Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
162 words
A solid-state watthour meter for registering AC electrical energy consumption by a load connected to a source of AC load current and AC line voltage, comprising: voltage sensing means for producing a first signal corresponding to the line voltage; current sensing means for producing a second signal corresponding to the load current; a solid-state measurement circuit having an input for receiving said first and second signals, an output, and means for producing a third signal at said output corresponding to the AC electrical energy consumption of the load; a power supply, including a regulator circuit having a first resistor, for providing a DC voltage to said measurement circuit, said DC voltage being dependent on the impedance of said first resistor, and means for calibrating the registration of said meter including means in said measurement circuit for relating the registration of said meter to said DC voltage, and further including means for readily removably electrically connecting said first resistor in said regulator circuit.
Claim 2
Dependent Claim
162 words
A solid-state watthour meter for registering AC electrical energy consumption by a load connected to a source of AC load current and AC line voltage, comprising: voltage sensing means for producing a first signal corresponding to the line voltage; current sensing means for producing a second signal corresponding to the load current; a solid-state measurement circuit having an input for receiving said first and second signals, an output, and means for producing a third signal at said output corresponding to the AC electrical energy consumption of the load; a power supply, including a regulator circuit having a first resistor, for providing a DC voltage to said measurement circuit, said DC voltage being dependent on the impedance of said first resistor, and means for calibrating the registration of said meter including means in said measurement circuit for relating the registration of said meter to said DC voltage, and further including means for readily removably electrically connecting said first resistor in said regulator circuit.
Claim 3
Dependent Claim
62 words
The solid-state watthour meter of claim 1 wherein said calibrating means further includes a second resistor readily removably electrically connected in said regulator circuit in parallel with said first resistor, said DC voltage being dependent on the impedance of said second resistor, wherein said first and second resistors are sized relative to each other to respectively provide coarse and fine calibration adjustments.
Claim 4
Dependent Claim
26 words
The solid-state watthour meter of claim 2 wherein said replaceable resistor has a resistance value tolerance of ±1% and a temperature coefficient of 50 PPM/° C.
Claim 5
Dependent Claim
59 words
A method for calibrating the watthour meter of claim 2, comprising the steps of: (a) determining the desired meter registration; and (b) selecting said first resistor and said second resistor having resistances values which satisfy the following proportionality: ##EQU2## wherein R20 is the resistance value of said first resistor and R21 is the resistance value of said second resistor.
Claim 6
Dependent Claim
26 words
The solid-state watthour meter of claim 1 wherein said replaceable resistor has a resistance value tolerance of ±1% and a temperature coefficient of 50 PPM/° C.