Computer Dimmer (Voltage Controller) (Arduino+Processing)

Hi:
This is a computer dimmer built with Arduino UNO and Processing 1.5.1. The voltage applied to the Lamps is varied from 0-10V using PWM Arduino outputs 3,9,10,11. and analogWrite(). In reality it is a voltage controller that can be use to drive many other different loads. The voltage readings indicated in the Galvanometers on the screen, represent the voltage settings and they are not measuring the actual voltage applied to the Lamps, which is very different from that. The Multimeter in the image, is connected to the Lamp driven by Dim 1 only. It is measuring the voltage applied to that Lamp as example. The other Lamps voltages are not being measured.
Thanks,