(Topic ID: 259423)

Upgrading a Bridge Rectifier? What say you...

By Mikedenton49

4 years ago


Topic Heartbeat

Topic Stats

  • 24 posts
  • 6 Pinsiders participating
  • Latest reply 4 years ago by Pin_Guy
  • Topic is favorited by 1 Pinsider

You

Linked Games

Topic Gallery

View topic image gallery

20200110_191408 (resized).jpg
20190125_225244 (resized).jpg
Screenshot_20200111-110400_Firefox (resized).jpg
Screenshot_20200111-100718_Firefox (resized).jpg
Screenshot_20200111-093830_Firefox (resized).jpg
#1 4 years ago

Top 'o' the mornin' pin brethren...

I've been kicking around some slick ideas on modding the light show on a METprem and even implemented a few. The problem, obviously, is the tight tolerances of modern day sterns and fear pushing the circuitry. I found that adding even a modest additional load will cause the dreaded flicker effect. While sure, there are other options, why not simply increase the available amperage? Shoot, pinball life even has said part for a song in the form of an upgraded rectifier.

Are there any useful opinions on the matter? I'd be obliged to sling mad props and high fives for a reasonable analysis.

Screenshot_20200111-093830_Firefox (resized).jpgScreenshot_20200111-093830_Firefox (resized).jpg
#2 4 years ago

See? Right there in HD+ black and white. Higher rated.

Worth a shot? Anybody? You, over there in the corner...

Screenshot_20200111-100718_Firefox (resized).jpgScreenshot_20200111-100718_Firefox (resized).jpg
#3 4 years ago

35 amps is the max current rating of the rectifier not the output current. I'm not sure what the rating of the stock rectifier is but I would venture to guess the only thing you'll accomplish by doing this is risking damaging your board with unnecessary soldering.

#4 4 years ago

Actually looking at the stock part it's a DB3501 which is a 35A 100V rated part. So you'll literally gain nothing.

#5 4 years ago

Thanks fattdik.

The rectifier is mounted remotely. No risk there. As to you second post, well, hmpf. That, my friend is a useful observation and thanks for looking it up.

Surely PBL realizes that voltage isnt the issue, well, in a sense. I find it absolutely impossible to believe the GI is pulling 35 amps and stressing the rectifier. Yet, an inspection of the evidence says it's so. Hmmmmm....

#6 4 years ago
Quoted from Mikedenton49:

Surely PBL realizes that voltage isnt the issue, well, in a sense. I find it absolutely impossible to believe the GI is pulling 35 amps and stressing the rectifier. Yet, an inspection of the evidence says it's so. Hmmmmm....

Its not the rectifier that's the issue, the problem you are seeing is the transformer is not able to support the additional load.

#7 4 years ago

Would you be so kind as to refer me to the page you found the part number?

Screenshot_20200111-110400_Firefox (resized).jpgScreenshot_20200111-110400_Firefox (resized).jpg
#8 4 years ago

Pin_Guy, aptly named, could you please elaborate a hair more? See any potential solutions?

#9 4 years ago

I have no idea what you have in mind or what the schematics look like but if youre adding a load, could an arcade style power supply work as a secondary power supply. Run the mods only off that?

#10 4 years ago
Quoted from Mikedenton49:

Pin_Guy, aptly named, could you please elaborate a hair more? See any potential solutions?

I'll try to get you more information later, I have to head out now to get my practice in for the state championships next weekend.

#11 4 years ago

Could you be more detailed on what you're actually trying to do? That will help find a solution.

#12 4 years ago

You bet...

I have mounted comet matrix strips in red white and blue in speaker light frames, 3 rwb strips on the backboard, 3 rwb in the trough, and 3 rwb 6led pads beneath the apron art. The idea is to tap off the GI lines to sequence all of them with the games normal operation. The rectifier, or as i just learned, the transformer will support about half of this. It literally comes down to the connection of a single strip then strobing occurs. I realize this is asking a lot of the system, but dang will it ever be freaking sweet if I can find a way to pull it off.

Heres a pic, but I'm sure you get it. I'd take a better one but I'm not currently home. As you can see, the trough/art is currently blue, as the other colors arent capable of being driven.

Open to any suggestions.

20190125_225244 (resized).jpg20190125_225244 (resized).jpg20200110_191408 (resized).jpg20200110_191408 (resized).jpg
#13 4 years ago
Quoted from Phat_Jay:

I have no idea what you have in mind or what the schematics look like but if youre adding a load, could an arcade style power supply work as a secondary power supply. Run the mods only off that?

In fact I'm already running several strips off a dedicated power supply. The issue is getting said strips to interact with the GI. There isnt a reasonable way to do this without tapping the GI in some fashion.

I worked with another pinsider a while back to do insane things with flashers using a dedicated PS which uses optical sensors to fire strips and flashers all over the place. It's truly one hell of a light show. Rock914 Wish I could show you guys but it doesnt photograph or video well at all, obviously. The reason the same sensors cant work with the the GI is that the resolution and dimming arent accurate enough to make a smooth performance. Trust me, I tried. Started with that in fact.

#14 4 years ago
Quoted from Mikedenton49:

See? Right there in HD+ black and white. Higher rated.
Worth a shot? Anybody? You, over there in the corner...

Challenge accepted.
I'm sorry but "higher rated" - how is this higher rating achieved?

Higher voltage?
If part was rated too low then this can be an improvement. Going to a higher voltage gains nothing if the bridge was sized properly to begin with. I have yet to see one that actually had too low of a voltage specified unless the bridge was replaced with a lower voltage part during repairs. Nobody used anything lower than 100V that I have ever seen. 100V works well for most but pushing threshold for coils. 200V usually used there. I tend to only go 400V since the cost is the same as a 50, 100 or 200V part. Does it gain anything? No, but if replacing the bridge and the cost is the same then why not.

Higher Current?
Higher current rated bridges can handle current surges better but in the long run - you usually have the same power loss and heat dissipation. And in the case of the cheaper bridges (including full metal body bridges) - it is often worse due to cheaper diodes with higher forward voltage drop resulting in higher power loss. And for most machines - you are already using a 35A bridge.
I sold the top of the line Diodes Inc Bridges for a long time (until they quit making them). Were they an improvement over the originals with same current rating? no, not really. They are merely just a replacement for what is there.
Going to full metal body bridges tends to be an issue due to one fact: Look at the surface of that bridge, especially where it attaches to a heatsink. Got that nice and very smooth surface required for attaching a heatsink? No, instead they have that rough, cast look and texture to them. This impedes thermal transfer between bridge and heatsink. The heat slug type bridges (phenolic body) tend to have a MUCH better heatsink mounting surface. The Diodes Inc GBPC3504W bridges were pretty much mirror smooth. Today's On-Semiconductor/Fairchild bridges aren't nearly as smooth but still not bad.

Unless you are drawing near the rated current of the existing part (>50%) and the existing part is rated at 25A then going to these 35A, 100V bridges won't help. The biggest improvement to a bridge rectifier circuit is drawing heat away from the part. Buy dedicated heat sinks for bridge rectifiers rather than using the low power transistor heatsinks. A popular heatsink used by many people for bridge rectifiers is the Aavid 563002 folded aluminum type heatsink which is actually intended for transistors. These have a thermal resistance of 13C/W. If a bridge is dissipating a light load of 5W (often higher) then the heatsink related temp is rising by 65C. Add that to 25C room temp for 90C surface temp. Smallest dedicated bridge rectifier heatsink (folded aluminum) is rated at 9.4C/W. Same load would result in 47C temperature rise. Add 25C room temp for 72C surface temp. Nearly 20C drop just by changing to a similar but proper heatsink. Imagine how much cooler it can run with one of those massive extruded heatsinks.

* It's usually not the bridge rectifier, it's how you get heat away from the bridge rectifier *

And don't even begin to mention the so-called 50 amp versions of these bridges. It's nothing more than specmanship and BS. Under the lid - it's pretty much the same part.

#15 4 years ago
Quoted from G-P-E:

Challenge accepted.
I'm sorry but "higher rated" - how is this higher rating achieved?
Higher voltage?
If part was rated too low then this can be an improvement. Going to a higher voltage gains nothing if the bridge was sized properly to begin with. I have yet to see one that actually had too low of a voltage specified unless the bridge was replaced with a lower voltage part during repairs. Nobody used anything lower than 100V that I have ever seen. 100V works well for most but pushing threshold for coils. 200V usually used there. I tend to only go 400V since the cost is the same as a 50, 100 or 200V part. Does it gain anything? No, but if replacing the bridge and the cost is the same then why not.
Higher Current?
Higher current rated bridges can handle current surges better but in the long run - you usually have the same power loss and heat dissipation. And in the case of the cheaper bridges (including full metal body bridges) - it is often worse due to cheaper diodes with higher forward voltage drop resulting in higher power loss. And for most machines - you are already using a 35A bridge.
I sold the top of the line Diodes Inc Bridges for a long time (until they quit making them). Were they an improvement over the originals with same current rating? no, not really. They are merely just a replacement for what is there.
Going to full metal body bridges tends to be an issue due to one fact: Look at the surface of that bridge, especially where it attaches to a heatsink. Got that nice and very smooth surface required for attaching a heatsink? No, instead they have that rough, cast look and texture to them. This impedes thermal transfer between bridge and heatsink. The heat slug type bridges (phenolic body) tend to have a MUCH better heatsink mounting surface. The Diodes Inc GBPC3504W bridges were pretty much mirror smooth. Today's On-Semiconductor/Fairchild bridges aren't nearly as smooth but still not bad.
Unless you are drawing near the rated current of the existing part (>50%) and the existing part is rated at 25A then going to these 35A, 100V bridges won't help. The biggest improvement to a bridge rectifier circuit is drawing heat away from the part. Buy dedicated heat sinks for bridge rectifiers rather than using the low power transistor heatsinks. A popular heatsink used by many people for bridge rectifiers is the Aavid 563002 folded aluminum type heatsink which is actually intended for transistors. These have a thermal resistance of 13C/W. If a bridge is dissipating a light load of 5W (often higher) then the heatsink related temp is rising by 65C. Add that to 25C room temp for 90C surface temp. Smallest dedicated bridge rectifier heatsink (folded aluminum) is rated at 9.4C/W. Same load would result in 47C temperature rise. Add 25C room temp for 72C surface temp. Nearly 20C drop just by changing to a similar but proper heatsink. Imagine how much cooler it can run with one of those massive extruded heatsinks.
* It's usually not the bridge rectifier, it's how you get heat away from the bridge rectifier *
And don't even begin to mention the so-called 50 amp versions of these bridges. It's nothing more than specmanship and BS. Under the lid - it's pretty much the same part.

^This guy electrics... lol.

Fantastic, and I do believe I follow the intended point that, 1, the PBL part wont do jack, and 2, the only improvement is to add heat sinks. While the later could certainly be doable, I dont see it really benefiting to the level I'd like to operate at as, even when the circuit is fresh and cold, adding just that one more led strip pushes something past its capabilities.

So, you've answered the question as asked. *Tips hat*
Given your prowess in such regard, can you think of any other avenues I could explore?

#16 4 years ago

Would it be possible to use something like an Arduino or Raspberry Pi to sense the voltages on the GI and control the LED strips with a separate power source?

#17 4 years ago

https://www.mouser.com/ProductDetail/653-G2R-1-AC6?r=653-G2R-1-AC6

Why couldn't you use one of these tapped off the GI circuit?

#18 4 years ago
Quoted from TreyBo69:

Would it be possible to use something like an Arduino or Raspberry Pi to sense the voltages on the GI and control the LED strips with a separate power source?

I've heard of such things but it is a country mile outside of my capabilities to program such a thing. Let me look into it though. Nice idea.

Quoted from Deez:

https://www.mouser.com/ProductDetail/653-G2R-1-AC6?r=653-G2R-1-AC6
Why couldn't you use one of these tapped off the GI circuit?

I like where your head is at, but in effect such is the same as the optical sensor route. No telling how quick it switches and all dimming effects would be lost.

-2
#19 4 years ago

Have you tried pinstaduum lights?

#20 4 years ago

Pinstadium? I mean, sure. Have a set on TSPP. I like them for certain applications, but MET is practically blinding as it sits.

#21 4 years ago
Quoted from Mikedenton49:

Pinstadium? I mean, sure. Have a set on TSPP. I like them for certain applications, but MET is practically blinding as it sits.

It was a joke. Those things are awful.

#22 4 years ago
Quoted from Deez:

It was a joke. Those things are awful.

Well, for the price, yeah. They have their place though. Also, bump. Surely someone somewhere, knows something about this. My OCD cant leave it alone.

3 weeks later
#23 4 years ago

So a follow up in case the strobing problem pops up for anyone else and cable wiggling and CAT cable replacing doesnt cut it...

I ordered and replaced the rectifier outright for lack of any other ideas and used the part number G-P-E suggested above, and the flicker issue is solved. I have no idea the theory behind it, nevertheless...

I also added a set of clip on heatsinks to perhaps keep the temp down giving it a better life span as he suggested as well.

Thanks for the helpful knowledge friends.

#24 4 years ago

Thanks for posting the fix, I'm shocked a 35 AMP bridge wasn't cutting it. Yo'll have to post a video of the lightshow!

Promoted items from Pinside Marketplace and Pinside Shops!
11,600 (OBO)
Machine - For Sale
Lubbock, TX
10,999
$ 55.00
Gameroom - Decorations
The Flipper Room
 
$ 7.00
Playfield - Toys/Add-ons
Pinball Z
 
11,000 (OBO)
Machine - For Sale
Mount Pleasant, WI
$ 9.99
Cabinet - Other
Bent Mods
 
$ 15.00
Cabinet - Other
Rocket City Pinball
 
$ 69.99
Playfield - Toys/Add-ons
Lighted Pinball Mods
 
$ 68.50
Playfield - Toys/Add-ons
Lermods
 
$ 200.00
Lighting - Interactive
Professor Pinball
 
$ 14.00
Playfield - Protection
SilverBall Designs
 
$ 49.00
Playfield - Toys/Add-ons
Lermods
 
$ 79.99
Cabinet - Armor And Blades
PinGraffix Pinside Shop
 
$ 22.50
Lighting - Led
Lermods
 
From: $ 35.00
Cabinet - Other
Rocket City Pinball
 
$ 30.00
Playfield - Other
YouBentMyWookie
 
$ 700.00
Hardware
Chrome Candy
 
$ 69.99
Playfield - Toys/Add-ons
Lighted Pinball Mods
 
From: $ 30.00
From: $ 99.99
Cabinet - Other
Lighted Pinball Mods
 
$ 9.95
Lighting - Led
Mitchell Lighting
 
$ 69.99
Playfield - Toys/Add-ons
Lighted Pinball Mods
 
$ 29.95
$ 24.00
Playfield - Other
Pin Monk
 
$ 1.00
Lighting - Led
Mitchell Lighting
 
$ 29.95
$ 19.95
Playfield - Protection
SilverBall Designs
 
10,650
Machine - For Sale
Ontario, CA
$ 25.50
Hey modders!
Your shop name here

Reply

Wanna join the discussion? Please sign in to reply to this topic.

Hey there! Welcome to Pinside!

Donate to Pinside

Great to see you're enjoying Pinside! Did you know Pinside is able to run without any 3rd-party banners or ads, thanks to the support from our visitors? Please consider a donation to Pinside and get anext to your username to show for it! Or better yet, subscribe to Pinside+!


This page was printed from https://pinside.com/pinball/forum/topic/upgrading-a-bridge-rectifier-what-say-you and we tried optimising it for printing. Some page elements may have been deliberately hidden.

Scan the QR code on the left to jump to the URL this document was printed from.