This is a class AB audio power amplifier circuit which built using a TDA2002 or TDA2003 power amplifier IC module. These are replacements for the original LM383 which is no longer available. It is easy to build and has a minimum of external components. The module has both short circuit protection and thermal protection. It can drive loads as low as 1.6 ohm and is capable of delivering over 10 watts from a 16 V supply.
Component parts:
| R1____________ potentiometer 10 k ohm R2____________ 220 ohm R3____________ 2R2 ohm R4____________ 1 ohm IC1___________ TDA2002/3 amplifier module 1 Heat sink | C1_____________ 10uF/50V electrolytic capacitor C2_____________ 470uF/16V electrolytic capacitor C3_____________ 2200uF 25V electrolytic capacitor 1 C4_____________ 100 nF mylar 1 C5_____________ 100 nF monoblock 1 C6_____________ 100uF 25V ecap 1 |
Specifications:
D.C. Input: 8 – 18V, 10 – 20 VA min.
Power output:
> 10 W RMS, 2 ohm load, 16V DC supply.
> 6W RMS, 4 ohm load, 16V DC supply.
> 4W RMS, 4 ohm load, 12V DC supply.
THD: < 0.2% (1W, 4 ohm load)
Gain: 40 dB maximum.
S/N ratio :
> 80 dBA. (G = 20 dB)
> 60 dBA (G = 40 dB)
Frequency response: < 20 Hz to > 40 kHz (-3dB, 4 ohm load)
Input level:
< 100 mV for full output (G = 40 dB)
< 1V for full output(G = 20 dB)
Maximum output power will only be obtained with a power supply of greater than 1A at 16V DC, and using 2 ohm speakers (or 2 by 4 ohm speakers in parallel). However approximately 4W RMS can be obtained with a 12V DC, 1A supply into a 4 ohm load.
The power supply should be well filtered to reduce mains hum, the on board capacitors alone are not adequate for this purpose but are necessary to ensure stability. Extra filtering is unnecessary if operating from a battery. If two boards are used for stereo, you will need to double the size of the power supply.
The kit of this amplifier circuit is available at kitrus.com
Download the complete guide here
