How to Provide Short Circuit Protection to Testing Equipment
When a large number of drivers / LED bulbs are tested, some could be shorted from inside.
This can damage the electronics testing equipment.
The below illustration explains how to provide short circuit protection.
Image 1: Connection diagram of 5 Watt LED bulb with testing equipment
In the above example, a LED bulb is being tested. The power strip is used to power the DPA-1 (using the black power cord). Also, the Red/Black wire is used as input power for the LED bulb.
Image 2: Connection diagram of incandescent bulb with testing equipment
We have provided short circuit protection by connecting incandescent bulb (100 W) in series, which has low resistance.
Image 3: Incandescent bulb connection
Have a closer look for the series connection on incandescent bulb
Image 4: Shorted load demonstration
Just see that we have shorted the load by wire. What happens?
Short circuit protection in LED driver testing for 5 watt LED bulb at 230 voltage. The Incandescent bulb lights up indicating a short to the operator.
Going Into More Technical Details
Example of short circuit protection for 5 watt LED bulb connected to 230 voltage
Calculation of resistance for 5 watt LED bulb and 200 watt incandescent bulb in short circuit protection
| Parameter | 5 Watt LED Bulb | 200 Watt Incandescent Bulb |
|---|---|---|
| Voltage | 230V | 230V |
| Power | 5W | 200W |
| Current | 21.7mA | 869.6mA |
| Resistance | 10,580Ω | 60.8Ω |
5 Watt LED Bulb Testing at 400 Voltage
For this problem we provide a circuit diagram in above page.
Protection Mechanism Explanation
When a short circuit occurs, the incandescent bulb acts as a current limiter due to its low resistance compared to the LED driver. This prevents excessive current from flowing through the testing equipment, protecting it from damage.