50 watt led driver schematics required

[audiospecialist]

Hi All,

looking forward for a simple constant current smps schematic to be driven from 150~260 volt Ac.

to drive 50 w led.
Led input voltage -36v
Max current 1.5 amp.
Thanks in advance.

 

[kam1787]

probably better to buy a commercial unit. Mine cost about 8USD. Otherwise there are many - often using a 555. Why SMPS?

 

[goldsmith]

Hi All,

looking forward for a simple constant current smps schematic to be driven from 150~260 volt Ac.

to drive 50 w led.
Led input voltage -36v
Max current 1.5 amp.
Thanks in advance.

Hi audiospecialist
I suggest you to pick up a TOP256EN/YN which is a good thing for this aim ! and then go through a flyback converter based on that .
Best Wishes
Goldsmith

 

[kam1787]

Hi audiospecialist
I suggest you to pick up a TOP256EN/YN which is a good thing for this aim ! and then go through a flyback converter based on that .
Best Wishes
Goldsmith

Is the TOP256 the simplest IC to implement?

 

[goldsmith]

Is the TOP256 the simplest IC to implement?

Hi kam 1787!

it is one of the simplest integrated circuits for this purpose .
Best Wishes
Goldsmith

 

[kam1787]

I'd suggest these are simpler.........

https://www.eevblog.com/forum/projects/pwm-signal-from-555-timer/

https://www.instructables.com/id/Yet-Another-Simple-Pot-controlled-555-PWM-generato/

**broken link removed**

https://www.edaboard.com/threads/228907/

https://www.personal.psu.edu/faculty/////a/x/axl17/242l9.pdf

**broken link removed**

https://www.edn.com/design/analog/4345674/Use-a-555-timer-as-a-switch-mode-power-supply

 

[goldsmith]

I'd suggest these are simpler.........

https://www.eevblog.com/forum/projects/pwm-signal-from-555-timer/

https://www.instructables.com/id/Yet-Another-Simple-Pot-controlled-555-PWM-generato/

**broken link removed**

https://www.edaboard.com/threads/228907/

https://www.personal.psu.edu/faculty/////a/x/axl17/242l9.pdf

**broken link removed**

https://www.edn.com/design/analog/4345674/Use-a-555-timer-as-a-switch-mode-power-supply

some of your links are like a toy for kids because they have no feedback path and it can not work in flyback mode and it can not deliver isolation so it is harmful and it needs an independent mosfet so it is not a good idea !
and just one of them which is used a feedback path can be good but not simple ! because it has used some integrated circuits !
So what you're suggesting is not SMPS in fact ! they are just hobbies !
I know how to make a good SMPS with 555 but it won't be simpler than what i've introduced .
Good Luck
Goldsmith

 

[kam1787]

1) they have no feedback path and it can not work in flyback mode
2) it can not deliver isolation so it is harmful and
3) it needs an independent mosfet so it is not a good idea !
4) because it has used some integrated circuits !

1 - not critical in the OP's application, and usually not a concern
2 - same as 1)
3) why? same argument you have as 1?
4) can you explain?

 

[audiospecialist]

probably better to buy a commercial unit. Mine cost about 8USD. Otherwise there are many - often using a 555. Why SMPS?

SMPs is for Efficiency and operation directly from mains,size advantage. Otherwise I would have used lm2577 with a trafo. I have 40 volt 120 va trafo at my disposal

Hi audiospecialist
I suggest you to pick up a TOP256EN/YN which is a good thing for this aim ! and then go through a flyback converter based on that .
Best Wishes
Goldsmith

Honestly I am not good at designing (Not a Mathematics friendly ) so expecting a tested schematics.
I do have a good test bench with tek oscilloscope,fluke multimeters,function generators but have enough of bad luck in design success.

- - - Updated - - -

some of your links are like a toy for kids because they have no feedback path and it can not work in flyback mode and it can not deliver isolation so it is harmful and it needs an independent mosfet so it is not a good idea !
and just one of them which is used a feedback path can be good but not simple ! because it has used some integrated circuits !
So what you're suggesting is not SMPS in fact ! they are just hobbies !
I know how to make a good SMPS with 555 but it won't be simpler than what i've introduced .
Good Luck
Goldsmith

Goldsmith,
It would be kind of you if you can post a good simple circuit.

Question is being a Diyer why should I buy smps ,I am supposed to make one ,right?

 

[kam1787]

Question is being a Diyer why should I buy smps ,I am supposed to make one ,right?

But SMPS is a non-trivial project. I would not attempt it. Cheaper, faster, easier to buy.

 

[goldsmith]

1 - not critical in the OP's application, and usually not a concern
2 - same as 1)
3) why? same argument you have as 1?
4) can you explain?

Hi Kam1787 !
About1 : do you know what a rubbish thing is a PSU without feedback ? and in flyback action without feedback means simply bad explosions on the circuit !!!!
About 2 : it is critical because a non isolated PSU is pretty harmful ! when it is dealing with the main power line directly !
About 3 : what i've introduced needs no kind of independent mosfet because it has one powerful switch internally !
About 4 : a good design requires simplicity ! when you can design a circuit with less number of components so if you do something than this then you are doing a bad design with unnecessary elements ! and it is dealing with higher price and less quality and more dimensions !

ok ?

Honestly I am not good at designing (Not a Mathematics friendly ) so expecting a tested schematics.
I do have a good test bench with tek oscilloscope,fluke multimeters,function generators but have enough of bad luck in design success.

Hi audiospecialist
Please take a look into the datasheet of the IC which i've introduced above then you'll see gang of circuits which can cover your aim with some simple changes .

But SMPS is a non-trivial project. I would not attempt it. Cheaper, faster, easier to buy.

Perhaps for you it is the best way but as it appears for the topic starter it is not a good way ok ?


Best Wishes
Goldsmith

 

[audiospecialist]

But SMPS is a non-trivial project. I would not attempt it. Cheaper, faster, easier to buy.

I do realize it.
It may be easier,faster,cheaper but may not be reliable.

If I can design my own I will know the limits.

Smps for me is not trivial ,rather very interesting and intriguing thing,A typical Electronic enthusiast here.
____________________________________________________________


@ Goldsmith,

Those Ics and switches I doubt are hard to find in my country.

Can you post some schematics with simple transistors like Irf840 ?
a transistor,an optocoupler, couple of capacitors and a transfo that would make my day.
I have few of them but not sure how reliable. I am bit wary of high voltage involved .
I am an audio guy where I rarely had to go above 90 volts.


Regards.

 

[goldsmith]

Those Ics and switches I doubt are hard to find in my country.

Hi
Please try to have search in your local markets if you could find then everything is simple if you couldn't find then i've to suggest you another way .
If you could find i can give you a schematic . if you couldn't find i can give you another schematic based on more components .

a transistor,an optocoupler, couple of capacitors and a transfo that would make my day.
I have few of them but not sure how reliable. I am bit wary of high voltage involved .
I am an audio guy where I rarely had to go above 90 volts.

i think i couldn't catch what you're meaning !

Best Luck
Goldsmith

 

[audiospecialist]

Hi
Please try to have search in your local markets if you could find then everything is simple if you couldn't find then i've to suggest you another way .
If you could find i can give you a schematic . if you couldn't find i can give you another schematic based on more components .


i think i couldn't catch what you're meaning !

Best Luck
Goldsmith

All I could find is a Viper ic, couple of Irf mosfets in local markets.

What I meant was I am not very used to high DC voltage of smps, typically 300volts.Bit anxious about testing part, bit of anxiety while I turn on these power devices.But I have to get used to it.

Being an audio guy I had played around with op amps,transistors,transformer which operates much below 90 volts which are not as fatal as online smps.

 

[tpetar]

Check TNY ICs (TinySwitch)

**broken link removed**
**broken link removed**

LYTSwitch-4
**broken link removed**



Also there is factory maded small compact transformers for these designs.

Simplest working SMPS designs can be made with these ICs.


Best regards,
Peter

 

[mtwieg]

Isolation isn't always necessary with lighting. If the electronics and lamp are properly insulated from the environment, then there's really no need for it. Whether this is the case usually depends on how the lamp and heatsink are built. So you should first determine whether you need isolation or not.

 

[audiospecialist]

Isolation isn't always necessary with lighting. If the electronics and lamp are properly insulated from the environment, then there's really no need for it. Whether this is the case usually depends on how the lamp and heatsink are built. So you should first determine whether you need isolation or not.

ISolation is not mandatory as the case for Led driving which will remain encapsulated.



I couldnt find tinyswitch from my local market. They have no stock of such a component.

 

[audiospecialist]

Icould find this ICin my locality
TOP261EN Power Integrations - Switcher, Offline
Can we go forward with it?


Please note,I know how to wind steel stamped transformers I have made transformers from 50Va to 600Va. But I have never ever attempted to wind a ferrite tranformers other than some ferrite core Inductors for Loudspeakers.

Please do help me with smps transformer design considerations as well for this specific purpose. I have been going through some online literature for same but it sounds complicated and hard to digest sometimes.

 

[audiospecialist]

I could find one more IC locally,TOP223. will it help me for a simple 50 watts constant current SMPS.

What is holding me back is the constant current part,I am not yet sure how smps are current sensed and controlled.I couldnt figure out from Led driving schematic either.
So in case if you could get a tested one if I could build one may let the cat out for me.

 

[goldsmith]

Hi

What is holding me back is the constant current part,I am not yet sure how smps are current sensed and controlled.I couldnt figure out from Led driving schematic either.
So in case if you could get a tested one if I could build one may let the cat out for me.

Did you see it's application note or datasheet ? did you see the example circuits which the manufacturer delivered ?

Best Luck
Goldsmith