imageoven Posted October 23, 2007 Share Posted October 23, 2007 Hi all, I have a problem with a 1500w strobe I'm hoping someone can help me with. The unit is from a fairground ride and is in a cast metal waterproof housing like that of a standard domestic 500w floodlight (scaled up). There is a name "EMCO" on the side but I'm not convinced that that doesn't just refer to the manufacturer of the casing rather than the strobe components. An Internet seach did not produce any strobe producers using this name. The unit came to me with a (physicaly) broken strobe tube. The cable connections at one end were also disconnected, having apparently pulled out of a ceramic screw connector block at the rear of the reflector. This was at the end of the tube with two wires, one being the insulated cable and the other the uninsulated wire which encircles the tube. Having nothing else to go on, when fitting a new tube I connected the two wires to the ceramic block guided by the fact that the cables passed through the reflector through seperate holes and these each lined up with one of the blocks terminals. As the origional tubes wires were still through these holes when I received it, I felt fairly confident I was connecting them up the correct way. The amount the two screws were tightened in the connector block also seemed to relate to the diameter of the wire which I was presuming to have come from each. Powering up the unit, caused a component, located on its own board imediatly previous to the connector block, to burn out. This component is approx. 10mm high and 10mm diameter with three legs, one of which is connected directly to the main capacitors and one of the tube connectors (which I connected to the insulated cable), One of which connects to the other tube cable (which I connected to the uninsulated cable) and the third which connects back to the control pcb. My question then is, A/ can anyone tell if I connected the tube cables the wrong way around, thus causing the components break down. B/ What is the correct term for this component so that I can try and source a replacement (the only remaining legend on the component is the number 15) Thank you for taking your time to read this, I hope its not too confusingly written. Link to comment Share on other sites More sharing options...
david.elsbury Posted October 23, 2007 Share Posted October 23, 2007 As always, if you are able to give us some photos to work with, someone may recognise the unit and be able to help. Link to comment Share on other sites More sharing options...
Dmills Posted October 23, 2007 Share Posted October 23, 2007 Guessing it is a pulse transformer, but most strobe tubes have 3 terminals (two carry the arc current, and a third connects to the transformer secondary to supply the voltage pulse to strike the lamp). Connecting the arc current to the pulse transformer will normally destroy it. I have (seldom) seen series mode ignition used, but that is mostly seen in specialist applications (pulsed lasers and the like). HTH. Regards, Dan. Link to comment Share on other sites More sharing options...
imageoven Posted October 23, 2007 Author Share Posted October 23, 2007 To be clear: the other end of the tube has the third connection (also insulated cable) which connects to the other side of the large capacitor. I have not altered any connections except for possibly connecting two of the tubes cables in reverse. Link to comment Share on other sites More sharing options...
Dmills Posted October 23, 2007 Share Posted October 23, 2007 Ok, I don't know this unit, but what normally happens is this: Wire from one end of tube (connected to the electrode) to one side of the capacitor,Wire from other end of tube (connected to the other electrode) to other side of the capacitor. (Reversing the above two may simply make the operation less then satisfactory as the tube ages).Third wire from fine wire wound around outside of tube, to the pulse transformer secondary (this is the critical one), if you swap this with one of the above wires, nothing works, and if you swap it with the other one, the full arc current flows via the pulse transformer secondary and cooks it (which is what I suspect happened). In fact, I bet one of the arc cables goes via the pulse transformer board on its way back to the cap, and this will be the one that must not be swapped for the pulse transformer output (which from the sound of it is what you did). Be careful in there, everything is live chassis, and that cap will reach over 300V in normal operation. Regards, Dan. Link to comment Share on other sites More sharing options...
musht Posted October 23, 2007 Share Posted October 23, 2007 As Dan said pulse also called trigger transformer. Link to comment Share on other sites More sharing options...
imageoven Posted October 23, 2007 Author Share Posted October 23, 2007 quote "Wire from one end of tube (connected to the electrode) to one side of the capacitor Wire from other end of tube (connected to the other electrode) to other side of the capacitor. " This is as it was when the fault occoured. one of these is also directly connected to the incoming Live supply. The third fine wire was connected only to the pulse transformer. If I had connected the wires the other way around the fine wire wound around the outside of the tube would have been directly connected to the capacitor and live. I may be confused, but from what you are saying I think it was wired the correct way. Anyway thank you all for prompt and useful responses.Other avenues of reseach have revealed that the unit was a prototype built by remco (missing stick on "r"!) who build effects specificaly for the fairground trade. They don't make it any more and cannot supply spares for it, so if anyone knows of a source of pulse transformers I would appreciate it. Thanks again. Link to comment Share on other sites More sharing options...
musht Posted October 23, 2007 Share Posted October 23, 2007 Maplin used to do trigger trafos but not sure if enough grunt to fire long tubes. http://www.maplin.co.uk/Module.aspx?Module...%20Transformers Clive Mitchell, http://www.bigclive.com might be able to help, he builds fairground controllers and strobes under the Emanator banner. Link to comment Share on other sites More sharing options...
KevinE Posted October 23, 2007 Share Posted October 23, 2007 If the tube is an XOP15 (Philips etc) then a standard encapsulated trigger transformer from any cap discharge strobe ought to do, try ringing someone like Anytronics and asking for a Deathstar trig transfomer. Bear in mind your little explosion may have damaged other components in the crossfire. Link to comment Share on other sites More sharing options...
bigclive Posted March 21, 2008 Share Posted March 21, 2008 Maplin used to do trigger trafos but not sure if enough grunt to fire long tubes. http://www.maplin.co.uk/Module.aspx?Module...%20Transformers Clive Mitchell, www.bigclive.com might be able to help, he builds fairground controllers and strobes under the Emanator banner. Waaaay too late to find this thread, but the strobe name might be missing a letter. One of the larger UK suppliers of fairground equipment including strobes is Remco. It was most likely the trigger transformer that had been smoked in this unit. If the trigger and DC connections at one end of the tube are swapped the full tube current tries to go through the transformer and it emits a puff of smoke and turns into a blob of wax. A good quality 4kV trigger transformer can be used as a replacement, but be aware that pin arrangements vary between different types. Maplins trigger transformers are just utter ######. No surprise there then. The capacitor inside doesn't charge up to 300V. It charges up to 600V via a single stage multiplier. Fortunately it is a fairly low value since it just helps initiate the strike and the tube then rides forcibly across the mains! Link to comment Share on other sites More sharing options...
imageoven Posted March 24, 2008 Author Share Posted March 24, 2008 Both above are correct, Remco helped me out. The unit was actually a very early model/prototype. A Maplins trigger transformer is doing the job so far... Link to comment Share on other sites More sharing options...
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