The circuit is designed for laptop battery charger with 20V output voltage. This circuit uses TOP 246 Y made by Power integrations. TOP 246 Y eliminates half the discrete components compared with the UC3842. As promised Power Integration, this IC is more reliable, has a smaller form, reducing the time in designing and saving costs.
Battery charger characteristic :
Input Voltage AC : 85 … 265V (universal input);
Overall efficiency at 85V AC power is not less than 79%;
Overall efficiency at 265V AC power is not less than 84%;
Output voltage DC : 20V;
Maximum load current : 3A.
Parts list :
|
Element |
Nominal |
Tolerance |
Note |
|
R1 |
2M |
5% |
Two series-connected resistors of 1M |
|
R2 |
7,5 M +5,6 M |
1% |
Connected in series |
|
R3 |
20,5 K |
1% |
|
|
R4 |
68K |
5% |
|
|
R5 |
4.7 |
5% |
|
|
R6 |
6.8 |
5% |
|
|
R7 |
68 |
5% |
|
|
R8 |
330 |
5% |
|
|
C1, C2, C3 |
0.47uFx400V |
||
|
C4 |
150uF/400V |
Possible, both in capacity and voltage. |
|
|
C5 |
4700/1kV |
Ceramics |
|
|
C6 |
1uF/50V |
||
|
C7 |
0.1uF/50V |
||
|
C8 |
10uF/25V |
||
|
C9, C10 |
1000uF/25V |
||
|
Z1 |
300V 2A |
||
|
TR1 |
10 Ohm 2A |
||
|
U1 |
PC817 |
||
|
D1 |
1N4937 |
Can be replaced with UF4005 |
|
|
D2 |
1N4148 |
||
|
D3 |
MBR760 |
Or other 5A 60V Schottky |
|
|
DA1 |
TOP246Y |
||
|
F1 |
1A 250V |
||
|
L1 |
47mkGn 1A |
||
|
L2 |
3.3 uH 3A |
||
|
ZD1 |
1N5249 |
||
|
BR1 |
RS207 |
Building guide : radiokot.ru
