Battery monitor circuits driver#

This is required so that the LEDs are restricted from drawing excessive current, unnecessarily making the IC warm. The transistor at the right end is configured as an emitter follower replicating a high current, constant voltage zener diode, fixed at 3V. In the proposed 10 step battery charging indicator and monitor circuit we assume the battery to be a 12V which is to be monitored, the circuit functioning may be understood as follows for the aforesaid condition: This input can be set with any voltage level right from 1 to 35V for acquiring a correspondingly sequencing readout of the voltages fed on that pin.

Battery monitor circuits driver#

The LM3915 is basically a 10 stage dot/bar mode LED driver circuit which provides a sequential 10 step LED display corresponding to the varying voltage levels set at its signal input pinout#5. The third circuit explained below allows you to visualize precisely what voltage your battery has at any particular instance while it's being charged. 3) Using a LM3915 IC for the 10 Step Function The article shows a simple method of using the IC LM3915 for monitoring battery voltages right from 1.5V to 24V in 10 discrete steps using 10 LED indicators. C1 = 100uF to 470uF depending on flashing rate preference.The above explained 4 LED battery status indicator can be modified appropriately for enabling it with flashing LED indicators, as shown in the following diagram: 2) Modifying the above 4 status Battery Indicator with Flashing LEDs 5V6 was chosen as the zener voltage because zener diodes running between 5 and 6 V have the highest thermal stability.ĪLL THE LED CATHODES ARE SUPPOSED TO BE CONNECTED TO THE GROUND LINE. The reference voltage is generated using a zener diode connected to a bias resistor R1 and allowing a current of roughly 6 mA. The device is based on a low-cost quad opamp Type LM324, which may be powered directly from the automobile battery.Ī comparison of the battery voltage and a reference voltage from each of the four opamp inputs generates the voltage readout. Because of its tiny size, it may be placed almost anywhere on the dashboard. The LED voltmeter discussed is generally used to track the charging and discharging of a vehicle battery. The above circuit can be also configured in the following manner: How it Works LEDs = 5mm, color as per individual preference.Parts List for the battery status monitor circuit This should instantly shut OFF the white LED. Next apply the second higher voltage or increase the voltage to the next level which is to be monitored and adjust P2 such that the yellow LEDs just switches ON. Using a regulated variable power supply apply the first voltage to be monitored starting from the lowest value to the circuit.Īdjust P1 such that at the above level the white LED just lights up. Initially keep all the presets slider arm shifted toward the ground end so that the potential at the non inverting pins become zero. The preset should be adjusted in the following manner: The non-inverting pins of the oipamps are configured as the sensing inputs and are terminated with variable resistors or the presets. Here the inverting pins of all the four opamps are clamped to a fixed reference level determined by the value of the zener diode which is not critical and can be any value close to the suggested one in the parts list. In the proposed LED battery voltage monitor/indicator circuit all the four opamps have been used, although a few of them may be eliminated in case they are not required or depending on the specs of the individual users.Īs can be seen the circuit diagram, the configuration is simple yet the outcome too effective. This IC is much versatile than the other opamp counterparts due to its higher voltage tolerance level and due to the quad opamps in one package. The proposed battery voltage status monitor circuit using 4 LEDs makes use of comparators in the form of opamps from the IC LM324. should we be using comparator circuit ?Ģ. Circuit should be compact in nature as much as possible.ġ. I've to design a circuit which will detect and indicate the voltage o/p by colored LED lamps. the output from a transformer is 6V, 12V, 24V resp., depending on the supplied input. basically its a battery voltage detector cum indicator circuit.Ģ. I've a project, if you could help me out:ġ.