2B-DELUXE REGULATED POWER SUPPLY
This project is a boon for the hobbyist. This project is different from the project earlier given in our book series. The main attraction is that you can calibrate it yourself. Suppose you have set the course voltage for 10V. You can further get the regulated variable output from 0 to 10V from this. With the help of this project you can get the desired voltages for the other projects.
TECHNICAL DESCRIPTION AND WORKING
This project has been developed and tested O.K. in our TV Engineers Technical Lab. The components and PCB used in the projects published in our books are available for sale at resonable price.
IC LM317 has been used in this project. This is a voltage regulated IC. There are 3 pins and inside the IC transistors, diodes and resistances are used. Pin no. 1 is a input and the unregulated DC supply from the bridge rectifier is given to this point. The regulated DC from the output is available from pin no. 3. The pin no. 2 of this IC goes to base of the transister inside the IC. The resistance and the preset connected to the output side controls the bias voltage given to the base of the transister. Changing the value of preset changes the base biasing and accordingly variable voltages are obtained from the output. In this project there are three controls. The tone control of 470E is used for 0 adjustment and 4K7 tone control sets the high voltage range. The third control of 5K adjust the voltage range of preselected voltage. It is type of course voltage tone control.
Through this project the voltages are controlled from 3V to 30Volts. Care should be taken that load current do not increase from 1.5Amp otherwise IC can be spoiled. To protect the IC heatsink should be used and diode is connected with the IC.
PRECAUTIONS WHILE ASSEMBLING THE PROJECT:-
- While connecting volt meter and Ammeter in this project take care that proper polarity is connected.
- While soldering diode take care of its polarity.
- First of all check all the components whether they are OK are not.
- Use the heatsink with the IC LM317.
- While connecting capacitor take care of its polarity.
- Connect the components as per the circuit.
PCB [CODE 6TP15]=1
ZEENER 6V =1
3K3=1, 47E=1, 560E=1, 4K7 =1
POT 470E =1
470mfd/40V =1,470mfd/63V=1, 1000mfd/50V, 100mfd/40V=1
HEAT SINK [ for IC ] =1