Hello All,
Let me start by saying I am a complete newbie electronic hobbyist. My experiences do not go much beyond cutting, stripping, and connecting wires and power sources.
With that said I thought it would be a simple enough project to create a motion sensor "something" simply by connecting together a PIR, Relay, power, and load. Not so simple based on the components I chose to work with.
Here are the two main components that bring the circuit together.
Here are the components I am using.
PIR sensor
http://www.amazon.com/2013newestsel...1&redirect=true&ref_=oh_aui_search_detailpage
3v Relay
http://www.ebay.com/itm/331413255692?_trksid=p2060353.m2749.l2649&ssPageName=STRK:MEBIDX:IT
While my project is not yet complete it has been discovered that I now have to create level shifting circuits to drive this 3v relay.
My question is this.... Is this relay module incorrectly rated since it truly needs more than 3 volts to drive it?
It was noted by member ericgibbs that...
"Your relay PCB has a EL817 opto-coupler for the input signal, it requires a 5V drive voltage on the Input in order to drive the onboard transistor which controls the relay coil current.
With only a 3v drive from the PIR output, there is insufficient current to drive the opto and transistor."
See.. when connecting the PIR to the Relay PCB, the voltage signal at the relay terminals is only 2.7-2.8 volts.
I realize the relay on the PCB is 3v, but the included circuitry on the PCB actually calls for 5v to drive it.
So... was this falsely spec'd as a 3v relay?
If you care to read how more on the project while I am waiting for transistors to arrive.
All thoughts welcome.
TRU
Let me start by saying I am a complete newbie electronic hobbyist. My experiences do not go much beyond cutting, stripping, and connecting wires and power sources.
With that said I thought it would be a simple enough project to create a motion sensor "something" simply by connecting together a PIR, Relay, power, and load. Not so simple based on the components I chose to work with.
Here are the two main components that bring the circuit together.
Here are the components I am using.
PIR sensor
http://www.amazon.com/2013newestsel...1&redirect=true&ref_=oh_aui_search_detailpage
3v Relay
http://www.ebay.com/itm/331413255692?_trksid=p2060353.m2749.l2649&ssPageName=STRK:MEBIDX:IT
While my project is not yet complete it has been discovered that I now have to create level shifting circuits to drive this 3v relay.
My question is this.... Is this relay module incorrectly rated since it truly needs more than 3 volts to drive it?
It was noted by member ericgibbs that...
"Your relay PCB has a EL817 opto-coupler for the input signal, it requires a 5V drive voltage on the Input in order to drive the onboard transistor which controls the relay coil current.
With only a 3v drive from the PIR output, there is insufficient current to drive the opto and transistor."
See.. when connecting the PIR to the Relay PCB, the voltage signal at the relay terminals is only 2.7-2.8 volts.
I realize the relay on the PCB is 3v, but the included circuitry on the PCB actually calls for 5v to drive it.
So... was this falsely spec'd as a 3v relay?
If you care to read how more on the project while I am waiting for transistors to arrive.
All thoughts welcome.
TRU