0
\$\begingroup\$

I want to know for a constant led driver having voltage ranges of min-max, like 21-42VDC,150mA minimum and maximum how many LEDs can be connected in series.

Please help me regarding above matters.

\$\endgroup\$
2
  • 1
    \$\begingroup\$ That would depend on the LED operating voltage. Different color LEDs have different operating voltages. \$\endgroup\$ – Justme Aug 13 '20 at 6:48
  • \$\begingroup\$ How long is a piece of string? No LED data sheet means it's guesswork. \$\endgroup\$ – Andy aka Aug 13 '20 at 8:03
1
\$\begingroup\$

A single white LED tends to have a voltage drop of about 3 V. That means 'about' 7 to 14 single white LEDs. Without knowing how much tolerance your power supply has to load voltages slightly outside the stated limits, it would be safer to restrict that to 8 to 13 series single LEDs.

LEDs sometimes come packaged in multiple series units, so would have a much higher terminal voltage. Connect the LEDs you want to drive to the supply (making sure they are specified to handle the 150 mA) and measure the voltage.

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.