Patent ID: 7498798

Claim:
A current-to-voltage detection circuit comprising: a detection part (F) is connected to a cathode end (I 3 ) of a system loop (I), and the other end of the detection part is connected to a grounding end (I 1 ) of an operational power supply (I 2 ), wherein the detection part produce a reference potential (H 2 ) of a tiny mV at a point A and effectively remove interference of noise of ambient environment; a reference voltage component (C) are used to produce a fixed reference voltage (H), the fixed reference voltage is compared to the voltage produced by the detection part, the fixed reference voltage is processed with a voltage dividing to come up with a reference potential (H 1 ) at a point B and a relative voltage of resistor with respect to a ground is used to serve as the reference potential (H 2 ) at the point A; a current being able to flow through a load (E) and the detection part when the load is turned on to form the system loop; a common reference potential to the point A and point B being produced by the fixed reference voltage; a variable resistor component (D) for setting the level of the reference potential H 1 at the point B to detect the size of the current; and an amplifier (G) for converting the voltage at its output end G 1 from low potential into high potential to detect and control the size of current of the loop when the reference potential at the point A is greater than the reference potential at the point B.