I though I could work this one out but I am having trouble.
I was to replace an LED with a 12v array of leds. As the source was only designed to power a single LED I figured a 4n25 opto would be ideal as the array only draws 40ma.
Problem .... I can't work out how to wire the array through the opto. Every way I try to use the transistor it permanently conducts giving me permanent power to the array.
I have not yet connected up the input of the opto so its not a input fault.
How should I use the 4n25 in a circuit to switch this ?
I was to replace an LED with a 12v array of leds. As the source was only designed to power a single LED I figured a 4n25 opto would be ideal as the array only draws 40ma.
Problem .... I can't work out how to wire the array through the opto. Every way I try to use the transistor it permanently conducts giving me permanent power to the array.
I have not yet connected up the input of the opto so its not a input fault.
How should I use the 4n25 in a circuit to switch this ?