A simple 24V flasher circuit is one that may be used to periodically turn on and off a 24V item, such as a lightbulb.
This may be used to make turn signals or flashing warning lights.
One common method for building oscillators and timers is to use a IC 555 integrated circuit.
You may adjust the circuits flash rate by attaching a resistor and capacitor to the timer integrated circuit.
Although simpler, this method may not be as adaptable as employing a IC 555 integrated circuit.
A basic relaxation oscillator that can turn on and off a lightbulb may be made with a transistor and resistor.
Circuit Working:
Parts List:
| Component Type | Description | Quantity |
|---|---|---|
| Resistors | 1k, 1/4 watt | 2 |
| 470k, 1/4 watt | 1 | |
| Capacitors | Ceramic 0.1μF | 1 |
| Electrolytic 10μF, 50V | 1 | |
| Semiconductors | IC 555 | 1 |
| IC 7812 | 1 | |
| Transistor 2N2222 | 1 | |
| Diode 1N4007 | 1 | |
| Other Components | 12V Relay | 1 |
| 24V Bulbs | 2 |
The two bulbs in the flasher circuit are controlled by a relay.
Both of the bulbs positive terminals are linked to one another and to the 24V power source.
The bulbs negative terminals are linked to the relay in order to turn them on and off.
Three crucial connections are included on the relay:
Common (COM): The relay itself is permanently linked to this pin.
Normally (NO): When the relay engages, this pin becomes connected to the circuit after being initially unconnected.
Normally Closed (NC): When the relay engages this pin is first linked to the circuit but is thereafter disengaged.
Only one light bulb may be illuminated at a time thanks to this arrangement.
Controlling Timing Using a 555 IC:
In order to provide the flashing effect, the relay must be turned on and off at predetermined intervals.
The IC 555 is the standard component in electronics used to generate timing signals.
We will be using an astable mode IC 555 in this design.
A continuous pulse with a specified on time (Ton) and off time (Toff) is produced by this mode.
Control of Bulb according to Timing:
The circuit uses the output of the 555 IC to regulate the lights.
Only the timer generated on time (Ton) will illuminate bulb 1, and only the off time (Toff) will illuminate Bulb 2.
In the simulation step, the intricacies of this procedure will be further investigated.
Supplying the Circuit with Power:
The circuit as a whole runs on 24V, on the other hand, a lower voltage is usually needed for the relay and the IC 555 to operate correctly.
This is where the voltage regulator IC2 7812 is useful.
The 555 IC and the relay are powered by the 5V that is produced after it controls the 24V input.
Using a transistor to increase the output of a 555 IC:
It is possible that the output current of pin 3 on the IC 555 is insufficient to trigger the relay directly.
An NPN transistor 2N2222 is utilized as an amplifier to remedy this.
The 555 ICs output signal is applied to the transistors base via a base resistor causing the transistor to function as a switch that increases the current that controls the relays on/off state.
Formulas:
The values of two parts that are attached to the 555 IC in astable mode determine the formula used to determine the circuits flash rate (frequency):
Timing Resistor R1: The 555 ICs pins 1 (positive trigger) and 8 (positive supply) are linked to this resistor.
Timing Capacitor C1: The 555 ICs pins 2 (output) and 6 (threshold) are linked to this capacitor.
The formula for flash rate (F) is:
F = 1.44 / (R1 * C1)
where:
- F is the flash rate in hertz Hz
- R1 is the value of the timing resistor in ohms Ω
- C1 is the value of the timing capacitor in farads F
The bulbs flash rate may be managed by varying the values of R1 and C1.
A slower flash rate will be produced by higher values of R1 or C1 whilst a quicker flash rate will be produced by lower values.
How to Build:
To build a simple 24V flasher circuit you need to follow the below mentioned steps for connections:
- Assemble all the components mentioned in the above diagram.
- Connect pin 1 of IC1 555 to ground.
- Connect pin 2 to pin 6 of IC1 555, connect a capacitor C1 from pin 2 and pin 6 to ground.
- Connect pin 3 of IC1 555 to base of transistor Q1 through resistor R3.
- Connect pin 4 and pin 8 of IC1 555 to Vout positive supply of IC2.
- Connect pin 5 of IC1 555 to ground through capacitor C2.
- Connect a resistor R1 between pin 6 and pin 7 of IC1 555.
- Connect a resistor R2 from pin 7 of IC1 555 to positive supply.
- Connect pin Vin of IC2 7812 to +24V positive supply.
- Connect pin ground to negative supply (0V).
- Connect pin Vout to the positive rail of the IC1 555 circuit
- Connect transistor Q1 collector to COM pin of 12V relay, connect base to pin 3 of IC1 555, connect emitter to ground.
- Connect 12V relay 1 coil pin to positive supply of +24V, 2nd coil pin to collector of transistor Q1.
- Connect COM pin of 12V relay to ground.
- Connect NO pin of 12V relay to L2 of 24V bulb, connect NC pin of 12V relay to L1 of 24V bulb.
- Connect a diode D1 across a relay coil terminals.
Safety Notes:
- Understanding the hazards is crucial when working with electronics.
- Be mindful of the risk of shock and use a voltage source that is suitable for the circuit.
- Your work on this 24V flasher circuit may be done with less danger if you adhere to these safety precautions.
- Always keep in mind that your safety comes first when using gadgets.
Conclusion:
- A 555 IC is used in this 24V flasher circuit to regulate the pace at which two bulbs flash.
- The greater current is handled by a relay and transistor, and the voltage regulator makes sure the timer runs safely.
- Always put safety first when constructing this circuit.