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Solar, Wind, Hybrid Battery Charger

The article explains a dual input hybrid solar and wind battery charger circuit using cheap and ordinary components. The idea was requested by one of the interested members of this blog.

Technical Specifications


Good after noon sir am designing a " Solar and Wind energy harvest regulator circuit" which has two inputs and one output.
The PV solar panel ( 0-21V DC) and the other input is a wind turbine (15V DC).
The circuit must be designed for charging a 12v battery . the output current being delivered to the loaded battery must not deliver more than 3.5A.
My group and myself have gotten a few circuits off the internet and simulated them using pspice none of them is giving us the output current of 3.5 A. please sir can you please help us with examples of circuits which we can use.

The Design


In one of my previous posts I introduced a similar concept which enabled a battery to be charged from two sources of energy such as wind and solar simultaneously and without the need of any manual intervention.

The above design is based on PWM concept and therefore could be a bit complex and difficult to optimize for a layman or a new hobbyist.

The circuit presented here offers exactly the same features, that is, it enables the charging of a battery from two different sources, yet keeping the design extremely simple, efficient, cheap and hassle free.

Let's understand the circuit in details with the help of the following explanation:

Circuit Diagram


The figure above shows the proposed solar, wind twin hybrid battery charger circuit, using very ordinary components such as opamps and transistors.

We can see two exactly similar opamp stages being employed, one on the left side of the battery and the other on the right side of the battery.

The left side opamp stage becomes responsible for accepting and regulating the wind energy source while the right side opamp stage processes the solar electricity for charging the single common battery in the middle.

Although the two stages look similar, the modes of regulation are different. The wind energy controller circuit regulates the wind energy by shunting or shorting the excess energy to ground, while the solar processor stage does the same but by cutting of the excess energy instead of shunting.

The above explained two modes are crucial since in wind generators which are essentially alternators require the excess energy to be shunted, and not cut off, so that the coil inside can be safeguarded from over current, which also keeps the speed of the alternator at a controlled rate.

This implies that the concept can be also implemented in ELC applications also.

How the opamp is Configured to Function


Now let's investigate the functioning of the opamp stages through the following points:

The opamps are configured as comparators where the pin#3 (non-inverting input) is used as the sensing input and pin#2 (inverting input) as the reference input.

The resistors R3/R4 are selected such that at the required battery charging voltage, pin#3 just becomes higher than pin#2 reference level.

Therefore when the wind energy is applied to the left circuit, the opamp tracks the voltage and as soon as it tries to exceed the set threshold voltage, pin#6 of the IC goes high which in turn switches ON the transistor T1.

T1 instantly short circuits the excess energy restricting the voltage to the battery at the desired safe limit. This process goes on continuously ensuring the required voltage regulation across the battery terminals.

The opamp stage at the solar panel side also implements the same function however here the introduction of T2 makes sure that whenever the solar energy is higher than the set threshold, T2 keeps on cutting it OFF, thereby regulating the supply to the battery at the specified rate, which safeguards the battery as well as the panel from unusual inefficient situations.

R4 on both the sides may be replaced with a preset for facilitating easy setting up of the threshold battery charging level.

Parts list for the solar wind dual hybrid battery charger circuit


R1, R2, R3, R5, R6 = 10k

Z1, Z2 = 4.7V , 1/2 watt zener diode

C1 = 100uF/25V

T1, T2 = TIP147,

T3 = BC547

D2 = 1N4007

D1 = 10 amp rectifier diode or Schottky diode

Need Help? Please leave a comment, I'll get back soon with a reply!




Comments

  1. Please mr swagatam can you provide me with a 6v 4.5amp transformerless power supply circuit and also help me with hint on how to measure voltage of a transformer...u can also provide the charger with transformer.

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  2. Pls mr swagatam please provide me with a 6v 4.5ah battery transformerless charger circuit and also help me with hint on how to measure transformer voltage...also i designed a cd4047 inverter but when i connect the drains to a transformer battery voltage immediately drops wats the reason behind it?

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  3. Mr victory, you can refer to the following article for the details on 6V 4 ah battery charger circuit.

    https://homemade-circuits.com/2012/07/make-6v-4ah-automatic-battery-charger.html

    It would be difficult to troubleshoot the inverter problem unless I have the schematic with me.

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  4. I designed the charger but i get 0.00v dc at the output and transformer is humming i then removed the transformer and placed the primary in the mains then i used a dmm to measure the secondary voltage and it's also 0.0v bt i can also sense sparks at the secondary when i connect the dmm but no voltage but the transformer is rated 12-0-12 1amp please suggest to me what i can do..regards

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  5. it will be difficult to identify the fault without practically checking the circuit...there could be something severely wrong with the connections...

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  6. but please can you help me as to how to check transformer secondary voltage when connected to mains i checked my connection but i don't sense anything wrong with it

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  7. you can check it with a multimeter by selecting the AC range in it

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  8. Thanks sir i think my transformer is faulty...please can i use a 12v 1.5 amp transformer for ur inverter circuit using cd4047?...2. If i can't use the transformer please help me with how to connect 4 12v 1.5amp transformers in parallel to get 12v 6amp..thanks in advance

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  9. you can connect the input winding in parallel, no issues......but the outputs of the individual transformers will need to be terminated to separate loads....do not parallel the output winding.....

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  10. Thanks sir but for the circuit in the above link that u sent to me can i use a tyn112 transistor in place of tip122

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  11. if it's a 1amp rated transistor then it would do...

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  12. Hello sir, can i use a 12v 1amp transformer to test the first stage of ur sinewave inverter using cd4047 and three 555ic will it give me 230v 12watt output?...if i connect 4 of them in parallel how many watt will it give me and can it function properly lyk a single 12v 4amp transformer? i will use a 12v 4.5ah battery please help me as i want to design this circuit also where will i connect the positive and negative terminals of the battery to after completing the 2nd stage...please reply a.s.a.p

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  13. hello victory, I think I have already replied you many times, that if you want many trafos in parallel for an inverter application you must only make the input side of a trafo in parallel, while the output winding needs to be terminated separately to the loads.

    don't jump to a sinewave directly...first make a basic square wave inverter successfully and then you can proceed for the sine mod...

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  14. Thanks Sir for your reply it has help me alot but sir can u go with detail specification regarding the solar paanel and can u help me in how does that windmill works ......reply as early

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  15. Sanket, the solar panel specs will depend on the battery specs that you may be intending to use with it...tell me the battery rating, and I'll tell you the solar panel ratings.

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  16. sir i want to charge the battery of Nokia c1-01 its specifications are 1020mAh,3.7V,,3.8Wh, and sir let me know about the wind energy gen for the above specs and what component are to be used for it??

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  17. Sanket, if you want to use only a wind generator then you can try a different circuit for it, the above hybrid design won't be applicable for you.

    You can try the following design

    https://homemade-circuits.com/2015/06/simplest-windmill-generator-circuit.html

    use a bicycle dynamo for the generator motor.

    and do not use the boost circuit, just use a bridge rectifier and followed by a LM317 circuit as shown here:

    https://homemade-circuits.com/2012/02/how-to-make-current-controlled-12-volt.html

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  18. Hello sir, is it possible to change the wind energy input with house grid input using this circuit? because I would like to recharge the battery using solar energy and grid energy. Thank you Sir.

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  19. the wind input cannot be changed with a mains adapter....but you can use the solar panel on the "wind" side and the mains adapter on the solar panel side for the intended results

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  20. hi sir.. can i used this circuit for solar/ac power supply dual battery charger circuit? means that i want to change wind to ac power supply. thanx in advance..

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  21. the wind input cannot be changed with a mains adapter....but you can use the solar panel on the "wind" side and the mains adapter on the solar panel side for the intended results

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  22. Is this charger efficient to charge 150Ah smps battery?
    And i also need to include a battery protection circuit to decouple the charging circuit whenever not required to keep battery at safe operating region right?

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  23. you can charge any battery using the above circuit just by modifying the output transistor accordingly, for 150AH use 2N3055 transistor for T1 and T2 with adequate heatsinking.

    yes you would require a high charge cut-off circuit at the respective inputs for preventing over charging of the battery

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  24. hi sir,

    i would like to design a mobile battery charger similar to the one shown here.
    what solar panel and wind energy dc o/p voltage is necessary to charge a mobile battery and what changes are to be made in the circuit?

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  25. angela, no changes would be required in the circuit for the mentioned application.

    the current from the sources should be equivalent to the AH rating of the battery

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  26. ..voltage could be much higher which may be ultimately regulated by the opamp setting

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  27. sir, the circuit above is not working in multisim. I replaced the wind and solar input sources with a constant dc voltage. How did you implement this to see the output. please help me soon.

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  28. Mohammed, I simulated the design successfully in my mind, and anything simulated by me works 95 times out of 100.

    I don't trust simulator softwares, neither do I use them, so I cannot comment on them.

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  29. is it possible to use 2N3773 instead of T1 and T2....the TIP 147 is not availiable in my place.....or what are the alternatives??

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  30. Something I have been looking for. Thanks for what you do sit

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  31. T1 will require a supporting BC547 with 2N3773, configured as Darlington...then it will work.

    for the other section T3 will need to be changed with 2N2222, and R5 replaced with a 470 ohm 2 watt, these mods would allow 2N3773 for T2 also

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  32. Hi, just out of curiosity, which ic would you recommend for the above application?
    thanks

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  33. Just out of curiosity, what ic would you recommend to replicate the above circuit?

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  34. Hi sir..thank u for the circuit..i m using 12 v 5w solar panel and 12v from wind and so charging battery..what should be the current given to battery?should it be constant or variable?
    reply soon sir...

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  35. Hi sir..thank u for the circuit..i am using 12v 5w solar panel with 12 v from wind and so charging the battery..the current which we are providing to battery..should it be constant or variable?..reply soon plz

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  36. Hi shekhar, what is the battery AH rating?

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  37. Actually sir can i use this circuit for
    Charging 12v 1.2AH battery with 12v 5W solar and 12v wind output?if yes then it will be fine,if not what should be changes required?..reply soon sir!

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  38. Shekhar, just add a 50 ohm 2 watt resistor in series with the battery positive, that'll do the job.

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  39. Hi Mr. Swagatam, I would like to use your circuit in my project. May I ask if I use a 4Ah or 7Ah battery, will a 40W solar panel do? Thanks sir.

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  40. good day, sorry presently i do not have it!

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  41. Hello Swagatam,
    I would like to contact you privately. Here is my email bvgohmslf@gmail.com. Thank you and cheers.

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  42. Hello Mr. Swagatam,
    I would really like to connect with you. If you could email me with this bvgohmslf@gmail.com, it will be helpful. Thank you and Cheers

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  43. Hello Michael, pleae feel free to express your thoughts in this website through comments, I'll try to help!

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  44. Okay, I would like you to show me a schematic design for a 3kva transformerless inverter. Thanks

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  45. you can try the following concept

    https://homemade-circuits.com/2014/11/48-v-inverter-circuit.html

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  46. for transformerless you can try this

    https://homemade-circuits.com/2016/02/pwm-sinewave-5kva-inverter-circuit.html

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  47. Really greatful for your help. I want to know what I would need to configure to make it 3.5kva, 24volts and 2kva, 24 volts form the schematic you have given to me. Thanks again.

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  48. you will have to reduce the primary turns of the ferrite transformer proportionately for 24V. rest everything can be kept as is for 3kva or 2kva.

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  49. Okay, thanks Boss.
    Another question, I want a schematic for a charge controller that has a combined wind turbine and solar PV input channel and that can be monitored preferably using a microcontroller. This I want to build along side the inverter. Thanks again

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  50. sorry i do not have a microcontroller circuit with me at the moment, if i find one will let you know...

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  51. Sir,can i use this circuit for charging 3.7v 3000 mAh Lithium Polymer Battery??
    if NO what changes do i need to make..?

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  52. Kaushik, yes you can, you can use it for charging any type of battery, just make sure the input current is approximately compatible with the battery specifications.

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  53. Hi Mr. Swagatam, your shematic is mirror which r5, r8, t2, t3 ... Please correct the scheme, thank you.

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  54. Bulent, the opamp sections are mirror images because they can be exactly the same.

    R5 = 10k, R8 is not there

    T2 value is given, T3 is at the bottom right side, T1, T3 typically can be a TIP142 or some other different depending on your battery AH value

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  55. Hello Firstly thank you for this project . I want to ask that how can I connect the load ?
    for example I want to make this project and I want to use for lighting so Lighting with wind and solar energy please help me ? thank you

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  56. thanks!! here the battery is the load....you can remove the battery and replace it with any other load that you may prefer...for example if it's light, you can simply connect the light across the points where the battery is shown connected...

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  57. Thank you for reply. But I mean both of them so battery and lighting for exaple : Battery is charging during day and when it's night then lighting will works also the Wind can generate electricity all day . Thank you

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  58. you can connect the load in parallel with the battery and add a switch to it for manual selection....for an automatic action you can add the second circuit from this link with the battery

    https://homemade-circuits.com/2011/12/how-to-make-simple-low-battery-voltage.html

    the load can be connected with the N/O contact of the relay

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  59. sir plz reply me if T3 is at bottom of the right side then what its no???
    Is it TIP 147

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  60. T2 can be any NPN power transistor...preferably use a Darlington pair such as by connecting 2N2222 and 2N3055

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  61. hello Swagatam Majumdar sir..
    i need a hybrid solar wind charging circuit based on pWM .. so would u like to give us some help ..
    and thank u ..

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  62. Hello I a working on something similar ,I am thinking of using a 7AH OR 40AH battery , would it work ?, and can i simultaneously connect it(the battery) to an inverter while its charging .

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  63. yes you can use the mentioned battery specs with the above explained design....you can simultaneously connect the inverter only if the panel is rated above the combined wattage rating of the battery and inverter

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  64. Dear Sir,

    I am Chathura in Sri Lanka.I am doing my final Year individual project about the Hybrid solar and wind turbine for rural domestic purposes(Stand alone-small scale).But,I have no idea about the control circuit.I try to generate ac through the wind generator and dc through the solar panel.If I use MPPT system how to design the circuit with all the protections.I use battery back for 2day storage capacity.connected load of the houses may be 500w nearly.I can't get the efficient control circuit to develop the system.What type of ac motor generator should be used for power generation and build the small model. My target is to make the hybrid small model.Please help me to success my project.Again I wish to thank your commitment to enhance the knowledge of society.
    Thank your kind cooperation.

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  65. Thanks Chathura for posting your question!

    An MPPT won't be required actually, there are much simpler and efficient design which you can try before thinking about an MPPT.

    However first you will need to develop the above dual control circuit, once you succeed in implementing the above then you can connect an MPPT or any other similar design just before the battery connections.

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  66. sir i need an mobile charger that works with wind power and also the fan should be easly availabel ie, of an SMPS fan of computer and that should be portable while traveling
    thak you sir

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  67. Manjunath, a small fan will not be able to generate electricity for charging a cellphone...it might require quite large fan propellers around 3 to 4 feet in diameter, and high wind speeds.

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  68. ..and a proportionately calculated motor as the generator....

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  69. Sir you said R1, R2, R3, R5, R6 = 10k but in the circuit i see R6 as 1K....
    any corrections?

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  70. Deogratia, R6 is actually not required, because already we have R5 to support the lower NPN, so you can replace R6 with a jumper

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  71. hello Swag.

    Z1, Z2 = 4.7V , 1/2 watt zener diodes hard to get here in my area

    can the zener diode be replaced with any other diode or component ?

    thxs

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  72. Hi Nito, the 4.7V value is critical, you can any other nearby value, upto 9V, or any value lower than the lower discharge threshold value of the battery

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  73. Hi, for me i have 500w wind turbines and it gives ac output,can I use the same diagram or if you have another one, am trying to use 6 150Ah batteries and 24vlt inverter, or if i can diagram which include both

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  74. Hi, I think the second configuration from the following article will better suit your application

    https://homemade-circuits.com/2016/04/simple-vertical-axis-wind-turbine.html

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  75. Kishor ChandrakarMarch 15, 2018 at 2:35 AM

    Can i use 16 amp rectified diode in place of 10 amp rectified diode ?

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  76. It will need to be as per your load specs, but higher rating than the required specs will be OK...that won't harm anything.

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  77. Kishor ChandrakarMarch 15, 2018 at 3:43 AM

    Thanku so much sir

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  78. Kishor ChandrakarMarch 16, 2018 at 6:55 AM

    For 12v,7Ah battery what will be the value of T1 and T2 ?

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  79. Kishor ChandrakarMarch 16, 2018 at 7:03 AM

    And for 12v,7Ah battery what is the rating of Opamp ?

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  80. it will be the same for all types of batteries.

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  81. Sir, can i use 3A Schottky diode inplace of 10A Schottky diode ?

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  82. Sir can you tell me the required input voltage of wind and solar in this circuit???

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  83. Kishor, 3A will not handle more than 2 Amp current, if it is OK for your load then you may use it...

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  84. Kafi, you can use IC LM321 for the opamps and use inputs voltage upto 30V

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  85. Sir, can you please tell me the required minimum input voltage for this circuit??

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  86. Kafi, you can use any desired voltage at the output, just make sure the BJTs are also rated according to this voltage and current specs. For better safety, connect the Vcc of the ICs to the positive with a 10K resistor, and attach a 12V zener diode from the same pin to ground, this will protect the IC from any adverse situation.

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  87. Sir, IC LM321 is not available in my country. Can you please suggest me other OPM IC for this circuit??

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  88. Kafi, you can use LM358, it has two opamps in one IC. Each can be used on either side as indicated in the diagram

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  89. Sir, thankyou so much for this project . i have a question . Do we require a DC to DC converter after the solar panels or AC to DC converter after the windmill in this project ...

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  90. You are welcome Vijyaa, No additional converters are required for this project.

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  91. Yusuf abdulazeezMay 7, 2018 at 7:53 AM

    Good day teacher. Pls, I need 1000 watt inverter which will work when there is no light frm grid. And when light comes, it will automatically charging the battery with the help of relay. Pls, help me out. God bless you sir.

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  92. Yusuf,

    you can modify the following concept and achieve the desired results as per your specifications

    https://www.homemade-circuits.com/how-to-make-simplest-200-va/

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  93. Can you please suggest the wattage of the solar panel to be used in the project. Thank you so much

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  94. Sir, I need to charge a 12 v , 7AH battery.What should be the specifications of solar panel and wind turbine to be used ? Is any changes in the circuit required. Please answer as soon as possible.

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  95. It will depend on the load consumption rating or the battery Ah rating. if it is battery make sure the current of the solar panel is 5 times less than the battery Ah rating

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  96. Abhishek, please specify your battery Ah rating that you want to charge through this circuit

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  97. sorry, for 7Ah, the solar panel can be a 1 amp rated panel at 17V, and the generator could be also rated identically

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  98. Thank you very much sir

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  99. Sir ,wind generates AC power , so how did you convert AC to DC power to charge the battery ? Can you give some brief explanation please ?

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  100. Vijaya, If a DC motor is used as the generator then the output will be pulsating DC, but if you are using an alternator as the generator then the output will be AC, in that case you can incorporate a bridge rectifier to rectify it into DC and then feed it to the above circuit

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  101. Is the output power equal (approx) the two comnined power?
    Can I change opamp to ardino?

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  102. yes that's right, the output current will be combined from the two sources....you can use Arduino but I wonder what benefit you will get by replacing the opamps with Arduino.

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  103. I think it would be easier to set threshold for each power source without calculating resistor, plus, I'm learning Arduino.
    Could you suggest a way to do it? Can a voltage sensor + relay do the job?
    do I need to use buck regulator? if so, how?
    Thanks a lot

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  104. I read somewhere that you cannot combine 2 power sources using voltage regulators, since there will always be a difference in the output voltage, and which power source has higher output voltage will tend to supply 100% power, which leads to component failure.
    Did your circuit address that?

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  105. Please ignore the previous comment, actually I wanted to say that there will always be some power available across the battery from at least one of the sources, so combined current may not be feasible but mostly never an absence of power.

    what kind of component failure are you referring to?

    the above stages are protected with diodes, so there's no chance of any component failure.

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  106. https://electronics.stackexchange.com/questions/55270/is-it-ok-to-connect-the-output-of-buck-regulator-in-parallel
    according to this, one of the regulators will be damaged.
    BTW, I want to teach my student about parallel power sources using solar/wind, instead of using 2 batteries. Will the following formulas be applied: U(total) = U(solar) = U(wind), I(total) = I(solar) + I(wind)

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  107. An Opamp comparator is perhaps the best and the recommended choice for sensing voltage and cutting of power. Using relay is a crude way of regulating voltage, because in a windmill the voltage can be quite fluctuating giving rise to rapid relay switching, so that's not advised.

    The idea shown above is perhaps the most suitable design for the application.

    Moreover for windmills shunting excess power is also a recommendation which ensures proper speed and safeguarding of the its winding.
    Buck converter can be used, I have a universal design shown in the following article, which you can modify as per your specs:

    https://www.homemade-circuits.com/5v-pwm-solar-battery-charger-circuit/

    I am not good with Arduino, so I wouldn't be able to help you with the codes.

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  108. The advise is for circuits without protection diodes. When you have diodes on both the sides you are 100% safe.

    As you pointed out earlier that two different power source can never be equal and therefore you can never have a combined power, therefore getting parallel power from two sources may not be possible.

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  109. Thanks a lot. I'll take notes

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  110. Sir please provide battery specfication

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  111. You can use any battery as per your own specifications, Just make sure to keep the full charge level preset adjustment slightly below the actual full charge value of the battery. Meaning if the battery full charge is 14.3V, adjust the preset cut-off at 14V. And also the battery Ah should be 7 times higher than the input current available from the renewable source if the battery is lead acid type.

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