I am looking for a simple mini rotating dimmer I can buy for a 5v to 8v circuit. Can I just connect a potentiometer to the LED and make it work? Is for 16 parallel 1 watts LEDs powered by 4 AA battery in series or powerbank.

thank you in advance for the help. best regards Vasco

  • \$\begingroup\$ Product recommendations are Off topic on this site. Also dimmers don't rotate, you mean a dimmer with a rotary knob. \$\endgroup\$ – Bimpelrekkie Jun 18 '20 at 19:36
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    \$\begingroup\$ I think 16 Watts is more than 4 x AA can manage. \$\endgroup\$ – Peter Bennett Jun 18 '20 at 19:39
  • \$\begingroup\$ 4x AA can do 16 Watts. It just wont be for multiple hours. 2.6 Amps isnt beyond their ability. But you have to adjust for voltage droop and capacity drain. 30 to 60 minutes would be a reasonable guess. \$\endgroup\$ – Passerby Jun 18 '20 at 21:25
  • \$\begingroup\$ Hi, thank you for the replies, I only need to run them in 20 minutes intervals in maximal power, If anyone could help me with the schematic for a mix of serial and parallel connections that make it work in maximal power? thank you \$\endgroup\$ – VOV Jun 19 '20 at 9:16

You can use a potentiometer in series with the LED (or a series of LEDs) to increase or reduce impedance. From 0 to 1000 ohms. But you won't find a pot able to work with 16W. (look for power dissipation formula). Power dissipation is the power transformed into heat generated by the resistance when current is crossing the pot or a resistor. Maybe several in parallel could work.

  • \$\begingroup\$ Thank you for the help, what is the maximal power that a potentiometer could deliver to a 5v circuit ? I can put some LED in serie to make it work maybe. I just need some help with the circuit design. thank you \$\endgroup\$ – VOV Jun 19 '20 at 9:20
  • \$\begingroup\$ It's better to put more LEDs in serie and try to match the voltage of the LED series with the power source. So the more LEDs in series, the more AA batteries in series too. If you are limited to 5V, it's not very good because you need more current (amperes) and the more current you need, the higher the power dissipation through the POT. 16W is already 3.2A. Meaning the power disspation could be too high. There is a formula for exact calculation but I forgot it right now, It also depends of the power rating of the POT. \$\endgroup\$ – Fredled Jun 23 '20 at 22:22

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