Author Topic: Adding LED lamps to Gi string  (Read 395 times)

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Offline Wotto

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Adding LED lamps to Gi string
« on: September 20, 2009, 06:04:25 PM »
I posted this question some weeks back at RGP - most guys said NOT to add to the Gi string on a game- but ALL but one assumed I was going to use 44 or 555 globes - I am not.

I want your opinions.
But please read thorouhgly before answering.

I am wanting to put lights inside the houses and shops on my Flintstones machine.
This would involve add ing a total of 6 'bulbs' to the existing Gi string.

I would use 6 x LED lamps and NOT normal 555 or 44 globes to do this.
Surely I can add LED's without causing the machine any trouble?

I did a test this afternoon and put 3 LEDs inside the houses on the right side of the game , I temporarily clipped the wires to my Gi string and below are the rsults ... it looks quite good.

The 1st image is the other side of the game unlit - then 2 images of the houses I lit up today.

Can someone with the techo knowledge please tell me if this is OK and safe to wire in place permanantly.

Cheers







« Last Edit: September 20, 2009, 08:01:08 PM by Wotto »
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Offline ddstoys

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Re: Adding LED lamps to Gi string
« Reply #1 on: September 20, 2009, 06:09:40 PM »
Im sure a few LEDs wouldnt affect your GI but then im only a hack

Offline Extra Ball

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Re: Adding LED lamps to Gi string
« Reply #2 on: September 20, 2009, 06:50:30 PM »
LEDs use a tiny amount of power compared to a norm bulb. Replace one bulb in that string with a LED, then add few LEDs to the string, and you would still be drawing less power. Well thats how I would look at it (better wait for a techy guy) lol

and it looks great Wotto

Offline beaky

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Re: Adding LED lamps to Gi string
« Reply #3 on: September 20, 2009, 08:14:36 PM »
do you know if the leds draw 25ma or do they have a higher current draw?
are they a standard led or are they the type that plug into a socket?
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Offline Wotto

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Re: Adding LED lamps to Gi string
« Reply #4 on: September 20, 2009, 08:17:09 PM »
Sorry - no idea on the 'current draw'.

They are the type of LED that suits a 555 / wedge holder.
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Offline elkor-alish

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Re: Adding LED lamps to Gi string
« Reply #5 on: September 20, 2009, 09:22:34 PM »
LEDs use a tiny amount of power compared to a norm bulb. Replace one bulb in that string with a LED, then add few LEDs to the string, and you would still be drawing less power. Well thats how I would look at it (better wait for a techy guy) lol

and it looks great Wotto

This sounds like good advice to me but I would change a couple on the same string with LED's before I added the ones in the shops etc. just to be sure.

Looks good mate. I love all these mods you come up with for your machines.   ^^^
Pins: The Getaway, TotAN, WH2O, Pinball Magic, Banzai Run, Flintstones, Judge Dredd, Lord of the Rings LE, Metallica LE, Iron Man VE, The Walking Dead LE, Star Trek The Next Generation.

Offline beaky

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Re: Adding LED lamps to Gi string
« Reply #6 on: September 20, 2009, 09:32:10 PM »
LEDs use a tiny amount of power compared to a norm bulb. Replace one bulb in that string with a LED, then add few LEDs to the string, and you would still be drawing less power. Well thats how I would look at it (better wait for a techy guy) lol

and it looks great Wotto

This sounds like good advice to me but I would change a couple on the same string with LED's before I added the ones in the shops etc. just to be sure.

Looks good mate. I love all these mods you come up with for your machines.   ^^^
i agree
better safe than sorry
once you change a few of the 555s for leds then the gi circuit would have no problems with the extra leds.
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Offline AskJacob

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Re: Adding LED lamps to Gi string
« Reply #7 on: September 21, 2009, 10:43:37 AM »
Ahhh LEDs. Something I play about with far too much.

Adding LEDs to GI strings - you can add about 10 to equal the same current draw as a single #47 lamp*, so no worries there about straining the GI circuit.

* this is if you use a resistor. If you don't, they will pretty much act as a short until they go pop...

----EDIT

I see you are using the pre-made LEDs - these have an integral resistor. Therefore they (if made correctly) should pull no more than 25 milliamps. the rest of my post below therefore is for curiosity more than anything else :D

----

Now for some fun though:

The GI circuit is AC, not DC. Add to that if it is a Williams WPC or higher, they are dimmable, the dimming is performed by chopping up the AC voltage which works wonderfully with the thermal inertia of a normal incandescent, but makes a flickery mess of LEDs (as they are pretty much instant on and off devices, unlike lamps which "ramp" up and down in brightness).

To prevent your LEDs dying quickly, please make sure you use an appropriate resistor for them - size it assuming the LED is powered by 6.3v DC.

Blue and White LEDs are not very happy running on AC, as the reverse voltage is higher than they are meant to handle (on the "back swing" of the AC cycle) and it will kill/dim them much quicker than their rated 50,000 hours. To fix that, use a 1n4001 or 1n4004 diode in series to "block" the reversed voltage, and adjust the resistor to 5.6v DC (there is a 0.7v drop across a single rectifier diode).

To minimise the flicker when the GI is dimmed, you can try 2 leds "back to back" so each one takes it's turn illuminating on their half of the AC cycle, or alternatively use a small bridge rectifier (like a W004) or make one with 4 diodes. Resist the temptation to also add a capacitor to "smooth" out the flicker - it does not work but does create some very interesting blinking effects  %$%

With so many LEDs available these days and so cheap, it really is a case of experimenting to see what works. A lot of the LEDs don't need to be run at their full brightness either, as they are extremely bright. If you run them "lower" they will pretty much last forever.

Cheers
Jacob
« Last Edit: September 21, 2009, 10:45:47 AM by AskJacob »

Offline Wotto

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Re: Adding LED lamps to Gi string
« Reply #8 on: September 21, 2009, 11:22:03 AM »
Arrrrr – thanks Jacob, that tells me that I am good to go for the Flintstones

Interesting info on the LED’s in general as well
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Offline ktm450

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Re: Adding LED lamps to Gi string
« Reply #9 on: September 22, 2009, 11:19:29 AM »
Arrrrr – thanks Jacob, that tells me that I am good to go for the Flintstones

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