Skip to main content

Build a Low Power Variable Voltage Converter


Using electronic diagram below can be made a voltage converter that allows laps positive voltage of existing power sources, or convert it into a negative voltage.

New supply is electrically isolated from the source through the ferrite transformer wound on a torus G2-3FT12. Primary winding consists of 30 turns. Number of turns in the secondary, n, is calculated using the equation: n = 30 Uo / Ui, where Uo is the desired voltage and Ui is the input voltage. Add to compensate pieriderior 20.05.10 turns. If the output voltage is higher, it can always reduce Pi. Both coil windings can be enamelled copper wire with a diameter of 0.3 mm.

 Low Power Variable Voltage Converter Circuit Diagram:

Converter Circuit Diagram

The transformer is controlled by a gate CMOS Schmitt trigger and Do with transformed into a rectangular signal generator R1 and C1.

Additional current to charge C1 is provided by R2 and Pi, which controls the duty cycle of the rectangular signal. The signal frequency is about 220 kHz and fill factor or should be less than 0.5.

When T1 is opened, some of the energy is transferred to the secondary winding and some is stored in the magnetic circuit. When T1 conduction ceases, the magnetic field energy transfer in the secondary winding.

The current through Q1 will increase dangerously if secondary task is too big. Average current through the primary should not exceed 150. The report gave the scheme, secondary task can not be less than 80 ohms.
Besides excessive loads should also avoid working without load.

Converter efficiency at a supply voltage of 15 V is about 65%. The low current load, it decreases to about 50%. Efficiency also decreases when the supply voltage is lower than indicated. The current drawn from the source of 15 V for a load of 80 ohms is about 165 mA.


Comments

Popular posts from this blog

PID instruction in Allen Bradley PLC Closed Loop Control

PID instruction in Allen Bradley PLC [Proportional/Integral/Derivative] Closed Loop Control For   Processor SLC 5/02SLC 5/03SLC 5/04SLC 5/05    MicroLogix 1200 and MicroLogix 1500 (A special PID file replaces the old integer file control block.) Description of PID in PLC   This output instruction is used to control physical properties such as temperature, pressure, liquid level, or flow rate of process loops. The PID instruction normally controls a closed loop using inputs from an analog input module and providing an output to an analog output module as a response to effectively hold a process variable at a desired set point. The PID equation controls the process by sending an output signal to the actuator. The greater the error between the setpoint and the process variable input, the greater the output signal, and vice versa. An additional value (feed forward or bias) can be added to the control output as an offset. The result of the PID calculation (control vari...

NE566 Function Generator Circuit Diagram

The NE566 Function Generator is a Voltage-Controlled Oscillator of exceptional linearity with buf fered square wave and triangle wave outputs. The frequency of oscillation is determined by an external resistor and capacitor and the voltage applied to the control terminal. The Oscillator CAN be programmed over a ten-to-one frequency range by proper selection of an external resistance and modulated over a ten-to-one range by the control voltage, with exceptional linearity.  FMAX = 1 MHz     WIDE 1000:1 Continuous Sweep Possible  NE566 Function Generator Circuit Diagram Pdf Datasheet  Sourced by : Circuitsstream

Long Loopstick Antenna Circuit Diagram

Circuit Diagram  Description Wound on a 3 foot length of PVC pipe, the long loopstick antenna was an experiment to try to improve AM radio reception without using a long wire or ground. It works fairly well and greatly improved reception of a weak station 130 miles away. A longer rod antenna will probably work better if space allows. The number of turns of wire needed for the loopstick can be worked out from the single layer, air core inductance formula: Inductance = (radius^2 * turns^2) / ((9*radius)+(10*length)) where dimensions are in inches and inductance is in microhenrys. The inductance should be about 230 microhenrys to operate with a standard AM radio tuning capacitor (33-330 pF). The 3 foot PVC pipe is wound with approximately 500 evenly spaced turns of #24 copper wire which forms an inductor of about 170 microhenrys, but I ended up with a little more (213uH) because the winding spacing wasn't exactly even. A secondary coil of about 50 turns is wound along the length of th...