### Introduction

On this problem, I am going to current you the suitable strategy to design a straightforward Battery Diploma Indicator Circuit using merely accessible components. Battery stage indicator signifies the standing of the battery just by glowing LED’s. As an illustration six LED’s are glowing means battery functionality 60% stays.

This textual content explains you methods design battery stage indicator. It’s best to use this circuit to check automotive battery or inverter. So by using this circuit, we’ll improve the lifetime of battery.

This circuit is designed based on lM3914 IC (Constructed-in chip). This IC is LED dot/bar present driver.

### Battery Diploma Indicator Circuit Principle

The middle of this battery stage indicator circuit is LM3914 IC. This IC takes enter analog voltage and drives 10 LED’s linearly in response to the enter analog voltage. On this circuit, there is not a need of resistors in assortment with LEDs on account of the current is regulated by the IC.

Get an thought regarding the related publish – How Computerized Battery Charger Circuit Works using LM317?

### Battery Diploma Indicator Circuit Diagram

Battery Diploma Indicator Circuit Diagram

### Circuit Elements

• LM3914 IC
• LED’s -10 (Purple – 3, Yellow – 4, Inexperienced – 3)
• SPST Swap
• Resistors – 18KΩ, 4.7KΩ, 56KΩ
• Potentiometer – 10KΩ
• 12V Battery (to test)
• Connecting wires

### Battery Value Indicator Circuit Design

On this circuit LED’s (D1-D10) exhibits the potential of the battery in each dot mode or present mode. This mode is chosen by the outside swap sw1 which is linked to 9th pin of IC. 6th and 7th pins of IC are linked to the underside by a resistor. This resistor controls the brightness of LED’s. Proper right here resistor R3 and POT RV1 sorts potential divider circuit. Proper right here pot RV1 is used for calibration. There is no need of any exterior power present to this circuit.

The circuit is designed to observe 10V to 15V DC. The circuit will work even when the battery voltage is 3V. The working voltage of this IC is 3v to 25v DC. Lm3914 drives led’s, LCDs and vacuum fluorescents. The IC accommodates adjustable reference and proper 10-steps divider. This IC might acts as sequencer.

#### LM3914 Choices

• Inside voltage reference from 1.2 to 12v DC.
• Programmable output current 2mA to 30mA.
• LED driver outputs are current regulated.
• No multiplexing interaction between outputs.
• It helps large number of temperature from zero to 70 diploma Celsius.
• For bar graph present – be a part of 9th pin of IC to the supply
• For dot present – go away the 9th pin of IC

We’ll moreover be a part of completely totally different shade led’s to level the standing. Be part of D1 to D3 crimson LED’s which signifies shut down stage of your battery and use D8-D10 inexperienced shade LED’s which signifies 80 to 100 proportion of the battery and use yellow shade for remaining.

Have you ever learnt regarding the thought – How a Wi-fi Power Change Circuit Works?

With barely modification we’ll use this circuit to measure totally different voltage ranges moreover. For this take away the resistor R2 and be a part of larger voltage stage to the enter. Now fluctuate the resistance of Pot RV1 till the D10 LED glows. Now take away larger voltage stage on the enter and be a part of lower voltage stage. Be part of a extreme price variable resistor inside the place of resistor R2 and fluctuate it till the D1 LED glows. Now disconnect the pot, measure the resistance all through it and be a part of resistor of comparable price as an alternative of R2. Now the circuit is ready to monitor totally different voltage ranges.

This circuit is most suitable for indicating 12V battery stage. On this circuit each led signifies 10 % battery stage. We’ll lengthen this circuit to 100 steps by cascading lm3914 IC’s.

### Recommendations on the way to Operate Battery Diploma Indicator Circuit?

• Be part of battery to be examined to the enter of the circuit.
• Now regulate the pot RV1 so that LED D1 merely begins glowing.
• Now improve the enter Dc voltage slowly and observe the LED’s
• First led will glow for 1.2V and second LED is for 2.4 V and so forth.

Beneath desk reveals the standing of LED’s with enter voltage stage.

Battery Diploma
Share
Standing of LEDs
1.2V
10
D1 – ON
2.4V
20
D1, D2 – ON
3.6V
30
D1, D2, D3 – ON
4.8V
40
D1, D2, D3, D4 – ON
6.0V
50
D1, D2, D3, D4, D5 – ON
7.2V
60
D1, D2, D3, D4, D5, D6 – ON
8.4V
70
D1, D2, D3, D4, D5, D6, D7 – ON
9.6V
80
D1, D2, D3, D4, D5, D6, D7, D8 – ON
10.8V
90
D1, D2, D3, D4, D5, D6, D7, D8, D9 – ON
12V
100
ALL LEDs – ON

### Battery Value Diploma Indicator Circuit Features

• We’ll use this circuit to measure automotive battery stage.
• This circuit is used to calibrate inverter standing.

### Limitations of the Circuit

• This battery stage indicator works only for small voltages.
• This circuit is theoretical and would require some changes to work in smart.

Provide