Circuit for detecting power in a multi-stage power converter
Aspects of the present disclosure describe power converters. A power converter in accordance with an aspect of the present disclosure may comprise a first stage, a second stage electrically coupled to the first stage, the second stage including an energy transfer element, and a sensor. The sensor may include a first circuit and a second circuit. The first circuit and the second circuit may respond differently to an output of the energy transfer element. The sensor may be configured to selectively provide power to the first stage based on a difference in response of the first circuit and the second circuit.
1. A power converter for delivering power to a load, comprising: a first stage; a second stage electrically coupled to the first stage, the second stage including an energy transfer element; and a sensor comprising a first circuit comprising a first diode and a second circuit comprising a second diode, wherein the first circuit has a first response to an output of the energy transfer element based on a reverse recovery time of the first diode and the second circuit has a second response to the output of the energy transfer element based on a recovery time of the second diode, wherein the sensor is configured to selectively provide power to the first stage based on a difference between the first response and the second response.
2. The power converter of claim 1 , further comprising a bias winding associated with the energy transfer element, wherein the first circuit and the second circuit respond differently to an output from the bias winding.
3. The power converter of claim 1 , further comprising a plurality of bias windings associated with the energy transfer element, wherein the first circuit responds to an output of a first bias winding in the plurality of bias windings and the second circuit responds to a second bias winding in the plurality of bias windings.
4. The power converter of claim 1 , further comprising a switching element, wherein the sensor selectively provides power to the first stage through the switching element.
5. The power converter of claim 1 , wherein the second stage comprises a flyback converter.
6. The power converter of claim 1 , wherein the first stage comprises a power factor correction circuit.
7. A power converter for delivering power to a load, comprising: a first stage; a second stage electrically coupled to the first stage, the second stage including an energy transfer element; and a sensor comprising a first circuit comprising a first diode configured to provide a first bias voltage based on a first circuit response to an output of the energy transfer element, the first circuit response based on a reverse recovery time of the first diode and a second circuit comprising a second diode configured to provide a second bias voltage based on a second circuit response to the output of the energy transfer element, the second circuit response based on a recovery time of the second diode, wherein the sensor is configured to selectively provide power to the first stage based on a difference in between the first circuit response and the second circuit.
8. The power converter of claim 7 , further comprising a plurality of bias windings associated with the energy transfer element, wherein the first circuit is coupled to a first bias winding in the plurality of bias windings and the second circuit is coupled to a second bias winding in the plurality of bias windings.
9. The power converter of claim 7 , wherein the sensor is further configured to selectively provide power to the first stage when the first bias voltage is greater than the second bias voltage by at least a threshold.
10. The power converter of claim 7 , further comprising a switching element, wherein the sensor selectively provides power to the first stage through the switching element.
11. The power converter of claim 7 , wherein the second stage comprises a flyback converter.
12. The power converter of claim 7 , wherein the first stage comprises a power factor correction circuit.
13. A power converter for delivering power to a load, comprising: a first stage; a second stage electrically coupled to the first stage, the second stage including an energy transfer element; and a sensor comprising a first circuit comprising a first diode configured to provide a first bias voltage based on a first circuit response to an output of the energy transfer element, the first circuit response based on a reverse recovery time of the first diode and a second circuit configured to provide a second bias voltage based on a second circuit response to the output of the energy transfer element, the second circuit response based on a recovery time of the second diode, wherein the sensor is configured to selectively provide the second bias voltage to the first stage based on a difference between the first circuit response and the second circuit response, the first bias voltage being greater than the second bias voltage by at least a threshold.
14. The power converter of claim 13 , further comprising a bias winding associated with the energy transfer element, wherein the sensor selectively provides power to the first stage based on a current in the bias winding.
15. The power converter of claim 13 , further comprising a plurality of bias windings associated with the energy transfer element, wherein the sensor selectively provides power to the first stage based on a first current in a first bias winding in the plurality of bias windings and a second current in a second bias winding in the plurality of bias windings.
16. The power converter of claim 13 , further comprising a switching element, wherein the sensor selectively provides power to the first stage through the switching element.
17. The power converter of claim 13 , wherein the first stage comprises a power factor correction circuit.
18. The power converter of claim 13 , wherein the second stage comprises a flyback converter.