{"product_id":"ct-40a-current-transformer-2500-turns-with-wire-leads","title":"CT 40A Current Transformer (2500 Turns) with Wire Leads","description":"\u003ch5\u003eOverview \u0026amp; Features\u003c\/h5\u003e\n\u003cp\u003eMeasuring high-voltage AC current safely and accurately is a fundamental requirement for modern energy monitoring systems. The \u003cstrong\u003e40A Current Transformer (2500 Turns)\u003c\/strong\u003e allows you to measure AC current up to 40 Amps non-intrusively, providing complete galvanic isolation between your high-voltage mains and your sensitive low-voltage microcontrollers.\u003c\/p\u003e\n\n\u003cp\u003eAvailable at Tomson Electronics, this solid-core toroidal transformer features a 1:2500 turns ratio. This means that for a maximum 40A load passing through the center hole, the transformer induces a highly linear, proportional micro-current (up to 16mA) out of its attached flying wire leads. These pre-attached wire leads make it incredibly easy to connect the sensor directly to a PCB terminal block or custom energy-metering circuit without the hassle of soldering rigid PCB pins.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAlso searched as:\u003c\/strong\u003e 40A CT sensor, 2500T toroidal current sensor, AC power measurement module, 40 amp current transformer with wires, inductive current sensor.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch5\u003eTechnical Specifications\u003c\/h5\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaximum Primary Current:\u003c\/strong\u003e 40A AC\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTurns Ratio:\u003c\/strong\u003e 1:2500 (2500T)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOutput Signal:\u003c\/strong\u003e AC Current (approx. 16mA output at 40A primary)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCore Type:\u003c\/strong\u003e Solid Toroidal Ring (requires wire to be threaded through the center)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConnection Type:\u003c\/strong\u003e Insulated Flying Wire Leads\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIsolation Voltage:\u003c\/strong\u003e Highly isolated (Galvanic isolation between primary and secondary)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch5\u003eCommon Applications\u003c\/h5\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSmart Home Energy Monitors:\u003c\/strong\u003e Building custom Arduino or ESP32-based whole-room power meters to track real-time electricity consumption.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOverload Protection Circuits:\u003c\/strong\u003e Triggering safety relays when a motor or appliance draws more current than its rated capacity.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIndustrial IoT:\u003c\/strong\u003e Monitoring the operational status and power draw of remote AC machinery.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSub-Metering:\u003c\/strong\u003e Measuring the exact power usage of individual high-draw appliances like air conditioners or water heaters.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch5\u003eFrequently Asked Questions\u003c\/h5\u003e\n\u003cp\u003e\u003cstrong\u003eQ: How do I connect this to a microcontroller like an ESP32 or Arduino?\u003c\/strong\u003e\u003cbr\u003e\nA: Microcontrollers can only read voltage, but this CT sensor outputs an AC \u003cem\u003ecurrent\u003c\/em\u003e. You must place a \"burden resistor\" across the two wire leads to convert the induced current into a measurable voltage drop. You will also need a DC bias circuit to shift the AC wave into a positive voltage range (e.g., 0V to 3.3V) so you do not damage your analog-to-digital converter (ADC).\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: Do I need to cut my AC mains wire to install this?\u003c\/strong\u003e\u003cbr\u003e\nA: You do not need to cut the copper wire, but because this is a solid-core transformer, you must temporarily disconnect one end of the Live (or Neutral) AC wire to thread it through the center hole of the transformer. Never run both Live and Neutral through the hole together, or their magnetic fields will cancel out and read zero.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: What does the 2500T rating mean?\u003c\/strong\u003e\u003cbr\u003e\nA: It indicates there are 2,500 wraps of fine copper wire inside the sensor for every 1 pass of the main AC wire. It sets the ratio (1:2500). If 10 Amps is flowing through the main wire, the sensor outputs 10A \/ 2500 = 0.004 Amps (4mA).\u003c\/p\u003e\n\n\u003ch5\u003ePackage Includes\u003c\/h5\u003e\n\u003cul\u003e\n\u003cli\u003e1 × 40A Current Transformer (2500T) with Wire Leads\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"TOMSON ELECTRONICS","offers":[{"title":"Default Title","offer_id":49510819430638,"sku":"SEN-28128","price":149.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/2132\/9029\/files\/40-amp-current-transformer-500x500.jpg?v=1787939450","url":"https:\/\/www.tomsonelectronics.com\/products\/ct-40a-current-transformer-2500-turns-with-wire-leads","provider":"Tomson Electronics ","version":"1.0","type":"link"}