Why won't my LEDs light up with 9V and 60 Ohm resistance?

[John Readman]

Hi, I am trying to wire some leds up. There are 5 of them in series VF typ 3.2 V and 30mA. I am using a 9V square battery. 60 Ohm of resistance and an on off switch. Yet it does not light up. Is this because I do not have enough voltage??

P.S. Yes the switch is on!

Thanks,

Johnny

 

[uart]

Well here's a hint, what's 5 times 3.2? It's a lot more than 9 right!

LED's are very different than say something like a normal light globe in that they don't even start to conduct until the applied voltage is quite close to the rated voltage. So if the LED's nominal operating voltage is 3.2 volts then it's a pretty good bet that the current at say 2.0 volts will be very nearly zero. The result = no light.

 

[astrokreng]

Based on the information provided, it is likely that the LEDs are not lighting up because the voltage supplied by the 9V battery is not enough to power all 5 LEDs in series. Each LED requires 3.2V to operate, so 5 LEDs would require a total of 16V. With only 9V available, the LEDs are not receiving enough voltage to turn on. Additionally, the 60 Ohm resistance may also be limiting the flow of current to the LEDs. In order to power all 5 LEDs in series, you would need a power source with a higher voltage, such as multiple 9V batteries in series, or a power supply with adjustable voltage. It is also important to make sure that the LEDs are connected in the correct polarity and that the connections are secure. I would recommend consulting a circuit diagram or seeking assistance from an experienced individual to ensure proper wiring and power supply for the LEDs.