I have a 100w LED that needs 36Volt DC and 3 Amps. I do not have a 100+ Watt transformer; to get me 36 Volt DC. I have 10 Amp Bridge that can easily convert the mains 220 Volt AC. If we "temprary" ignore protection( fuses etc) I need the minmum components to give 36V with constant current of 3Amp circuit. Can you please help me or at least direct me to a link to get the 36v/3a circuit from 220v ac mains?

 

It is not simple to you and it is not simple to me.
You need to go and buy the appropriate LED power supply.

 

It is not simple to you and it is not simple to me.
You need to go and buy the appropriate LED power supply.

That sounds pretty simple.

 

I have 10 Amp Bridge that can easily convert the mains 220 Volt AC.

You're contemplating working with lethal voltages and building a 100W power supply/current source is not trivial. I wouldn't waste my time on such an endeavor.

 

Well, just to be contrary, if you can find a 400V AC rated ~40uF capacitor, it is fairly simple. Of course the entire circuit would be live and must be completely enclosed in a suitable box.

 

Great response(s). I am looking into the HV9910B (Universal High-Brightness LED Driver)

 

I have a 100w LED that needs 36Volt DC and 3 Amps. I do not have a 100+ Watt transformer; to get me 36 Volt DC. I have 10 Amp Bridge that can easily convert the mains 220 Volt AC. If we "temprary" ignore protection( fuses etc) I need the minmum components to give 36V with constant current of 3Amp circuit. Can you please help me or at least direct me to a link to get the 36v/3a circuit from 220v ac mains?

Show me the LED, does it have a product code? manufacturer?

 

 

View attachment 325797

Here ya go - Amazon

 

Thank you so much. You cannot get simpler than that for a solution

 

Do you FULLY UNDERSTAND the datasheet on the HV9910B and know how to do the calculations to select the other components required ? This will require a good understanding of switch mode power supply design.

Les.

 

Thank you so much. You cannot get simpler than that for a solution

You should look for some junk stores or laptop, computer, electrical repair stores, these often have crates of old working chargers just sitting around, because these are always labelled with voltage, power etc they can be easily searched through, you might just find one for next to nothing if you're lucky.

I've got a box of these myself, might even have one 36V but that won't help you.

 

Here ya go - Amazon

View attachment 325799

I don’t think so. Did you look at the look at the specs of the COB LED? 36V is at the top of the voltage range. This adapter would likely destroy a typical one.

The solution is a 3A constant current driver with 28-36V within the compliance range.

 

Simple for me, not for you! very true. AND like was mentioned, READ THE DATA SHEET!!. AND, if it is not already mounted on a suitable heat sink, that comes first. And then get two of the 15 volt supplies so you can drive it with 30 volts and not burn it up in a few seconds. This COB, (Chip On Board) device MUST HAVE ADEQUATE COOLING. Consider that the 100 watts of power in will mostly become 100 watts of heat right away. So visit the manufacturer's website and learn about how to carry that excess heat away, so that the LED will not burn up right away.A pair of 15 volt power supplies will power it very well, and make a bit less heat.

 

Do you FULLY UNDERSTAND the datasheet on the HV9910B and know how to do the calculations to select the other components required ? This will require a good understanding of switch mode power supply design.

Les.

Of course not. So I appreciate your warnings.

 

Why risk a failed design when switchers can be purchased from GOOD SUPPLIERS for a reasonable price.

 

I have 10 Amp Bridge that can easily convert the mains 220 Volt AC.

Not sure what you mean by this. Convert the mains voltage to what?

Be that as it may, is there a reason that you aren't willing/able to purchase a proper driver for this LED? They have become so ubiquitous that you can probably buy one for less than you can build something suitable.

 

Not sure what you mean by this. Convert the mains voltage to what?

Be that as it may, is there a reason that you aren't willing/able to purchase a proper driver for this LED? They have become so ubiquitous that you can probably buy one for less than you can build something suitable.

I see that the TS is telling us that it will be simple to rectify and filter the 220 volt mains power, leaving only the task of safely dropping the resulting 300 volts DC to the 30 volt/3 amp power needed to supply the LED COB module. I would find that designing the system to do that safely, inexpensively, and efficiently would be a serious challenge for most skilled engineers, including myself. Designing a good switch-mode supply is not a simple task, not is even just assembling one that is a good design.