Showing posts with label based. Show all posts
Showing posts with label based. Show all posts

Thursday, November 6, 2014

Morning Alarm Circuit Diagram based LDR

This LDR based alarm can be used as get up alarm. The Alarm turns on in the morning automatically and turns off only when manually switched off ,so you will have to get up. It is a simple LDR based light sensor circuit.

LDR or Light Dependent Resistor is a kind of variable resistor and its resistance depends on the intensity of light falling on it. In complete dark, its resistance is as high as 1 Meg Ohm, but it reduces to 100 ohms or less in full light. So it is an ideal device to use as light switch. Sensitivity of LDR depends on its size also. Commonly available sizes are 3mm, 5mm, 10mm etc. But costly types with greater sensitivity are also available.

When the circuit is place in dark, near the window, LDR fails to conduct and T1 will not get base bias. So it remains off and buzzer will be silent. When the sunlight falls on LDR, IN the morning, LDR conducts and provides base bias to T1. T1 then conducts to activate the buzzer. Capacitor C1 is provided for the clean switching of T1. T1 will conduct only when C1 is charged fully. This prevents chirping sound during light transition.You can use an easily available Music buzzer to get melody tone.

Saturday, October 4, 2014

AM Receiver based on TDA1572 IC

The circuit is a high performance AM receiver based on the Philips TDA1572 IC. The TDA1572 is an integrated AM receiver circuit that has all the essential circuits such as RF amplifier, mixer, IF amplifier, AGC circuit, the pilot signal strength indicator, audio pre amplifier, etc. controlled oscillator incorporated into it. The internal oscillator frequency can be up to 50 Hz and the IC can accept RF signals up to 500 mV. HF inputs are static protected and separate buffer, voltage controlled oscillator makes it possible to use single coils in the circuit.

Inductor L1 connected between pins 14 and 13 of the IC sets the frequency of the oscillator. Potentiometer R12 is used to vary the voltage on the varicap tuning diode D2. C4 is associated with the internal balance of full-wave detector circuit. Pin 11 is the circuit output if the internal field indicator of strength. The power available on this pin is a function of field strength available and has a good linearity for logarithmic input signals.

The intermediate frequency of this circuit is built around 455 KHz. The band pass filter circuit ago about CF1 and CF2 6kHz select the band around the intermediate frequency. In simple words, IF double-balanced mixer output available on pin is filtered and applied to the input of gain controlled amplifier filter capacitors C16 and C17 are used to reduce the solution time of AGC. The transistor Q2 and associated components form the driver circuit M1 field strength meter. Resistors R9 R5and preset can be used to configure the meter. Capacitor C3 is a bypass capacitor for the audio preamplifier circuit of frequency within the IC. Capacitors C16 and C12 prevent noise (if any) of the power line.

TDA7052 is an audio stage 1W amplifier to drive the speaker. TDA7052 is an integrated bridge amplifier that can deliver an output power of 1W at 8 ohm speaker. Capacitor C18 couples the audio output of the TDA1572 to TDA7052. Potentiometer R10 can be used to control the volume.

Monday, September 15, 2014

Relay Based Motorcycle Alarm Wiring diagram Schematics

You can Make Relay Based Motorcycle Alarm Circuit Diagrams. You can use them to protect your motorcycle - but they have many more applications. If you use relays with 6-volt coils - theyll protect your "Classic Bike". Both alarms are very small. The completed boards occupy about half a cubic-inch - 8 cc. The standby current is zero - so they wont drain your battery.

Relay Based Motorcycle Alarm Circuit Diagram 1 uses a SPCO/SPDT relay - but you really only need to use a SPST relay. If you are going to use the veroboard layout provided - youll need to use the style of relay specified. But you can build the alarm using whatever style of relay you have available.

Relay Based Motorcycle Alarm Circuit Diagram 1




Any number of normally-open switches may be used. Fit the mercury switches so that they close when the steering is moved or when the bike is lifted off its side-stand or pushed forward off its centre-stand. Use micro-switches to protect removable panels and the lids of panniers etc. When one of the trigger-switches is closed - the relay will energize and the siren will sound.

You can choose what happens next. If you build the schema as shown, the siren will continue to sound until you turn it off - or until the battery is exhausted. But, if you leave out D3 - the siren will stop sounding immediately the trigger-switch is re-opened.

While youre within earshot of your machine - the former configuration is best. You can always turn off the alarm yourself. But if you are going to be away from your bike for any length of time - and you dont want to cause a nuisance - then the latter configuration is probably more suitable. If you include a SPST switch in series with D3 - you can select the behaviour that best suits the circumstances at any given time.

Relay Based Motorcycle Alarm Circuit Diagram 1a

Relay


Relay coils and some sounders produce high reverse-voltage spikes that will destroy sensitive electronic components. D1 and D2 are there to short-schema these spikes before they can do any damage. Although there is nothing in the alarm schema itself that could be damaged - I have no idea what other electronic equipment might be connected to the same power supply. So I included the two diodes as a precaution. If youre satisfied that theres nothing on your bike that might be damaged in this way - you can leave out the two diodes.

Relay Based Motorcycle Alarm Circuit Diagram 2 uses a DPCO/DPDT relay - but you really only need to use a DPST relay. If you are going to use the veroboard layout provided - youll need to use the style of relay specified. But you can build the alarm using whatever style of relay you have available.

Relay Based Motorcycle Alarm Circuit Diagram 2

Relay
 Any number of normally-open switches may be used. Fit the mercury switches so that they close when the steering is moved or when the bike is lifted off its side-stand or pushed forward off its centre-stand. Use micro-switches to protect removable panels and the lids of panniers etc. When one of the trigger-switches is closed - the relay will energize and the siren will sound.


You can choose what happens next. If you build the schema as shown, the siren will continue to sound until you turn it off - or until the battery is exhausted. But, if you leave out the (yellow) solder-bridge in the top left-hand corner of the diagram - the siren will stop sounding immediately the trigger-switch is re-opened.

While youre within earshot of your machine - the former configuration is best. You can always turn off the alarm yourself. But if you are going to be away from your bike for any length of time - and you dont want to cause a nuisance - then the latter configuration is probably more suitable. Connect a SPST switch in place of the (yellow) solder-bridge - and you can select the behaviour that best suits the circumstances at any given time.

Relay Based Motorcycle Alarm Circuit Diagram 2 a
Relay

 Relay coils and some sounders produce high reverse-voltage spikes that will destroy sensitive electronic components. D1 and D2 are there to short-schema these spikes before they can do any damage. Although there is nothing in the alarm schema itself that could be damaged - I have no idea what other electronic equipment might be connected to the same power supply. So I included the two diodes as a precaution. If youre satisfied that theres nothing on your bike that might be damaged in this way - you can leave out the two diodes.

Whichever alarm you build - the schema board and switches must be protected from the elements. Dampness or condensation will cause damage. Without the terminal blocks - the board is small. Ideally, you should try to find a siren with enough spare space inside to accommodate it. Fit a 1-amp in-line fuse as close as possible to the power source. This is Very Important. The fuse is there to protect the wiring - not the schema board. Instead of using a key-switch you can use a hidden switch; or you could use the normally-closed contacts of a small relay. Wire the relay coil so that its energized while the ignition is on. Then every time you turn the ignition off - the alarm will set itself.

When the alarms are not sounding - the diagram use no current. This should make them useful in other circumstances - where a power supply is not readily available. Powered by dry batteries - with the relay and siren voltages chosen to suit - the alarms could be fitted almost anywhere. 

Sourced By : Streampowers

Sunday, August 24, 2014

Basic Monostable Multivibrator based IC 555

The following diagram is the schema diagram of the very basic monostable multivibrator which built based on timer IC 555.

Basic



Parts list:
R1 = see notes
C1 = see notes
C2 = 10nF
IC1 = LM555

Notes:
  • R1 and C1 determine length of output pulse where t=R1xC1 and R1 is in ohms and C1 is in farads.
  • Pin 4 is the RESET. Leave it connected to power supply (+V) during normal operation. Bring pin 4 AND pin 2 low at the same time to reset timing cycle.