Leds

[chandu13]

Hi

Iam making LED TUBE light. In this light i want use 120 LEDs

I want glow 120 LEDS by using 230V.

Iam planning to use 24V DC transformer. How to connect 120 LEDS in parallel

or in series with 24V supply.

Thank you

regards

chandu

 

[audioguru]

A transformer makes AC not DC. A power supply makes DC. If you have a 24VDC power supply then connect a number of LEDs in series and in series with a current-limiting resistor. Repeat the LEDs and resistor strings with as many strings as you want until the power supply's max current is reached.

You need to know the usual operating current of the LEDs (most are 20mA to 25mA) and their typical forward voltage at that current. Different colours have different forward voltages.

 

[chandu13]

Thanks for the reply

Iam using 24V, 1A DC power supply and 20mA LEDs.

Here I want use only one resister in series with LEDs
or for each LED with series resister.

Please can you provied circuit for this one.

Regards

chandu

 

[picasm]

Use this array calculator to design your circuit:
**broken link removed**

You need to know the forward voltage for the colour/type of led you are using in order to get it right though.

 

[Hero999]

Save yourself the trouble and by a slimline fluorescent tube or a cold cathode tube for the 24DC option.