Method to power multiple electric heaters with a single power source

A vehicle, comprising:

• a diesel engine including an engine exhaust outlet;
• an engine exhaust system in fluid communication with the engine exhaust outlet such that the diesel engine is configured to receive engine exhaust gases from the diesel engine, wherein the engine exhaust system includes:
• a diesel oxidation catalyst (DOC) in fluid communication with the diesel engine such that the DOC is configured to receive the engine exhaust gases;
• a first electric heater coupled to the DOC such that the first electric heater is configured to heat the DOC;
• a selective catalytic reduction (SCR) device in fluid communication with the DOC such that the SCR device is positioned to receive the engine exhaust gases exiting the DOC;
• a second electric heater coupled to the DOC such that the second electric heater is configured to heat the SCR device;
• a power switch controller in electronic communication with the first electric heater and the second electric heater;
• a single power source electrically coupled to the power switch controller, the first electric heater, and the second electric heater such that the single power source is configured to supply an electrical current to the first electric heater, the power switch controller, and the second electric heater;
• and
• wherein the power switch controller includes a switch to control a power distribution between the first electric heater and the second electric heater as a function of time.

A method of controlling an engine exhaust system, comprising:

• determining that a diesel oxidation catalyst (DOC) is ready to be heated based on a temperature of the DOC, wherein a first electric heater is coupled to the DOC to heat the DOC;
• determining that a selective catalytic reduction (SCR) device is ready to be heated based on a temperature of the SCR device, wherein a second electric heater is coupled to the SCR device to heat the SCR device;
• and
• controlling, via a power switch controller, a switch to pulse electrical power between the first electric heater and the second electric heater in response to determining that the DOC is ready to be heated, the SCR device is ready to be heated, an engine speed of a diesel engine is greater than a predetermined speed threshold, an engine load of the diesel engine is greater than a predetermined load threshold, and an energy level of a single power source is greater than a predetermined level threshold, wherein the single power source is electrically coupled to both the first electric heater and the second electric heater.