PRECAUTIONS IN THE WORKSHOP AND LABORATORY

General precautions in workshop
 Always wear safety glasses when working with other than signal-level power.
 Use rubber door mats to insulate yourself from ground, when working in the Laboratories.
 Be sure about the location of fire extinguishers and first aid kits in Laboratories.
 A switch should be included in each supply circuit so that when opened, these switches will de-energize the entire setup. Place these switches so that you can reach them quickly in case of emergency, and without reaching across hot or high voltage components.

Precautions to be taken when preparing a circuit
 Use only isolated power sources (either isolated power supplies or AC power through isolation power transformers).This helps in using a grounded oscilloscope. This reduces the possibility of destroying the test equipment.

Precautions to be taken before powering the circuit
 Check for all the connections of the circuit and scope connections before powering the circuit, to avoid shorting or any ground looping that may lead to electrical shocks or damage of equipment.
 Check any connections for shorting two different voltage levels.
 Check if you have connected load at the output. This is very important in boost and buck-boost converters and converters based on them.
 Double check your writing and circuit connections. It is a good idea to use a point to point writing diagram to review when making these checks.

Precautions while switching ON the circuit
 Apply low voltages or low power to check proper functionality of circuits.
 Once functionality is proven, increase voltages or power, stopping at frequent levels to check for proper functioning circuit or any components is hot or for any electrical noise that can affect the circuit’s operation.

Precautions while switching on or shutting down the circuit
 Reduce the voltage or power slowly till it comes to zero.
 Switch of all the power supplies and remove the power supply connections.
 Let the load be connected at the output for some time, so that it helps to discharge capacitor or inductor if any, completely.

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Precautions while modifying the circuit
 Switch on the circuit
 Modify the connections as per you requirement.
 Again check the circuit and switch on the circuit

other precautions
 No loose wires or metal pieces should be lying on table or near the circuit, to cause shorts or sparking.
 Avoid using long wires, that may get in your way while making adjustments or changing leads.
 Keep high voltage parts and connections out of the way from accidental touching and from any contacts to test equipment or any parts, connected to other voltage levels.
When working with inductive circuits, reduce voltages or currents to near zero before switching open the circuits.
 BE AWARE of bracelets, rings, metal watch bands, and loose necklace (if you are wearing any of them), they conduct electricity and can cause burns. Do not wear them near an energized circuit.
 Learn CPR and keep up to date. You can save a life.
 When working with energized circuits (while operating switches, adjusting controls, adjusting test equipment), use only one hand while keeping the rest of your body away from conducting surface.

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