Hello, I signed up to this forum hoping to get some guidance for my project.

My goal is to wire/solder 10 3mm blue LEDs (3.3Vf & 20mA) into the thrusters of a gundam model kit. I've been looking at tutorials and guides for basic circuits, and have a decent understanding of ohms law and series circuits.

-The main issue I'm having is trying to figure out how to power all of these LEDs with a power source small enough to fit in the extremely limited space within the model. The model has a plastic fuel pod that is large enough to house a 1 AAA battery. That was my plan until I realized the 1.5V from that single AAA battery isnt enough to power the 3.3Vf needed for a single blue LED...

-I'm a little shaky in understanding how parallel circuits work but it sounds like that would be a better option than wiring the 10 LEDs in a series circuit. Is it possible to power all of these LEDs with a AAA battery? I think stacking CR1025 lithium (3V) button batteries could also be an option, since they have a similar diameter as a AAA battery.

-I understand that it is the current that determines how bright an LED glows. I dont want my LEDs to run at full brightness, so I want them to have about 10mA running through them.

Please keep in mind that I have little to no knowledge of anything outside of basic circuits and materials. And I have no materials to work with-- I've been writing down the supplies that I'll need for the project to save money. So if you're going to suggest any new items please describe what they do x__x

Thank you!

 

Well there's one problem that's hard to get around. You want 10 LEDs each consuming power at 3.3V x 10mA x 10 LEDs = 330mW. If you want to run those LEDs for an hour, you need 330mWh of battery capacity. Depending on the efficiency of the battery-to-LED solution, you might need 500mW, or 500mWh of capacity to get an hour of run time.

A CR1025 cell has a capacity of about 75mWh (~2.5V x 30mAh). So even if you stack 3 of them, you'll have less than half an hour of run time.

I think you need a Li-ion battery to get the highest energy density into your battery. Pick the biggest one you can live with.

As for the circuit, your life will be easiest if you wire a single series string of 10 LEDs. Then you need just one current controller (which might just be a resistor), and all the LEDs will be a similar brightness because they carry identical current. The downside is you'll need a boost converter that can output up to about 35V.

 

There is no such thing as a button cell you can get 20 ma out of.
And wayneh just beat me to the answer.
No point in continuing as I can't improve on his advice.

 

Hello, I signed up to this forum hoping to get some guidance for my project.

My goal is to wire/solder 10 3mm blue LEDs (3.3Vf & 20mA) into the thrusters of a gundam model kit. I've been looking at tutorials and guides for basic circuits, and have a decent understanding of ohms law and series circuits.

-The main issue I'm having is trying to figure out how to power all of these LEDs with a power source small enough to fit in the extremely limited space within the model. The model has a plastic fuel pod that is large enough to house a 1 AAA battery. That was my plan until I realized the 1.5V from that single AAA battery isnt enough to power the 3.3Vf needed for a single blue LED...

-I'm a little shaky in understanding how parallel circuits work but it sounds like that would be a better option than wiring the 10 LEDs in a series circuit. Is it possible to power all of these LEDs with a AAA battery? I think stacking CR1025 lithium (3V) button batteries could also be an option, since they have a similar diameter as a AAA battery.

-I understand that it is the current that determines how bright an LED glows. I dont want my LEDs to run at full brightness, so I want them to have about 10mA running through them.

Please keep in mind that I have little to no knowledge of anything outside of basic circuits and materials. And I have no materials to work with-- I've been writing down the supplies that I'll need for the project to save money. So if you're going to suggest any new items please describe what they do x__x

Thank you!

Is this model on a stand so you can put the battery in the stand? Maybe put the LEDs there also and run fiber optic cables up to the model?

 

Here's a circuit: