question about fuse...

csurban · Post by **csurban** » Mon Oct 02, 2006 9:30 pm

i know a little about fuses but still don't know enough to be able to buy one. I am under the impression that a fuse has a voltage and amprage rating. In my case, I don't need one that tests amprage, or shorts in the circuit, but one that limits the voltage to 10-11 volts... ish... ness... Can anyone find me one on the internet which would suit my needs or at least educate me enough so I can find one on my own?

evildragon · Post by **evildragon** » Mon Oct 02, 2006 10:08 pm

I believe what you are looking for, is a voltage regulator...

If you can deal with 12v, you can get a LM7812...

Krepticor · Post by **Krepticor** » Tue Oct 03, 2006 5:48 am

yea what a fuse does is whenever it reaches its limit current, it blows

they are cheap so fuses are used for protection purposes

evildragon is right hough you are probably talking about a Voltage Regulator, the LM7812 does the job and all, but I suggest the TI option since it is free and is much more efficient

Why is it more efficient?

The TI is a Voltage regulator, the LM7812 is an op-amp, one is simply designed to do what you want it to...if you want to know more someone else will have to take it from here

Post by **marshallh** » Tue Oct 03, 2006 5:10 pm

Krepticor wrote:The TI is a Voltage regulator, the LM7812 is an op-amp, one is simply designed to do what you want it to...if you want to know more someone else will have to take it from here

Actually, the TI regulators are of the switching type, which means they give pules of the input at varying speeds, to control voltage.
LM7805 type regulators are linear regulators, they are basically a big resistor that adjusts itself. All extra power is wasted as heat.
Go with a 78xx linear regulator until you have everything working, then replace it with a switching regulator if you are drawing a lot of current through it.