Inverter
AC to DC inverters that are formed from electronic switches, such as MOSFETs, that are controlled by gating pulses obtained from comparators. The comparators compare a varying signal against two closely spaced reference voltages so as to provide gating pulses with delays needed to prevent shoot-through in the electronic switches.
1. An electronic circuit, comprising:
a voltage reference source for providing a first reference voltage and a second reference voltage, the first reference voltage more positive the second reference voltage, the voltage reference source including a voltage divider connected between a first DC input terminal and a second DC input terminal, the voltage divider providing the first reference voltage and the second reference voltage, the voltage divider including a resistive voltage ladder providing a DC-offset reference voltage between the first reference voltage the second reference voltage;
a signal generator for generating a reference signal that varies between a maximum voltage that is more positive than the first reference voltage and a minimum voltage that is less positive than the second reference voltage;
a voltage follower connected between the resistive voltage ladder and the signal generator so as to provide the DC-offset reference voltage to the signal generator;
a first comparator connected to the signal generator and the voltage reference source so as to compare the reference signal to the first reference voltage and provide as an output a first series of output pulses each of which lasts during a discrete interval during which the reference signal is more positive than the first reference voltage; and
a second comparator connected to the signal generator and the voltage reference source so as to compare the reference signal to the second reference voltage and provide as an output a second series of output pulses each of which lasts during a discrete interval during which the reference signal is less positive than the second reference voltage.
2. The electronic circuit as defined in claim 1 , wherein the output pulses are positive going pulses.
3. An electronic circuit, comprising:
a voltage reference source for providing a first reference voltage and a second reference voltage, the first reference voltage more positive than the second reference voltage, the voltage reference source including a voltage divider connected between a first DC input terminal second DC input terminal the voltage divider providing the first reference voltage and the second reference voltage, the voltage divider including a resistive voltage ladder providing a DC-offset reference voltage between the first reference voltage and the second reference voltage;
a signal generator for generating a reference signal that varies between a maximum voltage that is more positive than the first reference voltage and a minimum voltage that is less positive than the second reference voltage;
a voltage follower connected between the resistive voltage ladder and the signal generator so as to provide the DC-offset reference voltage to the signal generator,
a first comparator connected to the signal generator and the voltage reference source so as to compare the reference signal to the first reference voltage and provide as an output a first series of output pulses each of which lasts during a discrete interval during which the reference signal is more positive than the first reference voltage; and
a second comparator connected to the signal generator and the voltage reference source so as to compare the reference signal to the second reference voltage and provide as an output a second series of output pulses each of which lasts during a discrete interval during which the reference signal is more positive than the second reference voltage.
4. The electronic circuit as defined in claim 3 , wherein the output pulses are positive going pulses.