To begin with, this article discuss how to make 100 Watt Amplifier Circuit using IC LM12, where there is no need of many parts or costly wires; we just need to follow some easy step and can get nice and powerful sound.
Also, this 100 watt amplifier is small and is build easy and is good for many uses, as it gives strong 100 watt sound to boost audio signal with LM12 IC.
Circuit Working:
Parts List:
| Components | Quantity |
|---|---|
| Resistors | |
| 3.3k 1/4 watt | 1 |
| 2.2k 1/4 watt | 1 |
| 1k 1/4 watt | 2 |
| Capacitors | |
| Ceramic 2.7nF | 1 |
| Ceramic 100nF | 2 |
| Electrolytic 4700μF 100V | 6 |
| Semiconductors | |
| Diodes 6A2 | 2 |
| Diodes 6A4 | 4 |
| IC LM12 | 1 |
| Transformer 24V-0-24V 5 Amp | 1 |
| Inductor L1 4μF | 1 |
| Speaker 4Ω | 1 |
Firstly, using the LM12CLK IC to make a simple 100-watt amplifier is easy and works well, because this strong IC can deliver up to 150W when we use a low-impedance speaker, such as a 2-ohm speaker.
Also, this circuit works best with 4 ohm speaker and it gives stable and safe power to around 100W RMS.
Here, transformer gives 24V + 24V AC with 5A for mono or 10A for stereo use, so better to use metal bridge rectifier with heat sink and not 4 diode bridge.
Furthermore, for output coil L make 14 turns and use 18 wire with no core and 1 inch wide and how far coil turns from each other does not matter much.
As a result, use exact 1k ohm resistor and at least 2W power for best result and also electrolytic capacitors must be 50V or 63V rated.
Hence, all parts work together to make strong and nice sound; as this project is small but gives powerful and clear sound and makes sound system better.
Moreover, this circuit is easy to build and we can enjoy great sound after, thus or next step is to make our own 100W amp using one IC only.
Formula:
Below formula show how one type of amplifier circuit work where voltage gain (Av) is in the formula:
Av = 1 + R3 / R2
here:
- Av is voltage gain of amplifier.
- If amplifier makes signal stronger then Av is more than 1.
- R3 is feedback resistor which goes between op-amp output and inverting input.
- R2 is gain resistor which goes between inverting input and ground.
Understanding non-inverting op-amp:
For non-inverting op-amp gain formula also is:
Av = 1 + R3 / R2
This mean voltage gain depend on R3 divide by R2 and if R3 is big and R2 is small then gain is high.
Important things to know:
Above formula is only for non-inverting op-amp and other types like inverting op-amp use different formula.
Also, this formula thinks of op-amp which is perfect with infinite gain, infinite input impedance but in actual circuit it is not perfect.
Real parts and limits may affect the actual gain, so choose the correct R2 and R3 values to get the desired gain.
As a result, that way we can build amplifier with needed voltage gain.
How to Build:
For building a 100 Watt Amplifier Circuit using IC LM12 involves several connections and assembling process:
First Safety:
- First, be sure we have right tools and clean safe work area and check all parts again and follow safety rules.
Power Source:
- Next, connect transformer to give power to circuit and use 5A current for mono and 10A current for stereo, also better use metal bridge rectifier with heat sink and not for four diodes.
Output Coil (L):
- After that, make coil L by winding 14 turns of 18 wire on 1 inch round with no core and exact space between turns is not important.
Use IC LM12:
- Then connect circuit board with LM12 IC and see datasheet or pinout for correct connection.
- Now connect 50V or 63V electrolytic capacitors and exact 1k 2W resistors to right LM12 pins.
Speaker Connection:
- Next, connect 4 ohm speaker to amplifier output.
- Also, check all connections two times and turn ON circuit slowly and watch if anything goes wrong or strange things happen.
- If possible use tools like multimeter or oscilloscope to check signal is good.
Conclusion:
To conclude, with LM12 IC we can make 100W amplifier with cheap parts.
Also, this 100 Watt Amplifier Circuit using IC LM12 give strong and clear sound and is good for music lovers who want better sound system.