Accidentally or carelessly touching the leads of the capacitor after disconnecting the power supply, on the misconception that the absence of a power supply makes it harmless, can bear consequences ranging from mild tingling or burn to fatal electrocution and fire, depending on the amount of charge present in the capacitor.
Disconnect Capacitor Leads: If possible, disconnect the leads connected to the capacitor to prevent any accidental discharge during the process. Connect Discharge Tool: With the capacitor leads disconnected, connect the leads of the discharge tool to the terminals of the capacitor. Ensure a secure connection.
For example, if a large capacitor is used in the smoothing circuit of a power supply, a large wave-like voltage *4 can be converted to a flat DC voltage, but if the capacitor is open, a large voltage wave is directly applied to the circuit, which may cause semiconductors and other components to fail. *4 It's called ripple voltage.
Select an appropriate discharge resistor based on capacitor voltage and capacitance. Connect the discharge resistor across the capacitor terminals using insulated probes. Monitor voltage decay using a high-impedance voltmeter in parallel with the resistor. Maintain the connection until voltage drops below 50V or to the specified safe level.
Manual discharge of capacitors is a critical skill for electronics professionals. The following step-by-step procedure outlines a safe manual discharge method: Verify power is disconnected and capacitor is isolated from the circuit. Select an appropriate discharge resistor based on capacitor voltage and capacitance.
Using a discharge tool with a resistor can control the discharge rate. Initial Voltage: The higher the initial voltage across the capacitor, the longer it will take to discharge. Capacitors with higher voltages will take more time to release their stored energy compared to those with lower voltages.