PWN or not on my Renard SS8?

[mlif]

Hi,

Thanks to the superb documentation on the wiki, I finished building my first Renard (SS8)! All that is left to do is program the chip. As I understand I just have to download the .asm file and run it through a programmer. I only need to modify the file if I want it to run PWN?

I don't fully understand the implications of either PWN or non-PWN. Which one is better? What are the practical differences? I will be running incandescent light bulbs, probably about 40 or 60 watts each, and I'd like them to be able to dim up from very low to relatively high.

Can anyone guide me here?

Thanks so much

[oldcqr]

PWM (pulse width modulation), not PWN.

IMHO: Since you have an SS, just turn on PWM and forget about it. The only difference (I am way simplifying here - and I know a electronics guru will come behind me and correct it) between PWM and NON PWM is how the PIC tells the Triac to stay ON. In non-pwm, a single pulse is sent twice a cycle, where as in PWM, the signal stays ON until the point where it is supposed to be off - IE, the pulse now has 'width' (width referring to time).

Why the 2 different ways? Non PWM works great for regular lights, and may not work all that well for LEDs (since they don't draw enough current to latch the triac ON). PWM forces the output ON. Setting it now means that if in the future you upgrade to LEDs, you won't be scratching your head why they don't work (or work well!)

Why not just ALWAYS set the PIC for PWM? It does draw more current on the 'logic' side of the board. For SS types it doesn't matter since the logic voltage is supplied on every board by the transformer, and there is plenty there. For non SS type Renards, the logic voltage is supplied externally. When dealing with multiple boards, setting PWM will eat up the available current on the logic side, requiring a larger or multiple power supplies.

[Pwmcguire]

Why not just ALWAYS set the PIC for PWM? It does draw more current on the 'logic' side of the board. For SS types it doesn't matter since the logic voltage is supplied on every board by the transformer, and there is plenty there. For non SS type Renards, the logic voltage is supplied externally. When dealing with multiple boards, setting PWM will eat up the available current on the logic side, requiring a larger or multiple power supplies.

I have a 12 volt 1 amp wall wart driving my zc voltage for 4 ren 16 xmus boards. Is this enough? I only have 8 channels of pmw.