That looks perfect to me. I first thought of using a voltage divider only I didn't think to interrupt it with the opto. This would shut it off completely when off and draw next to nothing (10v/60,000 ohms) when on. I can always use a regulator or just a capacitor to remove any ripple on the opto side.
Many thanks.

 

Have to ask one more question.
I tried the circuit with two voltage dividers. The first one was close to what you suggested 4,700 ohms and 28,000 ohms giving about 14.8 volts. That worked fine. Then I tried it with 200,000 ohms and 30,000 ohms giving also about 14 vdc. That wouldn't work at all. It would not turn on the opto isolator. Put the first one back on and it works fine. I didn't think there was any current draw on the mosfet gate to make any difference however there must be something there causing the difference. It is unfiltered dc so there is a 120 Hz frequency to deal with.
I can easily use the first combination as there is no real heat generated to deal with however I would still like to understand why.

Thanks again.

 

Have to ask one more question.
I tried the circuit with two voltage dividers. The first one was close to what you suggested 4,700 ohms and 28,000 ohms giving about 14.8 volts. That worked fine. Then I tried it with 200,000 ohms and 30,000 ohms giving also about 14 vdc. That wouldn't work at all. It would not turn on the opto isolator. Put the first one back on and it works fine. I didn't think there was any current draw on the mosfet gate to make any difference however there must be something there causing the difference. It is unfiltered dc so there is a 120 Hz frequency to deal with.
I can easily use the first combination as there is no real heat generated to deal with however I would still like to understand why.

What do you mean "It would not turn on the opto isolator."?
Those resistors are on the output of the opto, not the input, correct?

 

It would not turn on the mosfet. Yes I'm talking about the output of the opto.

 

It would not turn on the mosfet. Yes I'm talking about the output of the opto.

Sounds like the opto may have a high output leakage current when off.
What is the opto input when you turn it off?

 

The opto is turned on (input side) by 5 vdc from an atmel IC output (ATTIny 26). The output of the opto is attached to the voltage divider and sees approximately 14 vdc. When the opto is turned on by the IC, the 14vdc is put on to the gate of the mosfet. I had to wire the voltage divider differently than you had it. you had the output of the opto in the middle of the divider. When I wired it that way the mosfet would never shut off. It seems to me this left a rather large voltage on the input (of the output) of the opto even when it was supposedly off. the I now have the divider going directly to ground and the center tap going to the opto. It appears to be a clean on and off response to the signal.

Thanks in advance.