AFast charge 7.2V NiCad battery charger.
This design uses the Maxim,
MAX 713 NiCad battery charger IC to control the fast charge time and
provide cell voltage monitoring.
It charges a battery to approximately 80% charge in 22 minutes at a
current of 2.4 Amps. Once the fast charging has ended, it trickle
charges the battery. Power is from a 13.6V, 3 Amp, switchmode power
supply. There is also provision to use power from a 12V accessory
(cigarette lighter) socket. As there are no transformers inside the
case it is lightweight.
Note: You will require a power
supply of greater than 13V to operate this circuit. Failure to do so
will cuase the fast charge termination to operate incorrectly. I used
a car accessory adaptor from Halfords,
it provides 13.6V @ 5 Amps, more than enough for this circuit.
The design is based upon the example circuit from the MAX 713 datasheet. Due to the high current, there is a large heatsink on the power transistor, T1 and I also added a small CPU cooler to cool everything down. The cooling fan runs from the 12V supply to the PCB.
|
Part |
Value |
Device |
Package |
Description |
|
C1 |
10nF |
C-EU050-030X075 |
C050-030X075 |
CAPACITOR, European symbol |
|
C2 |
10nF |
C-EU050-030X075 |
C050-030X075 |
CAPACITOR, European symbol |
|
C3 |
10uF |
CPOL-EUE5-6 |
E5-6 |
POLARIZED CAPACITOR, European symbol |
|
C4 |
10uF |
CPOL-EUE5-6 |
E5-6 |
POLARIZED CAPACITOR, European symbol |
|
D1 |
1N4004 |
1N4004 |
DO41-10 |
DIODE |
|
H1 |
MOUNT-HOLE3.2 |
MOUNT-HOLE3.2 |
3,2 |
MOUNTING HOLE with drill center marker |
|
H2 |
MOUNT-HOLE3.2 |
MOUNT-HOLE3.2 |
3,2 |
MOUNTING HOLE with drill center marker |
|
H3 |
MOUNT-HOLE3.2 |
MOUNT-HOLE3.2 |
3,2 |
MOUNTING HOLE with drill center marker |
|
IC1 |
MAX713CPE |
MAX713CPE |
DIL16 |
NiCd/NiMH Battery Fast-Charge Controller |
|
KK1 |
SK104 |
SK104 |
SK104 |
HEATSINK manufacturer Fischer/distributor Buerklin |
|
R1 |
1K |
R-EU_0207/7 |
0207/7 |
RESISTOR, European symbol |
|
R2 |
150R |
R-EU_0207/7 |
0207/7 |
RESISTOR, European symbol |
|
R3 |
68K |
R-EU_0207/7 |
0207/7 |
RESISTOR, European symbol |
|
R4 |
22K |
R-EU_0207/2V |
0207/2V |
RESISTOR, European symbol |
|
R5 |
0.1R (5W) |
RKH206-8 |
KH206-8 |
Power Resistor |
|
R6 |
150R |
R-EU_0207/7 |
0207/7 |
RESISTOR, European symbol |
|
R8 |
1K |
R-EU_0207/7 |
0207/7 |
RESISTOR, European symbol |
|
Q1 |
TIP33 |
TIP33 |
TO220V |
TIP33 vertical mount NPN transistor |
|
LED1 |
LED5MM |
LED5MM |
LED |
|
|
LED2 |
LED5MM |
LED5MM |
LED |
|
|
X1 |
W237-02P |
W237-132 |
WAGO SREW CLAMP |
|
|
X2 |
W237-02P |
W237-132 |
WAGO SREW CLAMP |
|
|
X3 |
W237-02P |
W237-132 |
WAGO SREW CLAMP |
Updated 23 February 2010