Safety Always Comes First!

 

When designing & making, it's important to know if there are any hazards involved. For example, these may be due to the materials, components, tools, or pieces of equipment you intend to use.

Considering the hazards is part of a "Risk Assessment". Its purpose is to allow you to take the necessary steps to reduce the hazards and minimise any of the associated risks to a safer and acceptable level.

As we are working with electrical power it is important to know what levels are safe: Voltages under 50 volts are generally considered low risk and used in many portable products. Similar to hand-held torches, TrackLayer projects operate from two 1.5-volt batteries connected in series (giving a total of 3-volts). FastTrack and OnTrack projects operate from single 9-volt batteries.

Although these voltages are safe; it is important to use your common sense when doing practical tasks. Having an alert attitude will also help you have greater success & enjoyment in your project work...

 

Tips To Working Safely

 

1, Lower voltages can still cause sparks, or heat to     build up through short-circuits or other faults.     This could result in the breakup of wires or     components - possibly leading to fire or burns.

- Sparks/Heat -

What you can do to reduce the risk:

• Do not connect the power source to the circuit you   are making until it is finished and you have checked   over the work you have done.

• When modelling, or prototyping circuits with   "breadboards"; remove the power source when    altering or building your circuit.

• Check to see if any components are getting hot. If    you smell burning, immediately disconnect the power    source and examine your circuit to try and find out    where the fault is. For example, you could look for:

  - Broken-down wire insulation, or damaged copper     tracks on the circuit board.

  - Components which may have the wrong value or     been incorrectly soldered to the circuit board.

2, Water is a conductor of electricity and spillages     can inadvertently bring you into contact with     high voltages from the mains power supply.

- Water/Liquids -

What you can do to reduce the risk:

 

• Keep electrically-powered mains equipment (such as   soldering irons or power supplies) away from water or   any liquid.

• Use an RCD circuit breaker on the mains cable. It will   shut off the power supply in a fraction of a second   should a small earth leakage current be detected.

• Keep your work area dry.

• Do not work with wet hands.

 

3, Soldering irons operate at over 200° Centigrade.     They create fumes and can cause burns if not     held by the handle or used carefully.

- Heat/Fumes -

What you can do to reduce the risk:

• Never leave a soldering iron resting on a table top -   somebody may put their hand on it. Return it carefully   to its metal stand when it is not in use.

• Wear safety glasses to prevent the possibility of hot   molten solder accidentally entering your eyes.

• Use lead-free solder.

• Use a soldering iron with a Silicone cable as it will   resist damage to the cable if it is touched by the hot   iron tip.

• Work in a well-ventilated space, or with extraction, to   avoid/reduce the inhalation of fumes.

• Use a de-soldering tool when attempting to remove a   misplaced or damaged component from a circuit   board.

 

4, Batteries and some electronic components     contain chemicals which are toxic.

- Toxic Chemicals -

What you can do to reduce the risk:

•  Check component data sheets to find out if any of    the components you are using are constructed from    hazardous materials. Health and Safety COSHH    regulations say this information has to be provided    by law. If it is hazardous - find an alternative if    possible.

•  Dispose of your old, or damaged batteries and    components by recycling, rather than putting them in    the general waste.

•  Reduce the number of batteries you use by buying    rechargeable types.

•  Keep components, batteries and button cells out of    the reach of young children. Urgent medical help    should be sought if they are swallowed.

Safety In The Workplace

 

            

• It is important for workshops to have safety   equipment at hand - such as a nonconducting dry   powder fire extinguisher and a fully-equipped first-aid   kit.

        

• Due to the repeated use of equipment, it is important   to routinely check that portable mains devices do not   have frayed or damaged cables. This is part of the   PAT (Portable Appliance Testing) that has to be   carried out to comply with the law. The test also   checks devices are properly wired/earthed and   protected with the correct fuse so they are safe to   use.

Safety and Mains Power

In the U.K., many of the electrical dervices we buy and use, operate with mains voltages of 230 volts and high currents. It can be very dangerous to remove equipment housings or covers. Special precautions have to be taken by qualified technicians to prevent electrical shocks, or burns, when they are repairing or working on these types of products. It is beyond the scope of TRACKS to discuss this further.

In the last section: "10 - Chargers & Adapters", we will see how mains chargers and adapters convert the power from 13 amp mains sockets to levels suitable for charging devices with rechargeable batteries, or for powering products with lower voltage circuits.