Battery polarity check circuit

The topic of today's lesson is to explain a simple circuit that detects the electrodes of batteries or a continuous power source, in other words, a circuit that detects the positive pole and the negative pole of any continuous electrical voltage source, and the beauty of this circuit also is that it detects alternating voltage and it consists of simple electronic compounds and It is available in abundance, especially in old and modern electrical appliances. We will learn about the method of installation, as well as the method of conducting the examination. Just follow the explanation.

Explanation of the polarity check circuit:

Our circuit consists of three simple basic components, which are as follows: Electrical resistance from 220 Ω ohms up to 2 KΩ, why didn't I specify a value? The larger the resistance value, the greater. We will need one resistor, and you can use a 10KΩ variable resistor to calibrate the circuit according to the voltage to be checked. Now we pass to the second element:

An LED lamp of any type or size, provided that the voltage on which it operates does not exceed 3v, for the reason that we may use the circuit to check the polarity of batteries with low voltages. And we will need only two red and green hands. It is advisable to keep these colors in the same colors, for reasons that we will explain shortly.

And as for the last element, which is the diode compound, about which we have already provided explanations, I will leave you its links in the Read also feature in order to better understand the circuit. And we will need four diodes of any kind, as they will suffice.

Polarity detection circuit diagram:

Electronic components used in the polarity check circuit:

Green led light.

Red led light.

Four diodes 1N004.

1kΩ resistor or 10KΩ rheostat.

probes for examination.

How the polarity check circuit works:

The working principle of the circuit is very simple, we connect the sensors to the terminals of the batteries or the voltage source that we want to know who is negative and positive, and if the green light turns on, this means that the terminal connected to the red probe is positive, and the terminal connected to the black one is negative, and if the red light turns on, this means We reversed the polarity, which means the red is the negative and the black is the positive, and if the two work together, this means that the current that we are checking or checking is an alternating current (AC) and not a continuous DC.

important note :

After installing the circuit, we install sensors for testing, and you can use the sensors that come with the ohmmeter to make your circuit more professional, and I advise you to install the circuit on a PCB board, and I downloaded a topic and a book explaining the method of designing printed electronic circuits, and as usual, all links will be below .

Battery polarity check circuit