Showing posts with label regulated. Show all posts
Showing posts with label regulated. Show all posts

Thursday, August 28, 2014

Build a Regulated driven Converter Wiring diagram Schematic

How to Build a Regulated driven Converter Circuit Diagram?.This converter delivers up to 50 mA from a 6-V battery with 78% efficiency. This flyback converter functions by feedback-controlling the frequency of inductive flyback events. The inductor`s output, rectified and filtered to de, biases the feedback loop to establish a stable output. If the converter`s output is below the loop setpoint, A2`s inputs unbalance and current is fed through the 1-MO resistor at Al. This ramps the 1000-pF value positive. When this ramp exceeds the 0.5-V potential at A1 `s positive input, the amplifier switches high. 

 Regulated driven Converter Circuit Diagram

Regulated


Q2 turns on, discharging the capacitor to ground. Simultaneously, regenerative feedback through the 200-pF value causes a positive-going pulse at A1`s positive input, sustainlljg A1`s positive output. Q1 comes on, allowing inductor, 11, current to flow. When A1`s feedback pulse decays, its output becomes low, turning off Ql. Q1`s collector is pulled high by the inductor`s flyback and the energy is stored in the 100-I`F capacitor. The capacitor`s voltage, which is the schema output, is sampled by A2 to close a loop around Al/Ql. This loop forces A1 to oscillate at whatever frequency is required to maintain the 15-V output. 

In-phase transformer windings for the drain and gate of TMOS power FET Q1 cause the schema to oscillate. Oscillation starts when the feedback coupling capacitor, C1, is charged from the supply line via a large resistance; R2 and R3 limit the collector current to Q2. During pump-up, the on time is terminated by Q2, which senses the ramped source current of Ql. C1 is charged on alternate half-cycles by Q2 and forward-biased by zener D2. 

When the regulated level is reached, forward bias is applied to Q2, terminating the on time earlier at a lower peak current. When this occurs, the frequency increases in inverse proportion to current, but the energy per cycle decreases in proportion to current squared. Therefore, the total power coupled through the transformer to the secondary is decreased.

Monday, August 18, 2014

Regulated power expander



Commercially available voltage regulator IC’s can deliver up to 1A output current. For example 78xx series regulators are available in different voltage ratings, but in any case the current should not exceed 1A.





The transistor Q1 (2N 29055) used here has 5A current capacity. The resistor R1 is used to keep the current through regulator IC below 300mA. When the current through R1 increases the base current of Q1 (2N 29055) also increases &the load required load current flows through this transistor. By this way a current greater than the capacity of the regulator IC can be delivered to the load. The C1 is used to filter the ripples off the rectifier output.

Notes.


1. Assemble the schema on good quality PCB.
2. T1 can be a 230V primary,15V/1A secondary , step down transformer.
3. If 1 A bridge is not available,make one using four 1N 4007 diodes.
4. The series regulator IC should be selected according to the desired output voltage. * IC 7805 for 05V * IC 7806 for 06V * IC 7809 for 09V * IC 7812 for 12V