AllenPitts
Newbie level 4
Hello EDA forum,
Have developed circuit that uses a PIR sensor to drive a 555 timer and turn on a group of LEDs for a specific time.
This circuit and the PCB based on this schematic works. The PIR to 555 circuit is connected to a circuit/PCB called the
LED module.
Have connected the PIR to 555 circuit to four LED modules. daisy chained.
But, because it would work with the AC converters that are on hand, and because it
would allow me to drive more LEDs, it would be good to go to 12 volts instead of the 9
volts currently used.
It is known that the PIR (HC SR505) and the 555 timer will take the increased voltage.
The NPN transistors, BC 547 would have to be upgraded to BD 437 to take 12 volts.
But the rest of the components, the resistors and capacitors should be ok.
Is there any need to change the resistors and capacitors?
Thanks.
Allen in Dallas
Have developed circuit that uses a PIR sensor to drive a 555 timer and turn on a group of LEDs for a specific time.
This circuit and the PCB based on this schematic works. The PIR to 555 circuit is connected to a circuit/PCB called the
LED module.
Have connected the PIR to 555 circuit to four LED modules. daisy chained.
But, because it would work with the AC converters that are on hand, and because it
would allow me to drive more LEDs, it would be good to go to 12 volts instead of the 9
volts currently used.
It is known that the PIR (HC SR505) and the 555 timer will take the increased voltage.
The NPN transistors, BC 547 would have to be upgraded to BD 437 to take 12 volts.
But the rest of the components, the resistors and capacitors should be ok.
Is there any need to change the resistors and capacitors?
Thanks.
Allen in Dallas
