# BATTERY CHARGER USING SCR PDF

Battery Charger Circuit Using SCR. Introduction to SCR: SCR is abbreviation for Silicon Controlled Rectifier. SCR has three pins anode, cathode and gate as. Get an idea about circuit diagram of Battery Charger Circuit Using SCR by reading this post. You may also read about SCR - operating modes and applications. I would also like to thank Kelvin Omondi for his support in using his computer. This project requires the design of an SCR controlled battery charger with. Author: LAVETTE BAROODY Language: English, Indonesian, Arabic Country: Mongolia Genre: Academic & Education Pages: 487 Published (Last): 17.03.2016 ISBN: 551-1-60613-207-7 ePub File Size: 28.89 MB PDF File Size: 14.23 MB Distribution: Free* [*Registration Required] Downloads: 45073 Uploaded by: DANIELE Junaid Mandviwala for the guidance and valuable suggestions during the entire course of the Mini Project titled “Battery Charger Circuit Using SCR”. We also. This 12V SCR battery charger circuit differs from the norm in a number of ways, all of which make it difficult to understand. The smart battery charging system integrated an Astable Multivibrator using LM OP-AMP. 18 Final battery charging verification. 37 .. http:// nohalicanka.tk

Here the SCR acts as a rectifier as well as a switch to allow the rectified DC voltage to be fed to charge the battery. In case the battery gets fully charged, this situation is detected using a comparator circuit and SCR is turned off. When the battery charge drops below a threshold level, the comparator output is so as to turn the SCR on and the battery gets charging again.

Here the comparator compares the voltage across the battery with a reference voltage. Designing the whole circuit depends on the kind of battery used to be recharged. Suppose we are using a 6 cell, 9V Ni-Cd battery with an ampere hour rating of 20Ah and a single cell voltage of 1.

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This would set the required optimum battery voltage to be around 9V. For a voltage of 9V across the potential divider, the voltage across the pot and resistor should be above 5. For this purpose we select a potential divider arrangement consisting of 22K resistor, 40K resistor and a 20k pot. Output current from LM is about 50mA and since here we are using transistor BC with a low base current, we require a resistor of about ohms. Primary of the transformer is connected to V AC supply whereas the secondary is connected to the rectifier.

Initially when the circuit is powered and the battery level is below the threshold voltage, the circuit performs the task of charging the battery. It then starts rectifying the AC voltage, though only for the half cycle. As the DC current starts flowing to the battery through the resistor R2, the battery gets charged.

The voltage across the potential divider consisting of the pot RV1 and resistor R4 depends upon the voltage across the battery. The non inverting terminal is given a reference voltage of 5. For normal charging operation, this reference voltage is more than the voltage across the potential divider and the output of the comparator is less than the threshold voltage required to trigger the NPN transistor into conduction.

Now when the battery starts charging and at a certain point when it is fully charged, the voltage across the potential divider reaches a value above the reference voltage. This implies the voltage at the inverting terminal is less than the voltage at non inverting terminal and the output of the comparator is more than the threshold base emitter voltage for the transistor.

This causes the transistor to conduct and it is switched on. At the same time as the diode D3 is forward biased, it starts conducting and this blocks the triggering the SCR gate voltage as it is now connected to low potential or ground.

## Battery Charger Circuit Using SCR

The SCR thus gets switched off and the charging operation is stopped or paused. Again when the battery charge drops below the threshold level, the charging operation resumes in the manner described above. The resistor R7 and diode D4 are to ensure a small amount of trickle charging takes place in case of the SCR being in off condition. Thanks for sharing a good post…. I need a charging circuit with SCR for 4 volts 4. Thank you….

## Battery Charger Using SCR

Lithium ion and Lithium Polymer batteries need constant current and constant voltage. When the battery voltage is dropped the forward bias will be decreased and transistor gets turned off. When the transistor is turned off automatically the diode D1 and resistor R3 will get the current to the gate of the SCR, this will triggers the SCR and gets conduct.

This will charge the battery when the voltage drop in the battery decreases the forward bias current also gets increased to the transistor when the battery is completely charged the Transistor Q1 will be again turned on and turned off the SCR.

The AC signal is rectified using a SCR and a comparator is used to detect the battery charge voltage with respect to a reference voltage so as to control the switching of the SCR. Principle Behind this Circuit The principle behind the circuit lies in controlling the switching of an SCR based on the charging and discharging of the battery.

Here the SCR acts as a rectifier as well as a switch to allow the rectified DC voltage to be fed to charge the battery. In case the battery gets fully charged, this situation is detected using a comparator circuit and SCR is turned off.

When the battery charge drops below a threshold level, the comparator output is so as to turn the SCR on and the battery gets charging again. Here the comparator compares the voltage across the battery with a reference voltage. Suppose we are using a 6 cell, 9V Ni-Cd battery with an ampere hour rating of 20Ah and a single cell voltage of 1. This would set the required optimum battery voltage to be around 9V. For a voltage of 9V across the potential divider, the voltage across the pot and resistor should be above 5. For this purpose we select a potential divider arrangement consisting of 22K resistor, 40K resistor and a 20k pot.

Output current from LM is about 50mA and since here we are using transistor BC with a low base current, we require a resistor of about ohms. Primary of the transformer is connected to V AC supply whereas the secondary is connected to the rectifier.

Initially when the circuit is powered and the battery level is below the threshold voltage, the circuit performs the task of charging the battery. It then starts rectifying the AC voltage, though only for the half cycle.

As the DC current starts flowing to the battery through the resistor R2, the battery gets charged.The non-inverting terminal is given a reference voltage of 5. The supply voltage will increased from initial value zero when it reached to A as shown in the graph below and start conduction from this point also it there will be the voltage drop due to the load resistance and fall down to point B.

## How To Make Automatic Battery Charger?

PCB Wizard offers a wealth of clever new features that do away with the steep learning curve normally associated with PCB packages. As the DC current starts flowing to the battery through the resistor R2, the battery gets charged. The design is tough and durable. Fuses are an alternative to circuit breakers.

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