Velleman K8200 powersupply
When I was working with a Velleman K8200 3D-printer I had a little accident with the original Velleman controller board. This Velleman controller boards are pretty expansive to buy.
After this I was forced to use a cheaper version of a Ramps 1.4 and an Arduino Mega 2560 board. With this setup and using the original Velleman power adapter I blew up my Arduino Mega board!!! The power adapter of the Velleman is like a laptop power supply which has a 15V/6.5A DC output. How...! According the specs of an Arduino Mega board the maximum input voltage Vin=20V.
Input Voltage (recommended) 7-12V
Input Voltage (limit) 6-20V
I took a photo of this, AAAARGH!, velleman power supply.
After this painfull moment I wanted to modify my Ramps board. There is already an onboard regulator at the Mega board so to get enough input voltage at this Vin-pin I used in this case a LM7809. The input pin, Vin, at the picture below on the LM7809 is NOT the input pin directly on the Arduino Mega board.
A wire soldered to the GND-pin at the back of the voltage regulator LM7809.
The diode desoldered from the top and resoldered to the bottom of the ramps board.
The output pin of the voltage regulator is soldered to the board where as the kathode of the diode has been.
The input pin of the voltage regulator is soldered on the diode's kathode.
Here you see the voltage regulator which is
sandwiched between the Ramps and Arduino boards.
A wire soldered to the GND-pin at the back of the voltage regulator LM7809.
I took some several pictures of this sandwiched regulator. You can clearly see that this voltage regulator fits nicely between this two boards. Now you can power up your 3d-printer and use it for voltages up to 30V MAX!!! So now you can use the heatbed at 24 Volts, if you prefer to use this configuration.
