Arrangement and method for accurately sensing voltage of a high-impedance source and supplying power to a variable burden

An arrangement for accurately measuring an input voltage to a circuit supplying a load circuit including a variable burden load comprising:

• voltage sensor means connected to the input voltage and providing an output generally representative of the input voltage, said output of said voltage sensor means having the characteristics of a high-impedance source so as to behave as an ideal voltage source in series with an impedance of high magnitude such that the voltage of said output varies significantly with changes in load and is not an accurate representation of the input voltage in the presence of variations in the load on said output,
• a sensing element connected in series with said output of said voltage sensor means and the load circuit, the voltage developed across said sensing element being utilized to represent the input voltage;
• and
• voltage regulator means being connected with the variable burden load for maintaining a constant voltage to the variable burden load.

In an alternating current power system having a source that supplies a circuit having a variable load, an arrangement for sensing the voltage of the source comprising:

• voltage sensor means connected to the source and providing an output generally representative of the source voltage, said output of said voltage sensor means having the characteristics of a high-impedance source in series with an impedance of high magnitude such that the voltage of said output varies significantly with changes in load and is not an accurate representation of the source voltage in the presence of variations in the load on said output;
• load supply circuit means for supplying the variable load;
• a sensing element connected in series with said output and said load supply circuit means;
• means for sensing the voltage developed across said sensing element as a measure of the source voltage;
• and
• shunt regulator means connected across the variable load for maintaining constant voltage across the variable load in response to variations in the impedance presented by the variable load to thereby present a controlled, nearly constant burden to said output and improve the accuracy of the sensed voltage signal.

An arrangement for measuring the source voltage of a high-impedance source while supplying a load comprising:

• current-sensing means being connected in series circuit relationship with the series combination of the high-impedance source and the load, the voltage developed across said current-sensing means providing an output representing the source voltage of the high-impedance source, the source being an alternating-current source;
• the load including a variable load portion and rectifying means, the rectifying means including means for supplying the variable load portion;
• and
• voltage regulator means connected across the variable load portion for maintaining a constant voltage across the variable burden.

An arrangement for accurately measuring an input voltage to a load circuit supplying a variable burden load comprising:

• voltage sensor means connected to the input voltage and providing an output generally representative of the input voltage, said output of said voltage sensor means having the characteristics of a high-impedance source in series with an impedance of high magnitude such that the voltage of said output varies significantly with changes in load and is not an accurate representation of the input voltage in the presence of variations in the load on said output;
• sensing means;
• and
• voltage regulator means, said sensing means and said voltage regulator means being connected in series with each other and in series combination with said output of said voltage sensor means, said voltage regulator means comprising means for providing supply connections to supply the variable burden load, the voltage developed across said sensing means being utilized to represent the input voltage.

A method for accurately measuring the source voltage of a high-impedance source that supplies a variable load comprising the steps of:

• supplying the variable load from a voltage regulator that is connected in series with the source and a current-sensing element;
• maintaining the voltage across the variable load at a predetermined constant level;
• and
• measuring the voltage developed across the current-sensing element to provide a representation of the source voltage of the high-impedance source.