bigclive

Looking closer at the picture, it does offer phantom power. So that would definitely need a battery or power supply. I wonder how much circuitry is in these devices.

If that doesn't have a power supply or battery, then I'd be suspicious that it's just a potentiometer, capacitor and a resistor across the phone's mic contacts.

I've been pondering that. Using a battery to power the mic and a simple RC network to attenuate the boom. That could have the advantage of setting the mic output level too, and could be small enough to fit in a tiny travel-friendly box.

You can apply a line signal to a phone's jack by giving it a resistor to make it think a mic is there and then coupling onto the input line with a capacitor. I've been doodling circuitry that would give the needed bias voltage (a battery) and then use a minimalist high pass filter to cheat something basic. I kinda felt that doing it properly with a small equaliser could be advantageous. Especially if it allowed a volume boost or cut to random microphones. For my non-live videos I just run my videos through an app to adjust the audio for upload. But it's not so easy when streaming live. The Shark was indeed the one I was thinking about. I see it's out of stock at the moment. The rack version could have worked, but not so great for travelling with work. (Not that that's an issue right now!) Have you guys found the Shark to be useful/reliable?

In this instance the double sided PCB is the thinnest and there will be little if any cost difference. The postage will probably cost more than the PCBs. Before you proceed it's worth mentioning what is going on the PCBs. You mentioned LEDs and also photo resistors. If it's sensors then the PCB can be used as is, but if using LEDs there will either need to be resistors at your control circuit or on the PCB to limit current through them. If the PCB is good to go as it is then you can download the file at the link below. It's a zip file and should be kept complete as it is. http://www.bigclive.com/slimldr.zip To use it, go to this website:- https://cart.jlcpcb.com/quote Click "Add your Gerber file" and then select the entire zipped file. The only variable you should need to change is the quantity. Try running that PCB through their quote system. It's cheaper than I expected.

The microphone is a lavalier type designed for directly plugging into a phone. I'm getting very mixed feedback on the audio. Some people love it and some hate it. But then again, that happens every time I change something.

It's rare I have to ask audio questions, since I normally leave that to the sound departments to deal with, but I've managed to get myself in an audio pickle through over-effort. I've been live-streaming on Saturday's during the lockdown, and wasn't aware that the terrible acoustics of the box-like area I stream from were actually serendipitously taming the bass in my voice. Then I had this amazing idea to spray glue all over the walls and fit UK made fire-rated acoustic foam to "improve" the audio. It did. But not in a good way. It stripped all the bouncing treble and let the bass dominate the gain control of the phone I stream from, making my audio too bassy for devices with small speakers. At the moment I've semi fixed the situation by using an external mic mounted just outside the new boom-zone. But I fear I may have to use a small graphic equaliser to nudge the audio into the range of tiny (but well meaning) smartphone speakers. I recall the mixed praise and contempt for one of Behringers fix-it-all toolkit rescue-lego units. Does such a thing still exist and what's it called. Now I want you all to be calm about this. I realise that there's an amazing unit buy Chaux-son-vey Audio that costs £8000 pounds and will raise my sound stage and add subtle sibilance. But I'm streaming from a Moto G7 phone and I'm looking for something cheap, ugly and functional to match the rest of the equipment. It also has to be lampy-proof. For your acoustic pleasure I recorded my disastrous attempt at "improving" my audio with acoustic foam:-

(The reason I've marked it as LDR PCB is because your doodle said photo resistors.)

Something like this? Noting that it's 8/10" (about 20mm) wide to allow for decent solder pads. http://www.bigclive.com/LDR%20PCB.JPG Not sure that image worked, so here's a link:- http://www.bigclive.com/LDR%20PCB.JPG Or if width is an issue then here's a slimmer one with the jumper tracks on the front. It's a double sided PCB which makes servicing a little trickier. http://www.bigclive.com/slim.JPG http://www.bigclive.com/slim.JPG If either are suitable, let me know and I'll send you a zip file that can be dumped into JLCPCB for an instant quote.

How critical is the 75mm spacing between sensors. Is it something that could be rounded to the nearest 10th of an inch like 3"? If you plan on using a connector at the end then the usual pitch is around 2.54mm (1/10") so the width would have to be slightly wider than 15mm. And could the pass through tracks be on the quieter side of the PCB than the tracks going to the LDRs. That would allow thicker tracks and a single sided PCB making service easier.

If this is for a prop and the circuitry is very simple then it's not uncommon just to hand assemble and wire them without a PCB. Can you tell us a bit more about the circuit? Does it have active circuitry or is it just a group of LEDs?

You mentioned this is a school production, which has me a bit uncomfortable about some of the suggestions being made that involve cobbling stuff together with junction boxes. Are you a drama teacher or a pupil? Knowing that and a rough budget will allow more accurate suggestions for what you wish to achieve.

If all the fans run simultaneously when powered up it may be for a single aroma at high output. Aroma machines are so specialist that it seems to be common for them to be adapted to specific purposes by the manufacturers.

Any pictures of the inside? The compact fan units sometimes used wicks or granules for the aroma. The more industrial units tend to use a venturi atomising system.

Ozone exists at low levels in nature of around 0.04 parts per million. You can't really exceed about 0.05PPM At that point it's a potential breathing irritant. There's a lot to be said for plain simple forced air ventilation from outdoors, which could potentially be bringing that natural ozone in where it gets depleted by doing its job of attaching to bacteria, viruses and spores. I've been testing a couple of ozone meters from eBay which claimed a range from 0-10PPM, but their sensitivity in the safe range is useless. The sensors are also prone to degrading over time. Perhaps it's time to revisit Chizhevsky chandeliers. A Russian chandelier for public areas that didn't light up, but was covered in fine needle points energised by a high voltage DC power supply so it ionised the air. It would have precipitated dust out fast and produced low level ozone in the process.

The trick there is to make a special anti-viral auto-plug for the cheap machine. Basically a plastic 3-pin XLR with a link in it to make the machine run continuously so it can be put at the end of an extension lead and left to empty its tank into a room while nobody is in it.

The hotels use ozone machines to de-stink rooms that have been smoked in. With the current pandemic there are lots of units on eBay, many of which do put out significant levels of ozone, but are made to terrible safety standards and will often emit hideous RF noise due to simplistic high voltage circuitry that has a strong nod towards retro violet ray power supplies. I just got a complete Fog-It valeting kit so I could determine if they were sending out the cheapest disco fogger they could find after slapping a sticker on it. It is indeed the cheapest fogger with a sticker on it. The internal thermostat is the stock 240C one with a 130C thermal fuse on the block case. This unit is kinda double insulated if you overlook the screws on the base which on mine are literally a whisker away from being live due to the vicinity of the heater connections to the block housing. It also has the classic mains referenced 3-pin XLR and the absolute smallest solenoid pump I've even seen in a smoke machine, with a matching tiny capillary fluid tube that will probably not last that long before it blocks. Particularly with the aromas and colours in the valeting fog liquids.

I'll translate their hype for you. The purification plate is an ozone generator plate. It sounds like the type with stainless steel mesh on either side of glass or ceramic. The "PCO cell" is probably a UVC light photocatalytically activating a layer of titanium dioxide to create "hydroxyl radicals". That's a controversial area. The ioniser is a simple needle point ioniser that will help with precipitation of dust and bacteria electrostatically. It does look like they're keeping the ambient ozone level quite low when the unit is in occupied room mode. The higher ozone output in unoccupied area mode will definitely have a useful effect. A local catering company was touting a unit that is basically a fan with an ozone generating UVC U-tube. The units were sized to the area with bigger tubes in larger areas. They had colour coded tubes supplied with a "backup battery" that is used to monitor tube life by discharging the battery at a fixed current when the tube is being used, until the voltage reaches the "replace tube" level.

The FDA has this to say about Chlorine dioxide:- "Chlorine dioxide products have not been shown to be safe and effective for any use, including COVID-19, but these products continue to be sold as a remedy for treating autism, cancer, HIV/AIDS, hepatitis and flu, among other conditions, despite their harmful effects." The food industry uses low level ozone generators for large area hygiene improvement. Ozone is safe at natural levels in the region of 0.04 parts per million, but at around 0.1 PPM when you can start smelling it, it becomes an irritant. There are. But they tend to be very cryptic, with the Antari one being the worst until I found an "updated" one in a different country where they do actually make them declare everything instead of defeating the whole point of the MSDS system by stating "secret proprietary formula". They often hide the ingredients behind trade names and vague chemical groups. Yes, yes, of course it is, it's a fog machine. No. It's not just ANY old fog machine. It has a sticker on the side that says BIO CLEANSE hygiene-o-fogger. Just because it looks like a cheap eBay £20 (including P&P) smoke machine of dubious electrical standards, with a sticker on the side doesn't mean it IS a £20 (including P&P) smoke machine.

While researching some of the disinfecting foggers used in cars and also implied for use in buildings, I spotted a shady trend going on. People are selling highly marked-up cheap disco fog machines that come with a 1 litre bottle of fog fluid, along with a 5l bottle of disinfectant with the instructions to mix them in a ratio of 50/50, or with some it's 100ml fog fluid per 250ml disinfectant. I bought a unit from eBay specifically aimed at sanitising and internally it's just a standard smoke machine core with a timer and option to run the pump while cold to purge through cleaner. It has a very small 100ml bottle designed to hold enough sanitiser for a 5 minute fogging. The core temperature thermostat is 260C. (Which was higher than I expected.) I see that Antari have also got into the business with what looks like fairly standard units at a pandemic price (do they operate at a different temperature?) and a very secretive fluid at an eyebrow raising price of $99 for 500ml. Many of these fluids seem to be using benzalkonium chloride based disinfectant at a very low dilution (possibly as low as 0.01%) Some may be using thymol or variants (a natural plant biocide) I can't help feeling that these are largely a drama thing. Although the aforementioned agents are very potent at killing everything from bacteria to mould. I'm not going to suggest making your own sanitizing fog fluid, as that carries high liability. But I would suggest that if anyone does use these in your venue, that you avoid hanging about in the fog and give it plenty of time to clear. Neither of the suspected biocidal ingredients are good to breathe a lot of, even at the low concentration. I just dug deep and the antari thing seems to be connected with a taiwanese company called airguard with the main active ingredient of Isopropyl Methylphenol (thymol). They have rebadged some Antari units. It would be interesting to see if the heater core temperature is different.

Possibly this:- 3M overlaminate tape

How did he test the hardwired sockets to determine that there was power going to them? If there was power going to them then when a light was plugged in it should work. Cheers Gerry It's worth mentioning that many "facilities" companies give their caretakers a box-ticking electrical presentation to allow them to change lamps and possibly replace things like switches or sockets. You may need a real electrician to find this issue. Preferably one familiar with theatre equipment who does real electrical work for a living as opposed to a disk jockey.

Also bear in mind that the long term availability of lamps for these is in doubt, due to decisions made by people who don't actually use lamps in a professional environment and think that LEDs are the way ahead in every way.

The level of ozone in the air for a germicidal effect is a tiny fraction of the level required for odour removal. Literally at a level you can't even smell it. It's used in some food processing plants to reduce the risk of airborne contamination and to increase shelf life. For the "everything causes cancer" brigade, ozone is a naturally occurring component of outdoor air at an ambient level of around 0.04ppm and can be detected by nose at around 0.1ppm, which is the point it's considered to be at an undesirable level. But even if you did try to introduce measures like controlled ozonation, glycol dispersion, spacing or masks - you'd still be doing a large scale experiment in cross infection between large groups of people.

The theatre industry has been using the ultimate UVC lamp for decades. The 400W UVA one with the dark Wood's glass envelope. It's interesting to note that the 400W blacklight lamps are very inefficient compared to the phosphor coated fluorescent tube version, as they merely filter out the weak UVA peak and the strong UVC peak that normally gets converted to UVA by the phosphor gets blacked out. The point the 400W lamps become the ultimate germicidal lamp is when the outer glass gets broken, revealing the quartz tube inside. I have a very odd mercury lamp here from a very old cinema. It has the bare quartz tube inside a clear glass sleeve. I'm not sure what its original purpose was. I've not powered it, so it may be a UVC auditorium sterilisation lamp or just an early UV lamp with strong blue output.