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

[marconi]

Thank you. You can connect you figurines using the connector leads without a resistor to the eight 4.5V 30mA outlets instead of using a battery/batteries, one output and lead for each battery you substitute for - do not use the the higher amperage outlets though. One 30mA outlet replaces one battery in a compartment eg: in the head. Please confirm all works fine.

There is something in this which talks about what the higher amperage outputs can be used for - meant nothing to me though.

View: https://www.youtube.com/watch?v=r8JXlyZ3TpA

 

[T800mc]

Thank you. You can connect you figurines using the connector leads without a resistor to the eight 4.5V 30mA outlets instead of using a battery/batteries, one output and lead for each battery you substitute for - do not use the the higher amperage outlets though. One 30mA outlet replaces one battery in a compartment eg: in the head. Please confirm all works fine.

There is something in this which talks about what the higher amperage outputs can be used for - meant nothing to me though.

View: https://www.youtube.com/watch?v=r8JXlyZ3TpA

Thank you.

I watched them before I bought the soap reactor. I just thought I'd be sure before damaging anything.

I've tried the stubby thing both ways round via the soap reactor and the LEDs will not illuminate. I tried the stubby thing with batteries attached and they lit up fine. Something about the soap reactor that won't light up the LEDs in Batmans head.

 

[marconi]

I wonder if the stubby thing is not making contact with the terminals of the battery compartment.

Take two pieces of wire and sellotape one piece to one end and the other piece to the other end of the stubby thing. Touch the free ends on the contacts of the battery compartment - may have to swap over to get the polarity right.

The soap reactor is turned on?
[automerge]1597930633[/automerge]
A test: Using the stubby thing connected to the battery and inserted into the battery compartment please use your MM to measure the current through Batman's head LEDs.

 

[T800mc]

I wonder if the stubby thing is not making contact with the terminals of the battery compartment.

Take two pieces of wire and sellotape one piece to one end and the other piece to the other end of the stubby thing. Touch the free ends on the contacts of the battery compartment - may have to swap over to get the polarity right.

The soap reactor is turned on?
[automerge]1597930633[/automerge]
A test: Using the stubby thing connected to the battery and inserted into the battery compartment please use your MM to measure the current through Batman's head LEDs.

I opened the other large stubby thing and tried that and it worked. Excellent! Maybe an issue with that other one. Thank you so much for your help! How can I repay you?

 

[marconi]

I do not need recompense because I like helping out. These problems occupy me and give me 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/

I reckon some folk who may have been following this thread would like to see the working figures and a short ditty on your interest in these figures. Do you make films using them for instance? Pictures are always good.

Best wishes Marconi

 

[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 · Monday, Sep 28, 2020 🎬

Tap to view!

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 · Monday, Sep 28, 2020 🎬

Tap to view!

photos.app.goo.gl

View attachment 61102View attachment 61103

Looks great. Glad you got it sorted!