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PIR data sheet question

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MrDEB

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have several of these PIR modules and connecting to a PIC.
my question is will it draw less current if I run the PIR connected to 9v or 4.5v.
planned on inserting a base resistor on the output to take the 3v output LOW connected to my PIC to trigger the circuit (Q3)see schematic
as is without the PIR connected the circuit draws 2.3ma untriggered and 29.6 ma triggered.
trying to conserve as much battery power as feasible.
using AAA batteries.
the schematic shows 9v as I originally had an LM386 amp on the output but the amp draws 90ma by itself.
any suggestions??
 

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audioguru

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We don't know the spec's for your PIR.

An LM386 amplifier draws 90mA only if it is not connected correctly or if it is blasting loudly.
Now the output transistor is trying to put 0.5A DC pulses into the speaker but the 10k base resistor is so high that it reduces the current.
 

audioguru

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The datasheet for the Chinese PIR sensor does not make sense.
It shows a positive and negative supply but the negative supply might be able to be ground.
It does not spec an output high current but shows it driving the base of a transistor without a current-limiting resistor and the load on the transistor is unknown.
 

MrDEB

Well-Known Member
I guess Im not the only one confused??

In my circuit I put a 5k base and 22k loadresistor.
when the PIR triggers it turns on the 2n2222 and takes pin 9 of the PIC low thus triggering the PIC
I bread boarded and it works.
I just put what I thought would work.
as far as the sound - plenty loud as is.
 

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