Some of the circuit designs and ideas presented in this blog may not be tested or confirmed practically. Though the author firmly believes that all the circuits would work and provide the intended results as proposed in the articles, the user must exercise caution while deciding what's appropriate.
Also, many of the articles and diagrams are contributed by external authors, whose original source is unknown, and therefore the reliability of these designs are unconfirmed.
The author cannot be held responsible for any issues or damages either to life or property, or as monetary or physical losses, that might occur during the making of the listed circuit ideas in this blog, either due to negligence, ignorance or lack of proper knowledge about the subject, or perhaps an accidental mistake in the circuit design.
The user or the person who is involved with the building of the project her/himself will be solely responsible for the results, positive or negative, whatsoever.
Having said that, the author welcomes all suggestions and corrections from the readers for improving the blog content and is ready to help as far as possible whenever required.
And please remember electricity can be dangerous if it is not used correctly. Therefore, by using this site we assume that you are completely aware of this and are well versed regarding how to use electricity correctly to avoid fatal accidents.
About Diagram Copyright and Watermark
Many of the articles and diagrams were contributed or purchased from external sources. It isn't always possible for the author to identify whether the material is an original work from the contributor or is a Copyrighted work from some other source? If you think it is a copyrighted work, please inform me through the comment box with valid proofs, I'll try to remove it or replace it with an alternative content.
All the circuit diagrams presented in this website carry a watermark logo of either www.homemade-circuits.com or swagatam innovations. These watermarks are inserted to make sure that in case the images are copied by other websites, the watermark also gets published in their websites, informing the readers about the original source.
The watermarks does not necessarily mean or signify that the diagrams are designed or invented by the post author.
Admin
Swagatam.
Comments
Thank you , for a SLA battery what charging voltage is common ?
in normal temperature(20C to 40C) 13.7 is goood ? the battery is standby and it's not on load
14V is good and will keep the battery almost fully charged, at 13.7V the battery will be only 70% charged
Thank you,so I wanted to this charger for a battery backup setup,it means I should leave my battery permanently plugged to this charger,in this situation you think my battery will be damaged even with low amperage transformer?? If yes,so please help about a simplest automatic 12 volts battery charger ,besides I have to use 16 volts transformer,
Thank you again swagatam for all your supports
You are welcome shayan!
You can try the first circuit from this example article:
https://www.homemade-circuits.com/2012/08/make-this-48v-automatic-battery-charger.html
since yours is a 12V battery, you can eliminate all the 22k resistors and the zener diode connected with pin#7 of the IC.
Rest can be used as indicated in the diagram. This circuit will always cut off the supply to the battery whenever it's fully charged and resume as soon as it drops below that level.
yes it is not safe to connect a battery continuously with a source which may be above 1/10th of its AH value….you can use the above linked circuit with your LM317 circuit to ensure a constant 14V from the 16V source.
Thank you swagatam,
With all respects manufacturer said this is trickled mode charger and you can leave you battery permanently under charger !!
Also I myself leave a 12 4.5ah with this charger for months!! How can I be sure about this subject?
I used 220 to 16 volts 600 milli ampere transformer,but if this charger is not automatic why stop charging after battery reaches 13.6 ?!! So strange
when a battery gets fully charged it stops accepting further charge, that's why it seems the charging has stopped.
In that case you can simply use a supply from 14V rectified source, no need of 317 and the remaining circuit, you will still find the battery cutting off at 14V.
automatic charger will completely cut-off (switch off) the output supply to the battery through a relay or a transistor on full charge which your circuit is not equipped to do.
Shayan, if it' a trickle charger then automatic function becomes irrelevant, and anyhow the circuit does not have an auto-cut off and it is not required if it is a trickle charger. But a trickle charger will not have the ability to charge a battery if it's discharged below its optimum level…and a trickle charge current is supposed to be at least 10 to 30 times less than the battery normal charging current, so in your diagram the circuit is designed to provide 1.3 amps…that implies your battery should be at least 100AH to be trickle charged with this charger safely.
applying 1.3 amp to a 4.5 ah is suicidal, I am not sure how your battery is surviving for months connected to this charger.
OK I think I got, it's because your charger is set at 13.75V which is much less than the optimal 14.3V….so by keeping your battery undercharged you are able to carry on with this inefficient charger… for months 🙂
https://www.homemade-circuits.com/p/lm317-calculator.html
Hi Swagatam ,
first i want to thank you for all supports you have done for me
i have a very simple automatic 12 volts battery charger which working very well
i myself draw its schematic from the real board,
i need some modifications , i would be glad if you help me and also share this circuit on your wonderful site
this is the schematic :
https://drive.google.com/open?id=0B2VgP4YQwP4EYjlIZkF2MS0xUmM
1- i need to add 2 LED's to this circuit , one for charging indicator and one for indicating battery full charge
2-when main fails or unplug (for long time) battery current comes back to the circuit and it will drain the battery , we can not use diode because circuit cant detect battery voltage so automatic behavior of the circuit wouldn't work
thank you for you time and help
But I'm using this circuit from 2 year to now without any problem and it's detecting full battery and doesn't charge it,also its manufacturer said it's automatic and I,ve test it
It is working for you because you are removing the battery from the supply manually. If you keep it connected permanently then slowly your battery will get damaged with this charger, because the circuit does not have the cut-off facility or an automatic changeover from high current to a lower current level when the battery gets fully charged
batteryuniversity.com/learn/article/charging_the_lead_acid_battery
Hi Shayan,
first of all this is NOT an automatic battery charger
Adding LEDs for full charge and discharge is not possible in this circuit, you will need an opamp circuit for that, without a opamp it is not possible to get an automatic operation and the indications..
as shown here:
https://www.homemade-circuits.com/2012/07/make-6v-4ah-automatic-battery-charger.html
diode can be added at the output of your circuit, no problem with that, the circuit will still detect the discharge levels, because the moment you connect the battery it will pull down the LM338 output supply to the same level, through the diode.
Hello
Mr. Swagatam
I hope you are in a good live.
Sir i need your help if it is possible for you.
I need a electronic circuit for that i will explain it.
I want circuit uesing transistor or ice 555.
When i press on the switch the circuit. Start counting for one minute after counting the relay turn on and stay on for 3 minutes after 3 min the relay turn off.
Remember the main switch is on.
If i switch it off and switch it on again the circuit start same cycle.
Hello Mohammad, if it's possible I'll try to publish it soon
V1 = 12V
R2 = 150K
R3 = 10 Ohms
R4 = 10 Ohms
Q
D1 = D2 = 1N4007
C3 =
T1 = 13-0-13 step up transformer
i have no transistors TIP41/42A
But i have mosfet 7805.
Can u you hlp me to build a inverter grom these components??
No, these won't be enough for an inverter
A quick response as expected! Thank you very much.
Of course you are right. I will tell you where I went wrong. I was of the opinion that the CFL circuit just needs to produce sufficient initial voltage to initiate the discharge and then the potential falls to a safe value. So doing away with that portion of the circuit would straighten out the things. It is at this point that I sought your help. What I overlooked here is that it would actually incorporate a step up circuit as well to take the value to roughly 230V to keep the discharge going and CFL illuminating. And you do not need 230V to light up LEDs'. It is much easier construct a simple circuit for auto switching and battery overcharge/deep discharge protection than to try and take out those stages mentioned earlier from an already built circuit.
P. S.: Where do you procure components for your circuits here in Mumbai from? Is it from Lamington Road?
You are welcome!
Here's one emergency lamp circuit which you can included in your existing design:
https://www.homemade-circuits.com/2013/02/make-this-automatic-10-watt-to-1000.html
Yes, in Mumbai Lamington Road is the place where you can get all kinds of spare electronic components.
Dear Mr. Majumdar,
I stumbled upon this fantastic blog of yours while looking for some circuits online and I must say your work here is praiseworthy. I used to design circuits a long time ago when help was not readily available on the click of a button and you had to depend on some magazines to share your circuits with the world. That too if they chose to publish you. You, therefore, are doing a commendable job here; helping enthusiasts and hobbyists. As it appears you are devoting quality time here, not only publishing your circuits but also helping people construct them in addition to designing circuits requested by them, I think I could ask you to help me here as well. Could you suggest a way around so that an old Emergency Light Circuit meant for 9W CFL could be used with LEDs'?
Thank you very much Knight,
If your emergency light back-up is through a battery then probably you wouldn't require the CFL circuit, because LEDs can be illuminated directly with the battery… here it would be via a relay for the required switching actions.