Ears Ears Ears
Ears Ears Ears
Last edited by mrpackethead; 06-22-2012 at 10:58 PM.
I am in middle of running battery test and it is going very well. Past the 300 minute mark into test and all is still working great.
I am running 2 GECE pixels and an SX uProc controller through various fades and flashes all running on 4 AA batteries fed through 5 volt reg (LM2940L). Input side is ~ 6 Vdc output is 5 Vdc. I am monitoring battery levels every 15 minutes or so.
I predict when batteries get to ~4.6 V, the regulated side will drop to 4.4 V and uProc will start resetting itself (Did earlier test at low battery levels to determine cutoff). At current consumption rate it should last over 400 minutes (UPDATED 3pm).
Since headsets will be used sporadically throughout the night, this operating time is vey acceptable. Especially if I keep them on recharge while waiting for next set of guests.
Of course the IR Detector power requirement needs to be added... but I assume it will be in the mA range...so the operating time should be minimally affected. IMHO...
Will keep you posted...
Last edited by lightman; 06-18-2012 at 06:05 PM. Reason: added photo; Updated Prediction time
Just checking in... GECE Battery test still going strong after 300 minutes. Here is chart showing progress from a while back...
Blue data points are the raw battery voltage while the pink data points are the regulated 5 volts.
Note that there is a 0.18V delta between the Raw and regulated voltage with this regulator. As you can see the regulated voltage held up to around 125 minutes into test... then it started to drop. No worries the GECE and SX processor can operate below 5 volts.
Danger point is ~ 4.6 V (Battery voltage) when the SX processor may start resetting when large LED loads are incurred. We will see....
UPDATE 3PM... now past 300 minute mark and going strong!!
Last edited by lightman; 06-18-2012 at 06:07 PM.
I believe the default brownout voltage for the SX microcontrollers is 4.2 Volts.
You could try setting this for 2.4 Volts and get get a few more minutes on your test.
You need a low voltage FET circuit that connect the batteries directly when regulator starts dropping out.
Yep...You are right. I think if I was hurting for more time I would go that route. But probably not worth it for this application. I have over 6 hours of run time and it is still going strong! That will be plenty for one evening performance, even if I left all the necklaces on the entire time. I will recharge them every night.
Also, when I mentioned the 4.6V dropout voltage, that was at the raw battery. When passed through regulator it drops to ~4.4V that is fed to both SX and lights. When there is a surge from lights, it easily takes it below the 4.2V threshold Carl mentioned and I get a reset. So I am using the battery 4.6V mark as the critical point in my estimates.
Also, the duty cycle of light show will be nothing near what I am putting these batteries through.
Take a look at this video that recorded 55 seconds of the test routine. As you will see, it is near 90% duty.
All that said I am very impressed with the run time so far.
Last edited by lightman; 06-18-2012 at 07:47 PM.