- Resistor colour code calculator
- LED series resistor calculator
- Series / parallel resistor calculator
- Capacitance unit converter
- Charge / Energy calculator
- Capacitor code calculator
- Series / parallel capacitor calculator
- Convert colour code to inductance
- Convert inductance to colour code
- Ohm Law calculator
- Potential Divider calculator
- Wheatstone Bridge calculator
- Power (wattage) calculator
- Reactance calculator
- Technical Data
- Beginners Guide
WEEE / RoHS Directives
2 new European directives are due to come over the next 2 years, both of which will have an impact on the electronics industry and hobbyists alike. Now is the time to understand the implications of these directives and prepare for them.
WEEE (Waste Electrical and Electronic Equipment):
The WEEE directive will make manufacturers responsible for disposal and recycling of products they produce. A few products will be exempt from WEEE, but manufacturers of those that are not must make provisions for products to be returned to them at the end of their life cycle. The manufacturers must then bear the cost of recycling these products. It is expected that legislation will be introduced by the end of 2004, with compliance by August 2005.
Manufacturers must think about how they will provide for this, as well as designing products to minimise the costs and environmental impact. Currently over 6 million tons of waste electronic equipment is dumped each year, WEEE aims to reduce this by encouraging environmentally sound design and shifting responsibility for recycling onto manufacturers.
RoHS (Restriction of certain Hazardous Substances):
This directive will probably have a bigger impact than WEEE on hobbyists. From 2006 the use of 6 substances commonly used in electronics will be restricted. These are lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyls and polybrominated diphenyl ethers. In practice RoHS is linked to WEEE, as the environmental impact of these substances is greater than the health risks these pose.
RoHS will mean standard tin/lead solder can no longer be used, this in itself presents big problems. Firstly it is not just the solder you assemble boards with that is affected - components and PCBs must be lead-free too. Secondly lead-free solders have a higher melting point, increasing the risk of thermal damage to components and boards. RoHS could also affect the flux used in the solder too, again affecting the solder's properties. Thirdly there are a number of lead-free alternatives, often incompatible with one another, and as yet no set standard. If the solder you are using is not compatible with that used to tin component leads or the PCB you may run into problems. That said I have recently used lead-free PCBs with lead solder and experienced no problems.
See the May 2004 edition of EPE magazine for an excellent article on lead-free soldering and it's impact. If you plan to stock up on components or solder you should check whether they are lead free. Check this in catalogues and on manufacturers websites. Lead-free components should be kept separate from those containing lead. Businesses will need to keep documents from suppliers showing components are compliant in case a product's compliance is contested. More information about both directives can be found on the RS and Farnell websites, as well as Envirowise.
It must be remembered RoHS doesn't only affect solder, it will also affect other components that contain banned substances, such as Ni-Cad batteries. However in most cases alternatives are readily available. Controlled use of hazardous substances in some products will be permitted, most notably mercury in fluorescent tubes.