Monday, May 31, 2010
20 LED AUDIO VU METER
This circuit has 3 main sections, an inverting op-amp amplifier, a rectifier and LED display. The input can be from almost any low level source, but if not using an electret microphone, then omit R1 as it's not necessary. The gain of the amplifier based around IC1 is controlled by VR1. The output is rectified by D1,2 and filtered using C4,R6.The final stage is a standard design for the LM3914. Alter R8 to control LED brightness but be careful not to over-drive the IC's. It's recommended that you don't
Friday, May 7, 2010
TDA1562Q . . . 50W from a 12 V battery (Elektor 2/2000)
The integrated output amplifier described in this article consists of little more than one integrated circuit. It is intended especially for use in motor vehicles and other batteryoperated applications. Although it appears simple and hardly worth looking at, the amplifier can produce an appreciable audio power output.
technical data
Properties
High power output through Class-H operation
Low power dissipation during reproduction of music signals
Proof against short-circuits
Protection against excessive temperatures
Standby switch
No power-on or power-off clicks
Visible error indication
Measurement results (at Ub=14.4 V)
Supply voltage 8–18 V
Sensitivity 760 mV r.m.s.
Input impedance 70 kΩ
Power output 54 W r.m.s. into 4 Ω (f=1 kHz; THD+N=1%)
Harmonic distortion (THD+N) at 1 W into 4 Ω: 0.046% (1 kHz)
0.29% (20 kHz)
at 35 W into 4 Ω: 0.12% (1 kHz)
0.7% (20 kHz)
Signal-to-noise ratio (with 1 W into 4 Ω) 88 dBA
Power bandwidth 7.5 Hz – 185 kHz (at 25 W into 4 Ω)
Quiescent current about 135 mA (‘on’)
COMPONENTS LISTResistors:
R1 = 1MΩ
R2 = 4kΩ7
R3 = 1kΩ
R4 = 100kΩ
Capacitors:
C1,C2 = 470nF
C3,C4 = 10μF 63V radial
C5,C6,C8 = 4700μF 25V radial
(18mm max. dia., raster 7.5 mm)
C7 = 100nF, raster 5 mm
Semiconductors:
D1 = high-efficiency-LED
IC1 = TDA1562Q (Philips)
Miscellaneous:
S1 = single-pole on/off switch
Four spade connectors, PCB mount
Heatsink for IC1 (Rth<2.5>
Subscribe to:
Posts (Atom)