12v 7ah Battery Charger Circuit Diagram Pdf
Hello my dear, today i would to show you about How to make automatic cut off battery charger circuit 12V under 10AH Thank You for watching my video! Please kindly assist me to like share. Battery charger which will interest and appeal to the “cost-minded” customer. Lead-acid batteries are finding considerable use as both primary and backup power sources. For complete battery utilization, the charger circuit must charge the battery to full capacity, while minimizing over-charging for extended battery life.
Circuit Diagram of Automatic Battery Charger This automatic battery charger circuit is mainly involves two sections – power supply section and load comparison section. The main supply voltage 230V, 50Hz is connected to the primary winding of the center tapped transformer to step down the voltage to 15-0-15V. The output of the transformer is connected to the Diodes D1, D2. Here diodes D1, D2 are used to convert low AC voltage to pulsating DC voltage. This process is also called as rectification. The pulsating DC voltage is applied to the 470uF capacitor to remove the AC ripples. Thus the output of the capacitor unregulated Dc voltage.
This unregulated DC voltage is now applied to the LM317 variable voltage regulator to provide regulated DC voltage. The output voltage of this voltage regulator is variable from 1.2V to 37V and the maximum output current from this IC is 1.5A. The output voltage of this voltage regulator is varied by varying the pot 10k which is connected to the adjust pin of LM317. Also Read: Lm317 voltage regulator output is applied to the battery through the diode D5 and resistor R5. Here diode D5 is used to avoid the discharge of battery when main supply fails. When battery charges fully, the zener diode D6 which connected in reverse bias conducts. Now base of BD139 NPN transistor gets the current through the zener so that the total current is grounded.
In this circuit green LED is used for indicating the charge of the battery. Resistor R3 is used to protect the green LED from high voltages. Output Video: Circuit Principle If the battery voltage is below 12V, then the current from LM317 IC flows through the resistor R5 and diode D5 to the battery. At this time zener diode D6 will not conduct because battery takes all the current for charging.
When the battery voltage rises to 13.5V, the current flow to the battery stops and zener diode gets the sufficient breakdown voltage and it allows the current through it. Now the base of the transistor gets the sufficient current to turn on so that the output current from LM317 voltage regulator is grounded through the transistor Q1. As a result Red LED indicates the full of charge. Charger settings The output voltage of the battery charger should be less than 1.5 times of the battery and the current of the charger should be 10% of the battery current. Battery charger should have over voltage protection, short circuit protection and reversed polarity protection. NOTE: Also get an idea about 2.Automatic Battery Charger Circuit Diagram An Automatic Battery Charger Circuit for sealed lead acid batteries is mentioned in this project.
It is a pulsed-charger type circuit which helps in increasing the life of batteries. The working of this circuit is explained below. LM317 acts as voltage regulator and current controlling device. The 15V Zener diode is used to set the LM317 to supply 16.2V at output in the absence of load. When the 2N4401 is turned ON by the output of 555, the ADJ pin of the LM317 is grounded and its output voltage is 1.3V. LM358 acts as a comparator and voltage follower.
LM336 is used to supply a reference voltage of 2.5V to non-inverting terminal (Pin 3) of LM358. A voltage divider network is used to supply a portion of battery’s voltage to inverting terminal (Pin 2) of LM358. When the charge in the battery reaches 14.5V, the input to inverting terminal of LM358 is slightly greater than 2.5V at Pin 3 set by LM336. This will make the output of 555 go high.
As a result Red LED glows and the transistor is turned on. This will ground the ADJ pin of LM317 and its output falls to 1.3V. When the charge in the battery falls below 13.8V, the output of LM358 is high and the output of 555 is low. As a result, voltage flows from LM317 to battery and Green LED glows to indicate charging.
Related Post– 3.Battery charger Using SCR An automatic battery charger circuit using SCR is implemented in this project. It can be used to charge 12V batteries.
Batteries with different potentials like 6V and 9V can also be charged by choosing appropriate components. The working of the circuit is as follows. The AC supply is converted to 15V DC with the help of transformer and bridge rectifier and the Green LED is turned on. The DC output is a pulsating DC as there is no filter after the rectifier. This is important as SCR stops conducting only when the supply voltage is 0 or disconnected from supply and it is possible only with pulsating DC.
Initially, SCR1 starts conducting as it receives a Gate voltage via R2 and D5. When SCR1 is conducting, 15V DC will flow through the battery and the battery starts to charge. When the charge on the battery is almost full, it opposes the flow of current and the current starts to flow via R5. This is filtered with C1 and when the potential reaches 6.8V, Zener ZD1 starts conducting and supplies enough Gate voltage to SCR2 to turn it on. As a result, the current flows through SCR2 via R2 and SCR1 is turned off as both gate voltage and supply voltage are cut off. The Red LED is turned on indicating a full charge on the battery. Know how to design a circuit of auto cut-off and auto.
In the battery charger Using SCR circuit above, wanted to clarify regarding the maximum current which would pass through SCR1. Assuming we are connecting a discharged Lead Acid battery. Then when the circuit is powered ON, the peak AC voltage at the anode of the SCR1 would be 21V (15V rms). This would forward bias the SCR1 since cathode is at zero voltage (as battery output is zero).
The Gate of SCR1 is at higher potential than Cathode and hence SCR1 would conduct. At this stage since the internal resistance of a battery is in the range of 20-50 milli ohm. The current which would pass through SCR and battery as per Ohm’s law would be approx.
20V/20 milli ohm (assuming 1V drop across SCR in conduction phase). This would be a very large current which could potentially damage the SCR/battery. Is there something I am missing here? Hello, Thank you very much for sharing such knowledge. I have tried cut-off with SCR but I have used BUT12A instead os SCR. I also added Regulator with 7805 to the input of the Charger Using SCR circuit.
Now the 10K adjust the voltage very well but without SCR the red LED only turns off when it is higher than 13 V. I always use components from old electronic devices. I will try to charge my 12V battery from my wind tribune I have build with used electronic devices’ components. Thank you for your time and interest.
This is a simple DIY charge controller schematic posted in response to a request by one of our readers on our. The main component of this auto battery charger circuit is a 555 timer which compares the voltage in the battery. It turns ON the charger if the battery voltage is below the variable preset voltage (12 volt chosen here) and turns OFF the charger if the voltage reaches 13.8 volt. The battery charging voltage of the charger can be varied by adjusting the variable resistor. Recommented for you:. To understand the working of this 12 volt battery charge controller circuit you must have an idea of the internal diagram of 555. You can refer the pin out section at the bottom.
You must also check where you can find video demonstration too. Automatic battery charger circuit diagram Click on the image for enlarged view. Components Required. IC 555. Transistor BC 548. Diode (6A4 x5,1N4007). Zener diode (5.1V).
LED (red, green). Capacitor 4700uF,25V. Resistor (1K x 3,820,2x10E 10W). Variable resistor 10K.
12v 7ah Battery Charger Circuit Diagram Pdf By Solar Cell Diagram
Relay 12V,10A. Transformer 230V/0-15,5A Working. Positive terminal of the upper comparator of 555 is connected with reference voltage in order to turn OFF the charger if the battery charges above 13.8V. Reference voltage is obtained by connecting a zener dide in series with a resistor. If the battery voltage is greater than 13.8V, comparator output goes high and flip flop will be set. This turns OFF the transistor and the relay. For understanding relay working see.
If the battery voltage is below the preset voltage (set by us), lower comparator will reset the flip flop. This turns ON the transistor and the relay will switch to charge the battery. The recharge voltage (preset voltage) can set by varying the variable resistor. Power ON is indicated by a red LED and charger ON status is indicated by a green LED.
Components pin out. Caloy Your comment is awaiting moderation. November 23, 2014 at 2:16 am actually in my opinion i will not connect directly the TH to 12v from the relay, connect it to the output terminal of the VR which is the other terminals of the VR one is connected directly to +12v from the relay and the other connected to GND. And for the trigger terminal of ic555 use 33ohm 1/4w resistor connect to GND. Adjust the VR until you can reach the voltage of 13.8v.
Also use capacitor 100uf/16v filter it to the relays coil terminals. Just try, hope it can help. In this circuit you can expect that the red LED will always glow bcause it is connected direcly from the transformers DC outputs.
12v 7ah Battery Charger Circuit
Only the green LED will do the on and off during charging. During charge mode green LED glow and when fuylly charge greenLED turns off. Try this changes: connect directly the TH to 12v from the relay, connect it to the output terminal of the VR which is the other terminals of the VR one is connected directly to +12v from the relay and the other connected to GND. And for the trigger terminal of ic555 use 33ohm 1/4w resistor connect to GND. Adjust the VR until you can reach the voltage of 13.8v. Hope it can help. Hi my friend.
I have a 24V 2A transformer which i can reduce to 17V through an LM317 which will give i think 1.5A. I do not nee the red led and can therefore remove and the resistor. Can i place tactile switch before the Transistor to reset if required? As i am only using 1.5Amp and not 5Amp transformer, I think the two 5E 10w resistors will be to big, what size do they now need to be with the lower current?
Finaly in the diagram is the picture showing the relay normaly open or normaly closed?
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