Mono audio panoramic interference

The circuit spectator interference enables implantation mono sound at any point between stereo speakers. When P1 is in the middle of his journey, there is strengthening or weakening of the mark the entrance to the exit in any of the two channels. When the potentiometer placed elsewhere, away from halfway, the signal in one channel is supported 3dB more than the other. The input stage is a buffer (IC1). Inverts the input signal to ensure compliance with this phase of the output (Next steps' and reverse them the signal they receive to entry). The resistance value entry identifies to that of R 1 (1 A KO). The output buffer is driven in stereo amplifiers IC2 and IC3.

The potentiometer P1, in conjunction with the A3, R4, R8, and A9, affects the routes of feedback and two boosters. This result in any adjustment of P1 to make the opposite metavoles enischysi the two opamps. The series resistors A7 and A12 provide the possibility of output lead capacitive loads. Capacitors coupling C3, C6 and C9 can be omitted if the application for the intended circuit can tolerate continuous diversion trends in output of about 20-30 mv. The capacitors C2, C5 and C8 ensure stability amplifier, even with unit gain. The capacitors C 1, C4 and C7 minimize any interference r1, which is probably appears within the area 2.5IZ-200KIZ. The performance of the circuit is very good and can be used in High-quality consoles. The total harmonic distortion plus thorythoo the frequency of 1 kHz with a bandwidth of 22 kHz is 0.0014%. The circuit needs power supply 18 W of power which consumes approximately 16 mA.

 Mono audio panoramic interference

Stereo Tv Decoder Circuit

Ql is an audio amplifier and Ul is used as a 31.5-kHz subcarrier, which is similar to 38-kHz FM MPX. Pilot frequency is 15.734 kHz. 

Stereo Tv Decoder Circuit

FM tuners, the stereo indicator lights upon detection

On most FM tuners, the stereo indicator lights upon detection of the 19-kHz pilot tone. However, this doesn`t mean that the program is actually stereophonic, since the pilot tone is often transmitted with mono programs also. A similar situation exists on stereo amplifiers, where the stereo LED is simply controlled from the mono/stereo switch. The LED-based stereo indicator described here lights only when a true stereo signal is fed to the inputs. Differential amplifier Al raises the difference between the L and R input signals. When these are equal, the output of Al remains at the same potential as the output of A2, which forms a virtual ground rail at half the supply voltage. When Al detects a difference between the L and Rinput signals, it supplies a positive or negative voltage with respect to the virtual ground rail, and so causes C3 to be charged via Dl or C4 via D2. Comparator A3/A4 switches on the LED driver via OR circuit D3/D4. The input signal level should not be less than 100 mV to compensate for the drop across Dl or D2. The sensitivity of the stereo indicator is adjustable with Pl.

FM tuners, the stereo indicator lights upon detection

LM378 dual4-watt amplifier Mini-stereo

This circuit is built around two chips: the MC1458 dual op amp, configured as a preamplifier, and the LM378 dual4-watt amplifier. The gain of the preamp is given by R3/R1 for one side and R4/R2 for the other side, which is about 100. That gain can be varied by increasing the ratios. The left and right channel inputs are applied to pins 2 and 6. The left and right outputs of U1 at pins 7 and 2 are coupled through CS/ RlO and C3/R6, respectively, to U2 to drive the two 8-0loudspeakers.

LM378 dual4-watt amplifier Mini-stereo

Derived Center-Channel Stereo System

A simple method of deriving a center or third channel without the use of an extra transformer or amplifier, (a) 4- speakers are connected to 8- amplifier taps. 8 and 16- speakers connect to 16- taps, (b) By blending the inputs it is possible to cancel out undesired crosstalk.

Derived Center-Channel Stereo System

Audio Filter Analyzer

When this circuit is connected to a filter and an oscilloscope, the scope displays the filter`s frequency response. Afrequency that sweeps from low to high is applied to a filter. An oscilloscope is triggered by* the start of the sweep and ends its trace at the highest frequency of the sweep. The filter output goes to the vertical amplifier of the oscilloscope. Using bandpass filters as an example, as the bandpass frequency is approached, reached, and passed, the scope follows the peaking output and draws the response curve. A neat effect! The 566 VCO (Ul) produces a VLF triangle wave to frequency modulate the next stage. It also produces a square wave to externally trigger the scope. Op amp U2 (a 741 unit) optimizes the amplitude and the dc component. Another VCO (U3) produces the actual sweeping triangle wave. Its frequency is selectable via SI. Op amp U4 (another 741 op amp) is set up as a bandpass filter and has been included as an example filter. Finally, diode D1 chops off the bottom half of the output, and leaves a nice bell curve. lb set up and operate, power-up the circuit and scope. Set the scope`s TIME/CM to 50 ms/cm. Set the VOLTS/CM control to 2 V. Attach a probe from the circuit`s trigger to the scope`s external trigger input. Set the triggering mode to normal, external. Attach a probe from the vertical amplifier to TP1. You`ll see a diagonal line that runs across the CRT. Input coupling should be set to dc. Adjust the triggering level until the diagonal runs from the upper left to the lower right of the CRT to ensure a displayed sweep from low to high. Now, disconnect the probe from TP1 and attach it to the filter output past the diode. via next.gr

Audio Filter Analyzer

Audio Filter Circuits

The circuit as shown gives the bandpass operation the transfer function calculated from FBP(s) = where = 1 + s/Qo>0 + s2/w02. The cut-off frequency, 0, and the Q-factor are given by 0 = g/C and Q = gR/2 where g is the transconductance at room temperature. Interchanging the capacitor C with the resistor R at the input of the circuit high-pass operation is obtained. A low-pass filter is obtained by applying two parallel connections ctf R and C as shown in Fig. 2. The low-pass operation may be much improved with the circuit as given in Fig. 3.

Audio Filter Circuits

Here the gain and Q may be set up separately with respect to the cut-off frequency according to the equations Q = 1/fB = 1 + R2/R!, A = Q2 and 0 = g ffi/C.