Hello All About Circuits Form,
Have learned a lot about the PIR sensor/relay combination.
I have gone from
to
I have bread boarded this and done it on a PCB and it works great.
(Reload Ron lamented the demise of Radio Shack as a source for small
prototyping boards. Have found a supplier for the Archer 276-1591B at
http://www.mcmelectronics.com/product/DISTRIBUTED-BY-MCM-21-114-/21-4595
and board that in some ways is an improvement:
http://www.mcmelectronics.com/product/DISTRIBUTED-BY-MCM-21-117-/21-4610
)
Working on getting this PIR relay combination to work an LED display
http://www.vellemanusa.com/products/view/?id=351406
The schematic shows a momentary switch SW1:
It is a switch that connects two different traces at the same time. It seems they both must
be closed at exactly the same time because experimentation with using jumpers to close them resulted
unpredictable results.
So it was reasoned that a DPDT relay would get the job done.
Have tried two different DPDT relays:
CIT WJ0982Cs9VDC
and a
Kest KS2E-M-DC12
Here's the problem: Have breadboarded the PIR to Relay Schematic just like that shown herewith
above. I can get the either relay to work if I take out the LED and R1. But when I put the LED and the R1 the relay
won't close. The resistance of the relay was measured at about 130 ohms so it was tried with
100 ohms for R1. Same result. So it was tried with no R1 resistor between LED1 and Vcc. Still no relay
operation.
So it looks like the circuit will work with SPST relay but not a DPDT relay. That doesn't make sense.
What am I missing?
Thanks.
Allen in Dallas
Have learned a lot about the PIR sensor/relay combination.
I have gone from
to
I have bread boarded this and done it on a PCB and it works great.
(Reload Ron lamented the demise of Radio Shack as a source for small
prototyping boards. Have found a supplier for the Archer 276-1591B at
http://www.mcmelectronics.com/product/DISTRIBUTED-BY-MCM-21-114-/21-4595
and board that in some ways is an improvement:
http://www.mcmelectronics.com/product/DISTRIBUTED-BY-MCM-21-117-/21-4610
)
Working on getting this PIR relay combination to work an LED display
http://www.vellemanusa.com/products/view/?id=351406
The schematic shows a momentary switch SW1:
It is a switch that connects two different traces at the same time. It seems they both must
be closed at exactly the same time because experimentation with using jumpers to close them resulted
unpredictable results.
So it was reasoned that a DPDT relay would get the job done.
Have tried two different DPDT relays:
CIT WJ0982Cs9VDC
and a
Kest KS2E-M-DC12
Here's the problem: Have breadboarded the PIR to Relay Schematic just like that shown herewith
above. I can get the either relay to work if I take out the LED and R1. But when I put the LED and the R1 the relay
won't close. The resistance of the relay was measured at about 130 ohms so it was tried with
100 ohms for R1. Same result. So it was tried with no R1 resistor between LED1 and Vcc. Still no relay
operation.
So it looks like the circuit will work with SPST relay but not a DPDT relay. That doesn't make sense.
What am I missing?
Thanks.
Allen in Dallas