{"product_id":"under-over-voltage-and-current-protection-switch","title":"Under\/Over Voltage and Current Protection Switch","description":"\u003cp\u003eThis simple project allows users to design an\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eunder-voltage, over-voltage, under-current,\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eand\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eover-current\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eprotection switch. It is a highly useful system for safeguarding electrical loads against abnormal power or current conditions.\u003c\/p\u003e\n\u003cp\u003eThe project features a relay with\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eoptocoupler\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003einput, a current-sensing circuit based on the\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eINA195\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eamplifier, a\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e10mΩ\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eshunt resistor, and a voltage divider network for voltage feedback. It is primarily designed for low-voltage and low-current applications up to\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e4A\u003c\/strong\u003e, but the relay can handle loads up to 5 A at supply voltages up to 48 V.\u003c\/p\u003e\n\u003cp\u003eThe system can be easily controlled using an Arduino or other microcontroller. Voltage and current feedback signals are fed into the microcontroller’s ADC pins for measurement, while the relay can be switched using a 5 V control signal from the processor.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eOver\/Under Current Switch\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe INA195 current-sense amplifier measures the voltage across the shunt resistor and provides an output voltage proportional to the load current. This output can be read by the microcontroller’s ADC to implement over-current or under-current protection logic.\u003c\/p\u003e\n\u003cp\u003eThe INA195 has a fixed gain of 100 V\/V, providing an output of approximately 1 V per ampere of load current. For safety and relay handling limits, the recommended maximum current is below 5A. The system is designed for load voltages up to 48 V, ensuring that the ADC feedback voltage remains below 5 V.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eOver\/Under Voltage Switch\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA resistor divider network, formed by R5 = 10 kΩ and R10 = 1 kΩ, is used to scale down the load voltage for ADC measurement. This feedback allows the controller to detect both over-voltage and under-voltage conditions. At 48 V input, the divider provides approximately 4.364 V, and at 5 V input, about 0.455V.\u003c\/p\u003e\n\u003ch3\u003eFeatures\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eSupply 12V DC Relay and Current Sensor INA195\u003c\/li\u003e\n\u003cli\u003eRelay Trigger Input 5V 20mA\u003c\/li\u003e\n\u003cli\u003eCurrent Sensor Output 1V\/A (5V at 5Amps)\u003c\/li\u003e\n\u003cli\u003eLoad Up to 5Amps, Load Supply Up to 48V DC\u003c\/li\u003e\n\u003cli\u003eLoad Power Supply Feedback 4.364 @ 48V, 0.455 @ 5V Supply\u003c\/li\u003e\n\u003cli\u003e4 x 4 mm PCB Mounting Holes\u003c\/li\u003e\n\u003cli\u003ePCB Dimensions 35.56 x 35.40 mm\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"dotfry","offers":[{"title":"Default Title","offer_id":47170997289132,"sku":"G154","price":9.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0757\/6436\/7532\/files\/G154A.jpg?v=1789027289","url":"https:\/\/dotfry.com\/products\/under-over-voltage-and-current-protection-switch","provider":"dotfry","version":"1.0","type":"link"}