Scannermax 506s

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Originally Posted by f150trk21

Im having a weird problem I think with the 24v PSUs Im using, when I first power them up the PSUs leds will flash, usually one or the other. This causes the red led on the both amps to flash and makes the galvos oscillate. It does it about half the time. Eventually they stop flashing and work as normal. Im using 2 of the power supplies below and have them bridged.

http://www.jameco.com/webapp/wcs/sto...0001_323732_-1


Thanks

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Certain batches of 24V Meanwells that were sold very cheap to bulk vendors are showing startup issues. I have no idea which lot numbers show this. You are the third person to show this issue, but only the second one with Redboards. You can try adding a softstart delay relay with softstart resistors, and large external filter capacitors, or switch PSUs to something else of at least 4 amps per rail.
>
> ALL Galvo amps using LM3886 Amplifier chips draw a huge startup surge. But it should not be so large as to totally trip off the Meanwell overcurrent trip like that. There is nothing wrong with the AMP setup, its on the PSU end.
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Leaving the amps in startup or oscillation for more then a few hundred microseconds will eventually damage the amps... I strongly urge you to not allow the PSU to damage the amps, they are NOT easy to repair. The red coating, which spectacularly protects the board against damage, does not like to be hot-air reworked.
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For the record I generally have had very few issues with Meanwell products in both laser and lab work.

Steve

ok thanks Steve
Is there any specific psu you recommend?

Looking at MPJA.com, should I try my luck again with the meanwell 24v 4.5a psu
or try Hengfu 15v 4a psus? Anything bigger in size wont fit my case.

I am using this PSU... http://connexelectronic.com/product/smps300re/

They have a really small footprint, can deliver 400W peak and have given me no troubles. I wouldn't recommend anything else at this point.

Quote:

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Originally Posted by f150trk21

ok thanks Steve
Is there any specific psu you recommend?

Looking at MPJA.com, should I try my luck again with the meanwell 24v 4.5a psu
or try Hengfu 15v 4a psus? Anything bigger in size wont fit my case.

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Redboards cannot go down to 15V without modifications... The reason being they have +/- 15V regulators on board (lm7815, lm7915) and these need headroom of about 5 more volts each to function. I tested and tuned the RBs at 21 volts using bench supplies .. I would not go much lower. I'd go with Absolom's suggestion or something else designed for class AB amps...

The MPJA Meanwells were the same batch that gave trouble for another Redboard user :-(

Steve

Thanks Steve and absolom, just ordered that psu.

The only thing to make sure of when you get the PSU is that it has the 110V jumper installed. The first one of these that I got, had the jumper installed. The second time I ordered, the jumper wasn't installed and I pulled my hair out for about 45 minutes, trying to figure out why the PSU wasn't working until I found the problem. On the underside of the board, there should be two solder pads. If there is no jumper, solder one in. It should be about a 20awg jumper, I would say. See attached pic.

Attachment 48131

Thanks for the heads up on the psu.

Well..... I inadvertently got my first set of Compact 506's. I'm a little underwhelmed - at least at this point.

The backstory - at SELEM I impulsively purchased a brand new Kvant Clubmax projector because.... well.... I guess that's what I do. Hey... it was cute. And it has 506's along with Kvant amps.

Anyway, this week I've been running a number of LD2000 shows with it - both graphic and beam and it seems like every show I've had to go in and adjust the scan rate to eliminate tails, fix unclosed circles and sort other weird artifacts. The flicker on a number of graphic shows has been somewhat unwatchable. I don't think there is any issue with the projector or the tuning or anything... I just don't see them as being particularly the cat's meow at this point. I've had to slow some beam shows down to 14k or 15k in some cases just to eliminate tails from circles or to make dots look like dots. Or, I've had to crank it up to 40k to try and clean up some graphics. It's had to be adjusted some nearly every song. And I've used all sorts of scan angles from a small 4' x 4' square 40 feet away to 14' x 14' and even wider for beams.

Based on this, today I'm going to set up 3 different projectors side by side and run them all through a DZ splitter to get a fair side by side "shoot out" between the 506's, a set of PT-A40's and a set of CT-6215's. I can't believe the performance is really that lacking. I'll see about posting pics.

Hi Brad,

I appreciate your comments, and will not deny that this is your experience. However, I will take this time to point out a few things, especially since you used the words "shoot out".

First, I will wholeheartedly agree with you on the cuteness of that Kvant projector. FLEM and SELEM attendees may remember my own projector made back in 1995 which I had painted white rather than black. Somehow that has always been more appealing to me, especially if we are to view projectors as consumer products.

However, I will point out that there really weren't very many of those Kvant projectors made (although I understand that anybody can order this as an option -- perhaps this is not a very well-known fact). It could be that in fact, the Kvant projector you acquired was among the very first that they made and in which they used our scanners.

I will also say that not all Kvant projectors with C506 are created equal and that, unfortunately, I did not have a chance to look at projected images coming out of that particular projector. However, when Kvant just started using the C506, Brian Gonzales purchased a projector from them. That projector was delivered to the Pangolin office, and just before Brian picked up the projector, Aaron was projecting test patterns. I was really dissatisfied with what I was seeing, and upon investigating, I found that Kvant did not implement all of my recommendations for their amplifier at that time.

That was then and this is now... If you look on the ScannerMAX web site and at the C506 datasheet, you will see two separate versions. http://www.scannermax.com/pdf/Compact506.pdf

One version is our standard version, but another is the "AW50". The AW50 will give better performance with certain amplifiers. When we first came out with the AW50, we worked with Kvant to make further modifications to their amp. After that (and periodically) I made sure the recommended changes were made.

So the bottom line is -- while it would certainly be interesting to hear the results of your ILDA Splitter tests, I don't think that will be definitive. It will give all of us an idea what you, personally, are experiencing, but unfortunately due to the vintage of your projector (which I believe is among the first), it won't give all readers and indication of what all Kvant users are experiencing or even what all 506 users are experiencing.

Even in the case of the 6215 scanners you mentioned, the performance of these very scanners can vary wildly depending on the particular driver used. Kvant configured their driver to work with 6215s and I was not very happy with the performance. But even when using drivers from Cambridge themselves, you have three separate driver options. The 673xx option won't drive 6215s much better than Kvant, but their 671xx with high power option will deliver among the best performance found in the industry (performance exceeded only by our Saturn 1).

So while your test will give us all an indication of what you are experiencing, the test really won't reveal much useful data beyond that.

As a reminder of a previous comparison, you can see a video here, projecting shows and test patterns side by side with C506 and DT40 scanners.
https://www.youtube.com/watch?v=8iWjpz2YEO0

I expect the large-signal performance of DT40 scanners to be superior to anything that Phenix makes (especially as seen and as experienced by people -- including us -- using Pluto projectors).

Bill

PS: The video comparing C506 to DT40 was made nearly 2 years ago, and this was with our "Standard" C506. The AW50 would be delivering better performance in all respects. The Kvant amp shown in this video is basically the very first one -- modified by me. Had Kvant implemented all of my suggestions they would have (and eventually did) experience exactly the same performance shown in the video.

Also, I realized that the reason why the DT40s did not show as hotter is because they were bolted down to the projector base-plate where they could enjoy some heat-sinking action. Re-running the tests with the X-Y mount sitting on circuit boards might have led to their actual destruction!

Brad I PROMISE it isn't the scanners. I have a set running on just 18v and they are 100% as good as my 6215 at 30k and hold pretty well to 45k. Well to be fair at wide angle the 6215 does have sharper edges. Trails have nothing to do with the scanners and everything to do with the diodes and drivers. Unless you mean over shoots and rings. then you need to tune the drivers for the scanners. Since I went all diode trails have been a thing of the past.

I wanted to jump in here because I am SERIOUSLY impressed with the 506 scanner.