Clap operated Remote Control for Fans:-

Here is the circuit of clap-operated remote control fans is used to control not only switching properties but also control speed of fan. The main advantage of clap operated remote control for fan is, it can control up to ten-step speeds of fan where normally a fan has three to five step speeds.

Circuit description clap operated remote control for fan:-

                                                        This entire circuit clap operated remote control for fan is divided into four major section i.e. sound-operated trigger pulse generator, clock pulse generator, clock pulse counter and load operator.

Sound-operated trigger pulse: – The heart of this section is transistor T₁ BC148, configured as class-C amplifier mode. The MIC₁ is used to change voice signal into its corresponding electrical signal and is given to base of transistor T₁ in order to amplify and increase its intensity.

Clock pulse generator:- This section is build around timer IC NE555 and configured as monostable multivibrator. The trigger pulse generated by transistor T₁ is given to pin 2 of IC₁ and time period (T) for output high is calculated by formula.

T = 1.1RC

Clock Pulse counter:- This section is build around decade counter CD4017BC which counts the clock pulse generated by timer IC (IC₁). The output from IC₁ is given to pin 14 of IC₂. IC₂ has ten outputs, viz, o, 1, 2, 3, 4…..9. Here we use only three outputs i.e. output 1, 2 and 3 from pin 2, 4, and 7 respectively. Output 4 from pin 10 is directly connected to reset pin 15.

Load operator:- This section is build around three transistor as relay driver to operate three separate relay. Output from each pin of IC₂ is given to base of each transistor through 100Ω and LED as shown in circuit diagram. Output is taken from collector of transistor and is connected to relay. The three LEDs used to indicate gear or speed i.e. LED₁, LED₂ & LED₃ indicates gear 1, gear 2 & gear 3 respectively.

CIRCUIT DIAGRAM:-

NOTE:-This circuit used to operate in 1^st speed similarly, 2^nd clap for 2^nd speed, 3^rd clap for 3^rd speed and 4^th clap to switch off the fan.

PARTS LIST:-

• Resistors (all ¼-watt, ± 5% Carbon)
• R₁ = 10 KΩ
• R₂ = 1.2 MΩ
• R₃ = 2.2 KΩ
• R₄ = 150 KΩ
• 
  
• R₅ = 220 KΩ
• R₆ = 10 KΩ
• R₇, R₈, R₉ = 100 Ω
• Capacitors
• C₁, C₂ = 0.1 µF/16V
• C₃ = 4.7 µF/16V
• C₄ = 0.01 µF (ceramic disc)
• C₅ = 1000 µF/12V
• Semiconductors
• IC₁ = NE555 (Timer IC)
• IC₂ = CD4017BE (decade counter)
• T₁ = BC148
• T₂, T₃, T₄ = BEL187
• D₁, D₂ = 1N4001 silicon diode
• Miscellaneous
• MIC₁ = Condenser microphone 34LOD
• LED₁ = Green
• LED₂ = yellow
• LED₃ = RED
• 6V-0V-6V, 500mA secondary transformer
• ALL THE BEST.............//////////////////////////

Voltage Stepper:-

                                                   In conventional voltage multiplier circuits, AC is used to charge the capacitors network via diodes in one cycle and discharge in the other cycle in a particular combination, which thereby produces multiples of the peak voltage. However, this circuit works on a different principle, and it is DC which is doubled. It can be used to power low current circuits.

                                                               IC555 is configured as an astable multivibrator producing rectangular pulses of about 10kHz frequency. Its output is made to drive the transistor pair T₁ and T₂. Transistor T₂ being a pnp type, conduct when its base is negative, i.e. when the output of the IC produces a “low”. This charge C₄ via diode D₁ and ground (collector of T₂is grounded).

CIRCUIT DIAGRAM:-

                                                                           For the next pulse, i.e. when the output of IC is high, T₁ conducts but T₂ is cut-off, C₄ cannot discharge because of diode D₁. So the voltage across C₄ and input voltage adds up and charge C₅ via D₂. Voltage across C₅ will equal Vcc pulse voltage across capacitor C₄ and Diode D₁. Hence the operation.

However, it was found that if current greater then 50 mA and drawn, output voltage, hence regulation, is lost. Any DC voltage between 5V and 18V can be boosted (both voltage being the minimum and maximum range of the IC).

For better results, increase the value of C₄ and C₅ to 47 µF/40V.

PARTS LIST:-

• Resistors (all ¼-watt, ± 5% Carbon)
• R₁ = 220 Ω
• R₂ = 6.8 KΩ
• R₃ = 68 Ω
• Capacitors
• C₁, C₂ = 0.01 µF
• C₃ = 0.1 µF
• C_4­, C₅ = 22 µF/40v
• Semiconductors
• IC₁ = NE555
• T₁ = SL100
• T₂ = SK100
• D₁, D₂ = 1N4001

ALL THE BEST..................../////////////////////////////////

Mini amplifier:-


                                               Here is a simple project , mini amplifier built around LM1895 followed by passive components. The output of 10mW to 1W is obtained so, the circuit is called mini amplifier.

CIRCUIT DIAGRAM:-
Circuit Description:-
The output from mike or pre-amplifier is fed to pin no.4 through variable resistor VR1 and capacitor C4. Variable resistor VR1 is used to select the intensity of signal. Capacitor C2 and C6 is used to filter and develop the supply, where capacitor C3 and C5 is used to bias the audio frequency. The output of amplifier IC is obtained at pin 1 where resistor R4 and capacitor C8 is used as feedback component. The output is given to loudspeaker through capacitor C7 in order to produce sound.

PARTS LIST:-

Resistors (all ¼-watt, ± 5% Carbon unless stated otherwise)
R1 = 10 KΩ
R2 = 47Ω
R3 = 220Ω
R4 = 1Ω
VR1 = 50 KΩ
Capacitors
C1 = 470 pF
C2 = 220 µF/10V
C3 = 100 µF/10V
C4 = 0.1 µF
C5 = 10 µF/10V
C6, C7 = 470 µF/10V
C8 = 0.1 µF
Semiconductors
IC1 = LM1895N
Miscellaneous
LS1 = 4Ω/1W speaker
ALLTHE BEST.............//////////////////////////////////////////////////////

THREE IN ONE TONE GENERATOR:-

Various tone generator circuit is already published in www.electronicsproject.org. Now, here is unique tone generator circuit which produces three different type of sound according to input three different logic levels.

Circuit description:-

This circuit is designed around digital IC 7400 which is NAND gate. The working of the circuit is like the working principle of oscillator circuit, where frequency depends upon capacitors C₁ and C₂. The duty cycle of this circuit is 50%. The output is given to power amplifier circuit which further drive loudspeaker or head phone. For low frequency value of capacitor C₁ and C₂ must be high and vice-versa.

CIRCUIT DIAGRAM:-

PARTS LIST:-
Resistors (all ¼-watt, ± 5% Carbon)

R₁, R₄ = 1.2 KΩ

R₂, R₃ = 1 KΩ

R₅ = 10 KΩR₆, R₇ = 47 KΩ

Capacitors

C₁ = 100 kpF

C₂ = 220 kpF

C₃, C₄ = 10 kpF

Semiconductors

IC₁ = 7400 (NAND gate)

D₁, D₂ = 1N4148

]

Thermistor Temperature Sensing Alarm:-

                                                                           This circuit is a temperature sensing as well as alarm circuit. The circuit raises an alarm whenever the temperature crosses a certain limit. Temperature monitoring is a very important and frequently used application in industries and in many other places where the temperature should be kept below a maximum allowable level. This circuit comes to our rescue when a situation of that sort arises.

Circuit Diagram of Thermistor Temperature Sensing Alarm:-

WORKING OF SENSING ALARM:-       

                                                 The element in the circuit that senses the temperature of the environment is a thermistor. The name itself has its meaning. Thermistor means thermal+resistor. It means that the resistance of the thermistor varies with change in temperature. The relationship between the resistance of the thermistor and temperature is inversely related. This means that if the temperature in the atmosphere increases, the resistance offered by the thermistor decreases and if the temperature outside decreases, the resistance of the thermistor increases. This property of the thermistor helps us to make use of it to sense the temperature of the surroundings.

The circuit makes use of two BC547 NPN transistors to switch the alarm when the temperature above desired value is detected. The IC 4011 which is used in the circuit is a quad NAND gate integrated circuit. It has four NAND gates assembled in the single IC itself. This reduces the space and complexity of the circuit.

The combinational circuit which is built using the NAND gates is an oscillator circuit. As we know, any combinational circuit has an inherent time delay between the input and the output. This time delay is usually considered as undesirable but in this case we are making use of it to make it work like an oscillator. The circuit turns on and off repeatedly with a time delay operating as a square wave oscillator. The output of the oscillator is given to a buzzer which thereby operates at the audio frequency. The capacitors used in the circuit acts as filters to remove unwanted components of the signals and hence ensuring stability and proper operation.

How 555 Timer IC Testing Circuit Works:-]

                                                                                         NE555 timer IC is a 8 pin dip package IC which performs array of timing tasks in the electronic circuits. There is a huge list of experiments which can be performed with 555 IC, that’s why it is very popular among electronics hobbyists. But before using the IC, one should check it that it is working properly or not. So we have described  a simple circuit through which you can test 555 timer IC.

555 Timer IC Testing Simple Circuit:-

Components used in this Circuit:-

• IC-NE555
• R1-68K
• R2-39K
• R3,R4-20E
• C1-1uF/25V
• C2-1nF
• LED1,LED2

How to Check the 555 Timer IC:

First of all insert the IC in socket very carefully so that no pin of 555 timer get damage. Now to see the result, switch on the power supply.  If your 555 timer is working properly, both the LED1 and LED2 will glow. And any of the LEDs is off or both LED1 and LED2 are not glowing means your 555 timer IC is faulty.

Working of 555 Timer IC Circuit:

In this circuit, we have used the NE555 IC as an astable multivibrator and when power is provided to circuit, the LEDs will start blinking which will show that the IC is working. The blinking rate of LEDs can be changed by increasing or decreasing the values of resistor R1 and R2 and capacitor C1.

You can calculate the time duration with the help of formula given below:

T = 0.7(R1+2R2)*C1 in seconds.

As soon as power supply is provided, C1 will start charging through R1and R2.When the voltage across C1 rises above 2/ 3 of supply voltage, the internal Flip Flop toggles. As a result, pin 7 becomes low and C1 starts discharging. When the voltage across C1 goes below 1/ 3 of supply voltage, the internal Flip Flop resets and pin 7 goes high. The C1 again starts charging. All this will happen only when your IC is in good condition. According to the frequency as set with the help of resistor R1, R2 and capacitor C1 charging and  discharging  take place and LED1 and LED2 will flash accordingly. From these observations, we can conclude that IC NE555 is faulty or not.

.

Security Alarm Circuit:-

                                                                     This circuit will help you to guard your precious documents as well as jewellery from intruders or theft. All you need is just to place this circuit in front of the locker or below the mat so when any unknown person come and walk over the switch, the circuit will trigger and sound of alarm comes. The main benefit of the circuit is that these can be implied in two places at a time as two different switches produces two different sounds.

Circuit Diagram of Security Alarm:-

Circuit Components:

• Resistor
• R1, R2 (100K) – 2
• R3 (1.2K) – 1
• R4 (47E) – 1
• T1 (BC547) – 1
• T2 (BC558) – 1
• D1, D2 (1N4007) – 2
• C1 (. 1uf) – 1
• S1, S2 – 2
• Speaker – 1

Working of Security Alarm Circuit:-

                                                                              S1 and S2 are the two switches that are used in the circuit so that both can be put in two different places i.e. one of them can put in front of the locker while another one can be placed on the front door. When the switch S1 is pressed diode D1 which is linked with it starts conducting as the transistor T1 and T2, which is attached with the resistor begin its conduction. For the oscillation purpose Transistor T1 and T2 gets a positive feedback which is provided by capacitor C1. The presence of any intruder is indicated by the low tone frequency which is generated when switch S1 is pressed.

                                                    Same kind of condition occurs when switch S2 is pressed. Diode D2 which is linked with the switch S2 begin its conduction and offers power supply the transistor T1 and T2, which is in the waking state and as a result sound comes from the speaker attached to it. But in this instance a high frequency tone comes out which is a sign that there is some intruder present around the locker. The sound that came from the speaker can only be stopped by cut off the power supply.

Light Activated Switch Circuit:-

                                                                   The main principle of this circuit is to switch ON the light when the LDR is illuminated. The light dependent resistor will have high resistance in darkness and low resistance in the light. The comparator used here has LDR connected to its inverting terminal and potentiometer connected to its non-inverting pin.

                                                 When the light falls on the Light Dependent Resistor, the comparator compares the voltages at the reference pin that is with the non-inverting pin and the inverting pin of the op-amp. If the voltage at the non-inverting pin is greater than the voltage at the inverting pin the transistor cannot be switched. If the voltage at non-inverting pin is less than the voltage at the inverting pin, the output of the comparator can switch the transistor.

Light Activated Switch Circuit Diagram:-

Circuit Components:-

• LM358 comparator IC U1.
• Transistor Q1.
• Relay RL1.
• Light Dependent resistor LDR1.
• Resistor R1, R2.
• Potentiometer RV1.
• Bulb L1.
• Battery B1.

by veiwing this video u can prepare ur self

Light Activated Switch Circuit Design:-

                                                                                                                          The light activated switch mainly consists of comparator IC LM358.It can have voltages ranging from 3-32 volts. The LM358 IC has internally frequency compensated two operational amplifiers. In the present circuit only one op-amp is used for comparing the input voltages. It has 8pins.In these eight pins pin 1, 2, 3, are used by the first op-amp and 4,8 pins are common for both the op amps. Third pin is the inverting pin whose input is given from the Light Dependent Resistor. Second pin is the non-inverting pin and its input is given from the potentiometer. Eighth pin is connected to the supply voltage and 4^th pin is connected to the ground.

 Light dependent resistor has high resistance value in darkness as light illumination on the resistor increases resistance value decreases. Here a two mega ohm Light Dependent Resistor is used. It has resistance value ranging from 2000ohms to 2 mega ohms. This is connected to the supply through a resistor of 10k resistance.

BC547 is an NPN transistor. It has cutoff voltage of 0.7v. NPN transistors are initially open circuited that is when there no base voltage, there is no flow of current from emitter to collector. When the base gets required voltage transistor starts conducting. Here, base is connected to the output of the LM358 IC through a resistor of 10kohms.Emitter is connected to the ground. Collector is connected to the one of the relay pins.

Relay used here is a magnetic relay. It has 5 pins. They are normally open, normally closed, COM, A, B. The A, B are the coil pins. In A, B one is connected to the transistor and the other pin is connected to the supply voltage. Initially, the magnetic switch i.e. COM pin is connected to the normally connected i.e. NC pin. When voltage is applied to the relay COM pin is connected to the normally open pin.

One end of the light is connected to the COM pin of the relay and the other is connected to the ground. Power supply is connected to the normally open pin of the relay.

Motion Detector Circuit:-

                                                       The motion detector is not only used as intruder alarm but also used in many applications like home automation system, energy efficiency system, etc. The motion detector will detect the motion of the people or objects and give the appropriate output according to the circuit. In general, motion detector uses different types of sensors like Passive infrared sensor (which will detect the motion of the person using the person body heat), microwave sensor (Microwave sensor will detect the motion of person by measuring the change in frequency from the produced beam), ultrasonic sensor (It produces acoustic signals which will detect the motion of a person) etc.  There are some motion detectors which will use different technology and include number of sensors (PIR, microwave sensor, ultrasonic sensor, etc.) to reduce the false triggering and increase the accuracy in motion detection.

Block Diagram of Motion Detector:-

IR sensor will produce the high frequency beam which is projected on the photo transistor with the help of 555timer at the transmitter. When this high frequency beam has got any interruption, the photo transistor will trigger the 555 timer of receiver section and gives alert through the alarm.

Motion Detector Circuit Diagram:-

Motion Detector Circuit Explanation:-

• The IR sensor will make the high frequency beam of 5 kHz with the help of 555timer which is set to astable multivibrator mode at the transmitter section.
• The IR sensor will produce the high frequency beam which is received by the photo resistor at the receiver section. This frequency will be in one phase when there is no interruption between the IR sensor and photo transistor.  Total circuit will not give any output in this phase. When there is an interruption between IR sensor and photo transistor, the beam produced by the IR sensor will be in different phase. This different phase will be immediately detected by the photo resistor and make the 555 timer to give alarm through speaker.
• When there is no intrusion, the photo transistor will make the pin2 high of 555timer which is set in monostable mode, and there will be no output given in this configuration. When there is intrusion, the pin 2 of monostable timer is made low which will make the alarm to alert. The alarm time depends on the capacitor C1 and variable resistor POT

IR Remote Control Switch:-

                                     This circuit is low cost and can be constructed easily. By using this circuit, we can control any house hold appliance with the help of remote

Block Diagram of Infrared Remote Control Switch:-

Block Diagram Explanation:

• The main function of this remote control switch is to control any load (TV, Radio, Stereo, Fan, Light, etc.). In this circuit, we are using one switch for operating the transmitter, with this we can switch on or off the TV, motor, radio or any other home appliances.
• We can even control the volume of TV, radio and many more by adding extra circuitry to the actual circuit. Here in the transmitter section, we have NE555 timer which is configured in astable mode and infrared LEDs whose infrared rays are directed by the concave lens and the source of power is from 9V battery.
• Switch in the circuit plays the key role in the transmitter circuit. When the switch is closed, the power from the battery turns on the NE555 timer which will act as an astable multivibrator. The infrared LEDs which are connected to the output of NE555 will get high and produce the infrared beam through the concave lens.

Circuit Diagram of Infrared Remote Control Switch:-

Circuit Explanation:

• In the receiver section there are 3 photodiodes which will detect the infrared signals from the receiver and produce leakage current to the capacitor C1. This current is given to the inverting input of 3130 IC which will get triggered by this current and give amplified output. Remaining all other pins are connected to the ground.
• R2 and C2 are used to stop the unwanted signals from triggering the IC. C3 is used for high gain which is used as comparator amplifier.
• The output of IC3130 is given to the pin14 CLK of Johnson counter 4018. The output of 4018 IC will go high by applying successive clock pulses.
• The resistor R4 is used to stop loading the transistor. The transistor will get ON when the output of 4018 is high and drive the relay to operate in 12V. The diode D4 will protect the relay from reverse current.
• The relay will switch ON or OFF the appliance that is connected to it. LED will act as a visual indicator and also stops the reverse voltage which will effect the counter.
• In the transmitter section, the 555 timer is configured in astable mode and resistors R5, R6 and capacitor C6 are adjusted to give the 5Khz operating frequency.
• When the switch is ON, the capacitor C6 will get charged and when the switch is OFF, it will be discharged through R6 and 555 timer internal transistors. When switch on the 555 timer, output pin3 will be high this will trigger the transistor SK100.
•  Resistor R7 is used to stop loading of transistor. When transistor is ON, the infrared diodes which are connected to it will produce high intensity invisible infrared beam which should be given to the photo diodes of receiver.

Battery Charger Circuit Using SCR:-

 SCR Operating Modes:

• To turn on the SCR the small amount of voltage or voltage equal to break over voltage is required to the gate which will trigger the SCR and when the SCR is turned on, it will have very low resistance and allow the power to conduct and also increase the anode current. Even if we remove the gate voltage also it will be in conduction. The only way to make the SCR to turn off is to make the voltage to zero or make the current less than the handling current between the anode and cathode.
• There are two ways to turn on the SCR is the first way is to turn on by opening the gate and compensate the power supply to the break over voltage. And second way is to supplying the voltage to operate the SCR with less than break over voltage and applying the small amount of about 1.5V applied to the gate which will trigger the SCR.
• When the SCR is turned off it will have high resistance and restrict the current to the leakage current. To turn off the SCR from on state also have only one ways normally people think that if we stop the gate current the SCR will become turn off, but it will not this state is called “loss of control”, the only way is turnoff the SCR is reducing the supply voltage to zero.

Introduction to Battery Charger Using SCR:

The battery is charged with small amount of AC voltage or DC voltage. So if you want to charge your battery with AC source then should follow these steps, we need first limit the large AC voltage, need to filter the AC voltage to remove the noise, regulate and get the constant voltage and then give the resulting voltage to the battery for charging. Once charging is completed the circuit should automatically turned off.

Circuit Diagram of Battery Charger Using SCR:-

Circuit Diagram Explanation:

• The AC main voltage is given to the step down transformer the voltage should be down to 20V approx. the step down voltage is given to the SCR for rectification and SCR rectifies AC main voltage. This rectified voltage is used to charge battery.
• When the battery connecter to the charging circuit, the battery will not be dead completely and it will get discharged this will give the forward bias voltage to the transistor through the diode D2 and resistor R7 which will get turned on. When the transistor is turned on the SCR will get off.
• When the battery voltage is dropped the forward bias will be decreased and transistor gets turned off. When the transistor is turned off automatically the diode D1 and resistor R3 will get the current to the gate of the SCR, this will triggers the SCR and gets conduct. SCR will rectifies the AC input voltage and give to the battery through Resistor R6.
• This will charge the battery when the voltage drop in the battery decreases the forward bias current also gets increased to the transistor when the battery is completely charged the Transistor Q1 will be again turned on and turned off the SCR.

SUN BEAM SEEKER ROBOT:-

                  By watching this video u can make the sun beam seeker robot

all the best,,,,,,,,,,,,,.............//////////\\\\\\\\\

              

Traffic Light Control Circuit:-

                                                                      This page features a circuit that has twenty open collector outputs that turn on one at a time in a continuous sequential manner. The circuit make use of the 74LSxx family of TTL integrated logic devices. The circuits are designed to drive light emitting diodes or low current, low voltage incandescent lights but can also drive other loads of up to 80 milliamps.

As logic circuits go, the 20 Step circuit is fairly simple but due to the high speed nature of the TTL Logic devices used, care must be taken when wiring these circuits. Simply put; The neater the wiring the better.

                      If you would like to make use of these circuits, please take the time to find and read at least the first 2 pages of the manufactures data sheets for the integrated circuits. Using Google, search for "74ls(part number)" in the first box and "PDF" in the second box on the advanced search page.

PRINTED BOARD:-

                            

Parts List

The following is a parts list for use with the 20 Output Sequencing Circuit.Mouser Electronics part numbers are shown but the parts may be available from other sources as well. Suppliers that handle 'NTE' components should be able to get the ICs.

Part Number		Mouser Description		Mouser Part #		QTY
VR 1	-	Voltage Regulators TO-92 5.0V 0.1A	-	511-L78L05ABZ	-	1
IC 1	-	Timers DIP-8 Single Timer	-	512-LM555CN	-	1
IC 2	-	DECADE COUNTER DIP14	-	526-NTE74LS90	-	1
IC 3	-	DUAL J-K F/F DIP-14	-	526-NTE74LS107	-	1
IC 4	-	QUAD 2-IN OR DIP-14	-	526-NTE74LS32	-	1
IC 5, 6	-	BCD-DEC DECODER DP16	-	595-SN74LS145N	-	2
R1	-	100K ohm / 1/4 Watt Carbon Resistor	-	660-CF1/4C104J	-	1
R2	-	Trimmer Potentiometers 1Mohms 6mm	-	531-PT6KV-1M	-	1
R3	-	470 ohm / 1/4 Watt Carbon Resistor	-	660-CF1/4C471J	-	1
C1, C3	-	Radial Electrolytic Capacitors 25V 10uF	-	140-XRL25V10	-	2
C2	-	Radial Electrolytic Capacitors 25V 1.0uF	-	140-XRL25V1.0	-	1
D1	-	Green 3mm LED	-	859-LTL-4231	-	1
-	-	2 Position Terminal Block - 5mm	-	651-1729018	-	1

The 1N4148 diodes for the traffic signals shown below are Mouser part number 78-1N4148.

NOTE: The LEDS for the traffic signal lights must be selected by the user as their size and style depend on the mounting.

Basic Circuit Operation:-

• The circuit is stepped through the sequence by an adjustable LM555 astable oscillator.
• The Oscillators output is divided by a 74LS90 divider into a 10 step BCD weighted output.
• The BCD output then drives two 74LS145 - 1 of 10 decoders (See Notes) that are used to produce a 1 of 20 step output sequence.

Notes:-

• The circuit does not drive the 74LS145's directly but uses a 74LS107 JK Flip-Flop and four 74LS32 dual input OR gates to control to the inputs to the two 74LS145 output drivers. The 74LS107 and 74LS32 are used to create disallowed states in the output drivers alternately. The disallowed states prevent any of the ten outputs on that particular device from being turned ON while the other 74LS145 is in counting to ten.
• This produces a system where only one of the 74LS145's is able to produce a LOW output state at a time. In essence the circuit counts to 10 twice in succession rather than counting to 20 in a single cycle.
• This may seem like an unusual method but it allows the circuit to make economical use of the open collector outputs of the 74LS145s decoder/drivers rather using output buffer ICs driven by 74LS138 logic devices.
• The TTL logic devices in the circuit require a regulated 5 volt supply and draw approximately 60 miliamps. The outputs of the 74LS145's can be supplied from up to 15 Volts with a maximum current of 80 milliamps.
• The circuit above is shown in a continuous running mode. The circuit can also be externally stopped and reset as shown in later diagrams.