opto coupler

hi
my project is to have a circuit that switching on and off from an input voltage
of 1.7vdc. i already have an opto coupler circuit but it uses a 5vdc input voltage.
is there any possible way to redesign this ckt?

If you change the 10k input resistor to 1k, I think it will work at a lower voltage.

I don't get the 10K in the drawing? The specification for the diode portion of your opto coupler is typical 1.7 Volts Vf at 10 mA If, so 5 - 1.7 = 3.3 / .010 = 330 Ohms so a 330 Ohm resistor would be normally used for 5 volts and not 10K Ohm? I don't get that part. Anyway if you have 1.7 volts and a 1.7 volt forward voltage in theory you don't need a resistor in there but I would try a 10 ohm or 33 ohm simply for the sake of some current limiting. That or try 1 K as suggested and work down.

Ron

The input is a simple IR LED (about 1.7v @ 10mA)
Note: the 1.7V is +/-(0.3V??)

thanks guys,

my circuit is now working.