Voltage sensing circuitry for solid state power controllers

A solid state power controller possessing a power connector, a load connector and at least one communication connector, the solid state power controller comprising:

• a solid state switch coupled between the power connector and the load connector, the solid state switch comprising an input and configured to control a current flowing between the power connector and the load connector;
• a voltage measuring circuitry configured to measure a voltage at the power connector, the voltage measuring circuitry configured to minimize a current drawn from the power connector by the voltage measuring circuitry;
• and
• a microcontroller coupled to the input of the solid state switch and an output of the voltage measuring circuitry, the microcontroller configured to monitor a voltage at the power connector and to detect an overcurrent condition in the current flowing between the power connector and the load connector,
• wherein the voltage measuring circuitry comprises a diode coupled between a first resistor and a second resistor.

A solid state power controller possessing a power connector, a load connector and at least one communication connector, the solid state power controller comprising:

• a solid state switch coupled between the power connector and the load connector, the solid state switch comprising an input and configured to control a current flowing between the power connector and the load connector;
• a voltage measuring circuitry configured to measure a voltage at the power connector, the voltage measuring circuitry configured to minimize a current drawn from the power connector by the voltage measuring circuitry;
• and
• a microcontroller coupled to the input of the solid state switch and an output of the voltage measuring circuitry, the microcontroller configured to monitor a voltage at the power connector and to detect an overcurrent condition in the current flowing between the power connector and the load connector,
• wherein the voltage measuring circuitry comprises an operational amplifier in a voltage follower configuration.

A solid state power controller possessing a power connector, a load connector and at least one communication connector, the solid state power controller comprising:

• a solid state switch coupled between the power connector and the load connector, the solid state switch comprising an input and configured to control a current flowing between the power connector and the load connector;
• a voltage measuring circuitry configured to measure a voltage at the power connector, the voltage measuring circuitry configured to minimize a current drawn from the power connector by the voltage measuring circuitry;
• and
• a microcontroller coupled to the input of the solid state switch and an output of the voltage measuring circuitry, the microcontroller configured to monitor a voltage at the power connector and to detect an overcurrent condition in the current flowing between the power connector and the load connector,
• wherein the voltage measuring circuitry comprises:
• a first diode and a second diode, wherein the first diode and the second diode are coupled in a back to back configuration;
• and
• a first resistor and a second resistor, wherein the second diode is coupled between the first resistor and the second resistor.

A solid state power controller possessing a power connector, a load connector and at least one communication connector, the solid state power controller comprising:

• a solid state switch coupled between the power connector and the load connector, the solid state switch comprising an input and configured to control a current flowing between the power connector and the load connector;
• a voltage measuring circuitry configured to measure a voltage at the power connector, the voltage measuring circuitry configured to minimize a current drawn from the power connector by the voltage measuring circuitry;
• and
• a microcontroller coupled to the input of the solid state switch and an output of the voltage measuring circuitry, the microcontroller configured to monitor a voltage at the power connector and to detect an overcurrent condition in the current flowing between the power connector and the load connector,
• wherein the microcontroller is configured to detect the overcurrent condition by comparing a trip constant to a time variable calculated value which is a function of a measured load current, a rated current and a threshold current.

A solid state power controller possessing a power connector, a load connector and at least one communication connector, the solid state power controller comprising:

• a solid state switch coupled between the power connector and the load connector, the solid state switch comprising an input and configured to control a current flowing between the power connector and the load connector;
• a voltage measuring circuitry configured to measure a voltage at the power connector, the voltage measuring circuitry configured to minimize a current drawn from the power connector by the voltage measuring circuitry;
• a microcontroller coupled to the input of the solid state switch and an output of the voltage measuring circuitry, the microcontroller configured to monitor a voltage at the power connector and to detect an overcurrent condition in the current flowing between the power connector and the load connector;
• and
• a time delay circuit coupled between the input of the solid state switch and the power connector, wherein the time delay circuit is configured to change switching characteristics of the solid state switch.

A solid state power controller possessing a power connector, a load connector and at least one communication connector, the solid state power controller comprising:

• a solid state switch coupled between the power connector and the load connector, the solid state switch comprising an input and configured to control a current flowing between the power connector and the load connector;
• a voltage measuring circuitry configured to measure a voltage at the power connector, the voltage measuring circuitry configured to minimize a current drawn from the power connector by the voltage measuring circuitry;
• and
• a microcontroller coupled to the input of the solid state switch and an output of the voltage measuring circuitry, the microcontroller configured to monitor a voltage at the power connector and to detect an overcurrent condition in the current flowing between the power connector and the load connector,
• wherein the voltage measuring circuitry comprises:
• a first diode and a second diode, wherein the first diode and the second diode are coupled in a back to back configuration and coupled together by a common node;
• and
• an operational amplifier,
• wherein the first diode is coupled between the power connector and the common node, and
• wherein second diode is coupled between the common node and an input to the operational amplifier.