English 
dc 12v/24v red digital led car auto vehicle battery voltage gauge volt meter
The capacity detection methods of car auto vehicle include: voltage gear load detection of dc 12v/24v red digital led bettery voltage gauge volt meter or multimeter, capacity detection method of hydrometer and capacity detection method of special battery detector.
To detect the storage capacity of the battery , it is difficult to accurately check whether the storage capacity of the battery is sufficient only by using the voltage gear of the voltmeter or multimeter without load. When measuring the voltage alone , the current consumption is very small , so there will be no large voltage drop inside the battery , so the display voltage is not low . However, if a considerable load is added, such as turning on the headlamp (load current 10 ~ 15a) and honking the horn (load current 6 ~ 12a) , the battery will dim the light and make the horn hoarse , indicating insufficient storage .
The correct and reliable detection method is to connect the starter on the vehicle to detect the battery voltage. The steps are as follows: under the normal temperature of the engine, connect a voltmeter to the positive and negative poles of the battery, and pull out the wire of the fuel injector to prevent the engine from starting.
First of all, the voltage of the light bar is 12V, and the voltage after voltage stabilization must also be 12V. Otherwise, it won't work when you say "the fluctuation range is dc12-24v (36V)", which will burn the LED. A three terminal voltage regulator is recommended. It is our company's voltage gauge volt meter, which is cheap and simple . The output voltage of 7812 is 12V and the maximum current is 1a. It has three pins: input, ground and output (see Figure). Connect its input pin to the vehicle power line, connect the grounding at the foundation, and connect the output pin to the input end of the light bar to obtain a stable 12V .
For the power of 12vled lamp , a DC-DC switching power supply is designed. When 12vled needs to be connected to 24V power supply, how to make 12V and 24V common for automobile LED lamp can be achieved by connecting the designed DC-DC switching power supply.
Get a Quote / Info