The inverters have not yet been finalised and there is basically two ways by which they could be controlled:
1. Analogue voltage - with an input pin connected to ground the inverters will be at full power. With the input pin at 5V the inverters will be at minimum power. This method can be quite simply hooked up to a pot to allow manual adjustment and an LDR could also be used to provide some auto dimming. These inverters have an in-board PWM circuit.
2. PWM control – this is when the PWM is performed externally from a simple 555 IC. This gives us the freedom to tune the auto-dimming and also have push button control of the auto/manual mode and manual adjustment of the auto-dimming. Obviously this is our preferred method of control and primarily what this thread is for.
The inverters may have onboard PWM that can also be bypassed which would enable people to choose the complicated control circuit or simple manual adjustment.