Atari cone button wiring

[jcroach]

Good morning!

I'm the proud new owner of four low profile Atari "volcano" buttons.

[jcroach]

After further review, I found that the contacts are labeled NC and NO, but there are two of each. Hummmm

[SirPoonga]

Standard diode drops voltage by 0.7V. 

[jcroach]

Standard diode drops voltage by 0.7V.

[MinerAl]

The Atari arcade games powered the LED's with +5V and a 330 ohm resistor.

I asked that same question a while ago...

I seem to recall that two of the terminals under the switch are 90 degrees different from the other ones.  Those two are the light source.  You can test the LED with a couple of AA batteries.  Just don't leave 3V hooked to it for too long.  5V from your IPAC without any resistors will make the LED burn really bright for about 15 seconds and then pop and stink.

Do not use AC!

[jcroach]

Do not use AC!

Thanks.

[MinerAl]

Standard diode drops voltage by 0.7V. 

Thanks for the advice, but I'm completely illiterate when it comes to electricity.  What exactly does this mean?  When I go to the store, what should I look for so I don't blow this light up.

Thanks again.

Go to radio shack and tell the sweater-vest-wearing twit you'd like a pack of 330 ohm resistors.  They look like a wire with a little tubular ceramic bead attached to the middle.  Hook one end of the resistor  to the + terminal on the switch and the other to the +5v wire coming off the IPAC.  This will lower the voltage from 5v to 2v.

Good luck

Again AC=death.  don't use AC to power a DC LED.

[lordsaryon]

No, computer PSU's, and the little PSU that powers the board are usually DC.  Well computer ones always are, and I cannot make that guarentee about the board PSU

[SirPoonga]

A diode limited electricty to travel in one direction. Basically a one way valve for electricity.  One of the side effects is it will drop voltage down 0.7V.  Lets way you have a 5.2V supply (most likely your computer supply is within tolerances but not exactly 5.0V).  You add a diode into the system you now have 4.8V coming off the diode.  Do that until you get to the desired voltage.  Again, hopefully at 0.7 decrements you can get within desired tolerances.

For LEDs you don't have to worry too much.  Say it is a 2V LED.  If oyu run 3V too it, it will be brighter but not last as long.  If you run 1V to it, it will be dimmer but last longer.

So lets say you have an even 5V source.  Lets assume the computer averages to that. We need to drop about 3V.  Well, the closest to that will be 4 diode, dropping 2.8V.  You will get 2.2V output which is close enough for this situation.

So, how to wire?  Just wire the 4 diodes in series in the correct direction so the electricity flows the right way.  I don't think it matters what side of the LED you wire them too as long as they are in the right direction.  I can't remember, it's been awhile since I had to do something like this.

[ChadTower]

Isn't this AC power coming out of the PC? 

No.  The whole point of the power supply is to convert AC to DC, then step it down and distribute it over all the little ide power connectors/etc.

[Wade]

Are you sure those are Atari cones?  They look flatter than those on my Missile Command, and it has the shorter of the 2 varieties that I was aware of.  Did they have more than two heights?

Wade

[ChadTower]

Or, did anyone other than Atari make LED cones?

[NoOne=NBA=]

Based on cone height, I'd guess these are the Midway version.

[Stormy151]

Also, if the lights inside are really true LEDs, and not incandescent- you can't wire them up backwards, because they won't work.

Well, I suppose you COULD.  But why would you want to?

So get your 2v, then touch the wires to the contacts.  If they're backwards, the light won't light.

UNLESS, theyre regular light bulbs.  They don't care about + or -, they'll light either way.

[RayB]

SirPoonga...
Why diodes instead of a resistor?

[ChadTower]

My best guess is the 0.7v junction drop... a resistor would definitely be the right way to go.