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Sound Activated Switch circuitcategory: Varioustags: switchWith this sound activated switch, control by sound may be very useful, not just on a robot but also for a bit of home automation, for example a sound-activated light responding to a knock on the door or a hand clap. The light will be automatically switched off after a few seconds. An alternative use is burglar protection — if someone wants to open the door or break something the light will come on, suggesting that someone’s at home.

The circuit can work from any 5–12 VDC regulated power supply provided a relay with the suitable coil voltage is used.

When you first connect the supply voltage to the sound activated switch circuit, the relay will be energised because of the effect of capacitor C2. Allow a few seconds for the relay to be switched off. You can increase or decrease the ‘on’ period by changing the value of C2. A higher value results in a longer ‘on’ period, and vice versa. Do not use a value greater than 47 μ F.

Biasing resistor R1 determines to a large extent the microphone sensitivity. An electret microphone usually has one internal FET inside which requires a bias voltage to operate. The optimum bias level for response to sound has to be found by trial and error. All relevant electrical safety precautions should be observed when connecting mains powered loads to the relay contacts.

Sound activated switch circuit diagram

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category: Radiotags: 555 • CA3130 • rf detector

This handy mobile bug or cell phone detector, pocket-size mobile transmission detector or sniffer can sense the presence of an activated mobile cellphone from a distance of one and-a-half metres. So it can be used to prevent use of mobile phones in examination halls, confidential rooms, etc. It is also useful for detecting the use of mobile phone for spying and unauthorised video transmission.

The circuit can detect both the incoming and outgoing calls, SMS and video transmission even if the mobile phone is kept in the silent mode. The moment the bug detects RF transmission signal from an activated mobile phone, it starts sounding a beep alarm and the LED blinks. The alarm continues until the signal transmission ceases.An ordinary RF detector using tuned LC circuits is not suitable for detecting signals in the GHz frequency band used in mobile phones. The transmission frequency of mobile phones ranges from 0.9 to 3 GHz with a wavelength of 3.3 to 10 cm. So a circuit detecting gigahertz signals is required for a mobile bug.

Here the circuit uses a 0.22μF disk capacitor (C3) to capture the RF signals from the mobile phone. The lead length of the capacitor is fixed as 18 mm with a spacing of 8 mm between the leads to get the desired frequency. The disk capacitor along with the leads acts as a small gigahertz loop antenna to collect the RF signals from the mobile phone.Cell phone RF radiation detector Video

and another video from Sufyan Ghori

Op-amp IC CA3130 (IC1) is used in the circuit as a current-to-voltage converter with capacitor C3 connected between its inverting and non-inverting inputs. It is a CMOS version using gate-protected p-channel MOSFET transistors in the input to provide very high input impedance, very low input current and very high speed of performance. The output CMOS transistor is capable of swinging the output voltage to within 10 mV of either supply voltage terminal.

Capacitor C3 in conjunction with the lead inductance acts as a transmission line that intercepts the signals from the mobile phone. This capacitor creates a field, stores energy and transfers the stored energy in the form of minute current to the inputs of IC1. This will upset the balanced input of IC1 and convert the current into the corresponding output voltage.

Capacitor C4 along with high-value resistor R1 keeps the non-inverting input stable for easy swing of the output to high state. Resistor R2 provides the discharge path for capacitor C4. Feedback resistor R3 makes the inverting input high when the output becomes high. Capacitor C5 (47pF) is connected across ‘strobe’ (pin   and ‘null’ inputs (pin 1) of IC1 for phase compensation and gain control to optimise the frequency response.

When the cell phone detector signal is detected by C3, the output of IC1 becomes high and low alternately according to the frequency of the signal as indicated by LED1. This triggers monostable timer IC2 through capacitor C7. Capacitor C6 maintains the base

bias of transistor T1 for fast switching action. The low-value timing components R6 and C9 produce very short time delay to avoid audio nuisance.

Assemble the cell phone detector circuit on a general purpose PCB as compact as possible and enclose in a small box like junk mobile case. As mentioned earlier, capacitor C3 should have a lead length of 18 mm with lead spacing of 8 mm. Carefully solder the capacitor in standing position with equal spacing of the leads. The response can be optimised by trimming the lead length of C3 for the desired frequency. You may use a short telescopic type antenna.Use the miniature 12V battery of a remote control and a small buzzer to make the gadget pocket-size. The unit will give the warning indication if someone uses mobile phone within a radius of 1.5 meters.Check the related posts for more mobile phone detectors.

Cell Phone Detector circuit diagram

555 datasheetIC CA3130 datasheet

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     Written by Nithin on December 6, 2009.

MOBILE BUGPurpose of the circuitThis circuit is intended to detect unauthorized use of mobile phones in examination halls, confidential rooms etc. It also helps to detect unauthorized video and audio recordings. It detects the signal from mobile phones even if it is kept in the silent mode. It also detects SMS.

CONCEPTMobile phone uses RF with a wavelength of 30cm at 872 to 2170 MHz. That is the signal is high frequency with huge energy. When the mobile phone is active, it transmits the signal in the form of sine wave which passes through the space. The encoded audio/video signal contains electromagnetic radiation which is picked up by the receiver in the base station. Mobile phone system is referred to as “Cellular Telephone system” because the coverage area is divided into “cells” each of which has a base station. The transmitter power of the modern 2G antenna in the base station is 20-100 watts.When a GSM (Global System of Mobile communication) digital phone is transmitting, the signal is time shared with 7 other users. That is at any one second, each of the 8 users on the same frequency is allotted 1/8 of the time and the signal is reconstituted by the receiver to form the speech. Peak power output of a mobile phone corresponds to 2 watts with an average of 250 milli watts of continuous power. Each handset with in a ‘cell’ is allotted a particular frequency for its use. The mobile phone transmits short signals at regular intervals to register its availability to the nearest base station. The network data base stores the information transmitted by the mobile phone. If the mobile phone moves from one cell to another, it will keep the connection with the base station having strongest transmission. Mobile phone always tries to make connection with the available base station. That is why, the back light of the phone turns on intermittently while traveling. This will cause severe battery drain. So in long journeys, battery will flat with in a few hours.

AM Radio uses frequencies between 180 kHz and 1.6 MHz. FM radio uses 88 to 180 MHz. TV uses 470 to 854 MHz. Waves at higher frequencies but with in the RF region is called Micro waves. Mobile phone uses high frequency RF wave in the micro wave region carrying huge amount of electromagnetic energy. That is why burning sensation develops in the ear if the mobile is used for a long period. Just like a micro wave oven, mobile phone is ‘cooking’ the tissues in the ear. RF radiation from the phone causes oscillation of polar molecules like water in the tissues. This generates heat through friction just like the principle of microwave oven. The strongest radiation from the mobile phone is about 2 watts which can make connection with a base station located 2 to 3 km away.

How the circuit works?Ordinary LC (Coil-Capacitor) circuits are used to detect low frequency radiation in the AM and FM bands. The tuned tank circuit having a coil and a variable capacitor retrieve the signal from the carrier wave. But such LC circuits cannot detect high frequency waves near the microwave region. Hence in the circuit, a capacitor is used to detect RF from mobile phone considering that, a capacitor can store energy even from an outside source and oscillate like LC circuit.

Use of capacitorA capacitor has two electrodes separated by a ‘dielectric’ like paper, mica etc. The non polarized disc capacitor is used to pass AC and not DC. Capacitor can store energy and pass AC signals during discharge. 0.22 capacitor is selected because it is a low value one and has large surface area to accept energy from the mobile radiation. To detect the signal, the sensor part should be like an aerial. So the capacitor is arranged as a mini loop aerial (similar to the dipole antenna used in TV).In short with this arrangement, the capacitor works like an air core coil with ability to oscillate and discharge current.How the capacitor senses RF?One lead of the capacitor gets DC from the positive rail and the other lead goes to the negative input of IC1. So the capacitor gets energy for storage. This energy is applied to the inputs of IC1 so that the inputs of IC are almost balanced with 1.4 volts. In this state output is zero. But at any time IC can give a high output if a small current is induced to its inputs. There a natural electromagnetic field around the capacitor caused by the 50Hz from electrical wiring. When the mobile phone radiates high energy pulsations, capacitor oscillates and release energy in the inputs of IC. This oscillation is indicated by the flashing of the LED and beeping of Buzzer. In short, capacitor carries energy and is in an electromagnetic field. So a slight change in field caused by the RF from phone will disturb the field and forces the capacitor to release energy.

ROLE OF IC CA 3130This IC is a 15 MHz BiMOS Operational amplifier with MOSFET inputs and Bipolar output. The inputs contain MOSFET transistors to provide very high input impedance and very low input current as low as 10pA. It has high speed of performance and suitable for low input current applications.RANGE OF THE CIRCUITThe prototype version has only limited range of 2 meters. But if a preamplifier stage using JFET or MOSFET transistor is used as an interface between the capacitor and IC, range can be increased.

With this sound activated switch, control by sound may be very useful, not just on a robot but also for a bit of home automation, for example a sound-activated light responding to a knock on the door or a hand clap. The light will be automatically switched off after a few seconds. An alternative use is burglar protection — if someone wants to open the door or break something the light will come on, suggesting that someone’s at home.

The circuit can work from any 5–12 VDC regulated power supply provided a relay with the suitable coil voltage is used.When you first connect the supply voltage to the sound activated switch circuit, the relay will be energised because of the effect of capacitor C2. Allow a few seconds for the relay to be switched off. You can increase or decrease the ‘on’ period by changing the value of C2. A higher value results in a longer ‘on’ period, and vice versa. Do not use a value greater than 47 μ F.

Biasing resistor R1 determines to a large extent the microphone sensitivity. An electret microphone usually has one internal FET inside which requires a bias voltage to operate. The optimum bias level for response to sound has to be found by trial and error. All relevant electrical safety precautions should be observed when connecting mains powered loads to the relay contacts.

Sound activated switch circuit diagram

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category: Audio, Lightstags: noneThis sound controlled lights circuit design is used to control the brightness of the lights attached to it in sync with the sound that is being capturated by its microphone. This electronic circuit design is very common in disco houses, bars, parties …

Usually, sound controlled lights are just connected in parallel with the loudspeakers. This configuration has two disadvantages: first, a very power amplifier can destroy the lights or worse, a defective light can destroy the amp. This problem is avoided by the circuit by not connecting directly to the amp. Instead, it picks up the sound with its microphone.The power supply part is on the left of the electret microphone amplifier and the light controller part is on the right. The capacitors C2 and C3 are the capacitive voltage divider and reduces the power supply level. Diodes D1 and D2 rectify the positive swing of the AC voltage. The network composed of L1 and C1 protects the power line from voltages surges. In this circuit design, an electret microphone is being used. Take note that there are 2 types of electret mics. The first type has three pins for power, ground, and output. The second type has only two pins. The second type is used for this circuit.

Sound controlled light circuit diagram

In building this sound controlled lights circuit, take note that you are dealing with strong voltages and currents. The components used must have enough ratings to deal with those.The potentiometer P1, P2 and P3 must have plastic shafts and knobs. Use a shielded cable to connect the microphone to the circuit .

All wirings going to the main supply and lights must be isolated with shrink tubings. The case for the circuit must be made of plastic. Do not let anything metallic protrude out of the box.Even the heatsinks for the triacs are electrified. Beware that there is no isolation between

this circuit and the main power lines. The maximum power output of each outpuc (triac) is 400 watts, do not exceed that level!

Audio controlled lights PCB Layout

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A clap switch circuit is a classic beginner’s project. Equipment can be switched on and off by just clapping your hands. Add a tiny microcontroller and you can easily build-in some more useful features.The microcontroller in this circuit makes it a simple job to add some useful features that are not seen on other clap switch designs:

– Changeover relay contacts enable the unit to be wired in conjunction with a manual changeover switch sothat manual override of the switched equipment is always possible.– The unit is only responsive to a specific sequence of sounds i.e., two claps within a defined time window.– A safety feature masks the input for a given time window if misuse (repeated commands) is detected (useful if children have discovered how it works).The safety feature and two-clap sequence detector can be built using TTL or CMOS flip-flops but by using a single microcontroller the circuit can be greatly simplified. A mains power supply is included so no additional power source is required.The Microchip flash PIC12F629 microcontroller is a neat device; the small 8-pin package contains a complete microcontroller including clock generator, reset circuitry, Flash ROM, RAM and EEPROM. Two of the eight pins are used for the supply connections while the remaining six are general-purpose I/O pins. A few of these pins have special function like the comparator inputs. The sound sensitivity of the circuit can be adjusted by programming the comparator threshold level in software.

Maplin Velleman Clap On/Off switch Video

The circuit diagram in Figure 1 shows that besides the microcontroller there are very few other components. The two-pin electret microphone produces an electrical signal in

response to sound pressure waves. Transistor T1 amplifies the signal and preset P1 allows some adjustment of the circuit sensitivity by altering the bias voltage of T1.

Two of the PIC output pins are used to drive a bistable relay via transistors T2 and T3. This type of relay has two energising coils. A short electrical pulse on one of the coils is enough to switch the relay in one direction while a pulse to the other coil will cause the relay to switch back. This type of relay has two main advantages: the relay is latching in both open and close direction so a short pulse is all that is necessary to switch it. Secondly the latching feature ensures that the relay retains its switched state even during a power failure. Changeover relay contacts enable the unit to be wired together with a changeover type manual switch, allowing the equipment to be switched manually if for any reason the clap switch is switched off.

Pins 2 and 7 are used to switch a twocolour LED providing a visual indication of the switched state of the relay. The last output pin of the PIC is not used and is connected to a jumper to allow switching software options.Clapping relay SoftwareWhen the signal level at GP1 goes low (clap detected) the program waits for approximately 200 ms during which time the LED glows red. After this period the LED switches to green and the software samples the input for approximately three seconds. If a second clap is detected during this period, the controller switches the output. After switching, the controller ignores any further clap sounds for approximately 10 s and the LED lights red. The output state is stored in EEPROM so that if a power failure occurs the software will switch the correct relay coil when power is re-established.

A safety feature counts each switching event on an internal counter, which is decremented slowly in software. Should this counter exceed a threshold level, the circuit will ignore any input signals for approximately one minute and the LED blinks red. This will ensure that the circuit does not respond to an extended burst of noise (e.g., applause).

Clap switch PCB

The PCB layout shown in Figure 2 accommodates all components apart from the electret

microphone. This is attached to the board at the MIC +/– connections with a length of shielded audio lead (keep the wire length to less than around 10 cm).

Mounting the components onto the PCB should be quite straightforward. Start by fitting the single wire bridge next to rectifier B1. Ensure that all polarised components (diodes, LEDs, capacitors and the IC) are fitted the correct way round. The LED leads should be trimmed so that when it is soldered to the board it protrudes through a hole in the lid when the case is assembled; alternatively use a translucent enclosure.

Once all components have been fitted and all solder connections have been inspected the PCB can be fitted into an insulated enclosure. The mains input lead will require some form of strain relief. Be aware that some tracks carry lethal voltages. All appropriate safety guidelines must therefore be adhered to. A small hole can be made in the lid directly over preset P1 if it is necessary to adjust the sensitivity of the circuitwithout dismantling the unit. Lastly, don’t forget to add perforations in the case so that sound waves can reach the microphone capsule.

Clap switch COMPONENTS LIST:Resistors:R1,R6,R7 = 4kΩ7R2 = 150kΩR3 = 22kΩR4 = 10kΩR5 = 150ΩP1 = 100kΩ preset HCapacitors:C1 = 220μF 25V radialC2 = 100nFC3 = 1μF 16VSemiconductors:B1 = B80C1500 (round case, 80V piv, 1.5A)D1,D2 = 1N4148D3 = bicolour LED (red/green)IC1 = 78L05IC2 = PIC12F629CP, programmedT1,T2,T3 = BC238 or BC547Miscellaneous:JP1 = 2-way pinheader with jumperK1 = 2-way PCB terminal block, lead pitch 7.5mmK2 = 3- way PCB terminal block, lead pitch 7.5mmMIC1 = 2-terminal electret microphone capsuleRe1 = bistable relay, 2 x changeover (e.g., Schrack RT314F12)

Tr1 = mains transformer 1 x 6V, min. 2VA, short-circuit proof (e.g., Marschner VN30.15/10522 or Era 030-7340.0T; Conrad Electronics # 506141)

Clap Switch circuit diagram

LM723 Peak Level Indicator Circuit

LM723 Peak Level

Indicator Circuit

This circuit is a circuit diagram inspection signal sound level or Peak Level Indicator

circuit using LM723. Usually we are often led IC LM723 or UA723 do come to use, the

DC voltage regulator. But for this circuit, building a circuit can check the sound level

signal. When I saw changes in the structure of integrated circuits. The following is a

schematic drawing.

LM723 Peak Level Indicator CircuitElectronic Circuit Schematic Wiring Diagram

 

Home » Sound » DIY Sound Activated Lights Circuit Diagram

 DIY Sound Activated Lights Circuit Diagram

DIY Sound Activated Lights Circuit Diagram

This diy sound activated lights  circuit  turns a lamp ON for a brief length when the canine

barks (or a somewhat strong sound) providing an impression that the occupants happen to

be alerted. The condenser microphone fitted in a place to watch sound and generates AC

signals, which pass by means of DC blocking capacitor C1 for the base of transistor

BC549 (T1). Transistor T1 along with transistor T2 amplifies the sound signals and offers

existing pulses in the collector of T2. When audio is produced in front from the

condenser mic, triac1 (BT136) fires, activates lights plus the bulb (B1) glows for about

two minutes.

Assemble the sound activated lights circuit on a general objective PCB (circuit board)

and enclose inside a plastic cabinet. Energy for the sound activated change circuit is often

derived from a 12V, 500mA step-down transformer with rectifier and smoothing

capacitor. Solder the triac making sure adequate spacing among the pins to avoid short

circuit. Resolve the unit within the dog’s cage or shut to the audio monitoring spot, using

the lamp within or outdoors as sought after. Connect the microphone for the sount

activated lights circuit employing a brief size of shielded wire. Enclose the microphone

inside a tube to increase its sensitivity.   

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Voice-activated LED flashing lights circuit diagram

The circuit mainly consists of the condenser microphone, the transistor amplifier and the

light emitting diodes.

At stable state, VT1 in a critical saturation point, so that VT2 deadline, LED1 and LED2

neither LED, R1 to the capacitor microphone MIC to provide bias current, seized the

microphone in the indoor environment after the acoustic signal to a corresponding

electrical signal by capacitance C1 to VT1 to enlarge the base, VT1, VT2 composed of

two direct-coupled amplifier circuit, as long as the right to select R2, R3 to make a silent-

wave signal.

VT1 in a critical saturation point, and to enable VT in a closed state, two LED no current

flow through without LED, when the acoustic signal MIC seizure, there is audio signal

into the base of the VT1, the signal so that the negative half-cycle VT1 from the

saturation, VT1 rise of collector voltage.

VT2 conduction, LED1 and LED2 LED light, when the input audio signal when a weak,

not enough to withdraw from the VT1 saturation, LED1 and LED2 remain extinguished,

and only when a strong signal input to light-emitting LED was lit, Therefore, LED1 and

LED2 will sound as the environment (such as music, speech) signal strength of ups and

downs and flashing LED.

Components List:

VT1 - 9014

VT2 - 9014

BT200- Microphone

C1 - 1uF/16V

R1 - 4.7K R2 - 1M R3 - 10K C2 - 100uF/10V

LED assembly and debugging:

1. According to the principle of the assembly drawing pictures, and then assembled by

the assembly.

2. The attention of the transistor can not take the wrong polarity, components neatly

arranged, beautiful.

3. Electricity VT after the first test of the collector voltage to between 0.2 ~ 0.4, if the

voltage is too low to exert the voice signal, VT1 can not withdraw from the saturation

point, VT2 conduction can not be, if the voltage exceeds the VT2 dead-zone voltage,

when the static on the on-VT2 to LED1 and LED2 LED light, so.Capacitance for

different microphone sensitivity, and β values of different transistor, VT1 of the size of

the collector resistor R3 to determine through testing.

4. From about 0.5 meters away from the microphone, the voice of the ordinary (moderate

volume) speech, LED1, LED2 should be with the scintillation voice.

For loud, the only flashing light-emitting LED, can be appropriate to reduce the

resistance value R3 can also be a greater value of the replacement transistor &beta.

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Voice-activated lighting circuit

  

The circuit shows a sensitive voice-activated electronic on / off of the lights.

When the applause sound hits the mic,the mic detects the signal, and for every clap, lights

gets ON. If the clap sound is detected once again, then, lights goes OFF, and so on.

Working Principle:

The circuit uses six-NOT gate IC's CD4069, in the door 1, door 2, door 3, and R1, R2, R3

composition of three-signal amplifier. For each clap, applause will electret microphone

MIC to pick up. The RP adjust the sensitivities, and it is followed-up by three amplifiers

for signal amplification. Then by C5, D5, D6, C6 detector, access to DC control voltage,

this voltage pass through the door RP-4, after that its followed-up by bistable  circuit to

control the flip.Bistable circuit from gate 5, gate 6 and the surrounding components, the

turnover the level for the negative pulse. When there is No clap no trigger signal is

received, the gate 4 inputs for the low ground by the R4, then the gate 4 output high,

bistable circuit does not flip.  When a clap is received, it gives a trigger signal, the door 4

input is high, then the gate 4 output is low, this negative pulse falling edge  so that

bistable electronic switch gets flipped.Assumption, a time gate 5 outputs low, VT cut-off,

then the time gate 5 outputs high, VT saturated conduction,  relays have electricity, its

normally open contacts JK Pick-up, connected to light circuit, lamp H light.  At this

point, C6 level of control of the detector gradually discharge through R4, the door 4

output high again.  When the re-clap at palm blow, the door again, detected four high

inputs, then the gate 4 output is low, this negative pulse falling edge to bistable electronic

switch again, and turned over to the door 5, the output is low, VT cut-off , JK jump, light

H off, and so on and realized with the applause of the attack on and off control lamp.

Component selection

Gate 1 to Gate 6 for the CD4069, D1 ~ D9 as the 1N4001, C1 = 220µF, C2 = C3 = C4 =

C5 = 0. 01µF, C6 = 0. 02µF, C7 = C8 = 0. 1µF,  RP = 15kO, R1 = R2 = R3 = 1MO, R4 =

2MO, R5 = R6 = 43kO, R7 = R8 = 10kO, R9 = 1kO, VT for the 9013 relay for the JZC-

21F, MIC for small electret microphone.

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Voice-activated LED flashing lights circuit diagram

The circuit mainly consists of the condenser microphone, the transistor amplifier and the

light emitting diodes.

At stable state, VT1 in a critical saturation point, so that VT2 deadline, LED1 and LED2

neither LED, R1 to the capacitor microphone MIC to provide bias current, seized the

microphone in the indoor environment after the acoustic signal to a corresponding

electrical signal by capacitance C1 to VT1 to enlarge the base, VT1, VT2 composed of

two direct-coupled amplifier circuit, as long as the right to select R2, R3 to make a silent-

wave signal.

VT1 in a critical saturation point, and to enable VT in a closed state, two LED no current

flow through without LED, when the acoustic signal MIC seizure, there is audio signal

into the base of the VT1, the signal so that the negative half-cycle VT1 from the

saturation, VT1 rise of collector voltage.

VT2 conduction, LED1 and LED2 LED light, when the input audio signal when a weak,

not enough to withdraw from the VT1 saturation, LED1 and LED2 remain extinguished,

and only when a strong signal input to light-emitting LED was lit, Therefore, LED1 and

LED2 will sound as the environment (such as music, speech) signal strength of ups and

downs and flashing LED.

Components List:

VT1 - 9014

VT2 - 9014

BT200- Microphone

C1 - 1uF/16V

R1 - 4.7K R2 - 1M R3 - 10K C2 - 100uF/10V

LED assembly and debugging:

1. According to the principle of the assembly drawing pictures, and then assembled by

the assembly.

2. The attention of the transistor can not take the wrong polarity, components neatly

arranged, beautiful.

3. Electricity VT after the first test of the collector voltage to between 0.2 ~ 0.4, if the

voltage is too low to exert the voice signal, VT1 can not withdraw from the saturation

point, VT2 conduction can not be, if the voltage exceeds the VT2 dead-zone voltage,

when the static on the on-VT2 to LED1 and LED2 LED light, so.Capacitance for

different microphone sensitivity, and β values of different transistor, VT1 of the size of

the collector resistor R3 to determine through testing.

4. From about 0.5 meters away from the microphone, the voice of the ordinary (moderate

volume) speech, LED1, LED2 should be with the scintillation voice.

For loud, the only flashing light-emitting LED, can be appropriate to reduce the

resistance value R3 can also be a greater value of the replacement transistor &beta.