normal. It worked perfectly, and I'll bet that wasn't the cleanest of switches.

but anyone who comes anywhere near my computers with any kind of magnet, permanent or otherwise, suddenly discovers how difficult it is to hold a magnet without hands.

Afraid of magnets? You must still be using floppies. Gosh, how 20th century!
Oh, don't place a motorcycle alternator rotor near the screen of a CRT. You'll have a daisy patterned shadow for weeks...

built a CPU out of relays instead of transistors.

Like this?

[OvRiDe]

Oh, don't place a motorcycle alternator rotor near the screen of a CRT. You'll have a daisy patterned shadow for weeks...

Sounds like experience talking there. Unfortunately I know exactly what you are talking about.. hahaha