DigiTech AA-0375, User Manual, Page: 3 / 6

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The red LEDs are the lowest voltage, and the yellow
LEDs are the highest voltage. Adjust the trimpot to suit
the voltage reading for your application.
•
A Light Dependent Resistor (LDR) can be connected to
the unit for the LEDs to adjust their brightness
according to the ambient light. Use the trimpot to
adjust the dimming.
Setting up for an Oxygen Sensor:
Links LK1 and LK2 should be out and link LK4 should be
installed.
- Set the trimpot VR1 fully clockwise and trimpot VR2
fully anticlockwise.
- Start the car, let the oxygen sensor warm up and
confirm that the LED display changes.
- Go for a drive and briefly use full throttle. The end
yellow LED should light up. Back off sharply – the end
red LED should light.
- Check that the LEDs travel back and forth when the
engine is at idle.
- If the end yellow LED never lights, even at full throttle,
adjust VR1 so that it lights when the mixtures are fully
rich.
- During normal driving, the LED should move back and
forth around the centre LED. If the oscillations are all
down one end after adjusting VR1, adjust VR2 to centre
the display.