Output sensor circuit for power supply

An output control for an electrical circuit having a control loop and a main output and a switched output, comprising:

• an output sense circuit including:
• a first connection to an output of the electrical circuit to receive a main output signal of the electrical circuit;
• a second connection to the switched output to receive a switched output signal of the electrical circuit, said switched output being selectively switched between first and second output states depending on a signal at a track input;
• and
• a sense circuit having inputs connected to said first connection and said second connection, said sense circuit having a sense output connected to the control loop, said sense output being at a level to effect control of the main output signal through the control loop regardless of a condition of the switched output.

A power supply sense circuit for a power supply having a main output signal and a control loop, comprising:

• a sense input connected to receive a signal derived from the main output signal of the power supply;
• a sense circuit constructed to establish a first threshold of a difference between said main output signal and a reference signal, said sense circuit constructed to establish a second threshold of a difference between said reference signal and said signal derived from the main output signal, said sense circuit having a sense output for a sense output signal;
• and
• a connection from said sense output to the control loop.

A switching power supply with a sense circuit, comprising:

• a power regulating circuit having a main power output and a control input;
• a switching circuit connected to said main power output and having a switching output and a tracking input, said switching circuit providing a switched output signal dependant upon said tracking input;
• a reference circuit connected to generate a reference signal;
• a control loop connected to compare said main power output to said reference signal;
• and
• a sense circuit having an input connected to receive a signal derived from said main power output, said sense circuit establishing at least one threshold, said sense circuit having a sense output connected to said control loop, said sense output being dependent on said threshold being exceeded.

A sense circuit for a switching power supply having a main output signal and a switched output and a control loop with a reference signal, comprising:

• a sense input connected to receive a signal derived from the main output signal;
• a sense circuit constructed to establish a first threshold of a difference between said main output signal and the reference signal, said sense circuit constructed to establish a second threshold of a difference between said reference signal and said signal derived from the main output signal, said sense circuit having a sense output for a sense output signal;
• a connection from said sense output to the control loop;
• said sense circuit including:
• a first voltage divider connected to said reference signal and a predetermined circuit signal;
• a buffer connected to said signal derived from the main output signal;
• a first comparator having a first input connected to said first voltage divider and a second input connected to an output of said buffer;
• a second voltage divider connected to the main output signal and to said predetermined circuit signal;
• a second comparator having a first input connected to said second voltage divider and a second input connected to said reference signal;
• and
• a switch connected between said output of said buffer and the control loop, said switch having a switch control connected to outputs of said first and second comparators, said switch being a field effect transistor and said switch control being a gate of said field effect transistor.