DC-to-DC converters and methods for determining outputs of the same
Example DC-to-DC converters are described herein. An example DC-to-DC converter includes an input connected in series with an output. The input is to be connected to a voltage source and the output is to be connected to a load. The DC-to-DC converter also includes a first switch connected in series with the input and the output, a second switch connected in parallel with the output, a first current sense transformer connected in series the first switch, a second current sense transformer connected in series with the second switch, and a switching controller to determine an estimated output current at the output based on the measurements from the first and second current sense transformers.
1 . A DC-to-DC converter comprising:
an input connected in series with an output, the input to be connected to a voltage source and the output to be connected to a load;
a first switch connected in series with the input and the output;
a second switch connected in parallel with the output;
a first current sense transformer connected in series the first switch;
a second current sense transformer connected in series with the second switch and in parallel with the output; and
a switching controller to:
determine a first estimated output current at the output based on measurements from the first and second current sense transformers during a first cycle of a pulse width modulation (PWM) cycle;
determine a second estimated output current at the output based on measurements from the first and second current sense transformers during a second cycle of the PWM cycle; and
determine a total output current at the output based on an average of the first estimated output current and the second estimated output current.
2 . The DC-to-DC converter of claim 1 , wherein the switching controller is to cycle the first switch on and off according to the PWM cycle.
3 . The DC-to-DC converter of claim 2 , wherein the first current sense transformer is used to determine a first current value during a first portion of the first cycle, and the second current sense transformer is used to determine a second current value during a second portion of the first cycle.
4 . A DC-to-DC converter comprising:
an input connected in series with an output, the input to be connected to a voltage source and the output to be connected to a load;
a first switch connected in series with the input and the output;
a second switch connected in parallel with the output;
a first current sense transformer connected in series the first switch;
a second current sense transformer connected in series with the second switch; and
a switching controller to:
cycle the first switch on and off according to a pulse width modulation (PWM) cycle; and
determine an estimated output current at the output based on an average of (a) a sum of a first current value and a second current value, the first current sense transformer used to determine the first current value during a first portion of a first cycle of the PWM cycle, and the second current sense transformer used to determine the second current value during a second portion of the first cycle of the PWM cycle, and (b) a sum of a third current value and a fourth current value, the first current sense transformer used to determine the third current value during a first portion of a second cycle of the PWM cycle, and the second current sense transformer used to determine the fourth current value during a second portion of the second cycle of the PWM cycle.
5 . The DC-to-DC converter of claim 4 , wherein the switching controller is to control the PWM cycle based on the estimated output current.
6 . The DC-to-DC converter of claim 1 , wherein the first and second switches are transistors.
7 . The DC-to-DC converter of claim 6 , wherein the switching controller is to cycle the first and second switches on and off in an alternating manner.
8 . The DC-to-DC converter of claim 1 , wherein the second switch is a diode.
9 . The DC-to-DC converter of claim 1 , further including:
an inductor connected in series with the input and the output;
a first capacitor connected in parallel with the input; and
a second capacitor connected in parallel with the output.
10 . The DC-to-DC converter of claim 1 , wherein the DC-to-DC converter is a buck converter.
11 . The DC-to-DC converter of claim 1 , wherein the load is an actuator on an aircraft.
12 . A non-transitory machine-readable storage medium comprising machine-readable instructions to cause at least one programmable circuit to at least:
determine a first current value based on a measurement from a first current sense transformer in a DC-to-DC converter during a first portion of a first pulse width modulation (PWM) cycle;
determine a second current value based on a measurement from a second current sense transformer in the DC-to-DC converter during a second portion of the first PWM cycle;
determine a first estimated output current of the DC-to-DC converter by summing the first current value and the second current value;
determine a third current value based on a measurement from the first current sense transformer during a first portion of a second PWM cycle;
determine a fourth current value based on a measurement from the second current sense transformer during a second portion of the second PWM cycle;
determine a second estimated output current of the DC-to-DC converter by summing the third current value and the fourth current value; and
determine a total output current of the DC-to-DC converter by averaging the first estimated output current and the second estimated output current.
13 . An aircraft comprising:
a power supply;
a load; and
a DC-to-DC converter including:
a circuit to reduce a voltage between the power supply and the load; and
a switching controller to:
determine a first current value of a current flowing in the circuit in series with the load during a first duty cycle;
determine a second current value of a current flowing in the circuit in parallel with the load during the first duty cycle;
determine a first estimated output current of the circuit by summing the first current value and the second current value;
determine a third current value of the current flowing in the circuit in series with the load during a second duty cycle;
determine a fourth current value of the current flowing in the circuit in parallel with the load during the second duty cycle;
determine a second estimated output current of the circuit by summing the third current value and the fourth current value; and
determine a total output current based on an average of the first estimated output current and the second estimated output current.
14 . The aircraft of claim 13 , wherein the circuit of the DC-to-DC converter includes a first current sense transformer used to measure the first current value and a second current sense transformer used to measure the second current value.
15 . The aircraft of claim 14 , wherein the circuit includes a first switch and a second switch, and wherein the first current sense transformer is connected in series with the first switch and the second current sense transformer is connected in series with the second switch.
16 . The aircraft of claim 13 , wherein the load is an actuator to move a flight control surface on the aircraft.
17 . The aircraft of claim 13 , wherein the aircraft is an unmanned aerial vehicle.
18 . The non-transitory machine readable storage medium of claim 12 , wherein the DC-to-DC converter includes a switch, and wherein the machine-readable instructions are to cause one or more of the at least one programmable circuit to control a third PWM cycle of the switch based on the total output current.
19 . The non-transitory machine-readable storage medium of claim 18 , wherein the first current sense transformer includes a resistor and the measurement corresponds to a voltage measured across the resistor.
20 . The DC-to-DC converter of claim 4 , wherein the first current sense transformer includes a first winding, a second winding, and a resistor, the second winding in parallel with the resistor.