A Simple Car Reverse Horn with Musical Tone Circuit offers a easy and creative way to change the usual beeping sound of a cars reverse horn into a more pleasant and musical tune.
The main part of this circuit is the IC UM66 chip, which is famous for creating lovely melodies.
And the other IC is voltage regulator 7805 which reduces the car battery voltage to 5V.
It also includes some extra parts that work together to make a reliable and efficient musical horn system.
This circuit can be easily added to cars giving drivers a nicer sound when backing up and making the whole driving experience better.
Circuit Working:
Parts List:
| Component | Specifications | Quantity |
|---|---|---|
| Resistors | 100Ω, 1/4 watt | 2 |
| Capacitors | Ceramic 0.1μF | 1 |
| Electrolytic 100μ 25V | 1 | |
| Electrolytic 1μF 25V | 1 | |
| Semiconductors | IC 7805 | 1 |
| IC UM66 | 1 | |
| Diodes 1N4007 | 3 | |
| Transistor 2N2222 | 1 | |
| Other Components | 8Ω Speaker | 1 |
The above circuit gets its power from the cars battery which usually provides 12V.
To make this power easier to use the 7805 voltage regulator IC1 changes the 12V down to a steady 5V direct current.
This 5V is just right for powering the IC2 UM66 integrated circuit and other parts connected to it.
To protect the circuit from damage caused by wrong connections or voltage spikes diodes D1, D2 and D3 which are 1N4007 are used for safety.
When IC2 receives the necessary 5V it can play a pre-set melody.
However, this melody is weak so it needs to be amplified to work with a speaker.
The output from IC2 goes to the base of the NPN transistor Q1 known as 2N2222 through a 100 ohm resistor R2.
In this setup Q1 acts as an amplifier boosting the signals strength.
The stronger output then drives an 8 ohm loudspeaker which produces the sound of the melody.
There is also a reverse gear switch that turns on the circuit when the vehicle is put into reverse.
To keep everything running smoothly capacitors C1 and C2 are added to filter out any noise and stabilize the power supply.
Note: It is really important to understand your cars electrical wiring before you try to work on the circuit.
If you make a mistake with the connections, it could damage your cars electrical system.
Formula:
The formulas with calculations for Simple Car Reverse Horn with Musical Tone Circuit is mentioned below to design your own circuit.
Resistor Calculation:
R1 controls the amount of current going to the UM66 IC and other parts.
R2, which is 100Ω is selected to make sure that Q1 gets enough base current to work well for amplification.
Ib = Ic / hFE
where,
- Ib is the base current
- Ic is the collector current calculated based on the speakers power requirements)
- hFE is the current gain of the transistor 2N2222.
How to Build:
To build a Simple Car Reverse Horn with Musical Tone Circuit follow the below mentioned steps for connections:
- Assemble all the components mentioned in the above circuit diagram
- Connect a capacitor C3 from input of IC1 and GND.
- Connect a D1 from input of IC1 to 12V from car battery through reverse switch
- Connect the GND pin of IC1 to GND
- Connect the output pin of IC1 to D2 and D3 in series.
- Connect the positive of capacitor C1 from output pin of IC1 to negative of capacitor C1 to GND.
- Connect the GND pin of IC2 to GND.
- Connect the VDD pin of IC2 to one end of resistor R1 and other end of resistor R1 between diode D3 and one end of 8 ohms speaker
- Connect the Output PIN OF IC2 to base of transistor Q1.
- Connect a positive of capacitor C2 between resistor R1 and VDD pin of IC2, connect the negative of capacitor to GND.
- Connect the collector of transistor Q1 to one end of 8 ohms speaker, connect the base of transistor Q1 output pin of IC2 and emitter of transistor Q1 to GND.
Conclusion:
The Simple Car Reverse Horn with Musical Tone Circuit is an easy and affordable project that can make your cars reverse alert system more fun.
By using the UM66 melody IC along with a few other parts this circuit creates a nice tune instead of the usual beeping sound when you back up.
It is a great project for car lovers and electronics fans who want to add a cool and useful twist to their vehicles.