SMT Current Sense Transformer CT Transformer Current Sampling Detection

CT/SMT Current Sense Transformers

In all kinds of electronic circuits design and application,there is common core component which is small and silk printed CT,It is SMT Current Sense Transformer,also called SMT Current Sensor，Letter C means Current，T means Transformers，Therefore we also call CT Transformer among the industry，it is a small component which is responsible for monitoring current in the circuit.

1.SMT Current Sense Transformer Core Function

SMT Current Sense Transformer core effect,detects accurately actual time current in working circuit.It transfers high current signal in the circuit to small voltage signal that can be recognized by the control chip，realizes non-contact monitoring of current,sampling and protection,it is indispensable basics component in the circuits for monitoring current,overload protection,power control.

2、SMT Current Sense Transformer inner construction

SMT Current Sense Transformer has compact construction,high integration,it mainly consist of two parts: primary coil and secondary coil，pin function is clear division of work:

1、Primary coil

Construction of primary coil is very simple，there are entire 8 pins on the component，among them,7,8 pin dedicate in primary coil，only have one turn ration,connect directly in series with the input end of the circuit.It dedicates in design of detecting current,different models support input current among 7A-40A,Using common model EE5 as example，it primary coil can bear maximal current is 20A,it is  suitable for current sampling need of high power circuits.

2、SMT Current Sense Transformer secondary coil

Secondary coil has multi turns ratio wound densely on the magnetic core,is core of signal output.The common winding methods are 1-3 pin winding or 4-6 pin winding,The white dot unifies marking on pin 1,As the signal output terminal of the secondary winding，connect the circuit to the back-end control chip；The remaining un-wound pins only have function of surface mount fixation,welding reinforcement effect, no electrical conduction.

3、SMT Current Sense Transformer Working principle

The SMT current sense transformer operates based on the principle of electromagnetic induction, with a clear and efficient process:

When circuits current go through primary coil,coil will produce corresponding alternating magnetic field along with current changing. After sensing this magnetic field,secondary coil which is winding on the same magnetic core,will base on magnetic field strength producing induced electromotive force at the same time.Large current signal in the circuits transfer into week voltage signal.This voltage signal transfer to back-end controlling chip finally.The chip analyzes the voltage values,then can get accurate actual time current in the circuits, to finish detection closed loop of current.

4、SMT Current Sense Transformer Common Models Replacement

There are common SMT Current Sense Transformer models in the market, can achieve whole series compatibility and replacement. Common Models including: CST1,CST2,CST4835,CST2010,CST7030,8965D,PH9494.200NLT,P8208NLT,CT050.

EE series：EE4（EE4.2,EE4.4）,EE4.6,EE5,EE6,EE8.3（EE8.5,EE9）,EE12.6 and so on.

5、SMT Current Sense Transformer Typical Application Fiels

Because the SMT Current Sense Transformer takes advantage of small size,high accurate Surface Mounted,easy to integration,it is widely used in high accurate and compact electronic equipment, including :

1.Photovoltaic micro-inverter,Micro energy storage converter

2.Industrial laser marking machines, industrial control automation equipment

3.High Accurate medical detecting equipment,Portable medical equipment

4.Power management, charging stations, home appliance control boards, and other scenarios of current monitoring