Schematic & Wiring Diagram

This is the circuit diagram of cricket chirping sound generator based on IC 4060, a 14 stage ripple counter and oscillator IC. A suitable audio wave form is produced by IC2 and related electronic components, driving the mini speaker through Q1. To allow a more real-life behavior, the chirp is interrupted in a pseudo-casual way by two timers built around IC1C and IC1D, whose outputs are mixed into IC1B and further time-delayed by IC1A, driving the reset pin of IC2.

An optional Photoresistor can be wired across this pin and positive supply, it is to make the circuit operates in the dark and stops when light is coming, thus imitating the cricket's behavior even more closely. R9 acts as volume control and can be a preset trimmer or a small potentiometer.

Components List:

R1 = 330K 1/4W
R2 = 220K 1/4W
R3,R6 = 100K 1/4W
R4 = Photo resistor (Optional, see text)
R5,R7 = 22K 1/4W
R8 = 10K 1/4W
R9 = 470R 1/2W Trimmer Cermet or Carbon
R10 = 22R 1/4W
C1,C2,C3 = 47µF/25V
C4 = 10µF/25V
C5 = 1µF/50V
C6 = 10nF/63V
D1,D2,D3,D4 = 1N4148
Q1 = BC547
IC1 = 4093
IC2 = 4060
SPKR = 8 Ohm
SW1 = SPST Toggle or Slide Switch
B1 = 9V PP3 Battery (See Notes)

Circuit Notes:

• The circuit can be powered by any battery or power supply adapter with 5 - 12V range.
• For maximum performance results please use a loudspeaker as small as possible.
• In some cases, the chirp can be improved further on by pressing the loudspeaker against a flat surface, for example. a wooden table.

Cricket chirping sound generator circuit project, page source: schematicdiagram.s4s.in

Here the schematic diagram of one transistor LED flasher. This circuit can be the simplest circuit led flasher over the world.

This is a novel flasher circuit working with a single driver transistor that will take its flash-rate from a flashing LED. The flasher in the photo is 3mm. An ordinary LED is not going to work. The flash rate are not able to be altered by the brightness of the high-bright white LED can be adjusted by replacing the 1k resistor across the 100uF electrolytic to 4k7 or 10k.

The 1k resistor discharges the 100uF so that when the transistor turns on, the charging current into the 100uF illuminates the white LED. If a 10k discharge resistor is applied, the 100uF will not be completely discharged and also the LED isn't going to flash as bright.


All of the components within the photo are in the identical places as in the circuit diagram in making it easy to learn how the components are joined.

This is the circuit diagram of mice repellent. Mice are animals that are very annoying, because sometimes he is damaging the object stored in the form of archives that are still valuable.

To drive out the mice, you can create an electronic circuit of mice repellent as shown above. With 50KHz frequency generated by the timer IC 555. The mice would run because his ears will feel sore due to the signal frequency.

The work of this circuit is very simple. The timer IC act as the frequency generator, while the frequency value is decided by C1 and C3. The output of 555 will be amplified by the SC1162 transistor and then fed to the speaker so the audio signal can be heard by the mice.

Parts List:

R1 = 1K8
R2 = 1K
R3 = 5K6
R4 = 480R
C1 = 2,2nF
C2 = 0,022uF/6V
IC = 555
Q = SC1162
SP = Speaker 4 ohm

This is the magic lights circuit which use bi-colour LED as the output to provide the light. The circuit uses 14 bi-colour (red and green) LEDs having 3 terminals each. Various dancing colour patterns are generated utilizing this circuit considering that each LED can create three various colours. The middle terminal (pin 2) of the LEDs will be the common cathode pin that is grounded. When a positive voltage is applied to pin one, it emits red light. Similarly, when positive voltage is applied to pin 3. it emits green light. And when positive voltage is simultaneously applied to its pins 1 and 3, it emits amber light.

The circuit could be implemented for decorative lights. The IC1 (timer IC 555) is applied in astable mode of multivibrator to produce clock signal for IC2 and IC3 (CD4518) that are dual BCD counters.

The two counters of each one of these ICs have already been cascaded to acquire 8 outputs from each. The outputs from IC2 and IC3 are connected to IC4 through IC7 that are BCD to 7-segment latch/decoder/driver ICs. Therefore we acquire a complete of 14 segment outputs from each of the IC pairs composed of IC4 plus IC5 and IC6 plus IC7. While outputs from former pair are connected to pin No. 1 of all the 14 bi-colour LEDs through current limiting resistors, the ouputs of the latter pair are similarly connected to pin No.3 of all the bi-colour LEDs to acquire a magical dancing lights effect.

This schematic diagram is a light-operated, remote-controlled solidstate switch circuit to handle lamp. While in darkness, the resistance of Light Dependent Resistor (LDR) is extremely hight, it shoots up to megohm range. As a result, the triac isn't going to have gate drive and therefore it doesn't conduct.

When LDR is lighted by way of a torch-light beam, the level of resistance of LDR immediately reduces (under 10Kohm). This leads the triac to conduct and turn on the lamp. Light received from your lamp (normal lamp in the room, not from the torch) will keep LDR’s resistance low. So, the lamp stays continually "on". When the lamp is ‘on’, it could be turned "off’ once again by disturbing the light falling on LDR, by either waving hand in front of it or by disturbing power source for the circuit for just a moment.

RFC applied right here could be built by winding about 15 turns of 18 SWG wire over an insulated ferrite rod.
Circuit title: 220V Light-Operated On/Off Switch. This kind of circuit also can be modified to make a alarm circuit for security purpose.

This is a 2-station simple intercom circuit build based on transistors part and using common 8R mini speakers. The speaker works as microphone and generate sound, so there is no need microphone for this intercom. The "press-to-talk" switches should have a spring-return so the intercom can never be left ON, push on switch can be used for this kind of task.



The secret to preventing instability (motor-boating) with a high gain circuit like this is to power the speaker from a separate power supply! You can connect an extra station (or two extra stations) to this circuit design.

Build the circuit into two separated boxes (for 2 stations). On each box should be use 2 ports for external power supply port (if you use external power supply, not battery) and connection port to other stations. Create some holes for speaker push on switch.

Here the circuit diagram of Interior Light Fader for Automobile. The circuit is build using low power operational amplifier LM324 which only need around 3mA of current, so it won't bother the battery supply if left connected for extended periods. This circuit is similar to the fading eyes circuit above and is used to slowly brighten and fade interior lights of older cars.
The top two op-amps circuit module (pins 1,2,3 and 5,6,7) form a triangle wave oscillator running at about 700Hz while the lower op-amp (pins 8,9,10) produces a linear, 5 second ramp, that moves up or down depending on the position of the door switch. The two transistors and associated resistors serve to limit the ramp voltage to slightly more and less than the upper and lower limits of the triangle waveform. These two signals (700 hZ. triangle wave and 5 second ramp) are applied to the inputs of the 4th op-amp (pins 12,13,14) that serves as a voltage comparator and produce a varying duty cycle square wave that controls the IRFZ44 MOSFET and lamp brightness. The 5 second fade time can be adjusted with the 75K resistor connected to the door switch. A larger value will increase the time and a smaller value will speed it up.

When the door switch is closed (car door open) the voltage on pin 8 slowly increase above the negative peaks of the triangle wave producing a short duty cycle output and a dim light. As the ramp moves farther positive, a greater percentage of the triangle wave will be lower than the ramp voltage producing a wider pulse and brighter light. This process continues until the ramp is 100% above the positive peaks of the triangle wave and the output is maximum. When the door switch is open, the reverse action takes place and the lamps slowly fade out.

The MOSFET IRFZ44 shouldn't need a heatsink if the total load is 50 watts or less but the temperature of the MOSFET should be monitored to make sure it doesn't overheat. The on-state resistance is only 0.028 ohms so that 4A of current (48 watts) is only around 100mW. For larger loads, a compact heatsink can be added to keep the MOSFET cool. - Interior Light Fader for Automobile circuit diagram

This is the schematic diagram of electronic siren circuit. The sound produced imitates the rise and fall of an American police siren. When very first switched on, the 10uF capacitors is discharged and each transistors are off. When the push button switch is pressed to 10uF capacitor will charge via the 22k resistor. This voltage is applied towards the base of the BC108B which will turn on slowly. When the switch is released the capacitor will discharge via the 100k and 47k base resistors and also the transistor will slowly turn off. The change in voltage alters the frequency of the electronic siren.



Electric current drain is fairly high in this electronic siren circuit so a appropriate power supply is needed. The duration the tone takes to rise and fall is determined by the 10uF and 22k resistor. These values may possibly be varied for various effects.

Well, for those of you who want to make a small project, this alarm may be an option for you. This circuit will generate the canary chirping sound. The chirp sound of a canary is generated by the oscillation process by resistor R1 and capacitor C1. The capacitor, having a capacitance value of 100 uF, is charging through the resistor, having a resistance of 4.7 K ohms. During this stage, R1 is the bias for the transistor making it operate in the cut off. When the transistor is in cut off mode, the base-emitter voltage is very minimal for any considerable current to flow. This mode triggers the oscillation to end but will start again once the capacitor discharges across the transmitter’s base-emitter circuit.

The frequency of the chirp may be modified by changing the values of the resistor and capacitor. The charging of the capacitor occurs when operating the push button switch. By releasing the button, the chirping runs quicker whilst the oscillation weakens.

The loudspeaker is being driven and coupled to the circuit by the miniature audio transformer of LT700 which having a frequency of 1 kHz. This circuit can be supplied with 9V battery.

Electronic chirping canary circuit source: http://www.elecpod.com/circuit/av/2010/03011410.html

This is a very -very easy and simple LED flasher circuit with only needs three components that are: a flasher IC, a LED and a electrolytic capacitor.

Component list:

LED1_________Red LED
C1___________100uf/16V
IC1__________LM3909

Very nice for electronics newbie.. :)

This is a circuit diagram of light detector. This circuit can be used as a sensor of automatic lamp switch, thic circuit also can be used for anti theft alarm circuit.

Schematic diagram:

Use variable resistor R1 to adjust the light threshold at which the circuit triggers. R1's value is chosen to match the photocells resistance at darkness. The circuit uses a CMOS 4001 IC. Gate U1a acts as the trigger, U1b and c form a latch. S1 to reset the circuit. You may used piezo buzzer or LED as output indicator, you may use both of them.

This is an intercom circuit which use LM380 as the audio amplifier and 2 transistors as the microphone pre amplifier. The sound quality will be good enough with low cost building.

This circuit consists of two identical intercom units. Each unit contains a power supply, microphone preamplifier, audio amplifier and a Push To Talk (PTT) relay circuit. Only 2 wires are required to connect the units together. Due to the low output impedance of the mic preamp, screened cable is not necessary and ordinary 2 core speaker cable, or bell wire may be used.

Detail explanation about this intercom circuit include the PCB layout, please visit this page

This is the running LED circuit diagram. The LED will "running" (on) one by one. You can use this circuit for many purpose like motorcycle lamp, running character and much more.

Here the schematic diagram with IC timer 555:

And use this circuit use NAND logic:

This is the circuit of alarm system with 5 independent zones. Suitable for a small office or home environment. It uses just 3 CMOS IC's and features a timed entry / exit zone, 4 immediate zones and a panic button. There are indicators for each zone a "system armed" indicator.

Zone 1 is a timed zone which must be used as the entry and exit point of the building. Zones 2 - 5 are immediate zones, which will trigger the alarm with no delay. Some RF immunity is provided for long wiring runs by the input capacitors, C1-C5. C7 and R14 also form a transient suppresser. The key switch acts as the Set/Unset and Reset switch. For good security this should be the metal type with a key.

Circuit works:
At switch on, C6 will charge via R11, this acts as the exit delay and is set to around 30 seconds. This can be altered by varying either C6 or R11. Once the timing period has elapsed, LED6 will light, meaning the system is armed. LED6 may be mounted externally (at the bell box for example) and provides visual indication that the system has set. Once set any contact that opens will trigger the alarm, including Zone 1. To prevent triggering the alarm on entry to the building, the concealed re-entry switch must be operated. This will discharge C6 and start the entry timer. The re-entry switch could be a concealed reed switch, located anywhere in a door frame, but invisible to the eye. The panic switch, when pressed, will trigger the alarm when set. Relay contacts RLA1 provide the latch, RLA2 operate the siren or buzzer.

This is a simple electronic buzzer circuit diagram. Cheap and easy to build.
The 555 is used as astable multivibrator operating at about 1kHz and produces a shrill noise when switched on. The frequency can be adjusted by varying the 10K resistor. You may change the 10K resistor with variable resistor.

This is digital clock schematic diagram. This circuit is quite complex and quite difficult for a newbie because this circuit uses IC with some a complicated connections. The voltages that supplied to the circuit are divided in two lines.

The voltage +5VA supplies all IC except the IC9 until IC13 and is supplied with voltage in case of break of network voltage. On the other side, the voltage linr of +5VB only supplies the IC9 until IC13 and display and is interrupted in case of interruption of network voltage, it is to ensure the economy of battery.

You can find the complete explanation include the component part list on the original page.

This is dancing LEDs schematic diagram. the LEDs will dance squence to audio (music or speaking) from the microphone.

Components list:

R1_____________10K 1/4W Resistor
R2,R3__________47K 1/4W Resistors
R4______________1K 1/4W Resistor
R5,R6,R7______100K 1/4W Resistors
R8____________820R 1/4W Resistor

C1,C3_________100nF 63V Ceramic or Polyester Capacitors
C2_____________10΅F 50V Electrolytic Capacitor
C4____________330nF 63V Polyester Capacitor (See Notes)
C5____________100΅F 25V Electrolytic Capacitor

D1___________1N4148 75V 150mA Diode
D2-D11_________5 or 3mm. LEDs (any type and color)

IC1___________LM358 Low Power Dual Op-amp
IC2____________4017 Decade counter with 10 decoded outputs IC

M1_____________Miniature electret microphone

SW1____________SPST miniature Slider Switch

B1_______________9V PP3 Battery

Clip for PP3 Battery



Additional circuit parts (see Notes):

R9,R10_________10K 1/4W Resistors
R11____________56R 1/4W Resistor

D12,D13 etc.____5 or 3mm. LEDs (any type and color)

Q1,Q2_________BC327 45V 800mA PNP Transistors
Q3____________BC337 45V 800mA NPN Transistor

Circuit operation:

IC1A amplifies about 100 times the audio signal picked-up by the microphone and drives IC1B acting as peak-voltage detector. Its output peaks are synchronous with the peaks of the input signal and clock IC2, a ring decade counter capable of driving up to ten LEDs in sequence.
An additional circuit allows the driving of up to ten strips, made up by five LEDs each (max.), at 9V supply. It is formed by a 10mA constant current source (Q1 & Q2) common to all LED strips and by a switching transistor (Q3), driving a strip obtained from 2 to 5 series-connected LEDs. Therefore one transistor and its Base resistor are required to drive each strip used.

Notes:

• The sensitivity of the circuit can be varied changing R4 value.

• C4 value can be varied from 220 to 470nF in order to change the circuit speed-response to music peaks.

• Adopting the additional circuit, only one item for R10, R11, Q1 and Q2 is required to drive up to ten LED strips. On the contrary, one item of R9 and Q3 is necessary to drive each strip you decided to use.

• Each R9 input must be connected to IC2 output pins, in place of the LEDs D2-D11 shown. R8 must also be omitted.

• Whishing to use a lower number of LEDs or LED strips, pin #15 of IC2 must be disconnected from ground and connected to the first unused output pin. Example:
  if you decided to use 5 LEDs, pin #15 of IC2 must be connected to pin #1; if you decided to use 8 LEDs, pin #15 of IC2 must be connected to pin #9 etc.

• Current drawing of the circuit is about 10mA.

• Whishing to use a wall-plug transformer-supply instead of a 9V battery, you can supply the circuit at 12V, allowing the use of up to 6 LEDs per strip, or at 15V, allowing the use of up to 7 LEDs per strip.

This schematic in very simple and easy to made. The IC produces all the sound effects, the output at Pin 3 being amplified by the transistor. A 64 ohm loudspeaker can be substituted in place of the 56 ohm resistor and 8 ohm loudspeaker. The 2 pole 4 way switch controls the sound effects. Position 1 (as drawn) being a Police siren, position 2 is a fire engine sound, 3 is an ambulance and position 4 is a machine gun effect. The IC is manufactured by UMC and was available from Maplin electronics code UJ45Y. At the time of writing this has now been discontinued, but they have have limited stocks available.

This is a simple and easy to build multi tone alarm circuit that can be used in burglar alarms or sirens. The circuit is based on dual op-amp MC1458 and LM 380. The two op amps inside the MC 1458 are used to produce square and triangular waves.LM 380 is used to amplify the output.The first op amp IC1a is wired as an astable multi vibrator and second op amp IC1b is wired as an integrator, to make the square wave triangle.

The two output square ans sine can be selected using switch S1 to the input of IC2 which amplifies it to drive the speaker. POT R4 can be used for tone adjustment.

Notes .

• IC1a and IC1b are same. So their power supply is common.Wire exactly as shown in figure, nothing to care.
• C1 and C2 are ceramic, C3 is electrolytic capacitor.
• Pin 6 of IC2 (inv input) has no connection.
• A dual power supply is needed here.

www.circuitstoday.com

This schematics is a basic analog flip flop. As we know, there are analog flip flop which built using analog components like ordinary transistor and digital flip flop build using digital logic IC (integrated circuit) like TTL IC.



and here the result:



To control the speed of light's "on" and "off" in another word "control the flash rate", you can replace the Resistor 10K with variable resistor 20K or replace the electrolytic capacitor 100uF with other value.

Flip flop PCB layout: