dbuckley

I discovered these on T a while ago and had a binge watch.  Enjoyed.

On 1/6/2024 at 2:44 AM, adamburgess said:

I dare bet it's the power supply on the way out. My X32 rack has done this a couple of times.

Our X32 Rack had a power supply failure.  Cap went BANG about 20 minutes to curtain.  FOH staff with very worried expressions entered tech room thinking the world had ended, or I'd blown myself up.  The digital part of the machine was working fine, just lost analogue I/O.  ("just").  Quickly grabbed digi stagebox and repatched.  Did the rest of the run that way, prior to X32R being sent to the menders for a replacement PSU.

It heightens my mood to see yours has done this a couple of times, so I now have a triggered new fear, living in expectation of it happening again.....

Not lighting, but you do have your favourite kick drum mic under the ring and a few subs, yes....?

Back in the dark ages of 2016, the Blue Room recommended cheap LED PAR was the QTX 6x6, which several of us bought, and ours (in community use theatre, so not hammered) are still going well.  QTX still make this sort of thing.

On 1/12/2024 at 12:46 AM, timsabre said:

You could make a little circuit using an SN75176 chip to buffer the incoming DMX signal

 

I had this exact problem, and solved it with a pair of these chips wired back to back on a little bit of board, so DMX in, buffered DMX out.

Ugly, and to be fair, it was on the back of a mobile prop, but effective.  Built 2013!  One of the things on the "safe" side of this buffer was a smoke machine, so there was some serious willingness to get this problem out of the way...

Hi Paul, enjoyed the vids!  Best wishes for the season.

On 12/19/2023 at 7:18 PM, Stuart91 said:

...they had an HDMI splitter....

 

HDMI.  Yeah.  HDMI over Cat5 boxes can be really terrible, they act as a source of broadband noise, and the frequencies involved change with resolution.  The Cat5 cable acts as a very effective antenna for this form of interference.

Roger that; LED would explain it.  Bloody modern technology!

I like to have finger tips exposed, and the best gloves of these sort I've found you get at a yachting chandelary, and, as a bonus, the palm of the glove is usually reinforced and thus ideal for tugging on ropes, or perhaps sheets in sailor's parlance.

Interesting - you've got 100w of (I assume) incandescent lamps, and still getting glowworms.  I usually use a 60w lamp as a ghost load...

With the dimming of incandescent fixtures, the relationship between brightness and power consumed is not linear.  So 50% brilliance (or indeed 50% fader position, which may or may not be the same thing) may not be 50% power consumption.

Yes, a 1K parcan on for an hour is 1 KWH of electricity consumed.  One KWH is 1000 watts for one hour, so a 148W LED is indeed 0.148 KWH.

And yes, cost of power per KWH times the sum of KWH for the period involved will be the cost of power consumed.  So one needs to take a reasoned estimate of how much of the rig is on for a general situation.  So if it's "most" of the rig and an average of 75% on the faders, then use those numbers multiplied by the max theoretical load to get the estimated load, but be prepared to be a fair way out.  But for an estimate it may well do.

Silly (but can be useful) rule of thumb; if electricity is about 0.25 pounds (or dollars), then the cost to run that thing for a year continuously is about twice the wattage in pounds (or dollars). 

On 11/2/2023 at 2:06 PM, sunray said:

I sourced some transformers which appeared to have the same spec at £18 each and turned out to be rubbish, infact 

Colour me surprised.  Transformers are one of those things where you do appear to get exactly what you pay for.  I'll take a cheap active transformerless DI over something with a mediocre transformer every day of the week.  Strangely, or perhaps not, transformers that sound awful on critical listening are often entirely adequate used sniffing the speaker (obviously with a resistor inline) on the back of an overdriven guitar amplifier....

For those after "more" 13A sockets - MK do a triple with inbuilt fuse.

No use in the UK, but here in down-underland there are (unfused) quad 10A sockets, which is designed to replace a standard double.  I believe it's rated at 10A overall, which given it will probably be on a radial circuit, 2.5mm with a 20A breaker, could lead to interesting happenings.....

We also have four ways with ten sockets (with inbuilt 10A breaker), which are useful in many circumstances, theatrical and otherwise.

40 minutes ago, sunray said:

 

...should we make an assumption it defaults to DMX1? or is it a programming line which sets the address once and it's saved in the fitting?

I would guess absolutely that the thing will ordinarily be receiving DMX; the PI/PO is only needed if one wants to change the address of the thing. 

The pictures I found show PI/PO daisy-chaining, as I noted above, however, I didn't find anything (or, at least, anything I could understand!) about what to do with the first PI line when one doesn't want to fool with the programming.  I'd assume (yeah, we all know) that it can simply be left unconnected and insulated, as if it required to be pulled down or something it would be both damned inconvenient to the wirer-upper, and also prone to causing customer complaints when the pulldown wasn't connected.

Although this PI/PO thing is an interesting diversion, not to mention some education, I'd venture that it's not involved in the problem.

Other things that occur - the DMX line should be terminated; if adding termination causes problems, then the problem is not the termination, it's something else that is broken, and the presence or absence of the terminator is just exposing that problem.  Also, given that the PI/PO lines are directional (ie PI is in, and PO is out) I wonder if there is some directionality in the DMX flow too, implying DMX buffering per box, which would be, in a cheap Chinese box, highly unlikely, I grant you, but inbuilt buffering is not unheard of.

I'm still in the camp of corrupt signalling; is the CASbox adjacent to the chock blocks, or far, far away? I note the CASbox requires a class II power supply, so an ungrounded power supply. 

TimSabre earlier suggested getting a multimeter out, and checking resistances and voltages.  I support that suggestion.

No, no, no, no - that box is far more upmarket.  And either really awful, or incredible value for money.

Quote

All inputs and outputs are fully isolated from each other via a transformer.

A quality transformer would cost far more than they are selling the complete assembly for!  Which is why I'm suspicious of how good a transformer that costs next to nothing will sound.

Have a look here:  https://www.ranecommercial.com/kb_article.php?article=2106

You'll need to scroll down!

OK, it seems the PI/PO lines are used to set the DMX address, with the intention that one device's PO is connected to the next device's PI in a daisy chain.  A Google or Ali search for DMX address writer will bring up the devices used to do the programming.  It seems that a bunch of ICs used in LED fixtures and controllers use one of a number of ICs, with Chinese data sheets(!), which allow address programming. 

Until about a minute ago, I was totally unaware of this whole PI/PO thing.

On the wider issue; I'm not fond of the DMX ground being the same as the mains ground, I'd rather the DMX ground was floating, but on a short run with no electrical problems disturbing the ground reference, there shouldn't be any real impact on DMX ground.

Well done!

I've retired last year, and honestly, I have no idea how I found time to work.

And by "everywhere", that has included New Zealand for a while now.  We like to whine about it, cos, well, we're kiwis, but it does actually deliver the goods, and in a country that is prone to things happening, it's quite handy.

Here's a recent message:

The outcome was not good, the third major bout of flooding in a short time.

Different fogger.  I guess this one has some minor difference in hardware or firmware on the interface.

I’m one of those slackers that doesn’t terminate DMX runs, basically because we have opto-splitters all over the place, so having more than a handful of things on a line is unusual.  Trouble rarely occurs in such a system.

Until  it did, just last week.  A fogger lost its mind, and blasted the (small) stage, filling the auditorium, stopped only by a quick-thinking person hitting the machine power switch.  For a while I couldn’t see the stage.

Common  things occur commonly, so I assumed it was a show programming error.   But no, the following performance, instead of the machine doing a 5% slow fog, it went straight to flat out.  Fortunately, the innocent bystander was ready for the shenanigans, and hit the power switch.

After concluding there was no programm8ng fail, I humbled up to thinking “Do I need a terminator?”  Machine has been flawless since terminator added.

Arecibo was one of very few Radar Astronomy sites - with a 1MW radio transmit power

As far as I know, one of only two, and it had several transmit capabilities, including 2MW CW 100% duty cycle at (and now I'm going from rusty memory) 2148MHz, with a 34dB of gain from the antenna, if someone wants to work out what the EIRP of that is heading out to the sky, which is why it could bounce off Saturn :)

Do you mean a lighting control program with a real Windows user interface, as in designed in Windows and uses Windows GUI things?

Along with Gerry, I'm still using PCStage, but the only other product I know of that is from the ground up designed for Windows is Showmagic.