Controlling current for power stealing in climate control systems
First Claim
Patent Images
1. A thermostat operable to control a given function of a climate control system by switching a corresponding load of the climate control system between “
- on” and
“
off”
modes, the thermostat comprising;
a power stealing circuit configured to provide power from a voltage supply through a given load of the climate control system when the load is in an “
off”
mode;
the power stealing circuit having a current limiting circuit configured based on a plurality of predetermined instantaneous current values corresponding to a plurality of climate control system functions, including the given function, controllable by the thermostat, where each value is predetermined to be a maximum instantaneous current through an off-mode load of the corresponding climate control system function and above which the off-mode load would be switched to an “
on”
mode;
the current limiting circuit configured to limit instantaneous current received by the current limiting circuit to a fixed instantaneous current level predetermined, based on the predetermined instantaneous current values, to be a fixed maximum instantaneous current threshold at which each of the off-mode loads would not be switched to an “
on”
mode;
the power stealing circuit configured by the current limiting circuit to selectively provide the power through any of the plurality of off-mode loads.
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Abstract
A thermostat for use in a climate control system has a power stealing circuit that provides power from a voltage supply through a load of the climate control system when the load is in an “off” mode. The power stealing circuit has a current limiting circuit that provides a maximum level of instantaneous current predetermined to be a threshold beyond which the load is switched to an “on” mode.
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Citations
20 Claims
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1. A thermostat operable to control a given function of a climate control system by switching a corresponding load of the climate control system between “
- on” and
“
off”
modes, the thermostat comprising;a power stealing circuit configured to provide power from a voltage supply through a given load of the climate control system when the load is in an “
off”
mode;the power stealing circuit having a current limiting circuit configured based on a plurality of predetermined instantaneous current values corresponding to a plurality of climate control system functions, including the given function, controllable by the thermostat, where each value is predetermined to be a maximum instantaneous current through an off-mode load of the corresponding climate control system function and above which the off-mode load would be switched to an “
on”
mode;the current limiting circuit configured to limit instantaneous current received by the current limiting circuit to a fixed instantaneous current level predetermined, based on the predetermined instantaneous current values, to be a fixed maximum instantaneous current threshold at which each of the off-mode loads would not be switched to an “
on”
mode;the power stealing circuit configured by the current limiting circuit to selectively provide the power through any of the plurality of off-mode loads. - View Dependent Claims (2, 3, 4, 5, 6, 7)
- on” and
-
8. A power stealing circuit for obtaining power from a voltage source through a given control system load that is in an “
- off”
mode, the given load corresponding to a given function of the control system, the power stealing circuit comprising;a current limiting circuit configured based on a plurality of predetermined instantaneous current values corresponding to a plurality of functions, including the given function, of the control system, where each value is predetermined to be a maximum instantaneous current through an off-mode load of the corresponding control system function, above which the off-mode load would be switched to an “
on”
mode;the current limiting circuit configured to limit instantaneous current received by the current limiting circuit to a fixed instantaneous current level predetermined, based on the predetermined instantaneous current level values, to be a fixed maximum level of instantaneous current at which each of the off-mode loads would not be switched to an “
on”
mode, the maximum level of instantaneous current corresponding to a maximum voltage threshold at which the load is not switched to the “
on”
mode;the power stealing circuit configured by the current limiting circuit to steal power through any of the control system loads that is in the “
off”
mode and selectable for power stealing therefrom. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15)
- off”
-
16. A method of providing power stealing in a climate control system to provide power from a voltage supply through a load that is in an “
- off”
mode to one or more ancillary circuits of the system, the method comprising;determining a plurality of instantaneous current values corresponding to a plurality of climate control system functions, where each value is a maximum instantaneous current through an off-mode load of a corresponding climate control system function and above which the off-mode load would be switched from an “
off”
mode to an “
on”
mode for performing the corresponding function;based on the determined instantaneous current values, determining a fixed maximum value of instantaneous current for providing the power, the fixed maximum value being a maximum instantaneous current threshold at which each of the off-mode loads corresponding to the plurality of climate control system functions would not be switched to an “
on”
mode; andusing the fixed maximum value to limit current through one or more of the loads when in the “
off”
mode;the using performed by providing, in a power stealing circuit of the climate control system, a current limiting circuit that outputs instantaneous current at the fixed maximum value to provide the power. - View Dependent Claims (17, 18, 19, 20)
- off”
Specification