puffernutter
Puffernutter
- Messages
- 1,801
- Location
- Wiltshire
As some of you may know, welding is a hobby for me, the day job is railway signalling. Not controlling trains but for the last 35 years being involved in making sure that any changes to the railway system are done in a safe way, again, not the installation per se, but the safety of electronic systems being used.
My hobby extends to having a number of signals in the garden, controlled by a Raspberry Pi.
One particular signal called a mechanical banner repeater I spent last weekend cabling up. It has been on a post in the garden for the last three years and I finally found the time to connect it up and unfortunately find it didn't work.
Being a 1950s design it works off an electromagnetic mechanism causing a rotational movement to move the banner from horizontal to 45 degrees.
Unfortunately it didn't work and having removed and dismantled the mechanism I have established that the coils are open circuit. There are two coils on each bobbin. One that causes the movement and when it reaches the end of travel these are shorted out and it is held in that position by "holding coils".
It is these main coils that are open circuit.
Sorry for that long pre-amble.
I have removed the insulation and established it is varnished copper wire, but only about 1 thou diameter! The bobbins are also full.
I have tried a few companies but so far, nobody wants to touch anything with that small. diameter. The bobbins are about 2" long and have a depth of about 1". I attach a few pictures.
Can you suggest any companies that may be interested in doing this "one off" job at a reasonable (fair) price? They will need to unwind the existing coils, count the turns and then re-wind them.
I have heard there my be another owner of one of these who wants their coils rewound, so there could be 4 in total! (I know not exactly a production run!)
Cheers
Peter
My hobby extends to having a number of signals in the garden, controlled by a Raspberry Pi.
One particular signal called a mechanical banner repeater I spent last weekend cabling up. It has been on a post in the garden for the last three years and I finally found the time to connect it up and unfortunately find it didn't work.
Being a 1950s design it works off an electromagnetic mechanism causing a rotational movement to move the banner from horizontal to 45 degrees.
Unfortunately it didn't work and having removed and dismantled the mechanism I have established that the coils are open circuit. There are two coils on each bobbin. One that causes the movement and when it reaches the end of travel these are shorted out and it is held in that position by "holding coils".
It is these main coils that are open circuit.
Sorry for that long pre-amble.
I have removed the insulation and established it is varnished copper wire, but only about 1 thou diameter! The bobbins are also full.
I have tried a few companies but so far, nobody wants to touch anything with that small. diameter. The bobbins are about 2" long and have a depth of about 1". I attach a few pictures.
Can you suggest any companies that may be interested in doing this "one off" job at a reasonable (fair) price? They will need to unwind the existing coils, count the turns and then re-wind them.
I have heard there my be another owner of one of these who wants their coils rewound, so there could be 4 in total! (I know not exactly a production run!)
Cheers
Peter