-DIY- Powering a 3 volt LED from a 4.5V supply

[T800mc]

I do not need recompense because I like helping out and these problems provide me with interest and mental stimulation but if you feel inclined perhaps make a £5 donation to the NSPCC towards their very good work.

NSPCC - https://www.nspcc.org.uk/

Yep I will do that.

So would you say I'm fine to use the soap reactor on any LED light up features?

 

[marconi]

Yes - you are fine to use any of the eight 4.5V 30mA outputs.

Each output is the equivalent of a electro-chemical battery as used in a figurine to power the led lights. The internal resistance Ri of each output is acting as the 'compensator' you mentioned so there is no need for an external resistor to do that - a battery also has an internal resistance.

For the higher amperage outputs - if you want to use those to power LEDs we'd need to talk again because they will have a lower internal resistance which is most probably not suited to powering an LED directly without introducing an external resistor - which we'd have to determine - not difficult.

 

[T800mc]

Yes - you are fine to use any of the eight 4.5V 30mA outputs.

Each output is the equivalent of a electro-chemical battery as used in a figurine to power the led lights. The internal resistance Ri of each output is acting as the 'compensator' you mentioned so there is no need for an external resistor to do that - a battery also has an internal resistance.

For the higher amperage outputs - if you want to use those to power LEDs we'd need to talk again because they will have a lower internal resistance which is most probably not suited to powering an LED directly without introducing an external resistor - which we'd have to determine - not difficult.

Brilliant, thank you for all your help

 

[T800mc]

Pretty much got this finished now. 3D printed spear with LED and the eyes wired up. Works great! Thanks for all the help!

Videos:

New video by Mark

photos.app.goo.gl

 

[DPG]

Pretty much got this finished now. 3D printed spear with LED and the eyes wired up. Works great! Thanks for all the help!

Videos:

New video by Mark

photos.app.goo.gl

View attachment 61102View attachment 61103

Looks great. Glad you got it sorted!