peternewman Posted May 31, 2006 Share Posted May 31, 2006 what a #### and barmy systemAnd now a perfectly normal everyday saying has been editedThe bad word filter is automatic and was setup a while ago with general agreement from most of the members to ensure greater accessibility of the board and so as to remove any issues for those browsing behind content filtering systems. censuring postings for using too many quotes.Again general consensus is people don't want to read the entirety of the previous post again, directly below it, aside from which it reduces the browsing experience of those with small screens or dial-up, and is just a waste of bandwidth. I had one posting completely removed for using a double entendreIf you wish to discuss an individual act of moderation, please either send a PM to the original mod, or to one of the admin team. If you have any further issues, please can you post them in the issues forum. PN Link to comment Share on other sites More sharing options...
Ynot Posted May 31, 2006 Share Posted May 31, 2006 Assuming you have a Strand D54 demux with 25 Way D-type connectors (e.g. Action or F&D units), the simplest solution would be to build your own adaptors (with the help of a technician or teacher who knows about soldering).I'm a little bemused with all the talk of adaptors etc, as the way I see it all you need is a single cable with a D25 at one end plugged to the demux, and bare ends the other to terminate on the STM anaologue inputs. As far as I'm aware, the standard STM racks never had anything other than the line of choc-block type connectors, so unless it has been modified at some stage to a D25 in the fascia, then all you need to know is how the demux pin-outs number and relate to the channels on the rack.Or am I over-simplifying things....? TD Link to comment Share on other sites More sharing options...
paulears Posted May 31, 2006 Share Posted May 31, 2006 Makes perfect sense to me, Tony - that is exactly how our STMs are wired. 25 pin to bare ends, threaded through a grommet to the connector block - is there some problem with this? Link to comment Share on other sites More sharing options...
Brian Posted May 31, 2006 Share Posted May 31, 2006 And for those of you who love making up d-types as much as I do....go to maplin/pc world and buy a fully wired 25-pin parallel port cable and chop one end off. It's sooooooo much easier. Or chop the lead in half and you have 2 leads; or chop two leads in half and you have 3 with a spare. Brianwho just been making breakouts for his demux. Link to comment Share on other sites More sharing options...
Ynot Posted May 31, 2006 Share Posted May 31, 2006 Makes perfect sense to me, Tony - that is exactly how our STMs are wired. 25 pin to bare ends, threaded through a grommet to the connector block - is there some problem with this?:)Absolutely no problem at all.Glad I was right (for once!!):D :D :D Link to comment Share on other sites More sharing options...
ampcats Posted May 31, 2006 Share Posted May 31, 2006 You have 25 pins numbered 1 to 25, why ever not have pins 1 to 24 corespond to Chs. 1 to 24 and use the odd pin 25 for common.It would be so much less fun if they did that!! Thats where I went wrong when I made up leads, I looked at, but did not study the pin out diagram.We've all done it - or something like it in the past - not having a clear photo or a word for word pinout, without the box infront of me, until I corrected myself, I had told Paul to wire it back to front. On an aside, they didn'tcensuring postings for using too many quotes.they censored it ps - to prove strand think schools are scared of lighting and connectors - £319 for the S72 showtec -act-a-likehttp://www.stranduk.co.uk/education/produc...p?product_id=10 67 quid for 25 pin D to bare ends!!http://www.stranduk.co.uk/education/produc...p?product_id=11 Link to comment Share on other sites More sharing options...
Ellis Posted June 5, 2006 Share Posted June 5, 2006 ...snip... I'm a little bemused with all the talk of adaptors etc, as the way I see it all you need is a single cable with a D25 at one end plugged to the demux, and bare ends the other to terminate on the STM anaologue inputs. As far as I'm aware, the standard STM racks never had anything other than the line of choc-block type connectors, so unless it has been modified at some stage to a D25 in the fascia, then all you need to know is how the demux pin-outs number and relate to the channels on the rack.Or am I over-simplifying things....? TD The OP is a student at a school. In general it is not considered a good idea for a school to let students (or for that matter anyone other than a qualified electrician) work inside a cabinet that contains potentially lethal voltages. Making an adaptor for the low-voltage control signals, however is a task that should not be beyond the capabilities of a reasonably intelligent student with te support of a CDT/ICT/Physics lab technician or teacher (nowadays you should be able to find at least oe who knows how to solder in most schools). Such an adapter can be made and tested well away from the equipment and installed without opening up the dimmer cabinets (assuming that the existing D54 demultiplexer is not hard-wired itself). Link to comment Share on other sites More sharing options...
paulears Posted June 5, 2006 Share Posted June 5, 2006 The trouble here is that one end of the cable needs to enter the cabinet via a gland - so they will need to work inside the cab. However, with properly controlled power supply and a competent supervisor the risk is quite manageable. For what it's worth - "a qualified electrican" may be totally out of his/her depth working with analogue control systems - and the internals of a 30-40 year old dimmer rack probably totally alien anyway. I'd suggest that the type of school who would let students work inside a dimmer rack isn't actually that rare - judging by the comments we see on this forum. Not a new thing really - I built a dimmer system in the seventies for a local middle school. Basically a couple of dimmer modules and a few 15A sockets and a box with key switch. It was still being used when I visited last year - scary! Link to comment Share on other sites More sharing options...
Ynot Posted June 5, 2006 Share Posted June 5, 2006 The OP is a student at a school. In general it is not considered a good idea for a school to let students (or for that matter anyone other than a qualified electrician) work inside a cabinet that contains potentially lethal voltages. I'm well aware of that - my comments were conversational, BUT if I recall correctly I've used the words 'qualified sparks' at least once. Link to comment Share on other sites More sharing options...
Paul Roberts Posted June 6, 2006 Author Share Posted June 6, 2006 BUT if I recall correctly I've used the words 'qualified sparks' at least once.Even though staff at my school have never permitted me to look at the internals of the dimmers, I have always been adamant that anything involving potentially lethal amounts of electricity be left up to qualified sparks. Any work I have done at the school is well within my depth regarding knowledge of lighting (which, admittedly, isn't particularly deep :) ). This message was left just to clear up any confusion over whether I had been inside the dimmer racks or messed round with large amounts of electricity Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.