Lincoln Impinger Conveyor Ovens 1100 Series - Manual (Page 8)

The speed side of the Time/Temp. Display uses a slotted disc
(cemented to tach. coupling) to break the infra-red light beam
2011383 and above of the optical encoder(mounted on gear motor),
Refer to Page B15 producing electrical pulses that are transmitted to the display. The display
converts these pulses into a read-out of minutes and seconds. The
temperature portion of the Time/Temp Display uses a Thermistor Probe to
sense oven temperature. The thermistor outputs a resistance proportional
to the oven temperature. This resistance is then converted by the display
into a temperature reading.
AUTOMATIC COOL DOWN When this oven is started, the time delay relay timing circuit is enabled,
permitting the oven fans to run for approximately 20 minutes after the oven
is shut off, to cool the oven. The Time Delay Relay will keep the coil of
Relay closed maintaining operation of the Main Fan Motor and cooling
fans.
Impinger II - 1100 Series Service Manual - International 8