• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar

Circuit Ideas for You

Get free circuit ideas online.

  • Home
  • Privacy Policy
  • About
Home » 9V Loud Speaker Sound Generator Circuit

9V Loud Speaker Sound Generator Circuit

Last updated on 25 December 2025 by Admin-Lavi Leave a Comment

This article explains about a 9V Loud Speaker Sound Generator Circuit.

It is simple and is with low cost and it works on 9V DC power supply.

It gives loud sound compared to simple buzzer.

Therefore it is useful for alarms, door bells, alerts and projects.

Here, common transistors are used so beginners can build it easily.

Circuit Working:

9V Loud Speaker Sound Generator Circuit Diagram

Parts List:

Components ValueQuantity
Resistors (All resistors are 1/4 watt)1k, 4.7k, 2.7k, 68k, 1.2k, 330Ω1 each
CapacitorsElectrolytic 10uF 25V2
Electrolytic 1uF 25V, 33uF 25V1 each
Ceramic 0.047uF 50V1
SemiconductorsTransistors BC337 NPN2
Transistor BC557 PNP1
Transistor 2N2222 NPN1
Red LED1
8Ω speaker1
9V Power supply1

At first the power supply of 9V is applied to the circuit and then capacitors start charging.

Because of this Q1 starts oscillation and after that the signal goes to Q2 through coupling capacitor.

Therefore oscillation becomes stronger and then amplified signal moves to Q3 stage.

At the same time LED glows showing operation and next Q3 drives Q4.

Q4 works as power amplifier and as a result speaker gets high current.

So loud buzzer sound is produced and thus whole circuit works as sound oscillator and amplifier.

How to Build:

To build a 9V Loud Speaker Sound Generator Circuit follow the connection steps:

  • Assemble all the parts as shown in circuit diagram.
  • Capacitor C1 positive connect to Vcc and negative to GND.
  • Q1 2N2222 emitter connect to ground
  • Base connect to R2 and cathode of C4 junction
  • Collector connect to R1 and anode of capacitor C2.
  • Q2 BC337 emitter connect to ground.
  • Base connect to cathode of capacitor C2 and resistor R3.
  • Collector connect to anode of C3 capacitor and capacitor C4 and Vcc.
  • Q3 BC337 emitter connect to anode of LED and cathode connect to collector of Q2.
  • Base connect to resistor R5 one end and R6 resistor.
  • Collector connect to base of transistor Q4 through resistor R4.
  • Q4 BC557 emitter connect to Vcc.
  • Base connect to R4.
  • Collector connect to C5 capacitor one end and one end of speaker.
  • Speaker other side connects to ground.

Conclusion:

This 9V Loud Speaker Sound Generator Circuit is simple

It uses easily available parts which produces strong sound output.

Therefore it is suitable for alarms and alerts.

Moreover beginners can understand transistor working.

Finally this circuit is reliable and easy to build.

References:

Powering a 2 watt 6 ohm speaker with a 9V battery?

Filed Under: Audio Circuits, Oscillator Circuits

About Admin-Lavi

Lavi is a B.Tech electronics engineer with a passion for designing new electronic circuits. Do you have questions regarding the circuit diagrams presented on this blog? Feel free to comment and solve your queries with quick replies

Previous Post: « Simple Transistor Oscillator Speaker Circuit
Next Post: Bluetooth Controlled Police Siren Sound Circuit with Arduino »

Reader Interactions

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Primary Sidebar




Categories

  • Alarm Circuits (45)
  • Amplifier Circuits (67)
  • Arduino Projects (99)
  • Audio Circuits (114)
  • Automobile Circuits (19)
  • Battery Charger Circuits (65)
  • Free Energy (13)
  • Heater and Temperature Controllers (13)
  • High Voltage (1)
  • Indicator Circuits (45)
  • Inverter Circuits (20)
  • IoT projects (1)
  • LDR Circuits (26)
  • LED and Lamps (148)
  • Meters and Testers (30)
  • Motor Controllers (22)
  • Oscillator Circuits (39)
  • Power Supply Circuits (104)
  • Remote Control Circuits (10)
  • Security and Protection (29)
  • Sensors and Detectors (126)
  • Solar Circuits (29)
  • Timer Circuits (41)
  • Transistor Circuits (87)
  • Transmitter Circuit (17)
  • Tutorials (8)
  • Water Level Controller (6)

Recent Posts

  • 12V Battery Low Voltage Alarm Circuit
  • Low Voltage Alert Circuit for 9V Battery
  • Digital Code Lock Circuit using IC 4017
  • Darkness Activated LED Circuit
  • Fan Start 10 Second Delay Timer Circuit

Recent Comments

  1. TDHofstetter on DIY Variable Power Supply Circuit using Arduino
  2. feathbuff on Simple Micro Ampere Meter Circuit
  3. Admin-Lavi on Simple School Project Multimeter Circuit
  4. choke on Simple School Project Multimeter Circuit
  5. Admin-Lavi on Analog to Digital Converter Circuit using IC 555

Copyright © 2026 | New Circuit Ideas