3v step down from 12v

[Crafts4Me]

hi
thanks
that was the issue
output was 9.89 i was able to turn the potentiometer to read 3.10 the first flame bulb was burnt out but the rest are amazing.
i learned something.
thanks so much
1- i have the multimeter
2- that there is a potentiometer that can be adjusted

i appreciate all your assitance

is there a good tutorial to learn how ro use the multimeter across all applications?

 

[bertus]

Hello,

Perhaps this sparkfun page might give you an idea what is possible with a multimeter:

https://learn.sparkfun.com/tutorials/how-to-use-a-multimeter/all

Bertus

 

[Harald Kapp]

Good link by @bertus .
One simple tip to remember:
- voltages are measured in parallel
- currents are measured in series

 

[Martaine2005]

One other simple tip:
Using old baking trays are metal and conductive, always use an insulator material too so not to short the solder side of boards.
If you have a cutting board, place it between the baking tray and PCB.

 

[Crafts4Me]

hi
now that i added this bulb flame lamp to my project do i have to woory it will get hot over time or once ts been adjusted corectly and reads 3 v it will stay in a safe mode?

 

[Harald Kapp]

once ts been adjusted corectly and reads 3 v it will stay in a safe mode?

It should, indeed.

 

[Crafts4Me]

thank you
project completed perfectlyi appreciate all the help
i am sorry the photo isnt so clear so i cannot attach it

 

[Crafts4Me]

this worked wonderfullly. my display was a hit.
can i use the same board to step down to USB 5v ?
i want to add the following

https://he.aliexpress.com/item/1005005443652985.html?spm=a2g0o.order_list.order_list_main.5.5aa71802TmHllH&gatewayAdapt=glo2isr

Aquarium Oxygen Air Pump Fish Tank USB Silent Air Compressor Aerator Portable Mini Small Oxygenator Aquarium Accessories 5v
to simulate a bubbling pot.
i need to step down the 12v to the 5v

 

[Harald Kapp]

And with respect to your other thread: yes, you can use the module used here also for 5 V with the appropriate setting of the potentiometer.

 

[Crafts4Me]

how do i use the cigarette adaopter that seems easier

 

[Harald Kapp]

Look in your other thread. I described it there.

 

[Crafts4Me]

i saw but how do i attach my wires?

 

[bertus]

Hello,

Something like in this add should work:
https://www.walmart.com/ip/12-24V-D...Socket-Plug-Connector-Adapter-Cable/124493514

Bertus

 

[Harald Kapp]

i saw but how do i attach my wires?

Solder?

 

[Crafts4Me]

thats what i was asking regular solder+ and -?

 

[Crafts4Me]

would this work?

https://he.aliexpress.com/item/1005007247452607.html?spm=a2g0o.productlist.main.10.d37a553dXkJr4P&algo_pvid=8f275a92-9d3d-45b6-8bb8-1b6e4d380a16&algo_exp_id=8f275a92-9d3d-45b6-8bb8-1b6e4d380a16-9&pdp_ext_f=%7B%22order%22%3A%22100%22%2C%22spu_best_type%22%3A%22price%22%2C%22eval%22%3A%221%22%2C%22fromPage%22%3A%22search%22%7D&pdp_npi=6%40dis%21USD%213.13%210.99%21%21%213.13%210.99%21%40212e4e5517652873845277999e0e20%2112000039938123951%21sea%21IL%210%21ABX%211%210%21n_tag%3A-29910%3Bd%3A766c82f3%3Bm03_new_user%3A-29895%3BpisId%3A5000000187623793&curPageLogUid=KySWRyxiCcxu&utparam-url=scene%3Asearch%7Cquery_from%3A%7Cx_object_id%3A1005007247452607%7C_p_origin_prod%3A

splice the 5v side and attach my aerator and then splice the 12v side into my 12v adaptor with the rest of my leds?

 

[Sunnysky]

TL;DR
Why bother when you can put 4x 3VLEDs in series and repeat as many in parallel as you want and switch on/off from ground with an NPN.
If that isn't enough current or your 12V reg is worse than 2% use 3 in series with a R to drop slightly less than 3V for I=V/R

Or do you need 5V for something else? and that has nothing to do with the LED voltage requirement.

What LEDs are you using (link)? if Vled = 3.1V then 3x3.1 = 9.3 then if 12V is 12.0 the drop is 2.7V/20 mA=135 ohms or nearest higher value.,

 

[Crafts4Me]

hi
i added to the same therad once again step down form 12v
my dioramas are all wired for 12v with LEDs etc
i want to add a 5v USB bubbler to the same wiring without needed another plug

 

[Harald Kapp]

would this work?

No, thats a 5 V to 12 V converter. You need it the other way round as I have shown in the other thread (now locked). You can use this kind of adapter and plug it into the one @bertus has shown in post #53, if you don't want to solder directly to the USB Adapter.
Like so:

 

[Crafts4Me]

hi
so would this one work?

https://he.aliexpress.com/item/1005009450431260.html?spm=a2g0o.order_list.order_list_main.5.5aa71802MHdlEK&gatewayAdapt=glo2isr