968 Cabriolet L4-2990cc 3.0L DOHC (1993)
Block Diagram of the Heated-Wire Air Flow Sensor
1 - Control amplifier
RK - Intake-air compensation resistor
RH - Heated wire
IH - Heating current
RM - Measuring resistor
UM - Output voltage (dependent on the mass of the intake air)
R1 - Bridge resistor
R2 - Trimming resistor (characteristic)
R4 - Trimming resistor (burn-off temperature)
T - Transistor for burn-off function
UB - Supply voltage
m - Air mass