Hey,
I've bought high power LED and the seller told me that it is 50-watt and operate on 36 volt
then I've tried to turn it on with power supply and fix it on 36 volt, but when I measured the volt by a Multimeter I found it is just 26 volt, and when I disconnect the LED i found that it turns to 36 volt again. I am really in trouble because I am student and I have project to propose in some days. can anyone explain what's going on?
second thing i want to design a circuit to maintain a DC current with voltage and current intensity -that I still can't determine- from a usual 220 v-AC current.
first thing, I don't know what is the difference between stepping down the current with a transformer or by attaching high resistances to dissipate the rest f the volt, so please tell me the difference..
second thing, I've read about rectifier and using capacitor to smooth the waves of the current but still have no idea about how should I caculate the suitable value of its capacitance and am I need a regulator or not?
I am very grateful to anyone will try to help me
thanks

 

Hey,
I've bought high power LED and the seller told me that it is 50-watt and operate on 36 volt
then I've tried to turn it on with power supply and fix it on 36 volt, but when I measured the volt by a Multimeter I found it is just 26 volt, and when I disconnect the LED i found that it turns to 36 volt again. I am really in trouble because I am student and I have project to propose in some days. can anyone explain what's going on?
second thing i want to design a circuit to maintain a DC current with voltage and current intensity -that I still can't determine- from a usual 220 v-AC current.
first thing, I don't know what is the difference between stepping down the current with a transformer or by attaching high resistances to dissipate the rest f the volt, so please tell me the difference..
second thing, I've read about rectifier and using capacitor to smooth the waves of the current but still have no idea about how should I caculate the suitable value of its capacitance and am I need a regulator or not?
I am very grateful to anyone will try to help me
thanks

You will get more help if this is posted in general electronics.
Let's see if we can get a moderator to move it.

 

Power supply can't provide sufficient power.

What is its current capacity?

 

There are no mods signed in right now so I can sneak in a few comments.
1) Don't post duplicates.
2) ask only one or two questions at a time. Nobody wants to write a book covering 5 or 6 concepts from theory to application in one response.

 

So far, this guy has started FOUR threads on exactly the same topic. That's got to be a record.

ONE IS ENOUGH!!!!!!!

 

To turn on such LED, the 36Volt power supply must be capable of delivering at least 50 Watt, or at least 1.4 Amperes.
If the voltage drops from 36V to 26 Volt attempting to turn the LED on, that power supply is incapable to meet the requierements of such LED. Do NOT use more voltage. Choose 36V from a power supply labeled capable of more power (Watts)

 

I agree with Externet , Power supply is not able to deliver required power.

Voltage - 36V,
Power - 50W
required current - 50/36 = 1.388A.

May be power supply Maximum current is 1A or your current set at 1A, if it is bench power supply , try to increase the current limit , so that Voltage will regulate at 36V. If power supply is getting from Adapter , change it.

 

all right, what about designing the circuit ?

 

So far, this guy has started FOUR threads on exactly the same topic. That's got to be a record.

ONE IS ENOUGH!!!!!!!

I am sorry, I just have a problem

 

I am sorry, I just have a problem

Biting my tongue

 

I don't know what is the difference between stepping down the current with a transformer or by attaching high resistances to dissipate the rest f the volt, so please tell me the difference.

A transformer may be larger but certainly more efficient.

A resistor works by basically burning off excessive voltage as heat, so it is very inefficient. Also, doing this cannot be discussed here as it violated the terms of service (TOS) of this site.

I've read about rectifier and using capacitor to smooth the waves of the current but still have no idea about how should I caculate the suitable value of its capacitance and am I need a regulator or not?

A cap may not be needed depending on what you are doing when looked at as a whole. Right now you are trying to mail down little pieces that do not make the whole circuit.

To start, make a block diagram. Then thing about how the blocks could be made with some circuit. When you can post that we all have a defined something to discuss.

 

thanks about explaining the difference between the transformer and the resistance
Now, what can I attach to the pcb after the transformer to get a DC current of 36 v and 1.388 Ampere ?

 

If there is someone else feeling the same I am; explaining the basic of basics on what to do, may end poorly understood by the apparent limited knowledge of the original poster.
Just find and use a ----> https://www.aliexpress.com/item/Uni...lgo_pvid=83f83aac-3a53-449a-81b4-830cf0c845cf

 

it can't be delivered to my country
and I want to design and make it not just buying it

 

It is not necessary to import that exact supply. Look for an equivalent one at your local electronics stores.
In that linked page, that power supply is also shown without its cover. All those components are needed to power your LED properly. Are you ready to understand how each works, find all of them and purchase them at your location, make a printed circuit board and put them back together properly ?

This is a schematic useable to build/copy one ----> http://www.eleccircuit.com/wp-conte...iagram-of-0-45V-8A-switching-power-supply.jpg

To design one, it will take many years of electronics engineering school. Chances are that when finishing studies to design one, new components in the market will push you back to start the design all over again.

 

I really Break up XD