Led and battery selection
my plan is to create a double sided pov wand. I want to make it compact. my plan was to use a nano to control 4 shift registers to control 32 bits with 2 led on each bit. ( one on each side. ). So I can get good resolution and program images into the display. .. I was planning on getting a 7 v battery to supply the battery and the shift registers then run up to the led and run 2 off in series. But my 595 register cannot work on 7 v. Maxes out at 6v.
Also I couldn't find a small enough battery that can supply 1280 mA at 7 v. I want to make it small enough so I can attach to rope and swing 2 of them around like poi.
Is my best bet to make less led? Or does anyone know where I could get a hand held battery with that capacity. ? Also is there a shift register around that sinks 7v?
=Thanks in advance
Have you looked for a CMOS shift registers? CMOS can operate at higher voltage. You could also use a 5 volt regulator to get the voltage for your current shift register.
TPIC6C595, TPIC6B595 can sink from 7V.
Using two LiPo or LiIon battery in series will yield 8.4V down to 7.4V, use a switching regulator to make 5V for the logic devices.
example Pololu 5V, 500mA Step-Down Voltage Regulator D24V5F5
battery examples http://www.adafruit.com/search?q=battery&b=1
Thank you . I think my best bet is to use that 5 volt regulator to feed two shift registers and run its corresponding leds and the 5v pin to run the other two registers and their leds. They will both be running at 320 mA. I think I will use 2 red led that run at 2.5v and run 2 in series to spread the voltage.
Thank you everyone for your input. Was very helpful.