I am running 32 color scrollers off of 3 power heads. They are rainbow, forerunner, apollo, and chroma q. I am having data issues to them. I am running out of the light board to a dmx splitter. from that i am running to the forerunner and the rainbow power head. Out of a different port on the splitter i am running to the chroma q power head. My issue is when i power on they keep scrollering like they are resetting. I unplug the power to them and plug power back in and it stops. They power heads are plugged into the same outlet run as many other things in the booth. Can my problem be to much power one one outlet line that the scrollers keep restting?
Data issues
- Thread startersoccer6j
- Start date
We just changed over into our new show. We had 16 color scrollers before and they were working fine(the rainbow and they charma q) now that we added the 4 apollo and the 12 forrunners (all off the new power head) we are having issues with the rainbow and chrama q not setting when powered on and when we unplug and plug power back in they act fine. but randomly will reset during the show. is that an power issue to the power heads or an data issue.
I'd suspect the former. Provided you're using proper cable, terminating, and following all other DMX512 rules, there's little that one PSU can do signal-wise to affect anything else on the chain. I'd try putting the PSUs on different circuits; if that's difficult, flip the power switches on the PSUs at different times (probably even more difficult). When the scrollers reset during the show, is it at the same time the scrolls are moving, or being given a command to move?
You mention that the power supplies are in the booth. Is there a great deal of cable between the power supplies and the scrollers? If so, I'll bet the issue is the voltage drop from the resistance in the cable. At the low voltages and high currents involved, it's a real consideration. That is why the manufacturers go so far as to specify big conductors for the power cables, along with return lines for the Apollos. The solution would be to put the supplies near the scrollers that they feed.
Assuming the power supplies are regulated, I doubt a little voltage sag on the 120 V side is a factor. It still could be, but the scroller cable is a much bigger factor.
You also need to add up the load currents on both power supplies to make sure that they aren't overloaded. When you mix brands like that, you can't just take the book spec that says X sized supply can run X number of units. For example, the Apollos take 1.1 Amps, while the Forerunner takes 0.3 Amps. That's a big difference.
Assuming the power supplies are regulated, I doubt a little voltage sag on the 120 V side is a factor. It still could be, but the scroller cable is a much bigger factor.
You also need to add up the load currents on both power supplies to make sure that they aren't overloaded. When you mix brands like that, you can't just take the book spec that says X sized supply can run X number of units. For example, the Apollos take 1.1 Amps, while the Forerunner takes 0.3 Amps. That's a big difference.
When they reset when no comand is given. When power up they go crazy. Going between 2 colors really fast. I am having the issue with the rainbow freaking out on power up and the chroma q resetting randomly. The rainbow scrollers are on their own power supply. The chorma q are on a chorma power supply. These have been installed for years with no major issues till now.
The Chroma power supply may be getting tired from age. Large power supplies run hot internally. A key component in them are electrolytic capacitors. Electrolytics have a finite lifespan that is dramatically affected by heat, because they chemically dry out. I can't tell you how many times I have had to replace capacitors in power supply sections of all kinds of equipment.
Put a good DC voltmeter across the supply output and measure the voltage. Is it reasonably stable while the units boot? Switch the meter to mV AC and see how much ripple and noise is there. There is no hard and fast rule as to how much ripple is OK, but it certainly shouldn't be more than a fraction of 1 V. Poor voltage regulation or high ripple and noise is a sure sign of a failing power supply.
If you still think it is data related, disconnect all the DMX from the units and see if they boot properly.
Put a good DC voltmeter across the supply output and measure the voltage. Is it reasonably stable while the units boot? Switch the meter to mV AC and see how much ripple and noise is there. There is no hard and fast rule as to how much ripple is OK, but it certainly shouldn't be more than a fraction of 1 V. Poor voltage regulation or high ripple and noise is a sure sign of a failing power supply.
If you still think it is data related, disconnect all the DMX from the units and see if they boot properly.
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