An electric
motor uses electrical energy to produce mechanical energy. The reverse process,
that of using mechanical energy to produce electrical energy, is accomplished by
a generator or dynamo. Traction motors used on locomotives and some electric and
hybrid automobiles often perform both tasks if the vehicle is equipped with
dynamic brakes. Electric motors are found in household appliances such as fans,
refrigerators, washing machines, pool pumps, floor vacuums, clothes dryers, hair
dryers, forced air home furnaces, computers requiring cooling, many DVR
recorders, attic fans, range hoods, bathroom fans, boot dryers, pellet stoves,
many electric heaters, heat guns, and fan-forced ovens. They are also found in
many other devices such as computer equipment, in its disk drives, printers, and
fans; and in some sound and video playing and recording equipment as DVD/CD
players and recorders, tape players and recorders, and record players. Electric
motors are also found in several kinds of toys such as some kinds of vehicles,
fans, cool water mist fans, blow torches, pencil sharpeners, fan-forced ovens,
and robotic toys.
Analog
electronic circuits are those in which signals may vary continuously with time
to correspond to the information being represented. Electronic equipment like
voltage amplifiers, power amplifiers, tuning circuits, radios, and televisions
are largely analog (with the exception of their control sections, which may be
digital, especially in modern units).
In digital
electronic circuits, electric signals take on discrete values, which are not
dependent upon time, to represent logical and numeric values. These values
represent the information that is being processed. The transistor is one of the
primary components used in discrete circuits, and combinations of these can be
used to create logic gates. These logic gates may then be used in combination to
create a desired output from an input. In this page you can find one of the
circuit.
On-Off Motor Driver dengan
Pembalik
Rangkaian pada Gambar 1 dikenal dengan H bridge (jembatan
H). Rangkaian ini terdiri dari empat komponen switching (dapat menggunakan
transistor bipolar, Thyristor ataupun MOSFET). Rangkaian ini berfungsi untuk
menggerakkan motor DC dengan arah putaran yang dapat diubah. Empat buah
komponen switching ini bekerja secara berpasangan (a dengan a dan b dengan
b) serta bergantian tergantung fungsinya. Ketika pasangan a-a diberi
tegangan 5 volt serta b-b 0 volt, maka motor listrik akan dialiri arus
dengan arah ke kanan. Sebaliknya ketia pasangan a-a diberi tegangan 0 volt
dan b-b adalah 5 volt, maka aliran arus listriknya adalah ke kiri. Dengan
demikian maka putaran motornya juga akan berlawanan dengan sebelumnya.
Gambar 1. Rangkaian Driver Motor Menggunakan H Bridge.
Sinyal untuk pasangan a-a dan b-b dapat diatur
menggunakan rangkaian pada Gambar 2. Rangkaian berikut berfungsi untuk
memutar motor dengan arah putaran yang dapat dibalik. Ketika input
bertegangan 5 volt maka motor akan dialiri arus listrik oleh pasangan a-a,
sedangkan ketika input bertegangan 0 volt maka motor akan dialiri arus
listrik oleh pasangan b-b. Arus listrik yang mengaliri motor DC adalah arus
listrik dengan besaran yang tetap sehingga dapat disebut sebagai on-off.
Gambar 2. Rangkaian Pembalik Putaran Motor DC Mode On-Off.