Connecting and configuring up external MOSFET for heated Bed

Controllers Smoothie
1

I need help with connecting higher power needed heated bed then what the smoothieboard can provide.
I purchased on ebay “Heated Bed Power Module High Current 210A MOSFET upgrade RAMPS 1.4 3D Printer”. Connecting and configuring up external MOSFET for heated Bed.
But I have no clue how to connect it to the board and have it working??? I read about hooking up a SSR so I thought that should be same similar? But that did not work. I hope someone can help me of how to hook it up and changing configuration to make them work

thanks

Imported from wikidot

2

hey !

connecting it like a SSR should work, it is the exact same control method.
maybe it’s a problem with the mosfet board itself ?

cheers.

3

I do not think that it is MOSFET, If you are saying that it is the same way as hooking up SSR. Then maybe config incorrectly?
Here is some of the setting
temperature_control.bed.enable true #
temperature_control.bed.thermistor_pin 0.24 #
temperature_control.bed.heater_pin 2.5 #
temperature_control.bed.thermistor Honeywell100K # see
#temperature_control.bed.beta 3974 # or set the beta value

temperature_control.bed.set_m_code 140 #
temperature_control.bed.set_and_wait_m_code 190 #
temperature_control.bed.designator B #

#temperature_control.bed.bang_bang false # set to true to use bang bang control rather than PID
#temperature_control.bed.hysteresis 2.0 # set to the temperature in degrees C to use as hysteresis
# when using bang bang

## Switch module for fan control
switch.fan.enable true #
switch.fan.input_on_command M106 #
switch.fan.input_off_command M107 #
switch.fan.output_pin 2.6 #
switch.fan.output_type pwm # pwm output settable with S parameter in the input_on_comand
#switch.fan.max_pwm 255 # set max pwm for the pin default is 255

switch.misc.enable true #
switch.misc.input_on_command M42 #
switch.misc.input_off_command M43 #
switch.misc.output_pin 1.3 #
switch.misc.output_type digital # just an on or off pin

Thanks for the help

4

The MOSFET Board i have has two input modes, the ramps style D8 & Gnd and also an input directly from a Heatbed output (Negative & Positive), the second one works perfectly for me directly from the Heatbed output.

5

Is there anyone that is using the external\ MOSFET to power there heated bed? Can you share your configuration so I can see how it was setup, as that is something that I am not really familiar with.

Thanks

6

I am using a 120 volt heated bed. I did not change anything in my setup. I simply took the 12 volt leads from the mosfet that had powered my 12 volt bed and connected them to the input of my SSR. I hooked the 120 volts to the output side of the SSR and it works fine. You can PID tune and also the led for the mofset lets you see how it is working.