pmiller056

I'm not familiar with the internal details of these controllers. If the memory battery is soldered onto the PCB, there is a high risk that some of the internal battery fluids have leaked onto the PCB. This fluid is corrosive and will wreck a PCB, quickly eating through copper tracks and vias, Cleanup and restoration is possible, but time consuming if components have to be removed to repair damage. There is a high risk of further related problems in the future, compromising the reliability of the controller.

I don't have a service manual for that specific model. I did find a parts list online, but no further servicing detail. Other information available online suggests that this projector appears to be fairly typical for that age/price point. There will most likely be a coin-cell battery somewhere to remember settings which will have failed after nearly 20 years. The lamps used in similar projectors typically have a design service life of 2000 hours. Given the usage pattern that you've stated, I suspect that by now, the lamp will be due for replacement in the near term.

Given the age and poor accessibility of this projector, what's the remaining lamp life on it? If the lamp is near the end of it useful service life, I'd be inclined to replace the projector entirely. The total cost of replacing the lamp will be significantly more than the value of the projector re-lamped.

Custom extrusion profiles need custom made extrusion dies, which is expensive. Can you use a standard extrusion section (for engineering and fabrication work) from an Aluminium stockholder and get a machine shop to cut the needed slots in the correct places?

I've used the Micronic and CPC headsets noted above with Sennheiser beltpacks for amateur pantos. The headsets don't survive long with heavy handed performers putting them on and taking them off. A failing headset causes crackle and hiss problems. In my experience, attempted repair is unreliable and uneconomic. Lesson learned the hard way - make sure that you always have at least one spare headset available.

As noted in @bruce's link. The DIN connector does not have sequential pin numbering. Do pay attention to the D connector pin numbering and function in the Showtec Demux documentation, and on the D connector you are using - I got caught out by reversing everything L-R. I'd done a really nice and tidy job of it too. Ooops.

@Junior8 - For the benefit of less experienced forum users, what are the design sins and how would you mitigate them when doing a show? As @sunraystates, this is fairly typical of a community hall.

@kerry davies The legailties are similar, but subtly different in the devolved UK nations. One important point to consider is what requirements your fire insurer/underwriter has for system installation, maintenance and risk assessments for continued fire insurance cover. The insurer may have specific requirements related to training, qualification, trade association membership or accreditation of any business/person doing fire safety related work for cover to be effective in permises covered by the policy.

The person concerned is most likely guilty of an offence under Section 8 of the Health and Safety at Work Act 1974. At the very least the person concerned should be held liable for the bill to re-instate and re-certify the system by a qualified technician. And banned from every public building around.

A related query. Any metal lamp casing (unless built as double insulated - which I've not seen) has to be connected to mains/powerline earth/ground via the lamp plug. What is the consensus on connecting DMX pin 1 (cable screen) within a lamp to the metal casing and to earth via the power connector? This may be repeated many times in an installation, earthing the DMX cable screen in many places. I've got some small unbranded oriental DMX controlled lamps. They work ok for the intended use. As supplied, the power inlet earth connection is unconnected because a plastic case is used. I have no idea about the integrity of the primary/secondary insulation of the power supply module used in these lamps, so I have modified them to permanently connect the power inlet earth terminal to the power supply module output 0V terminal. This terminal is also connected to the DMX cable screen. The intention is to provide a local path for fault current if the power supply insulation breaks down and prevent the DMX system becoming live or carry fault current. Is this acceptable practice and within the DMX specification?

@J Pearce Yes, you can do this. In practice you need really good external filtering on both the transmitter and the receiver to prevent the continuously running transmitter from significantly interfering with the receivers. As an example, 430-440MHz full duplex amateur radio repeaters use a 1.6MHz or 7.6MHz split. They nearly always need to use bulky tuned cavity filters or large antenna separation distances to provide acceptable performance. For temporary/emergency use amateur radio does use wider, non-harmonically related splits such as 145/435MHz or 435/1300MHz which usually requires minimal external filtering. The frequencies I've quoted are used in the UK. Use in other countries will be different.

You could use one of the Bluecom beltpacks with simple extra circuitry to provide similar functionality to a TW-47 two-way radio interface. The radio part of the system is NOT full duplex because that can be awkward to do with analogue radios. Any audio on the radio system is fed to the wired system. The wired system call button must be pressed to make the base station radio transmit and send the wired system audio to the radio system. Note that most radio systems have an inherent short delay (around 0.5 to 1 second) to 'wake up' after pushing the transmit button. The transmitter needs to switch to transmit then the receiver 'squelch' circuit operates to pass incoming audio, assuming an FM system, which is most likely in normal use. Read the TW-47 manual and note in the applications section how the relay and the audio transformers (DI box?) are used to interface between wired system and the radio. For experimenting, cheap PMR466 handheld radios can be used, provided there is the means to easily connect an external speaker/mic or similar.

Have a look with your favoutie web searcher for 'Wled' by 'Aircoookie'. I've had good experiences playing around with it. Do remember that an ESP32 is a 3.3V device, so you need to be careful using it in conjunction with 5V devices/systems.

Using screened cable to distribute unbalanced audio over more than a few metres may be unsafe. The earth/ground/screen terminal of each bit of equipment connected will usually be linked to the earth connection of the local power circuit. Inevitably, depending on local conditions, all these different earth connections will be at slightly different potentials. Significant currents at powerline frequency will be forced to flow through the cable screen as it links the earth points of different circuits together, causing hum problems. This can be observed as 'hum bars' on video displays in some old analogue CCTV installations where screened cable is always used. Do bear in mind that under fault conditions, a portion of the fault current will flow through the cable screen to other connected equipment, possibly causing widespread damage. Distribute the audio as balanced line, with an isolation transformer at each tap-off. Connect the centre tap of the sending transformer only to local earth so that the line cannot become live under fault conditions. Alternatively, use a 100V line distribution system with a single suitable audio power amplifier. This will reduce the amount and complexity of remote equipment needed.

Hmmm. In this situation I've always tried to minimise the modifications to the host equipment so that it is easy to restore the original operation if things go wrong. In this case there's the complication of high power live circuitry and isolated low voltage parts that are accessible to the outside world, all in the same enclosure. I'd be inclined to modify the signal circuits in the dimmer pack to take a 0 - 3.3V analogue signal from the ESP32 (It's a 3.3V device). Use the analoge outputs from the ESP32 to control the dimmer pack in the conventional way. The ESP can be put under a plastic box 'lump' on the external metal dimmer case to let the RF in, or a suitable miniature 'rubber duck' antenna added to the case to feed the ESP inside. Just my suggestion......

Check the voltages from the power supply are correct and stay correct during use. I've had a similar fault on a cheap moving head lamp - when the power supply was heavily loaded doing fast moves with all LED elements on at full brightness, it missed steps and then totally lost the plot.... A replacement PSU fixed the problem.

@Stuart91 If the hotel is part of a chain or an independent, look on Companies House for the headquarters address. Phone them and ask to speak to the company director responsible for customer health and safety. In the past, I've found this to be an quick and very effective way of getting similar site problems sorted.

I've never been involved in the flying of performers, but I've often wondered 'How do they do it?'. I've learned a lot about the preferred techniques depending on context by following this discussion. Thank you for taking the time to share your knowledge and wisdom. I'll leave it to the experts...

Try asking in the High Voltage and Tesla Coil maker forums. You may find someone local to you willing to help, demonstrate or lend equipment. Do remember that a Jacobs ladder is effectively a spark-gap transmitter and will generate copious amounts of wideband RF interference. The arc is an ignition source for anything flammable nearby. Ozone and short wavelength (ie hazardous) Ultraviolet light can be produced by the arc too. Time to do a Risk assessment......

Microtherm still exist as a business. www.microtherm.de Farnell stock Microtherm and other brands of thermal switches. These switches are a widely used commodity part with standardised dimensions and ratings. I think '180' would be Farenheit. 180F is about 82C, which looks to be about right for your application. You need to be sure what type you need - Open on temperature rise (most likely) or close on temperature rise. Resetting temperature will be about 20C lower.

Here is a recent relevant news story https://www.bbc.co.uk/news/uk-england-cumbria-59564480 Local MP's are taking an interest in why things stopped working so quickly and took so long to recover, putting people at risk of serious harm. Ofcom appear to be sticking to their policy decisions regardless of the potential consequences. This show is not yet over....

Does the motor have 3 wires coming out of the windings? If so, it will most likely be a capacitor-start single phase induction motor. Can you have a look inside the working one and see what's there?

Yes, it's all very well providing your own UPS to keep *your* equipment alive for as long as you consider reasonable, this is no use if the standby battery in your comms provider's cabinet up the road fails after an hour. As far as comms providers are concerned, standby batteries in street cabinets and exchanges are an unreliable, expensive PITA and they'd really rather not have any in use anywhere at all... Emergency lighting in any public building must be able to (and proven to) operate for at least 3 hours in the event of failure of the public electricity supply, for good established reasons. For the same reasons I feel strongly that the public communications infrastructure (mobile/cellular and fixed) should have the ability to function for the same length of time when power fails - even if it's just VOIP (and not general internet) to essential and emergency services.

The existing houselights system is mostly made of 50W GU10 downlighters and a few older 100/120W E27 R80 downlighters. It is a community theatre, so it probably was minumium cost at the time of installation. Given the height that they are mounted at, the illumination provided has a spread and 'feel' to that people like. There's plenty of choice (ranging from excellent to horrible) for LED replacement GU10's. The R80's are much harder to get and I suspect a sensible move would be to replace them with an appropriate number of GU10's for consistency and rationalising purchasing and spares-holding requirements. If an Artistic Licence dimmer was chosen, it would need to go into a separate enclosure because there is no usable spare space in any relevant consumer unit. Being able to reuse the existing wiring in good condition with the AL dimmer along with good lamp choice data provided is a big reason for favouring it.

The fluorescent worklights have a total installed load of around 250W. 35p/hour doesn't sound much, but this adds up to a lot of money with too many 100's hours of running a year. The suggestions and information above from the community are useful and helpful, so the next time the managment committee are looking for suggestions to reduce operating costs, this is one that can be put to them. As energy and maintenance prices rise and the payback time becomes shorter this and similar upgrades becomes more attractive. Our mostly halogen stage lighting doesn't get used enough over a year to make replacement viable, yet....