Main Site Documentation

FEZ Relay Component (single)


#1

Hi,

I bought the FEZ Relay (single) together with my Fez Domino, but I seem to be having a hard time understanding the FEZ relay brochure to make the necessary connections.

http://www.tinyclr.com/downloads/Component/Broch_FEZ_Relay.pdf

In the FEZ Relay brochure, it is stated:

[quote]Relay has 3 pins that can be connected to the electrical device as
a switch,C (Common pin), NC (Normally closed) and NO (Normally
open) pins.[/quote]

and…

[quote]“IN” will be the common pin and “OUT1” and “OUT2” are the
normally open and normally closed.[/quote]

Based on this statement, I assume that “IN” = [italic]Common Pin[/italic], “OUT1” = [italic]Normally Open Pin[/italic] and “OUT2” = [italic]Normally Closed Pin[/italic]. However there is another pin labelled “NC” on the relay, which is the fourth pin. Does “NC” mean [italic]Normally Closed[/italic]? If then, what is “OUT2” pin? :o

Thanks in advance. :slight_smile:


#2

Yeah that needs to be clarified. We will update it shortly but for now, the NC pin is not connected. NC = No Connect


#3

The brochure is fixed


#4

I had a question about the relay and sensors.

Say I wanted to make a remote weather station that returns it’s data every 30 minutes. To have all the sensors running all the time would be a waste to battery life, since I only need to sample twice an hour.

Could you use one of these relays to disconnect the current to the sensor when not needed, and the turn it on when needed, perhaps a minute or so prior?

**

Granted the draw for these sensors may be very small and a battery may last for a while anyways, but this the best example I could think of at the moment.


#5

Relays are used to control large load at high voltage. You can use simple transistor to control your sensors’s power.


#6

Am I assuming correctly then that this transistor would be connected to an FEZ analog pin?

As a follow up - is the Electronics for Dummies a recommended book? Or is there another that’s recommended?


#7

No digital pin. Transistor are like small relays (simplified explanation)


#8

Thanks! The updated brochure is clear now. :wink:

This relay is used to power high voltage devices. e.g. FEZ Relay component is rated at 250 Volts 10Amps, so generally it will be able to switch electrical devices which are rated below this maximum.

For lower voltage, transistors can be used as switches. i.e. NPN transistors = [italic]Normally Open[/italic] (Off on LOW) and PNP transistors = [italic]Normally Closed[/italic] (On on LOW).