Thermo coal cutting machine with nichrome wire

Due to the dangerous voltages involved please provide more information on your application and electrical experience.

Nichrome wire of resistance is tied to satnd and given a variable voltage ranging from zero to 230 volts suply.through a dimmerstat.it will be having one ammeter .

Implementing this is really very, very dangerous. Fatal voltage levels, no isolation, (you do realise that coal can conduct electricity or catch fire under the right conditions don't you).

How about a safety low voltage DC circuit or perhaps a reciprocating table saw with a fine blade and adequate dust extraction facilities (you do realise that in the right dust/air concentrations coal dust will explode don't you).

Dear JOAT - The guest needs the solution to a requirement, not additional problems nor solutions with additinal problems. Sorry to put it that way.

Dear Guest - As JOAT suggested, its dangerous to have wires hanging with that High voltage.

Solution: Use a 5Amps 12 volts tranformer, a bridge rectifier (1 watt diode bridge ) and the RC network - All this for a pure 12Volts DC. Nichrome wire, yes, considering its low co-efficient of expansion, but would suggest to use any snapped up wire from any heater coil ( trial and error gauge ) and suitably spring load or preload the wire, so the tension is retained, inspite of expansion under heat. If all this works, invest in nichrome wire which is for sure expensive.

Solution 2 Have a EM coil to vibrate ( like the one in calling bell ), suitably positioned so that it can accomadate a avery thin wire stretched ( no heat application ). The friction developed would suffice to melt the thermo coal and have an nice edged finish......I guess thats your requirement in deed.

From Mr. Idiot always

Hot wires are normally used to cut low thermal conductivity materials with low melting points such as plastic foam. I would not recommend the technique for cutting higher thermal conductivity materials that will excessively chill the wire and might also combust.

<Thermo coal cutting>

Will you curse somebody if I tell you that the Q has to be respelt correctly as :

"THERMOCOLE"( =expanded polystyrene foam) CUTTING with a hot wire

Suggest you need to join an Anglo-technical club as well :-)

Yes, It is very much possible & it is simple...& easy to fix...safe if you wire it up right...I will revert with more details (photos of our model , circuit etc ) tomorrow...

You may also mail me at : guruprasad.kuppurao@cgl.co.in ( Gmail is off during office hours!)

Best of luck...

Guruprasad.K.Rao , Mumbai INDIA

As you said It is always suggested to use low voltages.

12V is OK or 24V is required.