Control arrangement for food heating device
First Claim
1. A control arrangement for an electric food heating device having heating elements for heating foodstuff and said heating elements providing a source of light impinging on the foodstuff, the control arrangement comprising:
- a peaking circuit to determine maximum reflected light from the foodstuff and provide a first signal, and measuring subsequently reflected light from the foodstuff and providing a second signal, said peaking circuit including an amplifier directly responsive to the maximum reflected light for initiating the development of the first signal and further for determining the difference between the first and the second signals, and providing a third signal; and
a comparator means for comparing the third signal and a preset signal, the preset signal developed independently of the third signal and being proportionate to a desired heating heating level, the comparator means providing a terminating signal to deactivate heating when the present and the third signals are substantially equal.
2 Assignments
0 Petitions
Accused Products
Abstract
A control arrangement for an electric food heating device having heating elements for heating foodstuff and providing a source of light impinging on the foodstuff, the control arrangement comprising: a peaking circuit (42, 30) to determine maximum reflected light from the foodstuff and provide a first signal (VI), and measuring subsequently reflected light from the foodstuff and providing a second signal (V2), said peacking circuit including amplifier means (30) for determining the difference between the first and the second signals, and providing a third signal (V3); and a comparator means (26) for comparing the third signal (V3) and a preset signal (VB), the preset signal being proportionate to a desired heating level, the comparator means providing a terminating signal (DONE) to deactivate heating when the preset and the third signals are substantially equal.
28 Citations
34 Claims
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1. A control arrangement for an electric food heating device having heating elements for heating foodstuff and said heating elements providing a source of light impinging on the foodstuff, the control arrangement comprising:
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a peaking circuit to determine maximum reflected light from the foodstuff and provide a first signal, and measuring subsequently reflected light from the foodstuff and providing a second signal, said peaking circuit including an amplifier directly responsive to the maximum reflected light for initiating the development of the first signal and further for determining the difference between the first and the second signals, and providing a third signal; and a comparator means for comparing the third signal and a preset signal, the preset signal developed independently of the third signal and being proportionate to a desired heating heating level, the comparator means providing a terminating signal to deactivate heating when the present and the third signals are substantially equal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21)
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20. A control arrangement for a food heating device having heating elements for browning foodstuff and said heating elements providing a source of light impinging on the foodstuff, the control arrangement comprising:
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means for determining maximum reflected light from the foodstuff and providing a first signal in response thereto; means for measuring subsequently reflected light from the foodstuff and for providing a second signal in response thereto; said means for determining maximum reflected light also being adapted to determine the difference between the first and the second signals and provide a third signal representative of the difference; means for establishing a preset signal independently of the third signal which is proportionate to a desired level of browning of the foodstuff; and comparator means for comparing the third signal and the preset signal, the comparator means providing a terminating signal to deactivate browning when the preset and the third signals are substantially equal.
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22. In a toaster, a peak detector comprising:
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a light detector for providing a first output proportionate to light received by said detector, a first amplifier coupled to said detector, the first amplifier having a gain proportionate to said first output, the first amplifier also coupled to a first reference, and having a second output, a second amplifier coupled to said first amplifier so as to form a closed or feedback loop, the second output being provided to said second amplifier together with a second reference and providing a third output, the third output being provided to a storage means and to said first amplifier, the storage means providing an indication of the measure of a peak level detected. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
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Specification