HELP !! Heated Bed connected directly to Ultimaker PCB

[flyguy 0]

Help !

This is my 2nd attempt to get this working. I used a switch before to turn on and off my heated bed. But I needed a 2nd micro controller to monitor to the temp and turn the switch on and off.

Right now I currently have it wired according to the 2nd power supply topic on the page

http://wiki.ultimaker.com/Heated_Bed#Heating_circuit

"Secondary DC supply, e.g. 12V for reprap pcbs:

The ground of this supply should be connected to the ground of the Ultimaker supply. Than one power connection of the PCB goes to the +12V of the secondary supply, while the other goes to the pin2 of the HotBed connector of the Ultimaker PCB. Its a lowside n-channel Mosfet circuit, thats why this should work. (I have not tried this personally, please be careful). Then the Ultimaker PCB should be able to control the bed."

2nd Power supply.

19v + -------------------- Heated Bed ---------------- Pin2 Hot_Bed

GND ---------- Ultimaker PCB ground (Power jack)

This does not work..... any idea's why ?

My ultimaker PCB is version 1.5.6

[Daid 306]

Have you hooked up the GND of the 2nd supply to the GND of the Ultimaker?

[flyguy 0]

Yes, It soldered directly to the power input of the 1st power supply.

This is a link to the picture of how its wired up.

https://plus.google.com/photos/10429557 ... 3516558898

 

The Terminal block is the 2nd power supply. The black color side is GND and the blue (un colored) side is +19v

The White and Black wire are what is run to the headed board.

The Grey wire, is where the 2nd Power supply GND is connected to the 1 st Power supply's GND.

I made the heated board at home, its has not extra components on it. meaning its just a long copper trace. I wonder if I need to add a resistor or LED or something to give the circuit polarity.

[flyguy 0]

HOT_BED Transisotor

Here are the voltage reading from the transistor to GND.

0v +19v 0v

Pin1 Pin2 Pin3

Seems like the transistor is not on....

[flyguy 0]

With more testing, I validated that #define HEATER_BED_PIN 4 was set in the Marlin pin define code.

I jumpped a +5v line for the Arduino to Pin3 of the transistor, and the Transistors light came one.

This leads me to believe that the Arduino pin 4 is dead. I'm currently in the process of switching the bed to run from heater 2

[ianeagland 0]

Hi

Did you get this to work with circuit as per your post?

I am just about to add a heated bed with a second power supply.