This is the circuit diagram of a simple three transistor audio amplifier that can deliver around 100mW power to a 25 Ohm speaker. The diodes D1 and D2 provides a constant bias voltage for the transistors Q1 and Q2. The transistor Q1 works as a preamplifier. Transistors Q2 and Q3 drives the speaker. The type no of the transistor is not very crucial
Click here to download the full size of the above Circuit.
here. You can use any NPN transistor for Q1, Q3 and any PNP transistor for Q2. Any way the minimum collector current capacity of the transistors must not be less than 100mA. The circuit will work well with an 8 ohm speaker too, but the volume will be a little less. I have two question. (1) can 16v rated capacitor replace the C1, C2. Because you said c1, c2 must be rated 15V. Then, secondly can we connect a speaker to the input of this circuit to make it a microphone I have two question. (1) can 16v rated capacitor replace the C1, C2. Because you said c1, c2 must be rated 15V. Then, secondly can we connect a speaker to the input of this circuit to make it a microphone hi can i ask if how much capacity of an amplifier would i use in a 400W speaker and should i install a capacitor on my speaker how much capacity should i put on the speaker pls i need your advice tnx our assignment is to make a combinational circuit of BJT and FET. at first we are to submit an amplier circuit with three stages. and we pass the circuit above. Hi RKH you can use a 10K potentiometer for volume control connect C2 negative terminal to slider of the potentiometer. one end of the potentiometer to common (emitter of Q3. now connect the input to common and and other (free) end of the potentiometer. Hi Raj, No major change is required. keep the same circuit assemble and change R1 to 390 ohms and change the Q3 base bias reistance R2 100K to 100k preset...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
characters left: