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Showing posts from December, 2013

Overload Indicator TL072

The overload indicator consists of a window comparator that measures the magnitude of an a.f. signal. Two of the opamps contained in an TL072 are supplied with a reference voltage by potential divider R1-R2-R3-P1. The outputs of the opamps drive T1 via diodes D1 end D2 (that function as half-wave rectifier), which in turn actuates D3. Network R5-R6-C2 ensures that the LED lights even during short signal peaks. Capacitor C2 is charged fairly rapidly via D1 (or D2)and R5, after which it discharges slowly via R6, R9 and the base-emitter junction of T1. Capacitor C1 also contributes to the longer lighting of the LED. .

     When the level of the signal at the input is high enough, IC1a, is toggled by the positive half periods of the signal and IC1b by the negative halves. In this way, a peak above the maximum level will be indicated even when the signal is asymmetrical. Because of the symmetrical power supply and design of the indicator, the reference voltage for both opamps can be set with…

BUZ23 MOSFET Audio Amplifier 1 x 240W

BUZ23 MOSFET general description:     A high power audio amplifier circuit which can output up to 240W on a 4Ω speaker. This mosfet amplifier is built with BUZ23 and uses a 40V symmetrical power supply. Connect the NTC close to the heatsinker.
BUZ23 MOSFET circuit diagram:

IRF9530 IRF530 Audio Amplifier 70 W

IRF9530 IRF530 general description:
This simple power mosfet audio amplifier circuit, with TL071C and 2 MOSFETs (IRF9530 and IRF530) can deliver up to 45 Watts on 8 Ω speaker. This schematic is based on Siliconix application and on variations of voltage on the 2 resistors that are serial inserted on the voltage supplier of the operational amplifier driver. The MosFet transistor must be mounted on a heatsink with at least 1K/W.

Amplifier’s efficiency is 70%, distortions at cut frequency were at most 0.2% at 20Hz on 8 Ω and 10W. With a power supply of ± 30V the mosfet audio amplifier can deliver 45W on 8 Ω and 70w on 4 Ω. Remember that this audio amplifier is not protected on shortcircuits so everytime you switch on check to see if the speaker is connected.
IRF9530 IRF530 circuit diagram:

FET Amplifier Configurations

When using FETs as amplifiers, the input signal is applied across two  terminals of the FET and the output is taken across two terminals.

Three FET amplifier configurations:

common source,common gate, andcommon drain.
Common Source Amplifier       The Common Source (CS) amplifier is the FET equivalent of the common  emitter transistor amplifier configuration. Like the CE amplifier, it is capable of high voltage gain. The CS amplifier has the input applied between the gate and source Terminals and the output signal taken across the drain and source terminals. Therefore, the source terminal is common to both the input and output signals. Use of coupling capacitors CIN and COUT. Their function is to block the DC or bias current from entering the AC signal source and load resistor RL.Conversely, during AC operation they couple the AC signal source to the input of the amplifier and the resulting output to the load resistor. Bypass capacitor C1 is used to bypass the source resistor and incre…

Overload protection for speakers

Although the protection circuit is fairly simple, it forms an effective guard against overload of the input of amplifiers and loudspeakers. Why these inputs may need protection now that line levels have been standardized is because there are signal sources on the market that generate outputs of several volts instead of the standardized 1 V r.m.s. Also, in some applications, the loudspeaker signal is applied to the line output of a separate amplifier via a voltage divider, in which case the levels may be well above 1 V r.m.s. The diagram shows a schematic that resembles the familiar series resistor and zener diode. Here, however, the zener is constructed from a small rectifier and a transistor, since commercial zeners appear to start conducting way below their rated values, which gives rise to unwanted distortion. The constructed zener makes a well-defined limitation possible and does not affect signals below the critical level. Configuring T1 as a diode reduces the number of comp…

Dual Voice Coil Subwoofers

Dual voice coil subwoofers are becoming a popular choice among car audio enthusiasts who want more flexibility in wiring their sound systems. While typical subwoofers have a single voice coil, dual voice coil (DVC) subwoofers use two separate voice coils, each with its own connections, mounted on one cylinder, connected to a common cone.

Parallel:A dual 4-ohm voice coil subwoofer with its coils wired in parallel presents a 2-ohm load to your amplifier. Since an amplifier produces more wattage at a lower impedance, the parallel connection ensures you'll get the most output from your amp. In the same fashion, if you have a stereo amplifier and two DVC subs, wire both subs for 2-ohm impedance (one per channel) for maximum output.The key difference between single and dual voice coil subwoofers is the multiple wiring options DVC subs offer:
Series: Series wiring lets you configure multiple woofers to one amplifier at an acceptable impedance. Wire both coils in series for an 8-ohm impedan…

Subwoofer Wiring Diagrams

A subwoofer or a complete loudspeaker, which is dedicated to the reproduction of low-pitched audio frequencies known as bass. The typical frequency range for a subwoofer is about 20–200 Hz for consumer products, below 100 Hz for professional live sound,and below 80 Hz in THX-approved systems. Subwoofers are intended to augment the low frequency range of loudspeakers covering higher frequency bands.

     Subwoofers are made up of one or more woofers mounted in a loudspeaker enclosure—often made of wood—capable of withstanding air pressure while resisting deformation. Subwoofer enclosures come in a variety of designs, including bass reflex (with a port or passive radiator in the enclosure), infinite baffle, horn-loaded, and bandpass designs, representing unique tradeoffs with respect to efficiency, bandwidth, size and cost. Passive subwoofers have a subwoofer driver and enclosure and they are powered by an external amplifier. Active subwoofers include a built-in amplifier.

Op Amp Circuit Collection - Basic Circuits

Op Amp Circuit CollectionBasic Circuits

Inverting Amplifier
Non Inverting Amplifier Diference Amplifier Inverting Summing Amplifier
Non-Inverting Summing Amplifier
Inverting Amplifier with High Input Impedance
Fast Inverting Amplifier with High Input Impedance
Non-Inverting AC Amplifier
Practical Differentiator
Fast Integrator
Current to Voltage Converter