Offline power supply and charging apparatus
An offline power supply includes a power supply circuit including a primary-side circuit for connecting to a power source, a secondary-side circuit for connecting to a load, and a transformer connecting the primary-side circuit and the secondary-side circuit. A switch operates to selectively connect the primary-side circuit to the power source. A trigger circuit is connected to the secondary-side circuit and has at least one input. The trigger circuit generates an output to selectively operate the switch based on the at least one input.
1. An offline power supply comprising:
a power supply circuit including a primary-side circuit for connecting to a first power source, a secondary-side circuit for connecting to a load, and a first transformer connecting the primary-side circuit and the secondary-side circuit;
a switch operable to selectively connect the primary-side circuit to the first power source;
a second power source derived from the first power source; and
a detection circuit powered by the second power source and connected to the secondary-side circuit, the detection circuit having at least one input and generating an output to selectively operate the switch based on the at least one input.
2. The offline power supply of claim 1 , wherein the second power source is a second transformer.
3. The offline power supply of claim 2 , wherein the second transformer is a step-down transformer connected to the first power source for lowering output voltage.
4. The offline power supply of claim 1 , wherein the at least one input includes a trigger input for monitoring the load.
5. The offline power supply of claim 4 , wherein the trigger input is a connection between the secondary-side circuit and the load.
6. The offline power supply of claim 5 , wherein the connection between the secondary-side circuit and the load is detected using a control pilot signal.
7. The offline power supply of claim 5 , wherein the connection between the secondary-side circuit and the load is detected using proximity detection.
8. The offline power supply of claim 1 further comprising:
a voltage isolation mechanism disposed between the output generated by the detection circuit and the switch.
9. The offline power supply of claim 8 , wherein the voltage isolation mechanism is an optocoupler.
10. The offline power supply of claim 8 further comprising:
a latch disposed between the output generated by the detection circuit and the voltage isolation mechanism.
11. The offline power supply of claim 10 , wherein the latch is connected to a microcontroller provided in the secondary-side circuit.
12. An apparatus, cord-set, or wall-station for charging a plug-in vehicle, the apparatus comprising:
a power supply circuit including a primary-side circuit for connecting to a power source, a secondary-side circuit for connecting to the vehicle, and a transformer connecting the primary-side circuit and the secondary-side circuit;
a switch operable to selectively connect the primary-side circuit to the power source; and
a trigger circuit connected to the secondary-side circuit and having at least one input, the trigger circuit generating an output to selectively operate the switch based on the at least one input,
wherein the at least one input includes a trigger input for monitoring the connection to the vehicle.
13. The apparatus of claim 12 , wherein the trigger circuit is a buffer circuit.
14. The apparatus of claim 12 , wherein the trigger circuit is a low power detection circuit.
15. The apparatus of claim 14 further comprising:
a step-down transformer connected to the power source for lowering output voltage, wherein the step-down transformer powers the low power detection circuit.
16. The apparatus of claim 12 further comprising:
a voltage isolation mechanism disposed between the output generated by the trigger circuit and the switch.
17. The apparatus of claim 16 further comprising:
a latch disposed between the output generated by the trigger circuit and the voltage isolation mechanism.
18. An apparatus, cord-set, or wall-station for charging a plug-in vehicle, the apparatus comprising:
a power supply circuit including a primary-side circuit connecting to a power source, a secondary-side circuit for connecting to the vehicle, and a transformer connecting the primary-side circuit and the secondary-side circuit;
at least one switch operable to selectively power one or more components contained in the secondary-side circuit; and
a trigger circuit connected to the secondary-side circuit and having at least one input, the trigger circuit generating an output to selectively operate the at least one switch based on the at least one input,
wherein the at least one input includes a trigger input for monitoring the connection to the vehicle.
19. The apparatus of claim 18 , wherein the at least one switch includes a positive voltage supply switch and a negative voltage supply switch for selectively powering the one or more components contained in the secondary-side circuit, and wherein power to the trigger circuit is unswitched.
20. The apparatus of claim 18 further comprising:
a latch disposed between the output generated by the trigger circuit and the at least one switch.