Pêşkêşkirina Berzavên Destpêkir: Schemaya Circûtk & Tîpa
Regulated Power Supply yekê çi ye?
Yek regulated power supply AC (Alternating Current) bê rêgîne birin wek DC (Direct Current) pêşdebirin. Regulated power supply biçavên din bikar îstendan de dike ku hewceyê dide ku deriyê da dest pê hatine ji bo vê yekê da ku input biguhezine.
Regulated DC power supply di navê linear power supply de an jî dikare were şeşikandin, ew yek circuit embedded e u ser bestanên cihazê têr têr bibin.
Regulated power supply inputê AC biqebûl dike u outputê DC pêşdebirin. Wêneya jêrîn block diagram-ê yek regulated DC power supply taybetand dîsa nîşan dide.
Bestanên asasi yek regulated DC power supply li jêrîn hene:
Step-down transformer
Rectifier
DC filter
Regulator
(Bilgekirin ku MCQs-yê digital electronics-yê me (digital electronics MCQs) pir serekanên elektrikî yên ji bo wan pên de)
Çalakîya Regulated Power Supply
Step Down Transformer
A step down transformer voltage-ya ji mains ac biqebûl dike u ji bo dîmena herî virast bike. Turn’s ratio-ya transformer-a wergera bike ku voltage value-ya hewceyî bide. Output-ê transformer-ê ji bo rectifier circuit-ê verast bike.
Rectification
Rectifier yek circuit elektronî e ku ji diodes ve girîng e ku rectification process-ê bikar îstendan de dike. Rectification process-ê ya ku alternating voltage an current-ê bihêvişîna direct (DC) quantity-ê guheztin. Input-ê rectifier-a AC e û output-ê unidirectional pulsating DC e.
Hesase half wave rectifier teknîkman bikar îstendin, power losses-ê wekî full wave rectifier-ê an bridge rectifier-ê bêtir ne. Ji ber vê yekê, full wave rectifier an bridge rectifier bikar îstendin ji bo rectify kirdina her du half cycles-ê yekê (full wave rectification). Wêneya jêrîn full wave bridge rectifier nîşan dide.
Bridge rectifier ji four p-n junction diodes ve çavdar e ku ji bo şekla wêneya jêrîn şeşikandin. Di positive half cycle-ê yekê de, voltage-ê induced across the secondary of the electrical transformer i.e. VMN positive e. Ji ber vê yekê, point E positive e ji bo F. Ji ber vê yekê, diodes D3 an D2 reversed biased ne an diodes D1 an D4 forward biased ne. Diode D3 an D2 wek open switches (practically there is some voltage drop) an diodes D1 anD4 wek closed switches an dike conducting bike. Ji ber vê yekê, a rectified waveform appears at the output of the rectifier as shown in the first figure. When voltage induced in secondary i.e. VMN is negative than D3 an D2 are forward biased with the other two reversed biased and a positive voltage appears at the input of the filter.
DC Filtration
The rectified voltage from the rectifier is a pulsating DC voltage having very high ripple content. But this is not we want, we want a pure ripple free DC waveform. Hence a filter is used. Different types of filters are used such as capacitor filter, LC filter, Choke input filter, π type filter. The figure below shows a capacitor filter connected along the output of the rectifier and the resultant output waveform.
