Reverse Engineering Strobe Tubes

[kolbep]

Good day all.
I am busy trying to reverse-engineer a set of strobe tubes, so that I can build a controller for them (The original controller has run away).
Anyway, the strobes are long transparent plastic tubes, with 4 Xenon? U Shaped strobe tubes. These plastic tubes are connected together, and then they all flash in series (so if there are 5 tubes, you will get 20 strobe flashes, 1 after the other).

From what I can see, the controller just needs to pulse it's output on and off for each time a tube must flash. I hooked up a 555 circuit on a breadboard, and got the 1 tube to flash each tube in turn, but then it did not repeat the sequence (no matter what frequency, or how many pulses), hence my wanting to reverse engineer the circuit.

I am hoping that I have not gone totally awry with my reverse engineering, so I was wondering if anybody can just take a peek at the Xenon part of the circuit, to see if I am so far on the right track. If I am, then I can go on to the control circuit.

Thanks
Peter

[Andy Watson]

There should be a connection to the other side of the pulse transformer - I assume that's just a drawing typo.

The drive needs to be a positive going pulse with more time off (low) time than on. I think this is contrary to the output of a 555, which is predominately high. The off-time allows it to charge - ready for the next pulse.

[David_AVD]

The trigger transformers often (usually ?) have a common pri-sec connection.

I've got some of those tubes lurking around here at work.  Can't recall if I have a controller though.

[kolbep]

Thanks for that. I am away from my bench at the moment, so I could not bother to figure out the common on the xenon transformer.
But anyway, there is quite a bit to the system.
The Controller sends a signal to the first strobepipes mother-board, which fires the 4 strobe tubes in sequence, then the signal carries over to the next strobepipes mother-board, which fires its 4 strobe tubes, etc.

Here is how I think the mother-board on the tubes is done (It is 00:30 in the morning here, so I could have made mistakes with my reverse engineering.)
I don't know why they would use the 4093 (nand schmidt gates). but maybe once I get some sleep, then I will be able to figure out how to control it.

[kolbep]

  edited my post. Meant 4093 not 4030.

Looks like first 2 gates are used as clean schmidt buffer,

Then when the 4017 has done its thing, it holds at the 5th output, inhibiting its clock in, then the 2nd set of nand gates act like an oscillator, and r3set the 4017 periodically.

Am I right In my thinking.

btw I know there are errors in my drawing,  I missed how the chips get their supply, as well as a link I think must be between 5 and 6 of the 4093

[kolbep]

Oh, I have split off the Input section to the Schmidt Nand gate.
From looking at this circuit, what voltage, and type of input is needed.
I am sending a 12v Pulse of equal mark/space ratio from a 555 (I have also tried from a 555 through an opto)
When I first power on the pipe, I intermittently get flashes in sequence, but then it is like it locks out.
If I  jumper over one of the resistors (I think R8, but more likely R9), then i get more regular flashes?
Perhaps I am not giving the right waveform.
I also cannot understand the 2 x 5W resistors, as well as the diode and cap are doing (although I think they may have been retrofitted after the existing resistor went o/c.)

Thanks
Peter

[kolbep]

I have spent some time re-reverse engineering the strobe system (This time I put it on Circuit Wizard, so that I can try simulate before I build a controller).
Here are shots of the Main Board (that is in each Pipe), and a shot of the pipe, and the insides (taken out), and the schematic and Circuitwizard file, for anybody that cares to make suggestions :

Thanks
Peter

[David_AVD]

Shoot me a PM so I remember to check if we have a controller at work.  I'm assuming you don't have a controller at all ?

[David_AVD]

Just checked and we only have some of the tube assemblies.  No controller unfortunately.

I do have a vague recollection that there was some sort of terminator that plugged into the last tube.  It allowed the effect to bounce back.

I don't remember if it was required to make it chase in just one direction (from controller end).