9V LED Blinker
Worked for 13 mins 11 sec
Created a project doc
Board Bring-Up Plan — 9V 555 LED Blinker
Equipment: multimeter, oscilloscope or logic probe optional, current-limited bench supply optional, 9V battery. Safety notes: do not exceed ...
Implemented the hand-solderable 9V 555 red LED blinker schematic and renamed the project to 9V 555 LED Blinker. The design uses a DIP-8 NE555P, 9V battery holder, on/off switch, through-hole passives, and a red LED; timing is ~1.06Hz using R1=1kΩ, R2=680kΩ, C1=1uF.
Open items:
- Electrical connectivity is complete; remaining review findings are schematic readability/portal-label spacing warnings, not functional floating-pin or power-pin errors.
Suggested next steps:
- Review the requirements in Project Specification.
- Use Board Bring-Up Plan when testing the assembled board.
- Ask me to proceed to PCB layout with through-hole placement and routing.
Fix and layout
Proceed to layout
Fix readability warnings
Verify BOM
Run schematic review
Refine this doc
Ask about this doc
Project Specification
Overview
Design a simple hand-solderable red LED blinker powered from a 9V block battery through an on/off switch.
Requirements
- Blink one red LED approximately once per second.
- Use a 9V block battery as the power source.
- Include a physical on/off switch in series with the battery positive lead.
- Prefer through-hole / hand-solderable components.
Chosen Architecture
- NE555P timer in DIP-8 through-hole package configured as a standard astable oscillator.
- Timing target: about 1Hz using R1 = 1kΩ, R2 = 680kΩ, C1 = 1uF.
- Mandatory support parts: 10nF control-pin bypass, 100nF supply decoupling, and 10uF bulk capacitor.
- Red 5mm through-hole LED driven from the 555 output through a current-limiting resistor.
Estimated Performance
- Astable frequency: f = 1.44 / ((1kΩ + 2 × 680kΩ) × 1uF) ≈ 1.06Hz.
- Period: ≈ 0.94s per blink cycle.
- Duty cycle: ≈ 50%.
- LED current with 680Ω resistor: roughly 8mA at a 9V battery and NE555 high output.
Validation Criteria
- Battery positive reaches the 555 VCC only through the on/off switch.
- NE555 pins 2 and 6 are tied together for astable operation.
- Pin 4 RESET is tied to switched +9V.
- Pin 5 CONTROL has a capacitor to ground.
- Pin 8 VCC has both 100nF and 10uF decoupling to ground.
- LED has a series resistor and no direct connection across the 9V supply.
Overview
Requirements
Chosen Architecture
Estimated Performance
Validation Criteria
