In the eKitchen, we will mostly be working with small low-power household appliances and consumer electronics. Repairing larger appliances is outside the scope of this post. Nonetheless, it is important to consider safety even when working with relatively low power devices.
Individual Safety
Before starting to do any work, check that you are prepared:
- Clothing: Don’t wear loose clothing that might fall into the circuit, or get in the way.
- Jewelry: Remove rings or dangling metallic jewelry.
- Hair: Tie back long hair.
- It is a good idea to wear protective gloves and glasses if in doubt.
Setting up your station safety
Check also that you have set up your station and equipment safely:
- Check for tripping hazards – extensions cords, or overcrowded outlets can be unsafe.
- Keep your work area well lit
- Work on a stable, dry surface
Before working on a new device
- Check for safety warnings on stickers, and understand these tips.
- Generally, turn off and unplug the device, and remove the battery. It might be necessary to measure voltage or current, in which case only power on the device only when performing these measurements.
- Understand how the device works – don’t be connecting things blindly for example. Be careful during disassembly – you never know when something might be spring loaded.
- Capacitors can store charge, which can be dangerous in some circuits. Always discharge large capacitors, as discussed below.
After repairs
Older electronics may contain toxic chemicals like lead and mercury. Wash your hands when you are done, and don’t eat or touch food when handling electronics.
Safe Soldering
When soldering, there are some additional safety tips:
- Work in a well ventilated area: Solder fumes can be toxic. Ideally set up a fan and work near a window.
- Be mindful of lead: Solder can contain lead. We will try to provide only lead free solder, but the solder in older electronics would likely not be lead free. Wash your hands when you are done.
- Be very cafeful with the iron: Soldering irons get extremely hot and its easy to burn your fingers. Always be mindful of this. Also, only set the soldering iron down on the iron stand, and don’t leave it unattended.
- Keep your workspace clear, and make sure that you have enough space. Also make sure that there is no chance of someone tripping on the soldering iron power cable.
Discharging Capacitors
Large capacitors can be quite dangerous, as they can store a lor of charge. Capacitors are typically cylindrical and may look a bit like battery cells. In the eKitchen we are going to be avoiding working with high power electronics with large capacitors, but it is very important to discharge all capacitors nonetheless. You can check the charge on a capacitor using the voltage setting of a multimeter.
To discharge a capacitor, connect a resistor across the capacitor. We will have one available for this purpose. Alternatively, in some cases you can use a screwdriver or a multimeter.
Avoid / exercise special caution …
Certain types of appliances and electronics can be particularly dangerous:
- PC power supplies, camera flashes and TVs and monitors contain high-voltage capacitors. Ensure they are discharged before doing anything else.
- Batteries: Never puncture or bend a battery, and be cautious with batteries that appear damaged. If you notice a battery smoking or swelling, step away.
- Microwaves: We won’t be working with microwaves in this course as they can be especially dangerous in terms of high voltage capacitors, radiation etc.
- Cathode ray tube displays: We probably won’t come across any CRT displays these days, and won’t be working with them. These have very high voltage capacitors and dangerous vacuum tubes.