Using a low power relay as a simple switch

Other Hardware General Electronics
1

I just picked up the following from my local store:

[ NEC EE2-4.5NUX ]

After doing quite a bit of searching I have not been able to find anything on how to use this low voltage relay. The datasheet is unfortunately very hard for me to understand.

All I want to do is switch another circuit on and off, but what are the six pins there? Which pin or pins do I power and which do I ground?

Here is a picture of the device, in case you have used this particular model:

EDIT: I have found a better schematic:

Not sure if that is accurate, but this device is a DPDT relay, can anyone explain the circuit there a little (primarily the N0 C NC pins)?

Thank you!

2

C stands for common, NO is normally open and NC is normally closed. Normal means with the coil not energised.
The coil needs to have power switched through it like the diagram but it also needs a component called a diode connected across the coil, anode to the +12V side of the coil. This protects against large voltages that are generate when the coil switches off.

3

Thank you mike!

After writing all that out and reading your post I realized that I should have been searching for how to wire the DPDT relay rather than the specific product itself.

As further reference the following seems like a good post as well: How to Connect a DPDT Relay in a Circuit

One more thing, are there any readily available low voltage solid state relays? [3.8v - 5v]

4

No solid state relays tend to befor AC only. For small DC voltages all you need is a transistor or a FET, that does exactly the same thing.

5

Just finished soldering and got this relay to function well. Currently I power it via the lilypad and a 1000mAH 3.7 lipo. Wish I could avoid the clicking sound though.

Thanks for clarifying the solid state relays. I have tried a transistor with this, but the other end of the circuit wasn't compatible with that method. :confused:

Thanks again.

6

What do you mean by not compatible?

7

power it via the lilypad and a 1000mAH 3.7 lipo

mAH is a batteries total capacity not the amount of current it can delver at any time.

Wish I could avoid the clicking sound though.

Do you mean the relay?

I have tried a transistor with this, but the other end of the circuit wasn't compatible with that method.

You need a circuit called a H-bridge, you can make them with transistors or get them ready made in a chip. They are made for driving motors in either direction.