Red LED Blinker Circuit Design

bryan

bryan

Make a circuit that blinks a red LED once per second.
Power it with a 9V block battery through an on/off switch.
Use components that are easy to hand-solder.

flux

0:10

Thought for 5 sec

Thought for a moment

I’ll build a hand-solderable 1 Hz red LED blinker using a 555 astable circuit, a 9V battery input, and an on/off switch. I’ll select through-hole parts, wire the datasheet-standard support capacitors, calculate the timing values, then run checks.

flux

7:46

Thought for 6 sec

Created 7 tasks.

1/7 Rename project and set description for 9V 555 LED blinker

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2/7 Select hand-solderable 555, battery, switch, LED, and passive parts

Thought for 4 sec

Ran calculation.

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Found 2 results for NE555P DIP-8.

Found 5 results for 9V battery snap connector.

Found 10 results for SPST slide switch through hole.

Found 1 results for 5mm red LED through hole.

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Ran calculation.

Ran calculation.

Ran calculation.

Read NE555P datasheet for NE555P pin functions pinout astable oper.

Read LTL-307EE datasheet for LTL-307EE red LED forward voltage recomm.

Thought for 5 sec

Ran calculation.

Found 10 results for Texas Instruments NE555P datasheet pinout astable supply voltage pin 5 control capacitor reset VCC GND.

Found 5 results for Generic Resistor.

Found 5 results for Generic Capacitor.

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4/7 Add all components with through-hole-friendly properties

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5/7 Wire 9V battery switch, 555 astable, decoupling, control bypass, and LED output

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6/7 Validate schematic connectivity and run ERC review

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Completed design checks — found 19 issues.

Read schematic.

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Completed design checks — found 11 issues.

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Completed design checks — found 11 issues.

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Completed design checks — found 14 issues.

Read schematic.

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7/7 tasks completed.

Thought for a moment

Built the 9V hand-solderable 555 LED blinker schematic and documented the design in Project Specification. It uses a DIP-8 NE555P, 9V battery holder, SPST switch, 5mm red LED, through-hole resistors, timing cap, pin-5 bypass, and supply decoupling/bulk caps; calculated blink rate is about 1.06 Hz.
Validation found no remaining schematic/ERC issues; the only unresolved review items are PCB airwires, which are expected because placement/routing has not started yet. Ready to move to PCB layout when you confirm.
Set board size
Place components
Run layout DRC
Add mounting holes

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Project Specification: 9V Hand-Solder 555 Blinker
Requirements
  • Blink one red LED approximately once per second.
  • Power source: 9V block battery.
  • Include an on/off switch in series with the battery positive lead.
  • Use components that are easy to hand-solder, prioritizing through-hole packages.
Circuit Architecture
  • U1: NE555P in DIP-8 package, configured as a standard astable oscillator.
  • BT1: 9V battery holder/input.
  • SW1: SPST on/off switch between battery positive and the switched 9V rail.
  • LED1: 5mm through-hole red LED with series current-limit resistor.
555 Astable Timing
Standard astable topology:
  • R1 from switched 9V rail to DISCH.
  • R2 from DISCH to the TRIG/THRES timing node.
  • C1 from TRIG/THRES timing node to GND.
  • RESET tied to switched 9V rail.
  • CONTROL bypassed to GND.
Selected values:
  • R1 = 1kΩ
  • R2 = 680kΩ
  • C1 = 1uF
Calculated timing:
  • Frequency ≈ 1.06Hz
  • Period ≈ 0.94s
  • High time ≈ 0.472s
  • Low time ≈ 0.471s
LED Current Limit
  • LED forward voltage from LTL-307EE datasheet: approximately 2.0V typical at test current.
  • R3 = 1.5kΩ gives about 4.7mA from a 9V rail, suitable for visible blinking with reduced 9V battery drain.
Required 555 Support Components
  • C2 = 10nF from CONTROL pin to GND.
  • C3 = 100nF from switched 9V rail to GND near U1.
  • C4 = 10uF bulk capacitor from switched 9V rail to GND.
Nets
  • BAT_9V_RAW: battery positive before switch.
  • VCC_SW_9V: switched 9V rail after on/off switch.
  • GND: battery negative and common return.
  • DISCHARGE: 555 discharge node between R1, R2, and DISCH pin.
  • TIMING_NODE: 555 TRIG/THRES node with timing capacitor.
  • CONTROL_BYPASS: 555 CONTROL pin bypass node.
  • LED_DRIVE: 555 output to LED current-limit resistor.
  • LED_ANODE: current-limit resistor to LED anode.
Validation Notes
  • All NE555 power, ground, reset, timing, control, and output pins are connected.
  • The schematic includes required NE555 pin 5 bypass and supply decoupling/bulk capacitors.
  • Remaining DRC airwires are expected before PCB placement and routing; they will be resolved during the layout/routing phase after user confirmation.

    Requirements

    Circuit Architecture

    555 Astable Timing

    LED Current Limit

    Required 555 Support Components

    Nets

    Validation Notes

Documents

    Project Specification: 9V Hand-Solder 555 Blinker

Assets

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9V Hand-Solder 555 Blinker

9V Hand-Solder 555 Blinker thumbnail
Hand-solderable 9V battery-powered red LED blinker using a 555 timer astable circuit, on/off switch, and through-hole support components.

Properties

Properties describe core aspects of the project.

Pricing & Availability

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