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Jasen Betts[_2_] Jasen Betts[_2_] is offline
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Default Activate PIR xmtr

On 2018-09-24, OGER wrote:
When looking for the LED, what description do I look for ?
I have never seen anything called a thermal LED.


you need a heat emitter, not a light emitter, use a small heat source, like
a small lamp or a resistor

an LM555 powered by 5V blinking a 0.3W 6V lamp would probably do the trick

digikey part number CM756-ND is a 14V lamp but using lower voltage
will make it last longer and produce more infrared than a 5V lamp

Wire the 555 discharge and output pins in parallel, this lamp is
borderline max load for a 555 so combining the two outputs will help..

----+-----------------+-- +5V
1Meg | |
+-[R1]--------|--------+--(@)---+
| | |
| +--------+ | lamp
| | | |
| | . . . .|. . . . |
| | . VCC(8) . |
| | . . |
| +--RES(4) OUT(3)--+
| . LM555 . |
+-------TH(6) DIS(7)--+
| . .
+-------TR(2) CV(5)-----+
1uF | . . |
===== . GND(1) . |
| . . . .|. . . . ===== 100nf
| | |
+-------------+ |
| |
+-----------+
|
---+-- 0V


run frequency is about 1.4Hz




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Bye.
Jasen



DigiKey have them. Their on-line catalog is impossible to find anything
especially LEDs.
Any part number for me ?

I am trying to build a garage door monitor.
My new garage door opener does not have a lock function like my previous
so I need a way to monitor the door state in my house,

The driveway monitor is almost all I need and if I had a schematic I
could modify it internally. Looking at the circuit board does not give
enough info.



Jasen Betts wrote:
On 2018-09-23, OGER wrote:
Suggestions please.

Taking a driveway PIR xmtr to modify for other purposes with no actual
internal mods.



What is needed to activate the PIR. LED color or type ?


changing thermal infrared
small 100 ohm resistor fed by 1Hz 5V square wave





Jasen Betts wrote:
On 2018-09-23, OGER wrote:
Suggestions please.

Taking a driveway PIR xmtr to modify for other purposes with no actual
internal mods.



What is needed to activate the PIR. LED color or type ?


changing thermal infrared
small 100 ohm resistor fed by 1Hz 5V square wave




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