[GreenKeys] GreenKeys Digest, Vol 102, Issue 64

[George B. Hutchison]

Haven't seen the schematic as it did not show in the attachment, but 
if you are switching a loop, use the H11D1 to drive an MPS A42 in a 
Darlington configuration.  Rugged little transistor good for 300 
volts.

You will get  hard saturation of the transistor so it will  never 
heat. Appropriate series resistor recommended to keep things at 60 
mils.

W7TTY