Quiescent current
The quiescent current , and bias (stream English bias-current ), is electrical current that continuously in a circuit flows, even if it is not active.
Semiconductor circuit technology
In general, the quiescent current reduces the efficiency of a circuit and is therefore mostly undesirable.
In semiconductor circuit technology , the quiescent current for setting the operating point is of great importance. In the case of amplifiers based on semiconductors, the quiescent current can - depending on the circuit technology - make up a considerable part of the total consumption.
It is also specified as an important parameter of integrated circuits and in their data sheets.
The quiescent current is also present in tube amplifiers and must be set manually on the output stage tubes, otherwise the tubes and / or the output transformer would be destroyed.
Alarm systems
In hazard alarm systems , the quiescent current is used to continuously monitor a detection line. This type of monitoring is known as the closed- circuit principle . Interruption or short circuit of the quiescent current leads to the alarm being triggered .
Quiescent current & battery
Quiescent currents are particularly harmful to batteries because they drain them but do not add any added value. In cars , quiescent currents over 50 mA are considered critical and indicate defective electronics.
literature
- Ulrich Tietze, Christoph Schenk: Semiconductor circuit technology . 12th edition. Springer, 2002, ISBN 3-540-42849-6 .
Individual evidence
- ↑ Johann Schmidt, article about quiescent currents in motor vehicles Archived copy ( memento of the original from October 6, 2014 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved October 5, 2014
