I have a Crouzet 84 134 900 solid state relay that I need to control with a 1,8V GPIO output from a Gumstix Overo Summit expansion board. I've tried the circuit drawn up for me in this answer, however my voltages are different and I don't know how to change it to make it work in my current situation.
I tried to modify the values using this "transistor calculator", and it said I needed a 100 ohm resistor instead of the 160 ohm. But when coupled to the relay, switching the GPIO output made no difference, the relay always got 5V and enough current to be on.
The GPIO output gives me 1.8V and 0.1mA. I have a power supply of 5v 2A available. The solid state relay requires 3-32V and 10mA. I have a few 2N4401 and 2N2222 available. Can I do this with the components I have, or is it a too great amplification for the transistors or something?