Power Supply Adapter

The following diagram is the circuit diagram of offline switching power supply circuit : Circuit Diagram: Parts List: This switching power supply is using a MOSFET. For 220V AC voltage input, use BUZ80A/IXTP4N8 MOSFET. And for 110V AC input voltage, use GE IRF823 MOSFET. The output will be 5 Volt DC with electric current can be reach 10A.

Here the schematic diagram of positive regulator with PNP and NPN transistor boost. Inside the circuit, Q1 and Q2 are wired in the classic SCR or thyristor configuration. In which higher input voltages or minimum element count are needed, the circuit for thyristor boost could be applied. The thyristor is working in a linear mode with its cathode as the control terminal and its gate to be the output terminal. This is known to be the remote base configuration.

This is the circuit diagram of 5V to Isolated 5V Converter, rated at 20mA electric current. In this converter circuit, a negative output voltage dc to dc converter generates a -5V output at pin A. In order to generate -5V at point A. the primary of the transformer must fly back to a diode drop more negative than -5V. If the transformer has a tightly coupled I : 1 turns ratio. there will be a 5 V plus a diode drop across the secondary. The IN5817 rectifies this secondary voltage to generate an isolated 5V output. The isolated output is not fully regulated since only the -5V at point A is sensed by the MAX635.

The 5V regulated power supply for TTL and 74LS series integrated circuits, has to be really precise and tolerant of voltage transients. These IC's are effortlessly damaged by short voltage spikes. A fuse will blow when its electric current rating is exceeded, but demands several hundred milliseconds to respond. This circuit will react in several microseconds, triggered when the output voltage exceeds the limit of the zener diode. This circuit uses the crowbar method, where a thyristor is employed and short circuits the supply, causing the fuse to blow. This will take position in a few microseconds or less, and so provides considerably higher protection than an ordinary fuse. If the output voltage exceed 5.6Volt, then the zener diode will conduct, switching on the thyristor (all in some microseconds), the output voltage is therefore reduced to 0 volts and sensitive logic IC's will probably be saved. The fuse will nonetheless take just a few hundred milliseconds to blow ...

This is a voltage regulator circuit built based FET KP103K. The FET VT3 acts as a dynamic load for the transistor VT2. Because of this factor increases the voltage regulation: when the input voltage from 11 to 19 V output voltage varies within ± 60 mV. Rated output voltage using Zener type D814B is 9 V. Voltage Regulator with FET KP103K circuit source: Voltage Regulator with FET

This is 1.5V-25V DC Variable Power Supply. The power supply use KR142EN14 or LM317 as regulator component . KR142EN14 or LM317 is capable to handle electric current up to 2A. You may use LT1083/84/85 to handle electric current of 7A/5A/3A. Resistor R9 is used as a current sensor to an ammeter. Components list: R1 : 4K3 R2 : 18K R3 : 100 R4,R8 : 100K R5 : 1K R6 : 240 R7 : 4K7 ( Variable resistor ) R9 : 0.33 E C2 : 0.1uF C3 : 10000uF/40V C4 : 100uF/25V D1 : KY202 D2 : KD521 D3 : D311 D4 : KC147 T1 : KT814B T3 : KT209 T4 : KT3102 IC1 : KR142EN14 (LM317) Circuit source: 1.5V-25V power supply with preregulator

This is a converter circuit which will convert 5VDC input to become 12VDC output. The circuit is based LT1070 which also will boost the current output. About LT1070: The LT ® 1070/LT1071 are monolithic high power switching regulators. They can be operated in all standard switching configurations including buck, boost, flyback, forward,inverting and “Cuk”. A high current, high efficiency switch is included on the die along with all oscillator, control and protection circuitry. Boost Converter circuit reference, download: LT1070 datasheet