Ren-C and Grinch

[RickeyS]

If I want to add a Ren-C to a Grinch to get dimming, will I need a Ren-C for each Grinch or will a Ren-C do more than one Grinch?

Thanks
Rick

[tfmacz]

One Ren-C - One Grinch

The Ren-C will do "Exactly 64 channels"

[Macrosill]

Do not forget you also need a Ren-T.

[RickeyS]

Will I need a Ren-T for each Grinch and Ren-C or will a Ren-T do more than one?
Thanks
Rick

[ben]

Will I need a Ren-T for each Grinch and Ren-C or will a Ren-T do more than one?
Thanks
Rick

A Ren-T will provide the zero cross signal to the Ren-C. You can use the Ren-T for as many Ren-C's as you need (there probably has a limit but noone has maxed it out :P )

Ben

[Macrosill]

Rick,
That is not an easy a question as it seems. You can run more than one Ren-C off a Ren-T in some instances but not all. How many ports will you be using from the pc? How many channels total? PWM or nonPWM firmware? Distance from the pc to the controllers? Are you looking to power the Ren-C and Grinch from the Ren-T or just looking for the Zero Cross?

This is something that is tough to answer in a post type arena. Come into the chat and it would be easier to help as it would be a real time dialogue.

[wjohn]

If I want to add a Ren-C to a Grinch to get dimming, will I need a Ren-C for each Grinch or will a Ren-C do more than one Grinch?

Thanks
Rick

Hi Rickey,

I designed the RENC PCB and Phil did the code.

THE RENC is powered from the GRINCH (5VDC) and you need one RENC per GRINCH.

The RENC needs serial data (232 or 485) and a source of ZC.

the general guidance for RENT to REN64 is two boards, with the RENC, as it is not powered by the RENT, you can go higher, up to the maximum of the Comms port/ Data rate/ Channel rate you are using..


Number of Channels Refresh Interval
Baud Rate 100 ms 50 ms 25 ms
115200 575 287 143
57600 287 143 71
38400 191 95 47
19200 95 47 23

http://doityourselfchristmas.com/wiki/index.php?title=Renard

Also, the RENC is a PWM dimming, while the REN64/24/16 can be std or PWM code.

John.

[teberle]

John,

If you can excuse my ignorance. What is PWM and what is it used for?

Tony

[P. Short]

Pulse Width Modulation.

In the case of Renard, it describes the waveform coming out of the PIC that is driving the SSR.

Here are some diagrams that show the difference between PWM and non-PWM waveforms.

http://www.doityourselfchristmas.com/wiki/index.php?title=How_Dimming_Works

The output from the PIC is a fixed-width pulse in the non-PWM case, where the brightness of the light depends on where the pulse occurs in the AC cycle (earlier means bright, later means dimmer). The non-PWM scheme relies on the SSRs becoming latched on for the remainder of the AC cycle. The benefit of this scheme is that it uses less DC power to control the SSRs (a benefit when driving the SSRs requires much more current than the microcontrollers and other logic requires). The disadvantage is that some SSRs don't latch at all (such as MOSFET or IGBT-based SSRs), and the low current consumption of LED lights also prevents latching in SSRs that would work fine with heavy loads.

The PWM firmware turns the SSR drive on at some variable point in the AC cycle, and keeps it on for the remainder of the cycle. This allows the use of MOSFET/IGBT-based SSRs, and allows proper operation of Triac/SCR-based SSRs under very light loads.

Hope this wasn't too condensed a description...

--

Phil