DIY Capacitor Discharge Device for Safety

After spot welding with the capacitor welder, the capacitor still holds a charge, and since it's exposed, any accidental contact could lead to a short circuit, which can have serious consequences. Therefore, a capacitor discharge device is necessary. If you're interested, keep reading.

This is quite simple; you can discharge it directly using resistors. You'll need ten 10W cement resistors, which can handle a discharge capacity of 6.25A at 5V. The 10W resistors won't get too hot, making it very safe. You can also discharge at 10A or 20A if needed.

In this setup, you can use ten 10W cement resistors rated at 8 ohms in parallel.

Board Setup

These cement resistors have a relatively rough finish, with some being white and others yellow.

Identification

After measurement, the results are as follows:

When connected in parallel, the values fluctuate between 1 and 0.7, possibly due to quality issues.

For the connections, you can use 2.5mm² silicone wire with plugs.

The spot welder has a voltage of 3.7V.

After placing the discharge board, the test current is 3.5A.

Finished