What Is a Spark Killer?
A spark killer is a device that suppresses sparks.
*Spark: A phenomenon in which a spark occurs when electricity flows in the air between two points that are not in contact with each other due to a potential difference in a switch, etc.
When a spark occurs, semiconductor elements and transistors in the circuit may be damaged, so it is necessary to have spark killers and other spark prevention measures in the circuit, especially when switches are used in DC current circuits.
Uses of Spark Killers
Spark killers are widely used in electrical equipment that operates on DC current. Especially when DC current is used as a power source, it is recommended to consider installing a spark killer because of the possibility of sparks around the switch.
Since spark killers have precisely determined the rated voltage, resistance, capacitance, and proper temperature for use, they should be selected appropriately in consideration of these factors.
If the spark killer cannot withstand the voltage in the operating environment, it may cause accidents.
Principle of Spark Killers
A spark killer consists of a resistor and a film capacitor connected in series. In a circuit consisting of a power supply, a switch, and a resistor, there are two basic ways to install a spark killer circuit: either place it in parallel with the switch or place it in parallel with the resistor.
When arranged in parallel with the switch, when the switch is off, the circuits are connected through the spark killer so that no large potential difference is created at the switch. When arranged in parallel with a resistor, one side of the switch will be at a high voltage when the switch is turned off, and sparks are likely to occur. Therefore, a spark killer prevents the high voltage from occurring, thus making it less likely to cause a spark.
The film capacitor to be used should have a large enough capacitance to prevent the voltage from becoming too high when in use. For resistors, resistors with sufficient surge immunity should be selected.