Identify diagram

This simple circuit indicates the quantity of energy that goes to a loudspeaker. The dual-color LED presentations green at an applied energy degree of about 1 watt. At 1.5 watts it glows orange and above three watts it is vivid crimson. The circuit is attached in parallel with the loudspeaker connections and that is energyed from the audio signal. The further load that this characterizes is 470 Ohm (R1//R3) will no longer be a problem for any amplifier. During the positive 1 of 2 cycle of the output sign the inexperienced LED in the dual-color LED will probably be turned on, supplied the voltage is sufficiently excessive.

At better output voltages, T1 (depending on the voltage divider R2/R1) can begin to conduct and the fairway LED will go out. During the terrible half of cycle the red LED is driven by the use of R3 and can activate when the voltage is high enough. In the transition area (where T1 habitss extra and extra and ‘throttles’ the golf inexperienced LED as a result) the combination of red/green provides the orange colour of the dual-LED. By selecting appropriate prices for the resistors the facility stages will additionally be adjusted to suit.

 

Audio Power Meter Circuit Diagram

 

The worths chosen here are for conventional lounge use. You will almost definitely be stunned at how loud you have to turn your amplifier up ahead of you get the LEDs to go! The resistors can be zero.25 W sorts, supplied the amplifier does now not ship greater than forty W constantly. Above this energy the transistor may not be that happy both, so watch out for that too. Because T1 is utilized in saturation, the gain (Hfe) is on no account important and any equivalent type can be used. The power degrees talked about are valid for 4-Ohm audio system. For 8-Ohm audio system the entire resistor values have to be divided by using two.