grinch power consumption

[dynochris1]

i read in a thread somewhere where a set or resistors was installed the chips ran cooler and power consumption dropped. i cant seem to find the thread maybe i left my brain in sleep mode. does the mod have an effect on dimming with a ren-c if it doesnt then approx. how much current will the grinch need.

i have a pc power supply with a regulator and filter setup but i want to keep it in the house with the pc. my concern is will cat5 be able to support the grinch/ren combo without overloading.

my intention is to feed 5vdc and zero cross down a cat5, and another cat5 for ren-c signal. this way my enclosure can remain small by keeping zc and power in the house and it keeps all 120vac current out of the box.

sorry about the long winded just got it up and running and was hopin to do a small display more as a dry run before i begin setting up for x-mas i know time is short but as i said a dry run.

[sjwilson122]

I think this is the thread you are talking about

http://doityourselfchristmas.com/forums/showthread.php?t=5448

[RPM]

Here's a document I wrote about doing this modification.

[daviddth]

I personally found that when driving the SSROZ direct from the Grinch I had no power issues, nor any heating problems as the SSR's limited the current to a low value anyway. Even with all 64 channels on the chips never got more than very slightly warm - just above skin temp.

I have seen people driving other setups that do, for whatever reason, seem to draw a lot more current, so I do think the current limiting is a good idea. I have 1 that is limited to a little under 100mA per channel, and is used to direct drive 10mm LED's (1 in parallel) as "Strobes" on my megatree. Turning on all 64 tends to cause some issue as 6.4A through a Grinch is a little overboard, but thats not the intention - the current was limited to protect the LED;s which have a 40mA continuous and 50mA peak current. There are no current limiting resistors on each output, so the current is limited by the type of chip & it's max current, or is set by the current-limiting resistor.

No mods gave measured currents of 110mA to 300mA depending on the type of chip used in the Grinch, so adding the resistor allowed me to mix & match chips without worrying about shortening the life of the LED's too badly.