smps based vrla battery charger

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 Hi everyone there,  my self  new to power supply design.  currently I have 2 x 12 v battery in series generating +12V , -12V ,+5V , -5V  with 0.5A , 0.25A , 1.0 A , 0.25 A Respectivly.  in above case I always use battery power & if battery is short / removed / discharged then my unit is totally dead ( Battery Must )  now my requirement is that I want SMPS for above battery charging ( C / 10 ) as well as SMPS to generate above  voltages in case  battery is not used. ( battery Optional )  I hope i made myself clear.   Plz help me to design  Thanks  

You need to design a switching power supply.  What I suggest, you download PI Expert program from the below link. Then you enter your variables in the program (Vin, VOUT, IOUT, ....) . and the program calculates for you the values of components and gives you schematic for you to follow. http://www.powerint.com/en/design-support/pi-expert-design-software Good luck   

Thanks for instant reply, Now i will share my actual requirement with you. there are four voltages +5,-5,+12,-12 now by designing smps having those output my problem will solve, but problem arises when mains not available then above four voltages should be generated by battery ( DC voltage in primary side is either mains generated DC around 350v or 8-14V according to battery charging status ) we want to use only single 12V battery instead of 2 battries. so when mains available power will be drawn to power up circuit + charge battery & in case of mains fail that battery should take over to generate above voltages without power fail glitch. I am not aware how to do this stuff. Thanks in advance

What I undertstand is that when you do not have AC line voltage available for the input, you would have 8 to 14 V available at the input of the power supplies,  Am I right? So from this VINDC you need to generate your DC voltages.

 

If this is the case, I think Power integrations products are not the best choice for you becasue the input voltage will be very low.  PI products need to work with larger input voltage. In your case you need to have boost type power supplies for your voltages to be larger that 8V.

 

 

 

 

 

 

Yes your understanding about my requirement is correct. Is it possible that I will use smps having two output one for battery charging, with charge controlling element in series with battery & smps output ( for battery protections ) & second output will be a single voltage output ( having wattage equal to my circuit total power drawn from my all 4 voltages ) then i will use LDO /Charge pump to get +/-5V & boost converter to get +/-12V. will it work if so please help me out to design smps having two output. 1. +10v / 3A = 30 W ( Main output from which all four op. will be derived ) 2. +13.7v / 0.5 A = 7w ( Battery charging Output exact voltage may be you can suggest ) for battery protections i will use external circuit. in case of mains fail i will use some relay circuit to switch power from battery & when mains available power will be drawn from smps. Basic smps should have all protections inbuild ( SC , OC , HV , LV ) plz advice Regards Santosh

I am sorry  I got lost in your last entry. Please post a diagram of your idea for me to understand.  I want to have a clear picture of what your question means

 Plz find block dia of scheme  

For the 10V 3 A power supply, you want it to run it with the main power supply or with the battery, am I right?

 

If I am right, and your battery voltage is only 12Vbatt, then this voltage is not enought for power integrations products to run. You need different kind of devices. Something that work with such low Vin .

 

For your 14V 0.5 Amps, what is the range of input you have ?

 

Thanks 

I have assembled following design for my smps requirement ( specification not exactly as required in above post )

there is some problem that at dc bus voltage 132V ( mains rectified which fed to drain ) my two op's are coming up alive but toggeling to some voltageinsted of fixed dc expected. i think either some protection get activated ( i dont know real problem could be can you help me out )

Aattached is software

I do not undertand whenyou said  " my two op's are coming up alive but toggeling to some voltageinsted of fixed dc expected. i"   

 

Please explain 

yes thanks for reply

 

I have made board as per design file attached in previous mail.

mains voltage less than 130v both smps outputs are zero.

above 130v ac mains, at outputs i got some voltage but not remains steady , but keep on changing, it seems that output switches on but may be due to some protection or because of  flyback transformer inductance etc etc ( i really dont know how to check & where to start ) outputs switches off again & this cycle keep on going.

Now while testing i am not connecting any load.

please explain how to proceed.

 

Regards

Santosh

 

You need to disable the V pin of the controller. Conect it to SOURCE pin and test your power supply again.  Let me know the results

 

 

HI,

As per your sugession I connected v pin to source & then following is readings appear at output

 

AC input 50 v 

Output1 - generates sawtooth waveform (peak 10v then discharges till 0.5v ) pattern repeats at interval of 2s

( My undewrstading - as smps designed for 65 V I belive due to not enough startup voltage this happens )

Output2 - above pattern as output1but at lesser voltageof peak upto 5V

( My undewrstading - as smps designed for 65 V I belive due to not enough startup voltage this happens )

 

AC input 100 V

Output1 - steady state voltage of 20V ( as per design output should be 13V @ 0.6A here )

Output2 - steady state voltage of 15V ( as per design output should be 5V @ 2A here )

 

AC input 150 V

Output1 - steady state voltage of 31V with little noise ( as per design output should be 13V @ 0.6A here )

Output2 - steady state voltage of 25V ( as per design output should be 5V @ 2A here )

 

AC input 200 V

Output1 - steady state voltage of 37V with peak to peak noise upto 5V ( as per design output should be 13V @ 0.6A )

Output2 - steady state voltage of 25V ( as per design output should be 5V @ 2A here )

 

AC input 240 v 

Output1 - steady state voltage of 37V with noise ( as per design output should be 13V @ 0.6A here )

Output2 - steady state voltage of 25V ( as per design output should be 5V @ 2A here )

 

Please  explain how to control , regulate voltage at output.

Santosh

 

 

I forgot to mention in previous reply that I have connected 1k as load to both outputs.

Did you disabled the V pin as I suggested you ?

 

HI,

As per your sugession I connected v pin to source & then following is readings appear at output with 1k as load to both output.

 

AC input 50 v 

Output1 - generates sawtooth waveform (peak 10v then discharges till 0.5v ) pattern repeats at interval of 2s

( My undewrstading - as smps designed for 65 V I belive due to not enough startup voltage this happens )

Output2 - above pattern as output1but at lesser voltageof peak upto 5V

( My undewrstading - as smps designed for 65 V I belive due to not enough startup voltage this happens )

 

AC input 100 V

Output1 - steady state voltage of 20V ( as per design output should be 13V @ 0.6A here )

Output2 - steady state voltage of 15V ( as per design output should be 5V @ 2A here )

 

AC input 150 V

Output1 - steady state voltage of 31V with little noise ( as per design output should be 13V @ 0.6A here )

Output2 - steady state voltage of 25V ( as per design output should be 5V @ 2A here )

 

AC input 200 V

Output1 - steady state voltage of 37V with peak to peak noise upto 5V ( as per design output should be 13V @ 0.6A )

Output2 - steady state voltage of 25V ( as per design output should be 5V @ 2A here )

 

AC input 240 v 

Output1 - steady state voltage of 37V with noise ( as per design output should be 13V @ 0.6A here )

Output2 - steady state voltage of 25V ( as per design output should be 5V @ 2A here )

 

Please  explain how to control , regulate voltage at output.

Santosh

You need to check your feedback.  Make sure the loop is not opened.

Check for continuity (no interruption) from R8 upper leg to be connected to the output.  Follow the branch to U2, U3, to output return. Check the components around U3. Do the same for U2B to Control pin of U1.  Check R5 and C5. 

 

If so far you do not find anything wrong, then add a DC source to the upper side of U2B. Add a diode and connect the anode of the diode to the +DC source, the cathode to the collector of U2B. The return of the DC source to primary return

 

Adjust the DC source to 12 volts,  now start again your power supply and see if it regulates.  Let me know what are the results you obtain

Dear sir, I want to use inn3379c but in power suit part was missing please suggest..

Hi sandeep,

Thank you for reaching out to us through this forum. We are willing to help you in your concern but I would like to request you to create a new thread for your inquiry. If you think that this thread is related to your concern, you may copy the link to your new post.

Looking forward to hear you again.

Thank you and Regards,

PI-Lupin the Third