Relays and LEDs

SonixOS · 09-22-2002, 06:16 PM

I was at Radioshack yesterday buying a whole lot of stuff. I saw relays there and wondered how they work. Can I use those to power a pump? Also How would I make a simple circuit to turn on and off (with a switch) a bunch of LEDs?

bigben2k · 09-22-2002, 09:55 PM

Relays: it's easier to think of them as "powered switches": you apply power, and they flip a switch.

You don't need a relay to turn on LEDs. How many LEDS anyways?

All you need is a fair DC voltage source (PSU), and the right resistor.

SonixOS · 09-22-2002, 11:01 PM

those r two different questions BigBen.

bigben2k · 09-23-2002, 10:02 AM

Ok, then...

To answser your first question, I'll refer you to this article

To answer your second question, you need to know the voltage drop across the LEDs that you plan to use (Vled), the voltage that you're going to supply (V), and the current that the LED needs (Iled).

The value of the resistor can be calculated as (V-Vled) / Iled. With that number in hand, you'd pick the next higher up resistor value.

I hope that answers your questions.

SonixOS · 09-23-2002, 06:14 PM

Thank you my gracious sire.

09-22-2002, 06:16 PM	#1
SonixOS Cooling Savant Join Date: Mar 2002 Location: Silver Spring, MD Posts: 282	Relays and LEDs I was at Radioshack yesterday buying a whole lot of stuff. I saw relays there and wondered how they work. Can I use those to power a pump? Also How would I make a simple circuit to turn on and off (with a switch) a bunch of LEDs? __________________ -sonix- ======================= Antec SX830 Abit KR7A-133 MSI Geforce3 Ti200 VT128 TV-IN and TV-OUT Sound Blaster Audigy Linksys LNE100 V2.0 Toshiba DVD Drive 40x/16x IBM Deskstar 60GXP 60gig Watercooled http://www.sonixnet.tk =======================

09-22-2002, 09:55 PM	#2
bigben2k Responsible for 2% of all the posts here. Join Date: May 2002 Location: Texas, U.S.A. Posts: 8,302	Relays: it's easier to think of them as "powered switches": you apply power, and they flip a switch. You don't need a relay to turn on LEDs. How many LEDS anyways? All you need is a fair DC voltage source (PSU), and the right resistor. __________________ WBTA (Water Block Testing Alliance) Nordic Hardware WC 101

09-22-2002, 11:01 PM	#3
SonixOS Cooling Savant Join Date: Mar 2002 Location: Silver Spring, MD Posts: 282	those r two different questions BigBen. __________________ -sonix- ======================= Antec SX830 Abit KR7A-133 MSI Geforce3 Ti200 VT128 TV-IN and TV-OUT Sound Blaster Audigy Linksys LNE100 V2.0 Toshiba DVD Drive 40x/16x IBM Deskstar 60GXP 60gig Watercooled http://www.sonixnet.tk =======================

09-23-2002, 10:02 AM	#4
bigben2k Responsible for 2% of all the posts here. Join Date: May 2002 Location: Texas, U.S.A. Posts: 8,302	Ok, then... To answser your first question, I'll refer you to this article To answer your second question, you need to know the voltage drop across the LEDs that you plan to use (Vled), the voltage that you're going to supply (V), and the current that the LED needs (Iled). The value of the resistor can be calculated as (V-Vled) / Iled. With that number in hand, you'd pick the next higher up resistor value. I hope that answers your questions. __________________ WBTA (Water Block Testing Alliance) Nordic Hardware WC 101

09-23-2002, 06:14 PM	#5
SonixOS Cooling Savant Join Date: Mar 2002 Location: Silver Spring, MD Posts: 282	Thank you my gracious sire. __________________ -sonix- ======================= Antec SX830 Abit KR7A-133 MSI Geforce3 Ti200 VT128 TV-IN and TV-OUT Sound Blaster Audigy Linksys LNE100 V2.0 Toshiba DVD Drive 40x/16x IBM Deskstar 60GXP 60gig Watercooled http://www.sonixnet.tk =======================

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