A while ago, I've started my project to convert all my lamps in the playfield to LEDs. My 1st phase, the general illumination, is completed with no issues. My 2nd phase has started and ran into a snag. I started to notice that after I installed the orange and yellow effin-bright LEDs, they started to dim and change color. Argh! Why is this happening?!

As I am changing the feature lights to LEDs, I noticed something unusual from the orange and yellow LEDs. When left on for a while, the oranges start to dim and turn almost red. The yellows will dim, too, and turn to orange. Wait a min. That's not supposed to happen unless the voltage to the feature lights are too high! Going back to the schematics I discovered that Bally/Midway invented a scheme to use a double-phase circuit that will light one group of lights while the AC voltage reaches the positive peak on one lead and then light a group of 2nd set of lights on a second lead when reversed. So, half of them operate 30 times a second not 60 like the general illumination does. They decided to step up the voltage to almost 11 volts AC, instead of 6.3 volts, to make up the lost power to the filament bulbs. Clever, huh? Not so for LEDs! (Bally/Midway harnessed the AC voltage to turn on their feature lights, not the lamp matrix scheme Williams used in their machines.) Before I go further, I will need to get some kind of current limiting power without building a complex circuit for 2 phases. I found a couple of rheostats that will handle the power, but they aren't cheap! (Rheostats are high-power potentiometers that can handle a lot of power at a constant length of time.) Now it makes me wonder how I will handle the brights, or flashers, they use. They, too, use a double-phase circuit to flash them at 24 volts AC.

Do you have a different solution? Is there such a thing like a solid-state AC dimmer, the one that does true voltage limiting and not the circuit that cuts off at a certain time of a sine wave? Let me know in your reply.

The LEDs I am purchasing and installing are the A-Blaze premium ghost-buster LEDs.

The GIs are fine with mine. I also use 4-LED super brights. I have the super-bright red ones at the Atom Smasher and they highlight this locking assembly wonderfully! The blue 4-LED lights light up the Anti-Gravity in the back is amazing!

My main concern is the feature lights. I have clear super-bright whites in my bonus count and they are f----king bright! They are blinding me while I play! LOL! They don't dim. But, damn--they are brighter than my flash bulbs! That's why I need to turn down the voltage.

Do you have A-blaze LED's? What's the manufacturer of your LEDs?

Didn't Bally stick with 555's throughout their production of solid-state games? I have a Kings of Steel that uses all 555's for everything: coin door, playfield GI's, scorebox, feature lights for playfield & scorebox.

Really nice work, dementedwarlok, on your pins! I am surprised that your LEDs work really nice in your Fireball home-use-only game! They step down the voltage from 6.3 to 5.25 for GI's.

Switching to all LEDs in the feature lights is 70% complete. As soon as I order the rheostats, I will continue. I might even install those new Britecaps that just came out. : ) I will also install a couple of spots at the flippers since that area looks dark now. I can see my shots with the upper flipper now that I installed 4-SMD LED lights! Eventually I will install a relay to switch off the playfield GI's when the flipper power is turned off. The coin door lights and apron lights will always stay on. That's gonna look cool during attract mode! And, if I feel like it--I will install white LED strips on the hidden side of the apron and connect it to the driver that blinks the neon topper. Make the game REALLY blink!

UPDATE: Ugh! I finally got the rheostats. I think I may have ordered the wrong resistance. There's too much resistance with little adjustment. So, what happens is that when there's a lot of power flowing through it limited the power to them! Voltage vs. current. I still have a bunch of bulbs to convert to, but I want to see how it will affect the outcome. I may opt to go with just buying a 12 volt center tap 10 amp transformer (6V-0V-6V). A seller on eBay has it up for ~$30. This is the quick alternative. But, I'm not through yet.

I've been looking at how they "dim" the AC electricity and the results was something I was not going for. So, basically like those X-10 modules Radio Shack sold back in the days, they are pretty much doing the same thing. They just alter the timing on the phase so this way it looks like it's "dimming" the table lamp, for example. But, I want to take it to another level. Why? So, no one has to buy a bulky, heavy transformer and install it somewhere in the scorebox where there's little to no room. (Yes, Strange Science has the transformer installed in the scorebox and not the playfield box.)

Minor updates to the GI such as an LED cool-white strip after I found the 12 volt circuit (A-HA!) for the flippers and an additional pole to light up the dark corner to the right of the bumpers and right ramp.

Stay tuned!

_{Post edited by GameGenius1: forgot to add the minor updates}

UPDATE: So... if anyone else is interested at what I did so far see below.

I pretty much custom made my LED transformation. All bulbs use the 555-type wedge sockets and the flash bulbs use the 906-type wedge sockets. I used two sources to get my LEDs:

Pinball Life (http://www.pinballlife.com):
4-SMD cool white LEDs for general illumination, qty. 13
1-SMD frosted-lens cool white LED for the ramps (2 on left, 1 right and 1 each under the comic apron), qty. 5
4-SMD red LEDs for the Atom Smasher, L-A-B in-between lanes, qty. 9
4-SMD blue LEDs for the Anti-Gravity ramp, qty. 2
1-SMD flexible white LED for "Collect Bonus" eject hole, qty. 1
1-SMD flexible yellow LEDs for each brain rollover target and Smash at the Atom Smasher, qty. 3 (substitute warm-white for reliability)
1-SMD frosted-lens cool-white LEDs for Bonus numbers 1-9, Shoot Again, and S-T-R-A-N-G-E, qty. 17
1-SMD frosted-lens (bright) purple LEDs for S-C-I-E-N-C-E, qty. 7
1-SMD frosted-lens warm-white LEDs for L-A-B, qty. 3
1-SMD frosted-lens yellow LEDs for bumpers, 2X, 3X, 4X, 5X, 6X bonus multipliers, 5, 10, 20, 50 bubble lights on each side, qty. 17 (substitute warm-white for reliability)
1-SMD frosted-lens orange LEDs for Bonus numbers 10, 20, 30, 40, 50, qty. 5 (substitute warm-white for reliability)
1-SMD frosted-lens green LEDs for Hold Bonus, 3X, 6X, 9X 12X playfield multipliers, qty. 5
1-SMD frosted-lens red LEDs for Extra Ball, Special, "Spark Bonus when lit" arrows. Some have 2 per arrow. Qty. 7
1-SMD clear-lens cool-white LEDs for Spark Bonus, Power Saver ON outlane and shooter lane, qty. 3
1-SMD clear-lens warm-white LEDs for Load Atoms, at upper flipper, 100, 200, 300, 400, 500, 600 volt lights at Volt Meter qty. 8
1-SMD clear-lens red LEDs for 700, 800, 900 volt meter lights, qty. 3
8-SMD 906 LED single-direction flashers for left ramp, volt meter, atom smasher ramp (2), anti-gravity loop qty. 5

Comet Pinball (http://www.cometpinball.com):
1-SMD frosted lens color-changing LED for atom above flasher at Anti-Gravity exit and far left corner where the ball loops up to lock into atom smasher, qty. 2 (these lights are tied with the general illumination)
8-SMD flexible cool-white 906 flasher LED for bumper flasher, anti-gravity exit flasher, 25K flasher, 50K flasher, 75K flasher above the bonus lights, 3 sockets that blink "Strange" in scorebox, qty. 8
5-SMD square-type cool-white 906 flasher LED for right ramp. Might sub to the 8-SMD (from Pinball Life)

WARNING: Bally 6803 systems use 11 volts AC to produce the necessary brightness for feature/switched light bulbs! This is NOT compatible with all LEDs!! A 6-volt 10 amp 2-phase transformer must be used! (12 volt center-tap, 6V-0V-6V). I got it from ebay. ( ebay.com link: 12V Transformer 6V 0 6V CT 10A 110Vac 220Vac to 12Vac USA Free Shipping ) You will need to bypass the 11 volt wiring before the power supply board.

MODS:
I used a cool-white waterproof LED lightstrip to light up the flippers. A 12 volt source is required. You can hook it up to the machine's power supply. You can get that at Ebay.
I also added a spotlight to light up the lady and gorilla playfield area. They use 1-SMD clear lens LEDs. They are connected to the general illumination circuit.
Another pair of spots to light the exit of bumpers and right ramp entrance since they were too dark. They also use 1-SMD clear lens LEDs. They are connected to the general illumination circuit.

ISSUES:
I later discovered that the yellow and orange LEDs were not designed to handle the proper voltages and in-time will dim to a different color regardless of which pinball machine and bulb type. This is why that I am substituting to warm-white LEDs for reliability. You can use pink or purple LEDs to give a unique look. Wouldn't hurt to experiment.

And, a YouTube link: