Load characteristics, environmental factors, control circuits, etc. should be considered in the circuit design of the whole vehicle. The selection of the actual relay model should be based on the specifications provided by the manufacturer, and then consider whether there is inrush current in the impedance form of the load and should be reserved. sufficient margin.
Selection of Front Fog Lamp Relay
●The front fog lamp is the lamp load, the nominal voltage is 12V, 55W.
●The vehicle uses 12V DC power supply mode, the rated voltage of the coil provided by the control circuit is 12 V, and the rated voltage of the relay coil should be selected to be more than 12V/DC.
●The position of the front fog light relay is set in the power distribution box of the cockpit, and the relay with an ambient temperature of -40 to 85°C can be selected.
●The coil end of the front fog light relay is given by the light switch, so that the contact end outputs signals to 2 front fog lights, and selects a normally open four-pin relay with one contact.
●The sum of the rated current of the two lamps is calculated to be about 9 A. According to the principle that the switching load of the relay is less than 70% of the rated current, and considering that the front fog lamp is a short-term working load, the rated current value greater than 13A is selected. Just the relay.