Fridge switch for caravans - 203 in book 308

[bradley]

I assumed that thiese circuits were all tried and tested. Has anyone taken a look at this comparator circuit, using a CA3140. Couldn't get it to work, then checked resistor values, and saw a 330K betwen the opamps pin 7 and the positive rail. This surely stops the 3140 from working (needs about 4mA), and also the two zener diodes used as a voltage ref. Can anyone help please? Is the schematic wrong, is the value wrong, or is there something else? I want to use this circuit this weekend! Thanks