RF Key Fob transmitter  - Page 1
Forum section: electronics / rf-microwave

author: ThomasC4
author_rank: Newbie
timestamp: December 14, 2018, 05:03:40 pm
content: HelloGot this key fob transmitter you see in the images, I want it to light the small led light while I am holding down the transmitter button on the key fob.Using 2 3v 2032 button batteries as the power. It needs to be the power for both the RF receiver and the LED light.Here are the wiring diagrams and I have tried to wire them but have NO success in getting the RF receiver to be the thing that is turning on the led light.I am sure it is simple and I am missing something obviously but what is it? The light works. I get continuity on the RF receiver.ThanksThomasC4

author: Ice-Tea
author_rank: Super Contributor
timestamp: December 14, 2018, 05:13:57 pm
content: - Would help if you posted datasheet.- A LED needs current limiting (ie. resistor)- A LED has a polarity. Have you verified that?

author: ThomasC4
author_rank: Newbie
timestamp: December 14, 2018, 05:29:36 pm
content: The LED will light just connected to the battery no resistor needed.Have verified polarity.DATA Sheet attached.Receiver working voltage DC 3.5V-DC12VI have a flashing light on the receiver if I connect the power to the + and - terminals on the receiver to the power supply and hit the key fob. there is a small LED on the board that will light and flash.I tried the wiring diagram they show but the light was just always on as I suspected it would be when I looked at the diagram. So I am missing something in the schematic, not reading it right.Thanks for the help.

author: ThomasC4
author_rank: Newbie
timestamp: December 14, 2018, 05:32:37 pm
content: I think I just figured it outIs the X in the circle on the diagram suppose to denote what you are Turing on? in this case the place the LED should be?It is isn't it. DUH ....

author: ThomasC4
author_rank: Newbie
timestamp: December 14, 2018, 06:09:22 pm
content: So now it lights but the Key Fob will only turn it on and not off again.There are the instructions about how to change momentary by connecting the right side two points? Which are the right side 2 points on the board?I did a mark up on the board are these the two point they are talking about connecting via soldering a very small wire or just a glob of solder?Thanks.

author: Ice-Tea
author_rank: Super Contributor
timestamp: December 14, 2018, 06:13:22 pm
content: Quote from: ThomasC4 on December 14, 2018, 05:29:36 pmThe fact that it works (more specific: that you haven't destroyed your LED) doesn't mean no resistor is needed.Quote from: ThomasC4 on December 14, 2018, 05:32:37 pmYes

author: ThomasC4
author_rank: Newbie
timestamp: December 14, 2018, 06:27:56 pm
content: bought some resistors but when I put one in line on the + line the light won't light....They may be the wrong kind? Or I chose one that was to large for the circuit.I have had the LED lit for 5 min at a time and NO damage to the LED that I can see... It would be nicer if it was dimmer for the application I want it used for. But a little paint or a sharpie may do just fine in reducing the brightness.Here are the resistors that I bought of amazon.Thanks for the help Ice-tea.If I can get this to work as planned it will help a lot.

author: ThomasC4
author_rank: Newbie
timestamp: December 14, 2018, 09:33:45 pm
content: Okay,Got it working but not really the way I would like.It is a click on and a click off light now.I would like it to be light is only on when the Keyfob button is being depressed and when you let up the light goes off.Does anyone know of an RF receiver like that? It needs to be small like the one seen here.Or is there some mod I can make to this board to make that happen?ThanksThomas

author: Ice-Tea
author_rank: Super Contributor
timestamp: December 16, 2018, 03:48:07 pm
content: Look at the "manual". It's the "momentary" setting.

author: ThomasC4
author_rank: Newbie
timestamp: December 16, 2018, 03:50:37 pm
content: I tried that, but it would still just click on click off.