Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

1.5v relay?????

Status
Not open for further replies.

saskpuller

New Member
What I am trying to do is build a device that will activate the remote start system on my truck with a pager. I have all the components except a relay with a 1.5v coil. I need to get a ground pulse to the remote start module to make things work. I thought that if I got 1.5v from the vibrator motor on the pager and ran it thru a relay to send a ground signal, that would do it. Problem is I'm having problems finding a 1.5v relay. Anyone know where to find something like this or a different way of doing this?
 

audioguru

Well-Known Member
Most Helpful Member
The relay is mechanical. Therefore it uses a very high operating current.
Why not use a transistor to drive a normal 12V relay instead?
 

saskpuller

New Member
Forgive me in advance but I'm quite uneducated when it comes to this stuff. (Polite way of saying stupid). Could please advise on how to use the resistor to make a standard 12v relay work.
Many thanks in advance
 

saskpuller

New Member
Bump. I've got the dash pulled out of my truck and was hoping to get this project completed before too long. How do I use a transistor to make this work?
 

saskpuller

New Member
Sorry, clear as mud to me. I'll need any exact drawing or description of what I would need to do here. Will it work? or should I give up on this dream and just buy the kit for $350.
 

audioguru

Well-Known Member
Most Helpful Member
The transistor costs 10 cents to 20 cents. The diode and two resistors cost less.
If you spend $350 for them then you are being ripped off.
 

saskpuller

New Member
I've got diodes and resistors in the shop from the r/s installs. Just need to know what transistor to get and a "diagram for a dummy".
 

Diver300

Well-Known Member
Most Helpful Member
https://www.electronics-tutorials.ws/transistor/tran12.gif

That is what you want to be using. Vin and the switch on the left are replaced with the 1.5 V from the pager. The relay can be an ordinary automotive one. The diode can be just about any diode. 12V comes from the car battery, and is connected to the point labeled Vcc on the diagram.

You will need to look up which connection is which on the transistor that you bought. https://upload.wikimedia.org/wikipedia/commons/c/cb/BJT_NPN_symbol_(case).svg shows which the connection names (Emitter, Base and Collector or E, B, C)

The diode has to go the correct way round.

1.5 V from the pager (or an AA battery for testing) will make the relay operate.
 
Last edited:
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top