* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download 3-Terminal Positive Regulators
Immunity-aware programming wikipedia , lookup
Mercury-arc valve wikipedia , lookup
Power engineering wikipedia , lookup
Spark-gap transmitter wikipedia , lookup
Electrical ballast wikipedia , lookup
Pulse-width modulation wikipedia , lookup
Electrical substation wikipedia , lookup
Power inverter wikipedia , lookup
Transformer types wikipedia , lookup
History of electric power transmission wikipedia , lookup
Variable-frequency drive wikipedia , lookup
Three-phase electric power wikipedia , lookup
Current source wikipedia , lookup
Power MOSFET wikipedia , lookup
Integrating ADC wikipedia , lookup
Resistive opto-isolator wikipedia , lookup
Distribution management system wikipedia , lookup
Stray voltage wikipedia , lookup
Surge protector wikipedia , lookup
Alternating current wikipedia , lookup
Power electronics wikipedia , lookup
Schmitt trigger wikipedia , lookup
Voltage optimisation wikipedia , lookup
Current mirror wikipedia , lookup
Buck converter wikipedia , lookup
Voltage regulator wikipedia , lookup
Mains electricity wikipedia , lookup
3-Terminal Positive Regulators The LM140/LM340A/LM340/LM78XXC monolithic 3-terminal positive voltage regulators employ internal current-limiting, thermal shutdown and safe-area compensation, making them essentially indestructible. If adequate heat sinking is provided, they can deliver over 1.0A output current. They are intended as fixed voltage regulators in a wide range of applications including local (on-card) regulation for elimination of noise and distribution problems associated with single-point regulation. In addition to use as fixed voltage regulators, these devices can be used with external components to obtain adjustable output voltages and currents. Considerable effort was expended to make the entire series of regulators easy to use and minimize the number of external components. It is not necessary to bypass the output, although this does improve transient response. Input bypassing is needed only if the regulator is located far from the filter capacitor of the power supply. • There are common configurations for 78xx ICs, including 7805 (5 volt), 7806 (6 volt), 7808 (8 volt), 7809 (9 volt), 7810 (10 volt), 7812 (12 volt), 7815 (15 volt), 7818 (18 volt), and 7824 (24 volt) versions. The 7805 is common, as its regulated 5 volt supply provides a convenient power source for most TTL components. • Complete specifications at 1A load • Output voltage tolerances of ±2% at Tj = 25°C and ±4% over the temperature range (LM340A) • Line regulation of 0.01% of VOUT/V of ΔVIN at 1A load • Internal thermal overload protection • Internal short-circuit current limit • Output transistor safe area protection • • • • • • • Transformer: isolation and voltage conversion Diode:rectification Input capacitor(electrolytic): Filter Input capacitor(AC): AC Filter 7815: regulator, a constant voltage Resistance: capacitors to discharge Output capacitor(electrolytic): to meet high load current • The maximum value of the output voltage of the rectifier Vdcgmax = 2. VF VAK a • The amount of ripple voltage at the capacitor is, V = Içmax .Ty / Cg • The minimum value of the output voltage of the rectifier Vdcgmin = Vdcgmax - V • To avoid deterioration of the output voltage Vdcgmin Vdcç + 1 V • • • • • • • VF : AC rms value VAK : Voltage drop of diode Vdcg : Input voltage at the regulator (DC) Vdcç : Input voltage at the regulator (DC) Iç : DC output current a : Transformer turn ratio V : The amount of ripple voltage at the capacitor • Ty : Half period of the AC main (10 ms) • Cg : Input capacitor To realize 12 V DC power supply, a single phase transformer which is 220/2*12 is used to insulation. The voltage drop value of the diode is 0,6 V and the input capacitor values is 470 F. The output current is 100 mA , a) V b) Min and max value of the DC voltage a) V I ç maxTy Cf 100.10 310.10 3 2,12 V 6 470.10 b) Vdcg max 2Vdc 0.6 2.12 0.6 16,37 Vdcg min Vdc 1 Vdcg min 13 V Vdcg min Vdcg max V 16,37 2,12 14,25 V