Convert 5v to 12v

[ChevyLT1Camaro94]

Hey i need to convert a 5v dc output from my tachometer to 12v dc for a different shift light i want to use. how can i go about doing this? include radio shack part numbers if possible, i dont like to order online due to credit problems so radio shack parts are prettty much my limit. thanks!

 

[flat5]

Vehicle already has 12 volts available. Right? Use that.

 

[blueroomelectronics]

Digikey sells em but they're not cheap. Radio shack won't have anything like a 5V to 12V DC-DC inverter.

 

[Andy1845c]

What is the 5v output designed to drive? An LED shift light or something? Whats the current draw of the shift light you want to use? I doubt the tach can even supply enough current.

Use the 5v output to turn on a transistor or small relay for your 12v shift light.

 

[ChevyLT1Camaro94]

What is the 5v output designed to drive? An LED shift light or something? Whats the current draw of the shift light you want to use? I doubt the tach can even supply enough current.

Use the 5v output to turn on a transistor or small relay for your 12v shift light.

exactly right, it had 2 leds hooked up to it, i made my own shift light with 8 leds and it lit that no problem so it has a decent current. i just need something like a relay tom get the 5v to transfer to 12 v.

 

[Andy1845c]

A little relay like this one may work. Jameco Electronics Electromechanical: OMRON ELECTRONICS: G6A-234P-ST-US-DC5&

Or you could use a transistor for even less current draw.

Let us know if you need more help.

 

[ChevyLT1Camaro94]

A little relay like this one may work. Jameco Electronics Electromechanical: OMRON ELECTRONICS: G6A-234P-ST-US-DC5&

Or you could use a transistor for even less current draw.

Let us know if you need more help.

Ok thats what i was hoping. I bought 2 15-packs of transistors today. 15 npn, 15 pnp. I honestly dont know anything about transistors and would like to figure them out a bit so what kind of transistor do i need? and will any of the ones i bought at radio shack work? If not do they have any that would work?
and how would i wire it up? A drawing would also be extremely appreciated. Thanks everyone

 

[Hayato]

There are thousands of transistor models. What are the transistors you've bought? (BC548? PN2222?...)

 

[ChevyLT1Camaro94]

i bout 2n222a, and 2n3906 and i have 2 model 2n3904's

 

[be80be]

Just use use 1 of them npn you got at radio shack the 1 that has 2n4401 on it will work the best with this don't load it with more then 200ma hope it helps i have used it 400ma

 

[ChevyLT1Camaro94]

thank u so much!@!!! lol i feel like such a noob but thanks again everyone

 

[ChevyLT1Camaro94]

one last question, with transistors, theres a flat side. in relation to your diagram, what direction would the flat side face, left or right?

 

[be80be]

The base is the is the tee looking part the emitter is the arrow going out to gnd. if you put the flat side to the right you should be right top pin collector middle pin base bottom emitter

 

[Andy1845c]

You will need to look at the datasheet for the transistor you are using. Or possibly the back of the package if you got them at RadioShack. You need to identify the base, collector and emitter. The flat side will allow you to tell if your looking and the front or back and then referance the datasheet.

 

[ChevyLT1Camaro94]

so i tried wiring it the way it said and i think i just fried the transistor. whats goin on here? i tried hooking up the 12v + to the top, and gnd to the bottom thinking it wouldnt connect because there was no 5v input. but it just smoked

 

[be80be]

Ok If you fried it you hooked it up wrong or you used the wrong transistor or it is using to much power. If you got the npn's from radio shack on the back it tell's you what pin is what. And every pack I have got from them that are npn has 2n2222a 2n3904 and 2n4401 in it you can get the most power with 2n4401. Do you no how much current your light is going to use. The thing your going to run in to is that your powering your transistor from a led off your tack which will not be able to put out so much current. so you'll have to use a transistor switch that's what I drawled you . If you could tell me what bulb your trying to lite I can draw you what you need.

 

[ChevyLT1Camaro94]

ok great i understand now, one thing though, is that a top view of the ransistor or a bottom view? because if i flip it it would be backwards haha. and the bulb is a 12v incandescent bulb. number 1107 i believe? its an autometer shift light im trying to adapt to my tach that uses an led shift light

 

[be80be]

Test the bulb to see how much current it will use. I think you have to go back to radio shack and get a tip 120 It can handle 5amps your bulb I think uses 1 to 2 amps
It may be a 22 watt bulb. The npn part 276-2068 it's a tip 120

 

[ChevyLT1Camaro94]

ok so i got the tip120 and wired it the same way and it did not work. what am i doing wrong? i wired it exactly as described in the diagram. someone help please

 

[holliday999]

I want to know too, I Know 12v to 5v, But I don't know 12v to 5v DC , About Rectify circuit?