วงจร IC LM317

     หลายคนคงจะเคยเจอปัญหา เวลาที่เราจะทดลองโปรเจคสิ่งประดิษฐ์ต่างๆที่เราคิดค้นขึ้นมา แล้วไม่มี Power supply 
     ไม่ต้องคิดมากครับนึกถึงนี่เลยครับถ้าหากต้องการ Power Supply ที่สามารถปรับแรงดันได้ตามต้องการ 

LM317 Voltage

LM317 เป็นไอซีเรกูเรเตอร์รักษาระดับแรงดันตามที่ต้องการ เหมาะกับการสร้างพาวเวอร์ซัพพลายจ่ายแรงดัน 1.25-30V กระแสไม่เกิน 1.5A  ( ใช้ไอซี LM317 ) วงจรง่ายๆ ไม่ยุ่งยาก แถมยังประหยัดตังค์อีกต่างหาก

ศึกษาจาก Data sheet ก่อนนะครับ
http://www.steveselectronics.com/files/LM317T_National.pdf


การต่อวงจรใช้งานก็ง่ายๆครับ

ส่วนนี่ก็เป็นวงจรป้องกันเมื่อเกิดการลัดวงจรครับ

หลายคนก็คงเกิดคำถามอีกว่าเราสามารถคำนวณหาค่า R1,R2 ได้อย่างไร

สูตร

Vout    =    1.25 * ( R2/R1 + 1 )

และสุดท้าย เป็น ค่า R ที่ผ่านการคำนวณมาแล้ว เพื่อความสะดวกในการทำ Power supply สำหรับท่านครับ

1.43V    R1 = 470, R2 = 68

1.47V    R1 = 470, R2 = 82

1.48V    R1 = 370, R2 = 68

1.51V    R1 = 330, R2 = 68

1.51V    R1 = 390, R2 = 82

1.52V    R1 = 470, R2 = 100

1.53V    R1 = 370, R2 = 82

1.56V    R1 = 330, R2 = 82

1.57V    R1 = 270, R2 = 68

1.57V    R1 = 470, R2 = 120

1.57V    R1 = 390, R2 = 100

1.59V    R1 = 370, R2 = 100

1.60V    R1 = 240, R2 = 68

1.63V    R1 = 330, R2 = 100

1.63V    R1 = 270, R2 = 82

1.64V    R1 = 390, R2 = 120

1.64V    R1 = 220, R2 = 68

1.65V    R1 = 470, R2 = 150

1.66V    R1 = 370, R2 = 120

1.68V    R1 = 240, R2 = 82

1.71V    R1 = 330, R2 = 120

1.71V    R1 = 270, R2 = 100

1.72V    R1 = 220, R2 = 82

1.72V    R1 = 180, R2 = 68

1.73V    R1 = 470, R2 = 180

1.73V    R1 = 390, R2 = 150

1.76V    R1 = 370, R2 = 150

1.77V    R1 = 240, R2 = 100

1.81V    R1 = 270, R2 = 120

1.82V    R1 = 150, R2 = 68

1.82V    R1 = 330, R2 = 150

1.82V    R1 = 180, R2 = 82

1.83V    R1 = 390, R2 = 180

1.84V    R1 = 470, R2 = 220

1.86V    R1 = 370, R2 = 180

1.88V    R1 = 240, R2 = 120

1.89V    R1 = 470, R2 = 240

1.93V    R1 = 330, R2 = 180

1.93V    R1 = 150, R2 = 82

1.94V    R1 = 270, R2 = 150

1.96V    R1 = 390, R2 = 220

1.97V    R1 = 470, R2 = 270

1.99V    R1 = 370, R2 = 220

2.02V    R1 = 390, R2 = 240

2.03V    R1 = 240, R2 = 150

2.06V    R1 = 370, R2 = 240

2.08V    R1 = 330, R2 = 220

2.10V    R1 = 220, R2 = 150

2.12V    R1 = 390, R2 = 270

2.13V    R1 = 470, R2 = 330

2.16V    R1 = 330, R2 = 240

2.16V    R1 = 370, R2 = 270

2.19V    R1 = 240, R2 = 180

2.23V    R1 = 470, R2 = 370

2.25V    R1 = 150, R2 = 120

2.27V    R1 = 270, R2 = 220

2.27V    R1 = 330, R2 = 270

2.29V    R1 = 470, R2 = 390

2.29V    R1 = 180, R2 = 150

2.31V    R1 = 390, R2 = 330

2.36V    R1 = 270, R2 = 240

2.37V    R1 = 370, R2 = 330

2.40V    R1 = 240, R2 = 220

2.44V    R1 = 390, R2 = 370

2.50V    R1 = 470, R2 = 470

2.57V    R1 = 370, R2 = 390

2.61V    R1 = 220, R2 = 240

2.65V    R1 = 330, R2 = 370

2.66V    R1 = 240, R2 = 270

2.73V    R1 = 330, R2 = 390

2.74V    R1 = 470, R2 = 560

2.75V    R1 = 150, R2 = 180

2.76V    R1 = 390, R2 = 470

2.78V    R1 = 270, R2 = 330

2.78V    R1 = 220, R2 = 270

2.84V    R1 = 370, R2 = 470

2.92V    R1 = 180, R2 = 240

2.96V    R1 = 270, R2 = 370

2.97V    R1 = 240, R2 = 330

3.03V    R1 = 330, R2 = 470

3.05V    R1 = 390, R2 = 560

3.06V    R1 = 270, R2 = 390

3.06V    R1 = 470, R2 = 680

3.08V    R1 = 150, R2 = 220

3.13V    R1 = 220, R2 = 330

3.14V    R1 = 370, R2 = 560

3.18V    R1 = 240, R2 = 370

3.25V    R1 = 150, R2 = 240

3.28V    R1 = 240, R2 = 390

3.35V    R1 = 220, R2 = 370

3.37V    R1 = 330, R2 = 560

3.43V    R1 = 270, R2 = 470

3.43V    R1 = 390, R2 = 680

3.43V    R1 = 470, R2 = 820

3.47V    R1 = 220, R2 = 390

3.50V    R1 = 150, R2 = 270

3.54V    R1 = 180, R2 = 330

3.55V    R1 = 370, R2 = 680

3.70V    R1 = 240, R2 = 470

3.82V    R1 = 180, R2 = 370

3.83V    R1 = 330, R2 = 680

3.84V    R1 = 270, R2 = 560

3.88V    R1 = 390, R2 = 820

3.91V    R1 = 470, R2 = 1000

3.92V    R1 = 220, R2 = 470

3.96V    R1 = 180, R2 = 390

4.00V    R1 = 150, R2 = 330

4.02V    R1 = 370, R2 = 820

4.17V    R1 = 240, R2 = 560

4.33V    R1 = 150, R2 = 370

4.36V    R1 = 330, R2 = 820

4.40V    R1 = 270, R2 = 680

4.43V    R1 = 220, R2 = 560

4.44V    R1 = 470, R2 = 1200

4.46V    R1 = 390, R2 = 1000

4.50V    R1 = 150, R2 = 390

4.51V    R1 = 180, R2 = 470

4.63V    R1 = 370, R2 = 1000

4.79V    R1 = 240, R2 = 680

5.04V    R1 = 330, R2 = 1000

5.05V    R1 = 270, R2 = 820

5.10V    R1 = 390, R2 = 1200

5.11V    R1 = 220, R2 = 680

5.14V    R1 = 180, R2 = 560

5.17V    R1 = 150, R2 = 470

5.24V    R1 = 470, R2 = 1500

5.30V    R1 = 370, R2 = 1200

5.52V    R1 = 240, R2 = 820

5.80V    R1 = 330, R2 = 1200

5.88V    R1 = 270, R2 = 1000

5.91V    R1 = 220, R2 = 820

5.92V    R1 = 150, R2 = 560

5.97V    R1 = 180, R2 = 680

6.04V    R1 = 470, R2 = 1800

6.06V    R1 = 390, R2 = 1500

6.32V    R1 = 370, R2 = 1500

6.46V    R1 = 240, R2 = 1000

6.81V    R1 = 270, R2 = 1200

6.92V    R1 = 150, R2 = 680

6.93V    R1 = 330, R2 = 1500

6.94V    R1 = 180, R2 = 820

7.02V    R1 = 390, R2 = 1800

7.10V    R1 = 470, R2 = 2200

7.33V    R1 = 370, R2 = 1800

7.50V    R1 = 240, R2 = 1200

8.07V    R1 = 330, R2 = 1800

8.08V    R1 = 150, R2 = 820

8.19V    R1 = 270, R2 = 1500

8.30V    R1 = 390, R2 = 2200

8.43V    R1 = 470, R2 = 2700

8.68V    R1 = 370, R2 = 2200

9.06V    R1 = 240, R2 = 1500

9.58V    R1 = 330, R2 = 2200

9.77V    R1 = 220, R2 = 1500

9.90V    R1 = 390, R2 = 2700

10.03V    R1 = 470, R2 = 3300

10.37V    R1 = 370, R2 = 2700

10.63V    R1 = 240, R2 = 1800

11.25V    R1 = 150, R2 = 1200

11.44V    R1 = 270, R2 = 2200

11.48V    R1 = 330, R2 = 2700

11.67V    R1 = 180, R2 = 1500

11.83V    R1 = 390, R2 = 3300

12.40V    R1 = 370, R2 = 3300

12.71V    R1 = 240, R2 = 2200

13.75V    R1 = 330, R2 = 3300

15.31V    R1 = 240, R2 = 2700

16.25V    R1 = 150, R2 = 1800

16.53V    R1 = 270, R2 = 3300

16.59V    R1 = 220, R2 = 2700

18.44V    R1 = 240, R2 = 3300

19.58V    R1 = 150, R2 = 2200

20.00V    R1 = 220, R2 = 3300

23.75V    R1 = 150, R2 = 2700

24.17V    R1 = 180, R2 = 3300

28.75V    R1 = 150, R2 = 3300