There are 4 types of couplings that are often used in electronic circuits
- Transformer Coupling
- RC Coupling (Resistor, Condensator)
- LC Coupling (Inductor/Coil, Condenser)
- Direct coupling
Coupling Function
- Passing AC signals from one level to the next level
- Preventing the entry of DC voltage from one level to the next, this is very important so that the DC voltage that functions as a bias at each level does not affect each other.
1. Transformer Coupling
Transformer Coupling
Transformers that function as couplings must be adjusted to their needs, basically for the Audio frequency region, Transformers can induce at high frequencies, in this frequency region the transformer can use an air core, while in special frequency regions such as IF, image carrier signals (38.9 Mhz) use Ferid cores.
Profit:
- By determining the number of primary and secondary coil groups, "matching" can be achieved so that the gain can be maximized.
- The transformer acts not as a load, but as a limiter (Coupling)
- Has small/low DC resistance.
Loss:
- Expensive transformers
- It takes up space (too big)
- Generates a hum if there is a leak in the magnetic field.
2. RC Coupling (Resistor Condensator)
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RC Coupling (Resistor Condensator)
Profit:
- Using space-friendly components, small size
- Cheap and economical component prices
- The gain is almost constant.
Loss:
- In wide frequency bands there is a loss of gain.
- The gain is smaller compared to a transformer, this is due to the difficulty of achieving good "matching" for large power or current.
- The voltage loss is so large that it can cause power loss in the resistor.
3. LC Coupling (Condensator Winding)
The circuit is the same as the RC Coupling, only the resistor component is replaced with a coil. This coupling is often used in high frequency circuits (transmitters).
The advantage is that the L load coil has low DC resistance so that the voltage loss in the collector is very small.
4. Direct coupling
No components are used in direct coupling, meaning that each block in the electronic circuit is directly connected without any limitations to the next level circuit block.
Profit:
- Complete signal amplification
- Cost is smaller
Loss:
- No filter for distortion
- There is no filter for DC voltage
- The potential for output devices to experience interference / damage is higher