I need current amplifier

[hossam abdo]

Dears

I want to design a circuit for lighting 150 high power led through NE555 and battery is 9v
but 150 led are more so i need current amplifier


thanks in advance

 

[mister_rf]

Read here:
https://www.edaboard.com/threads/218748/
Need to connect LEDs in series and to use additional transistors.

 

[mister_rf]

More details how to connect the LEDs and bipolar transistor:

 

[ZASto]

150 High Power LEDs and 9V battery? It ain't gonna work for long time.

 

[hossam abdo]

i can use an AC-DC adaptor
voltage range: 1.5v,3v,4.5,6,9,12
and the maximum current range is 1000mA

is this available to light 150 high power led
(the leds are connected in parallel without any resistance connected to it)

 

[mister_rf]

That’s not a very good idea connecting all the LEDs in parallel (especially without any resistors :shock: ).

Let’s suppose you may provide for each LED external current limitation at 20mA, in this case for 150 LEDs we need to supply a total of 150 x 20 mA= 3000mA = 3A.

If we combine 150 LEDs in strings of 3 LEDs, we obtain a total of 50 strings, each LED in string share the same current, so there’s a need only for 50 x 20 mA = 1000mA= 1A, three time less than the parallel connection.

 

[hossam abdo]

That’s not a very good idea connecting all the LEDs in parallel (especially without any resistors :shock: ).

Let’s suppose you may provide for each LED external current limitation at 20mA, in this case for 150 LEDs we need to supply a total of 150 x 20 mA= 3000mA = 3A.

If we combine 150 LEDs in strings of 3 LEDs, we obtain a total of 50 strings, each LED in string share the same current, so there’s a need only for 50 x 20 mA = 1000mA= 1A, three time less than the parallel connection.

but what i think about for , if any led is burnt out , does not affect the remain led.
in your schematic if one led from the string failed, all the leds through the string do not work

 

[mister_rf]

In a proper circuit, keeping the current/voltage to the normal settings, expected LEDs lifetimes are 25,000 up to 100,000 hours, so don’t worry, no LEDs failure for the next years…

 

[hossam abdo]

can i put a current amplifier

 

[mister_rf]

See the diagram I have already attached, there the NPN transistor is acting as a current amplifier.

 

[greentree]

Hi dear
you can't turn on your all of your leds at one time because the battery be empty!
but you can turn on for example 10 led together . the circuit of mr.mister_rf is true but you must not turn on all of the leds at one time.

Best wishes
Green tree