battery charger using op amps

1. BATTERY CHARGING CIRCUIT
NAME : KARTHIK.J.M
ROLL NO : 42
USN : 2BV13EC035
GUIDED BY
SNEHA.V.METI

2. Presentation Outline
Introduction
Basic circuit diagram
Application
Working
Source

3. INTRODUCTION
 OP AMP is a dc coupled high gain electronic voltage amplifier with a
differential input and usually a single ended output.
 OP AMP was invented by KARL.D.SWARTZEL JR in 1941.
 OP AMP has revolutioned the analog electronic field with
its wide variety applications .
 First it was used in analog computers for arithmatic and logic
operations.

4. INTERNAL CIRCUIT DIAGRAM OF OP AMP

5. SYMBOLIC REPRESENTATION
 V+ : Non inverting input
 v- : Inverting input
 vout : Output terminal
 V+ : Non inverting input
 v+ : Positive power supply
 v- : Negative power supply

6.  Current Limiting is the practice in electronic circuits of
imposing an upper limit on the current that may be delivered
to a load with the purpose of protecting the circuit generating
or transmitting the current from harmful effects due to
a short-circuit or similar problem in the load.
 The simplest form of current limiting for mains is
fuse. A circuit breaker is another device for mains current
limiting.
LIMITING CIRCUITS

7. CONTINUED..
 Classic 2 NPN transistor current limiter
 NPN + op amp current limiter
 Mosfet current limiter

8. CHARGER WITH LIMITING CIRCUIT
 The charger circuit is fundamental unit to any battery which
makes use of limiting circuits.
 So, an charging circuit has been designed using a op amp and
hence an application of op amp is developed.
 It basically consists of an LM741 op amp
and a transistor along with resistors and to reduce the input
voltage to required value.

9. Circuit Design

10. WORKING
 This circuit uses a potentiometer and an op-amp to make a 0
- 160 mA adjustable constant current source. A transistor is
used to boost the output current of the op-amp.
 The current flowing through the transistor is limited only by
the control signal from the op-amp.
 R5 is not a current limiting resistor. R5 is a sense resistor.
 R5 is far too small and lets far too much current through
before it starts to limit current.
 Divide the voltage drop across R5 to get charging current.
 1 ohm or 10 ohms or 100 ohms for the value of R5. This
makes for very easy calculation.

11. Resources……
For more information
visit www.google.co.in
visit www.engineeringgarage.com

12. THANK YOU