# 9V 555 LED Blinker ## Description Hand-solderable 9 V battery-powered 555 timer circuit that blinks a red LED approximately once per second through an on/off switch. ## Project Details - **Owner:** b3dn - **Created:** 5/15/2026 - **Last Updated:** 5/26/2026 - **Visibility:** Public ## Key Components ### Layout — Generic Capacitor - Role: Decoupling - Manufacturer Name: KEMET - Capacitor Type: Ceramic - Voltage Rating: 50V - Allow Substitutes: Yes - Package: CP_Radial_D4.0mm_P1.50mm - Part Type: Non-Polarized Capacitor - Capacitance: 1e-7F - Role Details: 0.1 µF ceramic bypass capacitor from U1 VCC to GND as recommended by the NE555 datasheet. - Manufacturer Part Number: C320C104M5R5TA **Pins:** - P1 [pin 1] - P2 [pin 2] ### Layout — Generic Capacitor - Manufacturer Part Number: EEU-FC1C101 - Capacitor Type: Aluminum Electrolytic - Capacitance: 0.0001F - Part Type: Non-Polarized Capacitor - Voltage Rating: 16V - Package: CP_Radial_D4.0mm_P1.50mm - Role: Timing - Manufacturer Name: Panasonic - Allow Substitutes: Yes - Role Details: 100 µF timing capacitor from the TRIG/THRES node to ground for approximately 1 second blink period. **Pins:** - P1 [pin 1] - P2 [pin 2] ### Layout — [Generic Resistor](https://www.flux.ai/jharwinbarrozo/generic-resistor~3e.md) - Allow Substitutes: Yes - Power Rating: 0.25W - Tolerance: 5% - Role Details: Limits red LED current to roughly 5–7 mA from the 555 output on a 9 V supply for battery-friendly visible blinking. - Resistance: 1000Ω - Manufacturer Part Number: CFR-25JB-52-1K - Part Type: Resistor - Package: H_AXIAL-P7.62_D2.5 - Manufacturer Name: YAGEO - Role: Current Limiting **Pins:** - P1 [pin 1] - P2 [pin 2] ### Layout — [LTL-307EE](https://www.flux.ai/vasy_skral/ltl-307ee~a2.md) - Manufacturer Name: Lite-On Inc. - Part Type: LED - Datasheet URL: https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/1153/LTL-307EE.pdf - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: LTL-307EE - Role Details: Red 5 mm LED blink indicator driven by the 555 output through a current-limiting resistor. - Role: Signal Generation **Pins:** - A [pin 2] - K [pin 1] ### Layout — [Generic Resistor](https://www.flux.ai/jharwinbarrozo/generic-resistor~3e.md) - Tolerance: 5% - Allow Substitutes: Yes - Manufacturer Part Number: CFR-25JB-52-4K7 - Resistance: 4700Ω - Part Type: Resistor - Power Rating: 0.25W - Role Details: RB timing resistor between DISCH and the TRIG/THRES timing node. - Package: H_AXIAL-P7.62_D2.5 - Manufacturer Name: YAGEO - Role: Timing **Pins:** - P1 [pin 1] - P2 [pin 2] ### Layout — [AS11CH](https://www.flux.ai/adrian95/as11ch~i2s.md) - Datasheet URL: https://www.nkkswitches.com/pdf/Aslides.pdf - Part Type: Switch - Manufacturer Part Number: AS11CH - Role Details: Main on/off switch for the 9 V battery supply; load is under 15 mA peak. - Role: Switching **Pins:** - P1 - P3 ### Layout — [967](https://www.flux.ai/jharwinbarrozo/967~fk9.md) - Part Type: Connectors - Manufacturer Part Number: 967 - Role Details: 9 V battery input connector; expected load is under 15 mA peak for the 555 and LED. - Datasheet URL: https://www.keyelco.com/userAssets/file/K75p36.pdf - Role: Power Conversion - Manufacturer Name: Keystone Electronics **Pins:** - NEG [pin 2] - POS [pin 1] ### Layout — [NE555P](https://www.flux.ai/kicad-part-library/ne555p~vhf.md) - Manufacturer Part Number: NE555P - Role: Signal Generation - Operating Voltage: 5V - Part Type: Precision Timer - Role Details: Astable oscillator powered from switched 9 V battery rail; RA=4.7 kΩ, RB=4.7 kΩ, C=100 µF gives about 1.02 Hz. - Manufacturer Name: Texas Instruments Inc. - Datasheet URL: http://www.ti.com/lit/ds/symlink/ne555.pdf - Domain: Consumer Electronics - Package or Case Code: DIP-8_W7.62mm **Pins:** - CONT [pin 5] - DISCH [pin 7] - GND [pin 1] - OUT [pin 3] - RESET [pin 4] - THRES [pin 6] - TRIG [pin 2] - VCC [pin 8] ### Layout — Generic Capacitor - Manufacturer Part Number: C315C103K5R5TA - Capacitor Type: Ceramic - Voltage Rating: 50V - Package: CP_Radial_D4.0mm_P1.50mm - Part Type: Non-Polarized Capacitor - Capacitance: 1e-8F - Manufacturer Name: KEMET - Allow Substitutes: Yes - Role Details: 0.01 µF capacitor from CONT to GND to improve astable operation per the NE555 datasheet application circuit. - Role: Decoupling **Pins:** - P1 [pin 1] - P2 [pin 2] ### Layout — [Generic Resistor](https://www.flux.ai/jharwinbarrozo/generic-resistor~3e.md) - Part Type: Resistor - Package: H_AXIAL-P7.62_D2.5 - Manufacturer Name: YAGEO - Allow Substitutes: Yes - Role: Timing - Role Details: RA timing resistor from switched 9 V rail to DISCH; part of the 555 astable timing network. - Power Rating: 0.25W - Tolerance: 5% - Manufacturer Part Number: CFR-25JB-52-4K7 - Resistance: 4700Ω **Pins:** - P1 [pin 1] - P2 [pin 2] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/b3dn/9v-555-led-blinker~v7](https://www.flux.ai/b3dn/9v-555-led-blinker~v7).* --- *Generated from [https://www.flux.ai/b3dn/9v-555-led-blinker~v7](https://www.flux.ai/b3dn/9v-555-led-blinker~v7)*