Edited 26 Feb 2018 14:59, 4 years ago, edited by KRviator

So anyways, I figured I might as well actually get a couple of photos of said staff instrument - that is still in my back shed.

I am just finishing up a few RDO's and with the inclement weather decided to see if I can convince the instrument to give up a few secrets as to just how it is wired so I can extract the replica staff. After trying to see whether or not it is feasible to make akey to open the head, and poking around with a borescope, I turned my attention to the electrickery side. As you can see, there is a loom of 10-core cable that connects the instrument to its' mate at the next station, and presumably a few other tidbits.

After separating out the wires and arbitrarily labelling them 1 through 10, I have found that 1 pair appears electrically connected inside the instrument with zero resistance between the pair, another pair shows an open circuit but zero resistance with the bell key pressed and a third pair shows 67 ohms, that suggests it may be running through a relay coil or similar, so that may be the pair that swings the galvanometer needle - though I haven't had any success doing that myself while using a 15VDC supply yet.

I might have a poke around Jaycar or similar and pick up a few 12V batteries to see if increasing the voltage will bring results. ARTC suggests 50VDC is typically used for signalling purposes.

Edited 26 Feb 2018 14:57, 4 years ago, edited by KRviator

So anyways, I figured I might as well actually get a couple of photos of said staff instrument - that is still in my back shed.

I am just finishing up a few RDO's and with the inclement weather decided to see if I can convince the instrument to give up a few secrets as to just how it is wired so I can extract the replica staff. After trying to see whether or not it is feasible to make akey to open the head, and poking around with a borescope, I turned my attention to the electrickery side. As you can see, there is a loom of 10-core cable that connects the instrument to its' mate at the next station, and presumably a few other tidbits.

After separating out the wires and arbitrarily labelling them 1 through 10, I have found that 1 pair appears electrically connected inside the instrument with zero resistance between the pair, another pair shows an open circuit but zero resistance with the bell key pressed and a third pair shows 67 ohms, that suggests it may be running through a relay coil or similar, so that may be the pair that swings the galvanometer needle - though I haven't had any success doing that myself while using a 15VDC supply yet.

I might have a poke around Jaycar or similar and pick up a few 12V batteries to see if increasing the voltage will bring results. ARTC suggests 50VDC is typically used for signalling purposes.

Edited 26 Feb 2018 14:55, 4 years ago, edited by KRviator

So anyways, I figured I might as well actually get a couple of photos of said staff instrument - that is still in my back shed.

I am just finishing up a few RDO's and with the inclement weather decided to see if I can convince the instrument to give up a few secrets as to just how it is wired so I can extract the replica staff. After trying to see whether or not it is feasible to make akey to open the head, and poking around with a borescope, I turned my attention to the electrickery side. As you can see, there is a loom of 10-core cable that connects the instrument to its' mate at the next station, and presumably a few other tidbits.

After separating out the wires and arbitrarily labelling them 1 through 10, I have found that 1 pair appears electrically connected inside the instrument with zero resistance between the pair, another pair shows an open circuit but zero resistance with the bell key pressed and a third pair shows 67 ohms, that suggests it may be running through a relay coil or similar, so that may be the pair that swings the galvanometer needle - though I haven't had any success doing that myself while using a 15VDC supply yet.

I might have a poke around Jaycar or similar and pick up a few 12V batteries to see if increasing the voltage will bring results. ARTC suggests 50VDC is typically used for signalling purposes.

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