LED 12v conversion advice

[CAPTAIN FANTASTIC]

I bought an LED strip light from Lidl; it uses 6 x 1.5 AAA batteries. It is very bright with swiveled lights; I intend to fix it inside the boat, however, I would like to convert it to 12v.

The 6 x 1.5v batteries will provide 9v in total; if I connect it to the 12v battery boat system, will blow up. I need a tiny voltage reducer, I pressume Maplins will have what I need; But what exactly do I need to buy?

 

[st599]

A resistor.

 

[VicS]

I bought an LED strip light from Lidl; it uses 6 x 1.5 AAA batteries. It is very bright with swiveled lights; I intend to fix it inside the boat, however, I would like to convert it to 12v.

The 6 x 1.5v batteries will provide 9v in total; if I connect it to the 12v battery boat system, will blow up. I need a tiny voltage reducer, I pressume Maplins will have what I need; But what exactly do I need to buy?

Maplins have an example of how to calculate the value of a series resitance in their paper catalog ( at least they used to)

Determine the current it draws from 9 volts Take the voltage you want to drop as 14 minus 9 ( ie 5 volts) Calculate the value of the resistance from ohms law.

 

[northwind]

I bought an LED strip light from Lidl; it uses 6 x 1.5 AAA batteries. It is very bright with swiveled lights; I intend to fix it inside the boat, however, I would like to convert it to 12v.

The 6 x 1.5v batteries will provide 9v in total; if I connect it to the 12v battery boat system, will blow up. I need a tiny voltage reducer, I pressume Maplins will have what I need; But what exactly do I need to buy?

Voltage regulator - MC7809CT

 

[CAPTAIN FANTASTIC]

thank you all

 

[st599]

Voltage regulator - MC7809CT

Why would you need a voltage regulator?

 

[VicS]

Voltage regulator - MC7809CT

Perfect. OTT but a perfect solution

 

[William_H]

Battery LED light

What might be a better idea is to fit 6 X NiMh rechargeable batteries. Then fit a connector and recharge it off the 12v system. This means you have a portable light if you need it. As suggested you need to know the current draw of the light say 100ma (.1 amp). A resistor will then be needed to drop the voltage to charge the batteries. 7.2 volt batteries 14v max + 7volts at .1amp = 70 ohms. So 68 ohm resistor rated at 1 watt or more will do. If you reckon on only 12v battery when using the light then a 50 ohm resistor will be better. If you don't wan to use the batteries then the resistor again depends on LED current draw but for 100ma about 40 to 50 ohms should be close. good luck olewill

 

[Conachair]

Why would you need a voltage regulator?

Nice stable 9v from whatever the batts are at for less than 50p. Why not??

 

[st599]

A voltage regulator only provides regulated supply under certain loads and doesn't fail gracefully.

 

[northwind]

Why would you need a voltage regulator?

Because a 12v battery is never at 12v. When fully charged or being charged the voltage is higher. A regulator will ensure the volts remain constant for LEDs regardless of the state of charge of the batteries.

 

[marklucas]

Voltage regulator - MC7809CT

And if one was clever one could house the regulator in the space taken up by the batteries - simples.

 

[Conachair]

A voltage regulator only provides regulated supply under certain loads and doesn't fail gracefully.

I´ll let RS know, they´ll probably stop selling them.

 

[Alpha22]

A resistor, or combinations of resistors will only make a potential divider. This will reduce the input voltage, but only by a factor. As the input voltage changes from 11 to may be 15 volts when charging, the output will change in proportion.

A 9 volt regulator will do just that, regulate the input and produce only 9 volts on the ouput, regardless of the input. (Within reason!)

Beware, they do get warm, experiment a little before enclosing in a small space.