The presence of light indicators of electrical household appliances allows a person to understand what condition they are in. The LED is a light indicator. But in some simple devices, there is no indication, for example, home lighting switches. This drawback can be fixed by mounting LEDs in the keys. The light beacon will make it easy to find the switch in complete darkness.

Connection method

Direct connection of the LED to the 220 volt network is not possible, this will lead to damage. Using a minimum of additional electronic elements, and calculating the load, you can collect the protection. Protection is necessary to equalize and lower the input voltage and current.

The easiest way is to connect a resistor or capacitor in series with the diode. Role of elements; decrease in incoming electricity to the light semiconductor. Should be considered; the network uses alternating current, which flows through the wires constantly changing direction with a frequency of 50 hertz. It is important to block the effect of reverse current. As a blocker, a regular silicon diode is suitable.

Simple and reliable way

The simplest methods do not differ in the reliability of the circuit execution. Any surge in electricity on the network will damage parts. Slightly complicating the scheme, we get a fully functional option.

With this connection scheme, the LED is most protected from power surges and increased loads. The scheme is simple, but requires the selection of parts. Resistor power not less than 0.5-0.6 watts, resistance not less than 250 kOhm. In the circuit, the resistor acts as a shunt device, and prevents the release of residual voltage of the capacitor.

Radio component calculations

The resistor is calculated according to the formula: R = U / I, R is the resistor resistance, U is the voltage, I is the LED current.

We calculate the capacitor according to the formula: C = 3200 × I / U. I - load current, U supply voltage. For better protection, the rated voltage of the capacitor should be at least 450 volts. This will protect the circuit from voltage surges. The capacitor must not have a polarity; electrolytic and tantalum capacitors cannot be used. It is better to take a ceramic, for example: K73-17, or pick up a foreign analog.

Safety precautions

When connecting the device to the network, it is necessary to strictly observe safety precautions. Important to remember; AC 220 volts is dangerous for humans. When mounting the circuit, make sure that the device is properly insulated. Circuit parts should not be touched with metal. Poor assembly can cause a short circuit in the network.