Download 5-Amp Adjustable Regulator LM338K Kit

 5‐Amp Adjustable Regulator LM338K Kit 1. Introduction
This module described here is based on 5-Amp Adjustable Regulator LM338K, which is
capable of supplying in excess of 5A over a 1.25V to 36V output range. The power input of
this module can be AC 3-30V from transformer directly because the rectifier bridge is on
board. The DC power input also can be applied.
This module can generate 1.25V – 30V DC output with adjustments. The output voltage
can be adjusted by the potentiometer with 5K. It can provide 50W power and the cooling
fan is used for cooling. Please note the voltage of the power output should be lower at least
2 volts than the VRMS (Root Mean Square) of the power input
http://www.eimodule.com 2. LM338K Schematic
http://www.eimodule.com 3. LM338K Components List
Item
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Reference
U1
U2
C3,C5,C7
C1
C2
C6
R18
W1
D1
D2,D3
CON1, CON2
Part Description
IC, LM7812
IC, LM338K
CAP 100nF，DIP
CAP 4700uF
CAP 2200uF
CAP, 10uF
RES, 200R,DIP,1/4W，1%
Potentiometer,5K
DIO，Rectifier bridge
DIO，1N4007，DIP
CON, 2PIN
Radiator
FAN
SCREW3
http://www.eimodule.com 4. LM338K Layout
http://www.eimodule.com 5. LM338K kits Assembly Guide
Step1：
Mount the components with low profile
Mounted components:
1) CON1,CON2
2) W1: Potentiometer 5K
3) C3, C5,C7: 100nF
4) C6: 100uF
5) D2,D3: 1N4007
6) R18: 200Ohm, 1%, 1/4W
7) U1: LM7812 (Please bend the pin as shown in the picture before soldering)
http://www.eimodule.com The components for J1, C4 are not assembled and don’t care them.
http://www.eimodule.com Step2：
Assembly the heat radiator and LM338K with two screws. Please tightened the screw
because these two screws are connected to the output of LM338K.
Assembly the cooling Fan with 4 screws.
TOP side:
Bottom Side
Note: Please add the pads when assembling the cooling FAN to avoid the short circuit.
http://www.eimodule.com Step3：
Solder the power supply wires for cooling FAN, which provided by the 12V output on the
boards.
Connect the black wire from FAN to the hole marked with ‘G’ and the RED wire from FAN
to the hole with ‘12V’ on the board.
http://www.eimodule.com Step4：
Assemble the C1, C2 and Rectifier Bridge
Here, we assembly C1 with 4700uF and C2 with 2200uF
http://www.eimodule.com