View Full Version : Turn On Thump

01-26-2008, 07:48 PM
I had a 123 channel Darryl Brown style Megatree for my first display in 2007. Controlled by two Ren-64’s with 20070407c nonpwm firmware. Each Ren-64 had its own power supply/ZC signal. All the SSR’s and controllers were powered by a single dedicated 20A circuit. With all channels on, the tree could draw 40A. The idea was that I would only have a maximum of half the lights on at one time. It ran great without a problem except when plugging in the power cord and a couple of power outages due to an ice storm. At power up, with the PC off, the breaker might trip or not trip. I suspect the SSR’s were all turning on for a few milliseconds and it depended when in the AC cycle if the breaker would trip or not. I measured the idle current with an amp probe, and it was less than an amp.

I’m just curious if anyone else had this problem. I have not seen any other posts on the subject.

For 2008, I’ll break down and run out another 20A circuit to help balance the line, but I still refuse to let it draw 40A! :)


P. Short
01-26-2008, 08:49 PM
That particular version of the firmware leaves the triacs turned on for about 1 AC cycle on power up, before it enters regular operation. Later versions of the firmware should correct this.

If you want to play with it a little bit, replace lines 256 and 257 with new code, as follows:

old code

clrf PORTA
clrf PORTC

new code

movlw 0xFF
movwf PORTA
movwf PORTC



01-26-2008, 09:12 PM
Easy fix... Thanks!

P. Short
01-26-2008, 09:14 PM
Problem fixed?



01-26-2008, 09:34 PM
Mean's I won't have to live with it. I'll just have to reflash the Pic's for the next season :)