Re: Thermistor in ATC spindle
Originally Posted by
joztheshark
Hello everyone,
I just got a Chinese ATC spindle that comes with a PTC 140 Thermistor and it has two cables coming out of the spindle that are about 24AWG. I contacted the manufacturer and they said the signal is either open or closed depending on if it's safe or not to operate the spindle (I tested it with a multimeter and its normally open). My question is how do I go about connecting this to either a Richauto controller or a relay connected to an alarm/warning light? the Richauto controller has an input for an alarm, it sends a 24v signal and when the signal is returned via the ground terminal the alarm gets triggered. The Richauto manual says it's for the alarm output on servo motors ( I don't have servos). Does anyone know if it's safe to send a 24v signal coming out of the rich auto or a power supply from a relay to a thermistor? Am I getting this totally wrong? has anyone done something similar with these Chinese ATC spindles?
BTW the manufacturer said the thermistor output gets triggered at 180C/356F witch is pretty hot!! they said it's because it's internal and "the internal insulation of this spindle will be destroyed at a high temperature above 180C ,but in theory and practice, the spindle's internal temperature will not reach such a high temperature". I still think thats pretty hot!.
Thank you and I really appreciate any help.
Strange comment from the manuf, "The thermal switch is either on or off" , thermistors change resistance with temperature, and are usually around 1.5k.( PTC = Positive Temperature Coefficient)
Thermal SWITCHES are either on or off.
If in fact it is a thermistor, then you would need a circuit based around a schmitt trigger device or IC etc.
Are you in fact sure it is not a thermal switch?
CNC, Mechatronics Integration and Custom Machine Design
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