Abstract: An improved temperature control device which is arranged to generate comparative output ratio signals linearly varying successively from a small value to a large value in a manner as in time series in correspondence to sampling period, at each proportional period including several periods of the sampling period, and also to successively compare the output ratio and the comparative output ratio at each of the sampling period, thereby to turn on an output control section at a subsequent sampling period when the sampling output ratio is larger than the comparative output ratio.

Abstract: Optical quotient thermometers are disposed on the operative end of pusher rods used to push coke from coke oven chambers. The actual value of the optical quotient temperature is measured by the thermometer on two closely-adjacent wavelengths and a quotient signal is produced from the top measured volumes which is converted in a measuring head secured to the pusher rod. An electrical signal is delivered by a converter in the measuring head by wires extending along the pusher rod to a point externally of the oven chamber to a recording and/or evaluating facility where the signal is recorded.

Abstract: To test the soldering temperature on the upper surface of an electronic circuit ceramic substrate (16) that is conveyed on a moving belt (12) over a plurality of heater platens (10), a thermocouple (20) is yieldably pressed to the upper surface of the substrate by a pressing mechanism (22). The pressing mechanism (22) comprises two flat springs (54 and 56) that press an insulator (52) down onto the thermocouple (b 20). The flat springs (54 and 56) are in turn pressed toward the upper surface of the substrate (16) by a coil spring (62) which pushes down onto a pressure plate (60). The pre-load of the coil spring (62) is manually adjusted by a nut (64) that has a groove (66) around which the wire (24) of the thermocouple (20) is wrapped for strain relief, as the wire extends to a digital readout device (26) that rides on the belt (12) along with the substrate ( 16).

Abstract: The circuit arrangement includes a first voltage divider including a temperature sensitive resistance 18 and resistor R1 which feed an analog signal through line 30 to comparators CP1-4, which also receive reference voltages from a second voltage divider comprising R2-5. CP1 goes high with a falling temperature of 26.degree. F. or lower, CP2 goes high when the temperature falls below 22.degree. F. and CP3 goes high when the temperature falls below 18.degree. F. A first timer 20 is turned on when any of the comparators are turned on and counts pulses from an R-C circuit including R8-11 and C1. Whether R8 and 9 are in the oscillator circuit depends upon whether the bilateral switches S2 and S3 controlled by the comparator CP2 and CP3 have shunted them out. Accordingly, the counting is speeded up as the temperature drops.

Abstract: Control system for a microwave oven or a combination microwave and convection oven where the on time of a microwave generating system is decreased while convection heater on time may optionally be increased as a food product cooks to a predetermined, desired temperature. A temperature probe inserted in the product senses temperature and connects to a wheatstone bridge. A differential amplifier connects to the wheatstone bridge, an up/down integrator circuit connects to the differential amplifier, and a comparator connects to the integrator and which includes a latch to generate a signal to control a triac for controlling the microwave generating system and to provide a closed loop feedback signal to the temperature probe. The control system starts the oven cooking with substantially one-hundred percent power and, as the desired predetermined temperature is reached, the microwave power level is decreased through the control system.

Abstract: A method for indicating the thermal state of cooking appliances with an optical and/or acoustic signalling device, comprising the steps of: counting forward from a starting number in response to the heating means of the cooking appliance being switched on; and, counting backwards after the heating means of the cooking appliance has been switched off, the signalling device being switched on when the count exceeds a first number and being switched off when the count falls below a second number.