[SOLVED] i need circuit for 24v to 5v dc please help me

[abc_de]

hello
i want circuit for 24v to 5 v converter circuit or regulator etc.
i am using 7812 + 7805 in series connection due to high voltage drop it cause of so much heat. i can't use heat sink in circuit due to board size.
please suggest me circuit which gives 24 to 5v, 500ma minimum.
thanks in advance.

 

[smijesh]

Low voltage dropout regulator LT1175 can be used.

 

[irfan ahmad]

whenever you drop voltage , the power will also dissipate.
whenever power is dissipate heat or light is generated.
so voltage drop method will not work.
switching regulator do not drop voltage .they step down or step up voltage without drop.
lm2576 is best solution.
see this https://www.ti.com/lit/ds/symlink/lm2576.pdf

 

[abc_de]

@irfan ahmad thanks for support. the application circuit diagram which is given in data sheet is sufficient or i have to add some more components

 

[Kripton2035]

search for "lm2596 5v" on ebay and it is soooo cheap that you better buy a ready made module than build it yourself.
just my 2 cts.
https://www.ebay.com/sch/i.html?_odkw=lm2596+5v&LH_BIN=1&_sop=15&_osacat=0&_from=R40&LH_PrefLoc=2&_trksid=p2045573.m570.l1313.TR0.TRC0.Xlm2596+5v+module&_nkw=lm2596+5v+module&_sacat=0

 

[irfan ahmad]

there are two models for lm2576.
1. LM2576T-5V or LM2576HVT-5V
2. lm2576 adj.
1st one gives fix output . which is 5 volt.
second one is adjustable regulator.
.
there is little bit difference between adjustable and fix version.
circuit diagram in datasheet is 100% working.
diagram is available for both versions in their datasheet .
just coil ampere should match with your requirement.


choose any one which is available .
booth are suitable.

 

[abc_de]

@irfan ahmad & @ Kripton2035 thanks alot
lm2576 dc dc buck converter is working without generation of heat.

 

[abc_de]

@irfan ahmad if i use 24v, 10Amps SMPS and output of SMPS is given to LM2576 it will work ok ??
can you tell me how much input current we can apply.

 

[irfan ahmad]

you can use 24v 1000 amp SMPS .
LM2576 will work ok.
there is no upper limit for input supply current .
lm2576 will give you only 3AMP maximum current.
only one thing is necessory.
your input power capacity should be grater then output requirement.

for example if you set lm2576 for 5v output. and connect a lamp of 3amp 5v.
it will consume P= V x I , 5v x 3a =15watt.

now multiply of input power supply voltage and input power supply current should be grater then 15 watt.
for example 24 0.5 amp supply can provide only 12 watt which is not suitable.
24 v 1amp can provide this power .
24v 10 amp can provide 240 watt, this will also work.
output circuit will only consume its require power , the remaining power will not use.


feel free for any further question.

 

[abc_de]

thank you
how i can calculate the amps of coil i am using color coated coil 220uh at output have a color code is red red black & silver.

 

[irfan ahmad]

THIS IS 220 micro Henry coil whit 1% tolerance .
current capacity can be measured with wire used in coil.
current capacity depends upon thickness of wire used in coil.
two coil can be same in their inductance but different in current capacity.
so wire thickness decide about current capacity.