Electronic – SC2272-M4 Behaviour when using relay SRD-05VDC-SL-C 5V DC

power supplyreceiverrelaywireless

I'm currently encountering a problem when using a relay switch with a 5v receiver. When using the same receiver with a row of LEDS it works flawlessly. I've noticed that the relay keeps making the switching noise over and over like I'm pressing the transmitter really fast apart from the fact I'm not. Also, when the transmitter is moved closer to the receiver from 20" to around 1" the problem stops. Below is some circuits to help show you my setup.

Any help appreciated thanks.

Setup Specs

  • USB 5v DC (2AMPS)
  • Receiver (XY-DJM-5V – SC2272-M4)
  • Relay (SRD-05VDC-SL-C 5V DC)
  • Transmitter (XY-04)
  • Diode (1N4001)
  • Transistor (2N2222A)
  • Resistor (1.8K Ohms)


simulate this circuit – Schematic created using CircuitLab

Antenna Signal Workaround or Booster

I believe this issue is related to wireless signal on D0. Basically above 20" inches the output to the relay drops from 5.05v to 0.5v and is obviously causing the problem. I think I need to boost the signal or replace the transistor with something that triggers at low and high current but have no clue. Any help appreciated, I'm new at this.

Board Setup




Best Answer

The XY-DKM-5V doesn't appear to have a data sheet so if you could find one that will help you immensely - any electronic module that can be bought that doesn't have a pdf data sheet in my book is not worth buying.

Anyway, I suspect the problem is glitching on the supply when the relay coil is first activated and this might be cured by adding a ceramic 10uF capacitor across the power rails of the feed to the module. You might also consider putting a small resistor in series with the relay to limit its current slightly - hopefully it will still work of course.

I don't know how you constructed this circuit but if on a breadboard then you will undoubtedly have to wire it together with more care and attention. If it's on a circuit board then there could still be issues so please show your construction.

Alternatively your relay may be demanding far too much current that what your power supply can give so please check this too.