Need current to flow one way

**Yuriy** · 06-25-2004, 06:27 AM

I need my current to flow only one way (this is for the laptop/battery setup).
From what I know, I need to use a diode, like this one:

In Russia I would normally just go to the radio market and buy a box of these, but where can I get them in US? Also, I think it might be possible to use the light diode (LED) - do any of you know if it's true?
Any cheap alternatives?
I'm going to disect a few of my old gadgets tomorrow and make my circuit, but I thought I'd first ask the experts what's best.

Cheers

**masch** · 06-25-2004, 07:15 AM

diodes are quite cheap.

In the US, visit your nearest Radio Shack if you want quick and easy.
LEDs dont work the same way. LEDs will need a resistance in series so it doesnt blow.

Some LEDs are bi-directional if I remember correctly

**djmickyg** · 06-25-2004, 07:32 AM

you can use an led but u gota rember the led will use some voltage where as the normal diode wont use hardly anything

and u can use a led without a resistor as long as the voltage is right,

**Yuriy** · 06-25-2004, 08:12 AM

Well, I came up with a solution. I know there are diodes in AC/DC adapters, so I'll just disect a few

**b_nom** · 06-25-2004, 08:24 AM

The reason LED's won't work is because they are low current devices (around 20mA) thus the need for a resistor in line for 12V use (around 600ohms resistor needed).

You have to make sure that whatever diodes you dissect are capable of handling the current that's going to pass through them i.e. whatever your system will use, because they could heat up and eventually break down or blow up.

WHen I was in school we use to blow up diodes in the electronics lab to stir up the teacher