Temperature based control of voice coil motor

A method, comprising:

• measuring a first responsive voltage value for a first voltage drop between a first terminal attached to a first suspension spring of an actuator housing a voice coil motor for moving a lens assembly and a second terminal of a magnetic coil of the voice coil motor, wherein
• the second terminal is attached to a second suspension spring of the magnetic coil of the voice coil motor for moving the lens assembly, and
• the first responsive voltage value is a voltage existing in response to passing a first electrical signal having a first current value through the first suspension spring to the magnetic coil;
• calculating a first resistance of the magnetic coil based at least in part upon the first responsive voltage value;
• measuring a second responsive voltage value for a second voltage drop between the first terminal attached and the second terminal, wherein
• the second responsive voltage value is a voltage existing in response to passing a second electrical signal having a second current value through the first suspension spring to the magnetic coil;
• calculating a second resistance of the magnetic coil based at least in part upon the second responsive voltage value;
• and
• calculating a relative temperature for the magnetic coil based at least in part upon the first resistance and the second resistance.

A non-transitory, computer-readable storage medium, storing program instructions that when executed by one or more computing devices cause the one or more computing devices to implement:

• measuring a first responsive voltage value for a first voltage drop between a first terminal attached to a first suspension spring of an actuator housing a voice coil motor for moving a lens assembly and a second terminal attached to a second suspension spring of a magnetic coil of the voice coil motor for moving the lens assembly, wherein
• the instructions to cause the one or more computing devices to implement measuring the first responsive voltage value further comprise instructions to cause the one or more computing devices to implement the first responsive voltage value that is a voltage existing in response to passing a first electrical signal having a first current value through the first suspension spring to the magnetic coil;
• calculating a first resistance of the magnetic coil based at least in part upon the first responsive voltage value;
• measuring a second responsive voltage value for a second voltage drop between the first terminal attached and the second terminal in response to passing a second electrical signal having a second current value through the first suspension spring to the magnetic coil;
• calculating a second resistance of the magnetic coil based at least in part upon the second responsive voltage value;
• and
• calculating a relative temperature for the magnetic coil based at least in part upon the first resistance and the second resistance.