Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

Sustitute LED by resistor ( or anything else)

Status
Not open for further replies.
W

Winsu

Full Member level 3
Joined
Oct 25, 2017
Messages
174
Helped
2
Reputation
4
Reaction score
4
Trophy points
18
Activity points
1,691
Hi All,

I am designing a board with a LED driver ( ZLED7730) and I am having a problem. Most of the LED that I could buy are very expensive and I don't have a reflow machine at home to solder them properly. The reason that I am designing this board is juts for fun. I am thinking to put another component instead of a LED that can behave as an LED. I have thought about a resistor, but if I run the "led string" at 350mA, it is difficult to find a resistor which can with stand the wattage dissipated. Anyone have an idea of how to do it, thanks?

Winsu,
Regards.
 

ehehheh, it is true, and it is very simple as LEDs are diode....I understand now you moved this thread to elementary questions, thanks!!
 

If it is just one LED you want to substitute, 8.2 Ohms 1W will replace a 3V/0.35A LED.
If you are substituting the whole string, tell us what the total voltage and current will be for more advice.

Brian.
 

Hi,

Watt is watt.
It does not matter whether you use a LED, resistor, diode, transistor .... if you have to dissipate 8W, then each device generates the same amount of heat.

Klaus
 

The maximum current will be 350mA. The total voltage is up to me really. There is a couple of equation in the data sheet of the LED driver to set the Ton and Toff. The recommendation is to have a duty cycle close to 0.5, then I can calculate the value of the inductor if I know how much is the total voltage.

- - - Updated - - -

I have chosen this diode- it should have a forward voltage of 0.42V at 350mA. I can put 10 diodes in serie to get 4.2V. Each one would dissipate 0.45 * 0.35 = 0.147w.

The maximum wattage is 0.7w so it should be safe. Does it make sense?

The LED chose is:

https://www.farnell.com/datasheets/...88.1412559566.1588345999-510073113.1588345999
 
Last edited:

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top