does anyone here know about electronics and voltage stuff for LED bulbs?

[MrMiles]

I am looking to buy these LED lights to put on a model

https://www.amazon.com/dp/B06XPV4CSH/?coliid=IV5IMRBPCE99G&colid=Z5AFC41ZTR4O&ref_=lv_ov_lig_dp_it&th=1

 

i want to use 4 of the orange ones and would like to light them with 1 switch.  According to the chart, on the page, the orange is 1.8v to 2.0v forward voltage.   I need to use really small batteries, so i was thinking of using the 3v disk battery. 

 https://www.amazon.com/Duracell-Lithium-Battery-lasting-battery/dp/B0855FD9P2/ref=sr_1_1_sspa?crid=15W7DWF18IETD&dchild=1&keywords=2032+battery+prime&qid=1629164122&rdc=1&sprefix=2032+batt%2Cautomotive%2C153&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExWUE1R09WSzM5Qk1FJmVuY3J5cHRlZElkPUEwNTI1OTMxMjlVTzU4UUFJOFM1NCZlbmNyeXB0ZWRBZElkPUEwMjk4MzI1M0MwM05QQTVZSlQzUCZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

here is where i get messed up. assuming that 4 oranges would need 8v total at the max range, would that mean i need to use 3 of the 3v battery and get a resistor to get rid of the extra 1 volt?  is this accurate? if yes, can anyone tell me which resistor to get?

i found this site, which looks like it is doing exactly what i am looking for (four LED in parallel. it looks like i need  

https://www.evilmadscientist.com/2012/resistors-for-leds/

 

or maybe i just have a 5th orange bulb and it would be exactly 9v if i assumed the 1.8v per bulb? i can run another bulb elsewhere and maybe i dont need a resistor

 

is my logic right?

 

 

Edited August 17, 2021 by MrMiles

[Ctmodeler]

11 minutes ago, MrMiles said:

I am looking to buy these LED lights to put on a model

https://www.amazon.com/dp/B06XPV4CSH/?coliid=IV5IMRBPCE99G&colid=Z5AFC41ZTR4O&ref_=lv_ov_lig_dp_it&th=1

 

i want to use 4 of the orange ones and would like to light them with 1 switch.  According to the chart, on the page, the orange is 1.8v to 2.0v forward voltage.   I need to use really small batteries, so i was thinking of using the 3v disk battery. 

 https://www.amazon.com/Duracell-Lithium-Battery-lasting-battery/dp/B0855FD9P2/ref=sr_1_1_sspa?crid=15W7DWF18IETD&dchild=1&keywords=2032+battery+prime&qid=1629164122&rdc=1&sprefix=2032+batt%2Cautomotive%2C153&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExWUE1R09WSzM5Qk1FJmVuY3J5cHRlZElkPUEwNTI1OTMxMjlVTzU4UUFJOFM1NCZlbmNyeXB0ZWRBZElkPUEwMjk4MzI1M0MwM05QQTVZSlQzUCZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

here is where i get messed up. assuming that 4 oranges would need 8v total at the max range, would that mean i need to use 3 of the 3v battery and get a resistor to get rid of the extra 1 volt?  is this accurate? if yes, can anyone tell me which resistor to get?

i found this site, which looks like it is doing exactly what i am looking for (four LED in parallel. it looks like i need  

https://www.evilmadscientist.com/2012/resistors-for-leds/

 

or maybe i just have a 5th orange bulb and it would be exactly 9v if i assumed the 1.8v per bulb? i can run another bulb elsewhere and maybe i dont need a resistor

 

is my logic right?

 

 

Run 1 3volt battery and wire all the led's in parallel so they'll all have 3 Volts. Even though they're rated 2 max I don't think 3 will blow em up. Go for it .

[peteski]

While connecting LEDs directly to a small 3V battery (which cannot supply high enough current to damage LEDs) should be safe, as a long life-long electronic hobbyist and professional electronic techcnician, I recommend using resistors with the LEDs.  Small resistors with 1/8W power ratin will work well.

If you Google for "LED calculator", you''ll find plenty of examples. Some better than others.  Here is I handy one I randomly chosen from that search: https://ledcalculator.net/

With a 3V power supply you will have to take each LED/resistor combo and connect them in parallel with  the battery.  This site shows how to connect them in parallel: https://www.ledsupply.com/blog/wiring-leds-correctly-series-parallel-circuits-explained/

A small 3V battery has very little capacity. It will not last very long with directly attached 4 LEDs. Well, that depends on how much current you pass through the LEDs (see the calculator).  10mA (or 0.010A) current is a good value for fairly bright light. Go higher (20mA or 0.020A) lower (5mA or 0.005A, or even down to 1mA or 0.001A).  If you hook the LEDs directly to the battery you have no control over the current. If you use resistors, you can control (lower) the current to make the battery last longer (but the LEDs will not glow as bright).

 

[MrMiles]

33 minutes ago, peteski said:

While connecting LEDs directly to a small 3V battery (which cannot supply high enough current to damage LEDs) should be safe, as a long life-long electronic hobbyist and professional electronic techcnician, I recommend using resistors with the LEDs.  Small resistors with 1/8W power ratin will work well.

If you Google for "LED calculator", you''ll find plenty of examples. Some better than others.  Here is I handy one I randomly chosen from that search: https://ledcalculator.net/

With a 3V power supply you will have to take each LED/resistor combo and connect them in parallel with  the battery.  This site shows how to connect them in parallel: https://www.ledsupply.com/blog/wiring-leds-correctly-series-parallel-circuits-explained/

A small 3V battery has very little capacity. It will not last very long with directly attached 4 LEDs. Well, that depends on how much current you pass through the LEDs (see the calculator).  10mA (or 0.010A) current is a good value for fairly bright light. Go higher (20mA or 0.020A) lower (5mA or 0.005A, or even down to 1mA or 0.001A).  If you hook the LEDs directly to the battery you have no control over the current. If you use resistors, you can control (lower) the current to make the battery last longer (but the LEDs will not glow as bright).

 

 

thank you both very much for the help. would this be the correct resistor?

https://www.amazon.com/8-Watt-Carbon-Film-Resistors-5-Pack/dp/B007Z7Q5QY/ref=sr_1_1?dchild=1&keywords=1%2F8w+power+rating+resistor&qid=1629169291&refinements=p_85%3A2470955011&rnid=2470954011&rps=1&sr=8-1

 

[peteski]

If the LED resistor calculator indicated that a 100 ohm resistor should be used, then yes, those resistors you liked to on amazon will work correctly.

But the price makes me cringe!  I buy my electronic components directly from large distributors (like Digikey or Mouser Electronics) and I get them usually for less than 10 cents each.  But those sites are a bit overwhelming for someone not familiar with electronic components. I guess if all you need is few resistors that are easy to order then paying $4 for 5 resistors is not all that bad.

Here is a similar resistor at Digikey (10 cents each, or 10 for 74 cents).  Of course there will be shipping charge.

https://www.digikey.com/en/products/detail/yageo/CFR-12JT-52-100R/13921235

[Cool Hand]

Check this place out.

https://evandesigns.com/

[jchrisf]

Get and learn something like this:

https://www.amazon.com/ELEGOO-Project-Tutorial-Controller-Projects/dp/B01D8KOZF4/ref=sr_1_8?dchild=1&keywords=electronics+kit&qid=1629320540&sr=8-8

And you could probably create something cool like this: