The article explains a basic battery 4 step DC voltage monitor circuit utilizing the versatile IC LM324.
The Design
The suggested battery voltage status indicator circuit making use of 4 LEDs utilizes comparators by means of opamps from the IC LM324.This IC is really a lot adaptable than the other opamp alternatives as a result of its higher voltage tolerance level and as a result of the quad opamps in one package.
In the presented LED battery voltage monitor/indicator circuit all the four opamps are actually utilized, even though some of those might be eradicated in the event they really are not preferred or based upon the specifications of the specific users.
As can be viewed the circuit diagram, the configuration is very simple yet the result too useful.
Right here the inverting pins of all the four opamps are clamped to a fixed recommendation level driven by the value of the zener diode which can be not crucial and can be any value close to the recommended one in the parts list.
The non-inverting pins of the oipamps are configured as the sensing inputs and are shut down with changeable resistors or the presets.
The preset ought to be modified in the following manner:
In the beginning keep all the presets slider arm shifted toward the ground end so that the potential at the non inverting pins become zero.
Making use of a controlled variable power supply apply the first voltage to be checked beginning with the lowest value to the circuit.
Adjust P1 such that at the above level the white LED just lights up. Fix P1 with some glue.
Next apply the second higher voltage or increase the voltage to the next level which is to be supervised and adjust P2 such that the yellow LEDs just turns ON. This would immediately turn OFF the white LED.
Likewise continue with P3 and P4. Seal of all the presets after they are set.
The presented battery indicator circuit is set up in the "dot" mode which means only one LED glows at any instant showing the pertinent voltage level.
If you need to ensure it is react in a "bar graph" mode, basically disconnect the cathodes of all the LEDs from the present points and all of them with the ground or the negative line.
Parts List for the battery status monitor circuit
R1---R4 = 6K8
R5 = 10K
P1---P4 = 10k presets
A1----A4 = LM 324
z1 = 3.3V zener diode
LEDs = 5mm, color as per individual choice.