LED Control with Relay

5:33

General
Chat History
Project
Calculator
File
Knowledge Base
Library
Web

Planning relay module setup.

Consulting component datasheet.

Navigating the datasheet query.

Using file tool for datasheet.

Linking parts and components.

Searching web for: "SRD-05VDC-SL-C datasheet coil resistance current pickup voltage release voltage pin configuration"

Found 1 results.

Using Calculator Tool.

Starting 9 component searches

Dispatching Library tool to find: "2N2222"

Dispatching Library tool to find: "1N4007"

Dispatching Library tool to find: "330Ω Resistor"

Dispatching Library tool to find: "680Ω Resistor"

Dispatching Library tool to find: "10kΩ Resistor"

Dispatching Library tool to find: "Arduino Uno R4 WiFi"

Searching: "SRD-05VDC-SL-C"

Searching: "1N4148"

Searching: "LED"

Creating search plan for: "2N2222"

Creating search plan for: "1N4007"

Creating search plan for: "330Ω Resistor"

Creating search plan for: "680Ω Resistor"

Creating search plan for: "10kΩ Resistor"

Creating search plan for: "Arduino Uno R4 WiFi"

Searching: "Looking for a general-purpose NPN bipolar junction transistor used in low-power amplification and switching applications. The part should have typical ratings such as Vce around 40V and Ic up to 800 mA, commonly used in small-signal circuits."

Searching: "Searching for a general-purpose NPN transistor suitable for switching and amplification in logic-level and low-power circuits. Preferred candidates include parts with similar electrical characteristics to the 2N2222, typically used in board-level designs."

Searching: "Identifying a part that functions as a switching transistor in digital and analog applications. Key requirements include general purpose usage, a collector-emitter voltage around 40V, and a current rating near 800 mA, as seen in the 2N2222 family."

Searching: "Exploring a known functional alternative to the 2N2222 for low-power amplification and switching. This search is to identify parts with similar characteristics (voltage and current ratings) and PCB package sizes, commonly available in through-hole formats for general applications."

Searching: "Looking for a standard 1N4007 rectifier diode used in power rectification. This is a general-purpose silicon diode with a forward current rating of 1A and a peak reverse voltage of 1000V, typically in a DO-41 package. The diode is used for AC to DC conversion in power supplies."

Searching: "Searching for a general-purpose rectifier diode in a DO-41 package. The component should be suitable for power rectification applications with a forward current rating around 1A and a high reverse voltage rating (~1000V), similar to the 1N4007."

Searching: "Seeking a silicon rectifier diode designed for rectification in power supplies. Technical specifications include approximately 1A forward current, 1000V reverse voltage rating, and a DO-41 package, suitable for converting AC to DC and replacing or substituting a 1N4007."

Found 72 results.

Searching: "2N2222"

Found 55 results.

Searching: "1N4007"

Searching: "Searching for a resistor with a 680 ohm nominal value. The component is needed for general biasing or current-limiting applications on a PCB. Key parameters include its resistance value of 680Ω, with likely tolerance options (e.g., 1% or 5%) and typical power rating (such as 1/4W). The search should identify both SMD and through-hole versions."

Searching: "Looking for a PCB-mounted, surface-mount resistor with a nominal value of 680 ohms. The resistor is intended for current limiting or biasing in a compact board design. Explore common packages (e.g., 0805, 0603) with standard power ratings (around 0.1W to 0.25W) and typical tolerances (1% or 5%)."

Searching: "Seeking a 680 ohm resistor in an 0805 surface-mount package for use in a PCB circuit. The resistor is required to have a power rating in the vicinity of 0.125W to 0.25W and available tolerance options. Ideal for designs where space is limited and precise resistance is needed for current limiting or biasing."

Searching: "Searching for a through-hole resistor with a nominal value of 680 ohms. This component is intended for applications where a larger, robust resistor is needed, typically with a power rating around 1/4W. It can be used in prototyping or designs requiring soldered leads rather than surface mount."

Searching: "General-purpose 10kΩ resistor for use in biasing circuits and voltage dividers. No specific package or tolerance is pre-defined. This query is intended to capture all types of 10k resistors available from different vendors when sizing for typical low-power applications."

Searching: "Surface-mount 10kΩ resistor with a tolerance of 5% designed for compact PCB layouts. The resistor is intended for biasing or voltage division in low-power circuits, typically in a 0603 or 0805 package, and should be available from multiple vendors for high volume sourcing."

Searching: "Through-hole 10kΩ resistor intended for prototyping and applications where conventional, larger footprints are acceptable. Likely rated at 1/4W with a standard tolerance (such as 5% or 1%), this query helps identify components suitable for manual board assembly or repairs in less space-constrained environments."

Searching: "Search for the official Arduino Uno R4 board featuring integrated WiFi. This board is designed for rapid prototyping in IoT and embedded applications, offering a powerful microcontroller with built-in wireless connectivity, robust I/O interfaces, and compatibility with the Arduino ecosystem. Key aspects include onboard WiFi functionality and an updated R4 design."

Searching: "Looking for a microcontroller development board from the Arduino R4 series that includes integrated WiFi capability. The board should support standard Arduino programming and offer connectivity for wireless applications, making it suitable for IoT projects and advanced embedded systems."

Searching: "Searching for an Arduino Uno R4 board optimized with onboard WiFi for enhanced connectivity in embedded and IoT applications. The requirement is for a robust, modern Arduino platform that integrates WiFi, delivers reliable performance for digital and analog signal processing, and maintains compatibility with existing Arduino shields and libraries."

Found 76 results.

Searching: "680Ω Resistor"

Searching: "Search for a generic 330Ω resistor intended for common applications such as current limiting or voltage division. Focus on components offering standard tolerance (e.g., 5% or 1%) and power ratings (typically 0.25W) in either through-hole or surface-mount formats, without a specific package requirement."

Searching: "Identify 330Ω resistors in a surface-mount device (SMD) package, which are suitable for compact PCB designs used in analog and digital applications. The component should be appropriate for current limiting or signal conditioning with standard specifications such as 5% tolerance and a power rating around 0.25W, with common SMD sizes like 0603 or 0805."

Searching: "Locate a high-precision 330Ω resistor in an 0805 SMD package, optimized for applications demanding tighter tolerance (around 1%) and enhanced stability for critical analog or sensor circuits. Important factors include a power rating typical for small SMD resistors and reliability under standard operating conditions."

Found 35 results.

Searching: "Arduino Uno R4 WiFi"

Found 52 results.

Searching: "330Ω Resistor"

Found 57 results.

Searching: "10kΩ Resistor"

Completed 9 component searches.

Using Knowledge Base Tool.

Starting 1 component search

Dispatching Library tool to find: "330Ω Through Hole Resistor"

Creating search plan for: "330Ω Through Hole Resistor"

Searching: "Searching for a standard 330 ohm resistor used in through-hole mounting applications. This component is typically used for current limiting, voltage dividing, or biasing in a variety of PCB circuits, and is manufactured in an axial package."

Searching: "Seeking a 330 ohm resistor specifically designed for through-hole (axial) mounting. The resistor should be appropriate for typical PCB applications such as LED current limiting and voltage division, with expected standard tolerances (e.g., 5% or 1%) and power ratings (commonly 1/4W)."

Searching: "Looking for a 330 ohm axial through-hole resistor, potentially from a range of resistor technologies (e.g., carbon film, metal film) to match application-specific needs. The resistor is intended for low-power circuit designs where precise current control is utilized, and should meet standard manufacturing specs for discrete resistor components."

Found 56 results.

Searching: "330Ω Through Hole Resistor"

Completed 1 component search.

Starting 1 component search

Dispatching Library tool to find: "680Ω Through Hole Resistor"

Creating search plan for: "680Ω Through Hole Resistor"

Searching: "Searching for a 680 ohm resistor for through-hole board mounting. This is a basic passive component used for current limiting, biasing, or voltage division in various circuits. Focus on standard resistor properties without specific power rating or tolerance constraints initially."

Searching: "Looking for a 680 ohm resistor specifically in a through-hole package for PCB applications. This search is for a standard resistor used in circuits where axial lead placement is needed, ensuring mechanical robustness and ease of soldering."

Searching: "Targeting a 680 ohm resistor with a typical 1/4 watt power rating in an axial through-hole package. This is for use in moderate power applications where reliability and typical tolerance (e.g., 5% or 1%) are adequate."

Searching: "Searching for an axial lead 680 ohm resistor designed for through-hole mounting. This part is intended for general purpose circuit applications such as biasing, voltage division, or signal conditioning, and should provide consistent electrical performance under standard conditions."

Found 76 results.

Searching: "680Ω Through Hole Resistor"

Completed 1 component search.

Retrieving coil specifications.

Great—let’s use your 5 V Songle relay to switch an LED from an Arduino Uno R4 WiFi using a safe transistor driver and a flyback diode.
Parts you’ll need
Why a transistor + diode
  • According to the SRD datasheet, the 5 V coil draws about 70 mA (coil resistance ≈ 70 Ω, pull-in ≤ 75% VNOM, drop-out ≥ 10% VNOM). An Arduino GPIO cannot source that directly.
  • Best practice: drive the coil with an NPN transistor and place a flyback diode across the coil. Knowledge rule: the diode current rating should be at or above the relay’s steady-state coil current (≥ 70 mA). Both 1N4148-1 and 1N4007RLG satisfy this.
Wiring (breadboard)
  • Power and ground:
    • Arduino 5V -> relay coil pin A2 (either coil pin; coil is non-polarized).
    • Arduino GND -> transistor emitter AND the relay’s LED return resistor’s ground.
  • Transistor driver (example uses Arduino D8):
    • Arduino D8 -> MF3W-680Ω±5%-QT73 -> PN2222A base.
    • Optional: 10 kΩ from base to GND (keeps it off at boot).
    • PN2222A emitter -> GND.
    • PN2222A collector -> relay coil pin A1.
  • Flyback diode across coil:
    • 1N4148-1 cathode to 5V (coil A2), anode to transistor collector (coil A1).
  • Relay contacts to switch the LED from 5 V:
    • COM -> 5V.
    • NO -> LED anode -> CFR-12JB-52-330R -> GND.
    • When the relay energizes, NO closes to COM and the LED turns on. If you prefer LED ON by default, move from NO to NC.
Arduino sketch (example on D8)

Cpp


const int RELAY_CTRL = 8;
void setup() {
  pinMode(RELAY_CTRL, OUTPUT);
  digitalWrite(RELAY_CTRL, LOW); // keep OFF at power-up
}
void loop() {
  digitalWrite(RELAY_CTRL, HIGH); // energize relay -> LED ON
  delay(1000);
  digitalWrite(RELAY_CTRL, LOW);  // de-energize -> LED OFF
  delay(1000);
}
Notes
  • The 680 Ω base resistor targets solid saturation for the ~70 mA coil current; 1 kΩ will also usually work for this relay, but 680 Ω gives more margin.
  • Tie Arduino GND and the relay driver’s GND together. Do not power the coil from a GPIO pin—use 5V + transistor as shown.
Want me to add these exact parts into a small schematic in your Flux project so you can follow it 1:1 on a breadboard?
20 days

Ready.


please explain what A1 does.

@copilot please explain what A1 does.
1y
Certainly! The relay you've mentioned, the SRD-05VDC-SL-C, is a Single Pole Double Throw (SPDT) relay, which means it has one common contact (COM) that can switch between two different contacts (normally open, NO, and normally closed, NC) when the coil is energized.
A1 and A2 are the pins for the relay coil. Here’s what each pin generally does:
  • A1: One end of the relay coil. When a voltage is applied across A1 and A2, the electromagnetic coil generates a magnetic field that either makes or breaks the switch between COM and NO or COM and NC.
  • A2: The other end of the relay coil. It pairs with A1 to complete the circuit for the coil.
In practical terms:
  • Applying 5V across A1 and A2 activates the relay.
  • When deactivated, COM is connected to NC.
  • When activated, COM switches from NC to NO, connecting to NO.
So, to summarize:
  • A1 and A2 are used to energize the relay coil.
  • COM, NC, and NO are used to control the switching part of the relay.
Would you like suggestions on how to connect these in a specific circuit?
1y
Someone is typing...
A2
COM
NC
A1
NO


  • Ground
    A common return path for electric current. Commonly known as ground.
  • Net Portal
    Wirelessly connects nets on schematic. Used to organize schematics and separate functional blocks. To wirelessly connect net portals, give them same designator. #portal
  • Power Net Portal
    Wirelessly connects power nets on schematic. Identical to the net portal, but with a power symbol. Used to organize schematics and separate functional blocks. To wirelessly connect power net portals, give them the same designator. #portal #power
  • Generic Resistor
    A generic fixed resistor for rapid developing circuit topology. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard resistor values: 1.0Ω 10Ω 100Ω 1.0kΩ 10kΩ 100kΩ 1.0MΩ 1.1Ω 11Ω 110Ω 1.1kΩ 11kΩ 110kΩ 1.1MΩ 1.2Ω 12Ω 120Ω 1.2kΩ 12kΩ 120kΩ 1.2MΩ 1.3Ω 13Ω 130Ω 1.3kΩ 13kΩ 130kΩ 1.3MΩ 1.5Ω 15Ω 150Ω 1.5kΩ 15kΩ 150kΩ 1.5MΩ 1.6Ω 16Ω 160Ω 1.6kΩ 16kΩ 160kΩ 1.6MΩ 1.8Ω 18Ω 180Ω 1.8KΩ 18kΩ 180kΩ 1.8MΩ 2.0Ω 20Ω 200Ω 2.0kΩ 20kΩ 200kΩ 2.0MΩ 2.2Ω 22Ω 220Ω 2.2kΩ 22kΩ 220kΩ 2.2MΩ 2.4Ω 24Ω 240Ω 2.4kΩ 24kΩ 240kΩ 2.4MΩ 2.7Ω 27Ω 270Ω 2.7kΩ 27kΩ 270kΩ 2.7MΩ 3.0Ω 30Ω 300Ω 3.0KΩ 30KΩ 300KΩ 3.0MΩ 3.3Ω 33Ω 330Ω 3.3kΩ 33kΩ 330kΩ 3.3MΩ 3.6Ω 36Ω 360Ω 3.6kΩ 36kΩ 360kΩ 3.6MΩ 3.9Ω 39Ω 390Ω 3.9kΩ 39kΩ 390kΩ 3.9MΩ 4.3Ω 43Ω 430Ω 4.3kΩ 43KΩ 430KΩ 4.3MΩ 4.7Ω 47Ω 470Ω 4.7kΩ 47kΩ 470kΩ 4.7MΩ 5.1Ω 51Ω 510Ω 5.1kΩ 51kΩ 510kΩ 5.1MΩ 5.6Ω 56Ω 560Ω 5.6kΩ 56kΩ 560kΩ 5.6MΩ 6.2Ω 62Ω 620Ω 6.2kΩ 62KΩ 620KΩ 6.2MΩ 6.8Ω 68Ω 680Ω 6.8kΩ 68kΩ 680kΩ 6.8MΩ 7.5Ω 75Ω 750Ω 7.5kΩ 75kΩ 750kΩ 7.5MΩ 8.2Ω 82Ω 820Ω 8.2kΩ 82kΩ 820kΩ 8.2MΩ 9.1Ω 91Ω 910Ω 9.1kΩ 91kΩ 910kΩ 9.1MΩ #generics #CommonPartsLibrary
  • Generic Capacitor
    A generic fixed capacitor ideal for rapid circuit topology development. You can choose between polarized and non-polarized types, its symbol and the footprint will automatically adapt based on your selection. Supported options include standard SMD sizes for ceramic capacitors (e.g., 0402, 0603, 0805), SMD sizes for aluminum electrolytic capacitors, and through-hole footprints for polarized capacitors. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard capacitor values: 1.0pF 10pF 100pF 1000pF 0.01uF 0.1uF 1.0uF 10uF 100uF 1000uF 10,000uF 1.1pF 11pF 110pF 1100pF 1.2pF 12pF 120pF 1200pF 1.3pF 13pF 130pF 1300pF 1.5pF 15pF 150pF 1500pF 0.015uF 0.15uF 1.5uF 15uF 150uF 1500uF 1.6pF 16pF 160pF 1600pF 1.8pF 18pF 180pF 1800pF 2.0pF 20pF 200pF 2000pF 2.2pF 22pF 20pF 2200pF 0.022uF 0.22uF 2.2uF 22uF 220uF 2200uF 2.4pF 24pF 240pF 2400pF 2.7pF 27pF 270pF 2700pF 3.0pF 30pF 300pF 3000pF 3.3pF 33pF 330pF 3300pF 0.033uF 0.33uF 3.3uF 33uF 330uF 3300uF 3.6pF 36pF 360pF 3600pF 3.9pF 39pF 390pF 3900pF 4.3pF 43pF 430pF 4300pF 4.7pF 47pF 470pF 4700pF 0.047uF 0.47uF 4.7uF 47uF 470uF 4700uF 5.1pF 51pF 510pF 5100pF 5.6pF 56pF 560pF 5600pF 6.2pF 62pF 620pF 6200pF 6.8pF 68pF 680pF 6800pF 0.068uF 0.68uF 6.8uF 68uF 680uF 6800uF 7.5pF 75pF 750pF 7500pF 8.2pF 82pF 820pF 8200pF 9.1pF 91pF 910pF 9100pF #generics #CommonPartsLibrary
  • Generic Inductor
    A generic fixed inductor for rapid developing circuit topology. *You can now change the footprint and 3D model at the top level anytime you want. This is the power of #generics
  • Terminal
    Terminal
    An electrical connector acting as reusable interface to a conductor and creating a point where external circuits can be connected.
  • RMCF0805JT47K0
    47 kOhms ±5% 0.125W, 1/8W Chip Resistor 0805 (2012 Metric) Automotive AEC-Q200 Thick Film #forLedBlink
  • 875105359001
    10uF Capacitor Aluminum Polymer 20% 16V SMD 5x5.3mm #forLedBlink #commonpartslibrary #capacitor #aluminumpolymer #radialcan
  • CTL1206FYW1T
    Yellow 595nm LED Indication - Discrete 1.7V 1206 (3216 Metric) #forLedBlink

Inspect

SRD-05VDC-SL-C

SRD-05VDC-SL-C
Description

Created
Last updated by jecstronic
2 Contributor(s)
jecstronic
jharwinbarrozo

Controls

Properties

Part Type
Relay
Manufacturer Name
Manufacturer Part Number
SRD-05VDC-SL-C
Designator Prefix
K

Availability & Pricing

DPNStockQty 1
154K$0.2987

Assets