Nicad Battery Charger by IC LM317T
Here is circuit Nicad Battery Charger. It use IC LM317T ( Hot IC) Control Current less 300mA, Size battery 2.4V,4.8V,9.6V.It Low cost circuit.
This is a NiCAD battery charger circuit. High-quality, Not necessary to have a full charge and cut, Because this circuit charges with constant current and voltage regulated. But this circuit is not difficult and cheap.
The basic principles of a NiCAD Battery charging. There are a number of ways, as follows.
1. A constant current.
The Nicad battery can provide current 500mA-hr charge rate that is 1/10 of the current capacity. Therefore should be charged with a constant current 50mA for 10 hours, but actually want to charge for 14-16 hours because when near full current to charge less. So lasts longer.
- In the NiCAD battery charger for fast charging current to about 100mA charging rate for 3-5 hours. But it has the disadvantage of charging, when the battery is fully charged, it must be removed, otherwise the chemical substances in the battery will be very hot and damage.
- But a slow charger will not do, because it can withstand heat.
2.A constant voltage or Fixed voltage regulator
The NiCAD battery, each battery has a voltage 1.2V, when it is fully charged voltage 1.25-1.3V. Therefore, we are charging a battery, the plus the voltage additive, such as 4 pieces, then the charging voltage 1.2×4 = 4.8V. But the charge like this, at first, a very high current flow. So, the voltage between NiCAD battery charger and very different, may have caused overheating and damage.
3. The Current and Constant voltage.
Like this charging, devices little more than the two first, but high quality. The safest way, and the battery the voltage is required by the specifications. When fully charged, the charger can be left in, because there is no current flow, Because the the voltage between the battery as well.
- I so chose the charging current and Constant voltage.
A constant current.
I am using LM317 as a constant current. Determined by the R6. In the circuit be defined output current (Iout) is about 50mA. If you want to current different from this, you can find out the R6. = 1.25V / Iout
this circuit is designed for charging multiple pieces. So it can select multiple the voltage levels is S1.
- 3.1V be applied to 2 battery (2.4)
- 5.5V be applied to 4 battery (4.8V)
- 10.3V be applied to 6 battery (9.6V)
Which we use Q1(C1061),Q2(C1815) And other equipment. Included circuit is maintained at a constant voltage. LED1 is used for the power on. T1 transformer size is 300mA.
The other parts please look in the figure circuit.
How to build. Friends can place the part in perforated board. Because this circuit has a few devices. You should check diagram well before use charge battery. Good luck.
Related circuits about battery chargers
Nicad Charger by IC CA3140E
Constant current battery charger circuit
Simple Ni-cad battery charger with little parts
Related Posts :
Nicad battery as the battery is good. Commonly used. If you do not have a battery charger. I recommend this circuit. It is suitable for beginners. ...
This is easy circuit charger batt Nicad. For batt 1.2V. When you have NiCad Battery should want to have Battery Charger Circuit. I begs for to ...
This is a Nicad battery charger circuit that old, but very effective. Because the principle of charging with Constant current And controlled by co ...
I am a big fan of your site, but that last time there are more and more errors (mistakes) in your circuitry. these charger circuits take the cake on that…..
LM317T Contant current and NiCd charger circuits;
A lot of errors damn!
circuit 2 ; + therminal of C1 bufferelco should be connected to the both cathodes of D1 and D2. Then the center tap CT should be connected to GND..
circuit 3 ; R6 and R7 should be connected to GND and not to the +….current flows out of the base of the PNP transistor Q2
circuit 3 with LM317 ; the diode D2 is shorted…take a look the line after the one that connects D1 with D2 should be removed.So that the tap 0V (center tap) is connected to the elco C1. next resistors are forgotten at the switch S1 5,5V and 10,3V settings…the are non now….so output is about 3V nou.
And the LM317 with resistor as current source take up 3V + 1.25V +(300mA x 5 Ohm) is 4.25V+1.5V=5.75V drop….so the batt get NOTHING and will not charge! That LM317T circuit should be placed between the buffer elco C1 and transistor Q1. So to charge even the 9.6V batt. the raw voltage at the rectifier sould al least be 10.3V+5.75V=16.05V
trafo 9V gives only squar root of 2×9 = 1.414=12.72V !!! So the trafo must at least be 12V AC.
http://www.eleccircuit.com/nicad-battery-charger-by-ic-lm317t/comment-page-1/#comment-16110