Monitoring RAMPS 1.4 driver temperature
Posted by doomstrike
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Monitoring RAMPS 1.4 driver temperature August 27, 2013 02:39PM |
Registered: 10 years ago Posts: 9 |
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Re: Monitoring RAMPS 1.4 driver temperature August 28, 2013 02:09AM |
Registered: 11 years ago Posts: 1,592 |
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Re: Monitoring RAMPS 1.4 driver temperature August 29, 2013 07:01PM |
Registered: 14 years ago Posts: 1,092 |
doomstrike:
If you're referring to the pololu's (or equivalent) driver chips:
1. The driver chips have built in over-temp protection. It's not infallible, but it aims to protect the device in case it gets too hot. For reliable operation, they must always have heatsinks on them, and always be cooled by a fan. To drive the stepper motors that most people use, they need to dissipate a fair bit of heat. Without heatsinks and a fan, there is simply no way to do this.
2. The driver chips are quite small, so any external temp monitoring device will take up a fair bit of room on top of the chips (which are quite small). Putting them on the extremities of the heatsink will not give you a true temp reading at the chip, due to the fact that the heatsink is actively trying to dissipate the heat. Either way, this room/surface area is then not available to dissipate heat, which can reduce the amount of power you can drive with them. Each external temp device would also increase the cost for no real gain.
3. If you detect the drivers are too hot, what do you do? The internal devices already shut down the driver to avoid damage. If you're printing, stopping the printer is pretty much not an option, as this either leaves the print head just in contact with a specific part of the object, which could deform that section, and/or the nozzle will leak plastic while not in use, leading to the possibility of this leaked plastic sticking to some other part of the print.
FWIW: If you suspect a driver is overheating, get a temperature probe (eg: many cheap multimeters come with temp probes now) and check yourself.
Admittedly I think electronics that need cooling should probably put in a 3 pin fan header specifically for cooling and check that the fan is running (since the 3rd pin is a tachometer output). This way, at least you will know if the cooling fan is not working as the electronics should do something to tell you that the fan isn't operational.
If you're referring to the pololu's (or equivalent) driver chips:
1. The driver chips have built in over-temp protection. It's not infallible, but it aims to protect the device in case it gets too hot. For reliable operation, they must always have heatsinks on them, and always be cooled by a fan. To drive the stepper motors that most people use, they need to dissipate a fair bit of heat. Without heatsinks and a fan, there is simply no way to do this.
2. The driver chips are quite small, so any external temp monitoring device will take up a fair bit of room on top of the chips (which are quite small). Putting them on the extremities of the heatsink will not give you a true temp reading at the chip, due to the fact that the heatsink is actively trying to dissipate the heat. Either way, this room/surface area is then not available to dissipate heat, which can reduce the amount of power you can drive with them. Each external temp device would also increase the cost for no real gain.
3. If you detect the drivers are too hot, what do you do? The internal devices already shut down the driver to avoid damage. If you're printing, stopping the printer is pretty much not an option, as this either leaves the print head just in contact with a specific part of the object, which could deform that section, and/or the nozzle will leak plastic while not in use, leading to the possibility of this leaked plastic sticking to some other part of the print.
FWIW: If you suspect a driver is overheating, get a temperature probe (eg: many cheap multimeters come with temp probes now) and check yourself.
Admittedly I think electronics that need cooling should probably put in a 3 pin fan header specifically for cooling and check that the fan is running (since the 3rd pin is a tachometer output). This way, at least you will know if the cooling fan is not working as the electronics should do something to tell you that the fan isn't operational.
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