Easy Knock sensor test

[am018]

Last night I hooked up Lucas Efi  knock sensor  (Bosch type ?) to my  PC
scope to measure the output --  I saw 750mv peaks. It occured to me that
this is the around same level as a Lambda sensor output   -- so I
connected my LM3914 based LED Lambda output indicator (which is powered
from dry cell not the vehicle battery) to it and turned up the led
brightness -- tap the block and and the first two lights illuminate for
an instant and the third flickers  slightly.   A very quick and easy
test much easier than hooking up a scope.

Andy