Help setting up SPDT relay with RC Receiver on Quadcopter

Installed SPDT relay (item 2485) on Quad. Three position switch mapped in PPM stream to control switch that will turn on and off LED lights I’m using via the relay. No issue wiring up the LED side of the relay, I have a LiPo battery powering the LED’s with the ground side of the battery going to the NO connection and the ground continuing to the LED. When powered on, the LED’s are to stay off until relay activated from radio via the receiver channel.
Problem: When I connect the receiver channels to relay, the relay LED is blinking rapidly on and off and it feels like the relay is just continuously triggering on and off instead of staying in one state until triggered. The switch I have mapped to the receiver channel has no effect.
Receiver setup: Futaba radio with 3 position switch. Using SPPM mode where all the channels are sent in a serial stream, 12 channels, received and processed by receiver. Ch 1-5 are sent to flight controller as SPPM. channels 6-12 are decoded and sent out as actual servo outputs to control various items I have installed on Quad. Video switch to change which camera active, LED landing strips to change brightness, etc. Two channels were assigned to relay control. These are the ones I get no response from the relays on.
Any help or insight appreciated.

Hello, Jay.

It sounds like you are trying to use our Basic 2-Channel SPDT Relay Carrier with 5VDC Relays with hobby RC signals. That relay carrier uses high or low logic signals to trigger the relays (e.g. when the signal voltage exceeds approximately 2.5V, the relay is triggered), so they will not work directly with RC signals. You might consider our RC Switch with Relay instead:

This board accepts RC signals and has a user-configurable threshold. I recommend reading through the “RC Switch with Relay” section of the RC Switch User’s Guide to get a better understanding of how it works and determine if it will work for your application.


Brandon, Thanks for reply…sighhhh, thought I had ordered the right switch. Good to know I’m not going crazy!! Help much appreciated. Is it possible to returned ordered switches in exchange for the correct models? I ordered 2 of the 2485 and 2 of the 2480.
Thanks again!!


Our standard return policy would apply. In short, if any of your items are unopened and it is still within 30 days of the order date, we will accept a return on them. However, if you email us at referencing this forum post and include your order information for those items, we can probably help you out with a small discount on the #2804 RC switches.


Hi Brandon, I went with the RC Switch with Medium Low-Side Mosfet. Was lighter and took up less space. Had no trouble wiring up switch, pretty basic. I put the switch into learning mode and the LED blinking changed into a slower blinking rate as said in the manual. I have tried both resetting the switch to default mode and also having it learn the RC threshold, either method results in the switch not behaving as it should. Toggling my radio switch does not toggle the relay. When in learning mode when I try to teach it using the threshold method by toggling my radio switch I get no response. When I repower the switch, I get the one blink a second. The only thing I can think of that may be a factor is that I’m using serial ppm mode. All radio signals sent on one pulse train and then decoded by receiver to the different servo outputs. Could this be causing my problem? Do I need traditional RC pwm signal?
Help much appreciated,

Our RC Switches accept standard hobby RC servo signals, so your PPM signal will need to be decoded appropriately before being sent to the switch.