Consider a situation where a tiny motorboat enters the room with ease.
In this design this small electronic device is sufficient neither water nor a complex wooden frame with a large engine connected are needed.
What is a Motor Boat Sound Generator Circuit:
A motor boat sound generator circuit is an electrical circuit designed to mimic the sound of a motor boat engine.
It generally consists of several kinds of electrical components that are mixed to produce sound signals that resemble the special “phut phut” sound produced by a moving motor boat.
This circuit is often found in model boats, hobby projects and entertainment because it creates realistic simulations or displays.
Circuit Working:
Parts List:
| Component | Quantity |
|---|---|
| Resistors | |
| 1k 1/4 watt | 2 |
| 10k 1/4 watt | 2 |
| 68k 1/4 watt | 1 |
| Potentiometer 100k | 1 |
| Capacitors | |
| Ceramic 0.22μF | 1 |
| Electrolytic 2.2μF 25V | 2 |
| Semiconductors | |
| Transistors BC547 | 2 |
| ON/OFF Switch | 1 |
| Push Button | 1 |
This device mimics the sounds of a motorboat while moving and its notes is adjusted with a knob to create actual sounds like throttle modulation and engine starter.
Luckily the complete system get fit within a tiny cabinet with controls on top for easy operation.
The controls have the following labels: idling, throttle, start and ON/OFF.
With the amplifier volume set to the desired level the units output gets connected to the input of any power amplifier or radio receiver.
The motor boat simulation will begin with a series of ‘phut phut’ sounds when you push the start button for a short while.
To mimic the engine warming up repeat this process one or two times.
The simulation will begin with an ongoing slow ‘phut phut’ that sounds like an idle motor when one turn on the ON/OFF switch.
Turn the potentiometer slowly to increase the pace of “phut phut” sound in order to modify the throttle.
A free running multivibrator is the heart of the device.
The potentiometer produces the throttling effect by fine tuning the multivibrators frequency.
The capacitor is charged to the supply voltage when the start button is pressed connecting the supply across the condenser.
The device is powered by this stored charge for a few seconds before discharging and producing a series of “phut phuts” sound that gets slowly fade like an engine starting.
The power supply is connected to the device when the ON/OFF switch is turned ON and it constantly releases low frequency “phut-phut” sounds to signal that the engine has started and is running.
Turn the potentiometer knob to speed up the engine.
‘Phut-phut’ sound becomes louder as resistance decreases.
The ‘phut-phut’ sound will slowly stop when the power source is turned off using the ON/OFF button to stop the motor boat engine.
A coupling capacitor connected in series with the output allows pulses to go through while blocking DC flow.
The connections between the switches are shown in the circuit diagram above.
Formula:
A good place to start while designing and understanding adjustable BJT astable circuits is with the following formula:
f = 1 / (1.4 * ln(1 + R2 / R1) * C1) (f2)
where,
- The output signals estimated frequency in hertz Hz is expressed by f.
- In the astable circuit R1 and R2 stand for the two external resistors that are connected to the BJT bases as these resistors are used to control the frequency.
- The capacitor that is connected to two BJTs bases and collectors is indicated by C1.
- The natural logarithms function is represented by ln.
Important points to remember:
This calculation considers that the BJT operates in the active zone and that the capacitors charge and discharge completely throughout each cycle.
Due to component limits and variations in the BJT gain the value obtained from the calculation will not be accurate to the actual frequency.
For flexibility R1 and R2 values can be modified.
The formula indicates that a higher R2/R1 ratio can often give rise to a lower frequency.
How to Build:
To build a Simple Motor Boat Sound Generator Circuit follow the below steps for connections and assembling:
Study the circuit diagram:
- Examine the circuit diagram carefully to understand where each component is places and how it is connected.
- Make a note of the resistor, capacitor and other electronic component values.
Assemble the parts:
- According to the circuit schematic gather all of the necessary electronic parts.
Get the board ready:
- If using a PCB, place the parts according to the circuit schematic in the proper locations.
- Use the circuit design as a guide while soldering the components onto a PCB.
Connect the Components:
- To create connections between components use connecting wires.
- Be careful of the polarity of parts like as diodes and capacitors.
Soldering:
- Carefully solder the connectors if using a PCB.
- Make sure there are no short circuits and that the solder connections are good.
Controls and Potentiometer:
- Follow the circuit schematic while connecting the potentiometer, ON/OFF switch and start button.
- These adjustments are essential for modifying the sound of the engine.
Source of Power:
- Connect the power supply to the circuits proper locations.
- Check that the voltage satisfies with the requirements shown in the circuit diagram.
- Turn the circuit ON then use a multimeter to look for any variations in the voltage.
- Press the start button and change the potentiometer to hear various engine noises to test the operation.
Modifications:
- To get the right engine sound effects fine tune the circuit by adjusting the potentiometer.
Take note:
- To prevent such problems always verify connections and component values.
- If electronics are unfamiliar think about asking an expert for help or looking up more information online.
Conclusion:
The ON/OFF switch, start button and potentiometer allow the user to control the engine sounds in several ways by including throttling, idling and start-up.
The end result is an electronic model that mimics the sound qualities of a motorboat engine.
These circuits are often used in projects by model boat enthusiasts and in other situations where adding a realistic sound effect improves the whole experience.