diode
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GC: n

CT: Diodes are components which allow current to flow in just one direction. It is often recommended that a diode be fitted in a photovoltaic solar panel to prevent reverse current from flowing back through the panel at night time. As current passes through a diode there is a voltage drop with power lost as heat.The diode should be fitted into the positive leg of the circuit between the fuse and the battery. If more than one battery is being charged from the same panel(s) then a diode (and a fuse) should be fitted for each battery.

S: REUK – https://goo.gl/zD4B9f (last access: 16 December 2016)

N: 1. 1886, from Greek di– ,’twice’ + hodos, ‘a way, path, track, road’, from Proto-Indo-European root ked-, ‘to go, yield’.
2. A two-terminal semiconductor device with asymmetrical voltage-current.
3. In principle, a diode acts like a valve: it conducts current when voltage is applied in one direction and it stops conducting when voltage is applied in the opposite direction. Semiconductor diodes existed many years before transistors, they were then called ‘crystal diodes’ as opposed to vacuum tube diodes.
4. In a solar photovoltaic system, problem may arise when photovoltaic modules are connected in series, or if part of the cell array is shaded. In these cases, an external diode is needed to play two important functions, according to which it is called:

  • bypass diode, which allows the current to flow from the good solar cells to the external circuit in case one of the panels is damaged or in shade. Thus, preventing the risk of overheating damage in the damaged or shaded panel;
  • blocking diode, which prevents reverse current from flowing back through a solar panel at night time.

5. The term ‘diode’ is customarily reserved for small signal devices, whereas the term ‘rectifier’ is used for power devices.
6. semiconductor diode: term standardized by the International Electrotechnical Commission.

S: 1. OED – https://goo.gl/wijoeh (last access: 16 December 2016). 2, 3 and 6. TERMIUM PLUS – https://goo.gl/w8ntVw (last access: 16 December 2016). 4. DiPVS – https://goo.gl/IfMNE2 (last access: 16 December 2016). 5. AAC – https://goo.gl/xN0CtD (last access: 16 December 2016).

SYN: crystal diode, semiconductor diode.

S: TERMIUM PLUS – https://goo.gl/w8ntVw (last access: 16 December 2016)

CR: electric current, electricity, light-emitting diode, photovoltaic module, photovoltaic solar energy, renewable energy, semiconductor , solar energy.