Thanks to everyone for their feedback. From what I have understood, I would be better off running everything off a 12V (2.5 amp) adapter. Take a look at the reworked circuit and tell me what you think.
**broken link removed**
Regarding the PIR sensor, the specs are as follows.
HC-SR501 Human Sensor Module Pyroelectric Infrared
Sensitive Setting: turn to right, distance increases (About 7M); turn to left, distance reduce (About 3M)
Time Setting: turn to right, time increases (About 300S); turn to left, time reduce (About 5S).
Description:
- Color: White + Green
- Dimension: 3.2cm x 2.4cm x 1.8cm (approx)
- Infrared sensor with control circuit board
- The sensitivity and holding time can be adjusted
- Working Voltage Range: DC 4.5V- 20V
- Current drain:<60uA
- Voltage Output: High/Low level signal:3.3V TTL output
- Detection distance: 3--7M(can be adjusted)
- Detection range: <140°
- Delay time: 5-200S(can be adjusted, default 5s +-3%)
- Blockade time: 2.5 S (default)
- Trigger: L: Non-repeatable trigger H: Repeat Trigger (default)
- Work temperature:-20-+80°C
- Trigger Method: L unrepeatable trigger / H repeatable trigger
I found a relay that might be suitable. This one is DPDT. Would an SPST relay with the same specs be appropriate for my project?
Nominal Operate Power 100-230mW
Arrangement 2 Form c
Switching Voltage 2VDC
Switching Current 170mA
Carrying Current 10A
Coil voltage 3 VDC
Ambient Temperature -40 to +85 °C
SafetyStandard UL,CSA,IEC
Note/Option Single coil latch type