0
\$\begingroup\$

I am trying to control an LED driver using a PWM signal but unfortunately the Raspberry Pi Pico is using 3.3V on PWM and the LED driver specification sheet specifies 10V. What can I do to step up the signal?

Documentation of the LED driver:

enter image description here

\$\endgroup\$
7
  • \$\begingroup\$ Add a link to the datasheet. Does it also have a absolute max and typical voltage chart? One option is to try it at 3.3V and see if it works (could fry the rpi maybe but unlikely). The other is to provide 10V with a separate power supply or even a 5v to 10v step up regulator. And then use a transistor or optocoupler to pwm it. \$\endgroup\$
    – Passerby
    Commented Mar 24, 2022 at 7:32
  • \$\begingroup\$ Looking at a random led driver of that brand, it has 10V dimming and it has pwm dimming, which you have to set using one of their programmers. It defaults to voltage based while the pwm option needs programming. Do you have the full datasheet or a programmer? \$\endgroup\$
    – Passerby
    Commented Mar 24, 2022 at 7:40
  • \$\begingroup\$ @Passerby I have full datasheet: inventronics-co.com/wp-content/uploads/2021/11/… \$\endgroup\$ Commented Mar 24, 2022 at 7:53
  • \$\begingroup\$ Yep page 5 says the default is the 0-10V positive logic voltage based dimming. You may want to confirm with their support but unless you program it into the pwm dimming mode it expects a steady voltage. \$\endgroup\$
    – Passerby
    Commented Mar 24, 2022 at 7:56
  • \$\begingroup\$ So I can make it work with optocoupler? \$\endgroup\$ Commented Mar 24, 2022 at 7:58

1 Answer 1

1
\$\begingroup\$

You may not need an external power supply since the pin appears to have a pullup (guessing 33K to internal +10 but it could be something else).

It may be worth trying this:

schematic

simulate this circuit – Schematic created using CircuitLab

If it works, it will work in reverse (100% PWM = off).

\$\endgroup\$
2
  • 1
    \$\begingroup\$ If I would need external power supply how should I connect it to the circuit? \$\endgroup\$ Commented Mar 24, 2022 at 8:16
  • 1
    \$\begingroup\$ Resistor from DIM+ to external power +, external power - to GND/DIM-. Try resistor 10K. \$\endgroup\$ Commented Mar 24, 2022 at 8:17

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

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