Showing posts with label Automotive. Show all posts
Showing posts with label Automotive. Show all posts

Simple Automatic Anchor Light Circuit Diagram

This is a Simple Automatic Anchor Light Circuit Diagram.Most of the cruisers do not use a masthead anchor light because the light is too high above the water level and actually makes it difficult to judge the position of the boat from just the anchor light, especially in a pitch-dark anchorage. That is why many people have devised their own forms of anchor lights that they stick lower to the deck on both sides of their boat.
Here is the circuit of a compact yet inexpensive automatic anchor light integrated with an ambient light sensor that turns it on and off automatically. This 12-volt LED light can be used as a traditional masthead anchor light and/or as an optional pretty clever custom-built anchor light. A typical commercial anchor light is shown in Fig. 2.
The circuit described here (refer Fig. 3) lets you control an electromagnetic relay so that it turns on a white LED light when the preset light level is reached and turns it off when a different preset level is reached. The circuit is built around NE555 IC (IC1). The 5mm light dependent resistor (LDR1) in the circuit triggers the 12V electromagnetic relay (RL1) as per the ambient light level. RL1 drives the 10mm white LED light source (LED2). Series resistor (R2) is included to limit the white LED current.
Automatic Anchor Light Circuit Diagram
 Fig. 3: Circuit diagram of the anchor light
Note that switching threshold is determined by a 470k potentiometer (VR1) that causes the output to toggle with the preset threshold values. The light source (LED2) automatically switches on when it gets dark and switches off when there is sufficient ambient light. The 100µF capacitor (C1) provides a bit of hysteresis to prevent the circuit from jittering near the threshold level. The circuit is optimised for use with a nominal DC voltage of 12V drawn from any standard accumulator commonly used in boats.
Construction and testing
A single-side PCB pattern for the anchor light circuit is shown in Fig. 4 and its component layout in Fig. 5.
PCB pattern of the anchor light circuit

Fig. 4: PCB pattern of the anchor light circuit

Component layout of the PCB
Fig. 5: Component layout of the PCB
The circuit assembled on the small PCB can fit easily inside most prototype/custom enclosures, which should be waterproof for mounting on the masthead.
Suggested enclosure layout
 Fig. 6: Suggested enclosure layout
 If possible, try to add some optics (lens and reflector) with the white LED (LED2) to spread the light outward. The 12V power supply input wires can then be connected to corresponding wires extending from the existing electric-points of the anchor light. Fig. 6 shows how the prototype may be assembled. Author’s prototype is shown in Fig. 7.
 Author’s prototype
 Fig. 7: Author’s prototype
 
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Park-Aid Circuit Diagram

This Park-Aid Circuit Diagram was designed as an aid in parking the car near the garage wall when backing up. LED D7 illuminates when bumper-wall distance is about 20 cm., D7+D6 illuminate at about 10 cm. and D7+D6+D5 at about 6 cm. In this manner you are alerted when approaching too close to the wall. All distances mentioned before can vary, depending on infra-red transmitting and receiving LEDs used and are mostly affected by the color of the reflecting surface. Black surfaces lower greatly the device sensitivity. Obviously, you can use this circuit in other applications like liquids level detection, proximity devices etc.

Circuit operation:
IC1 forms an oscillator driving the infra-red LED by means of 0.8mSec. pulses at 120Hz frequency and about 300mA peak current. D1 & D2 are placed facing the car on the same line, a couple of centimeters apart, on a short breadboard strip fastened to the wall. D2 picks-up the infra-red beam generated by D1 and reflected by the surface placed in front of it. The signal is amplified by IC2A and peak detected by D4 & C4. Diode D3, with R5 & R6, compensates for the forward diode drop of D4. A DC voltage proportional to the distance of the reflecting object and D1 & D2 feeds the inverting inputs of three voltage comparators. These comparators switch on and off the LEDs, referring to voltages at their non-inverting inputs set by the voltage divider resistor chain R7-R10.

Circuit diagram:


Park-Aid Circuit Diagram


Parts:
R1_____________10K 1/4W Resistor
R2,R5,R6,R9_____1K 1/4W Resistors
R3_____________33R 1/4W Resistor
R4,R11__________1M 1/4W Resistors
R7______________4K7 1/4W Resistor
R8______________1K5 1/4W Resistor
R10,R12-R14_____1K 1/4W Resistors
C1,C4___________1µF 63V Electrolytic or Polyester Capacitors
C2_____________47pF 63V Ceramic Capacitor
C3,C5_________100µF 25V Electrolytic Capacitors
D1_____________Infra-red LED
D2_____________Infra-red Photo Diode (see Notes)
D3,D4________1N4148 75V 150mA Diodes
D5-7___________LEDs (Any color and size)
IC1_____________555 Timer IC
IC2___________LM324 Low Power Quad Op-amp
IC3____________7812 12V 1A Positive voltage regulator IC

Circuit modification:
A circuit modification featuring an audible alert instead of the visual one is available here: Park-Aid Modification

Notes:
  • Power supply must be regulated (hence the use of IC3) for precise reference voltages. The circuit can be fed by a commercial wall plug-in adapter, having a DC output voltage in the range 12-24V.
  • Current drawing: LEDs off 40mA; all LEDs on 60mA @ 12V DC supply.
  • The infra-red Photo Diode D2, should be of the type incorporating an optical sunlight filter: these components appear in black plastic cases. Some of them resemble TO92 transistors: in this case, please note that the sensitive surface is the curved, not the flat one.
  • Avoid sun or artificial light hitting directly D1 & D2.
  • If your car has black bumpers, you can line-up the infra-red diodes with the (mostly white) license or number plate.
  • It is wiser to place all the circuitry near the infra-red LEDs in a small box. The 3 signaling LEDs can be placed far from the main box at an height making them well visible by the car driver.
  • The best setup is obtained bringing D2 nearer to D1 (without a reflecting object) until D5 illuminates; then moving it a bit until D5 is clearly off. Usually D1-D2 optimum distance lies in the range 1.5-3 cm.
  • If you are needing a simpler circuit of this kind driving a LED or a relay, click Infra-red Level Detector

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Test Beeper For Your Stereo Circuit Diagram

The test beeper generates a sinusoidal signal with a frequency of 1,000 Hz, a common test  frequency for audio amplifiers.  It consists of a classical Wien- Bridge oscillator (also known as  a Wien-Robinson oscillator). The network that determines the  frequency consists here of a series connection of a resistor and  capacitor (R1/C1) and a parallel connection (R2/C2), where  the values of the resistors and  capacitors  are  equal  to  each  other. This network behaves, at  the oscillator frequency (1 kHz  in this case), as two pure resistors. The opamp (IC1) ensures  that the attenuation of the net- work  (3  times)  is  compensated  for.  In  principle  a  gain  of  3 times should have been sufficient to sustain the oscillation,  but  that  is  in  theory.  Because  of tolerances in the values, the  amplification needs to be (automatically) adjusted.

Circuit diagram:
Test Beeper For Your Stereo circuit-Diagram
Test Beeper For Your Stereo circuit Diagram

Instead of an intelligent amplitude  controller  we  chose  for  a  somewhat simpler solution. With  P1, R3 and R4 you can adjust  the gain to the point that oscillation takes place. The range of P1 (±10%) is large enough the cover the tolerance range. To sustain  the oscillation, a gain of slightly  more than 3 times is required,  which  would,  however,  cause  the amplifier to clip (the ‘round-trip’ signal becomes increasingly  larger, after all). To prevent this  from happening, a resistor in se-ries with two anti-parallel diodes  (D1 and D2) are connected in  parallel  with  the  feedback  (P1  and R3). If the voltage increases to the point that the threshold  voltage of the diodes is exceed-ed, then these will slowly start to  conduct.

The consequence of this  is that the total resistance of the  feedback  is  reduced  and  with  that  also  the  amplitude  of  the  signal. So D1 and D2 provide a  stabilising function. The distortion of this simple oscillator, after adjustment of P1 and  an output voltage of 100 mV (P2  to  maximum)  is  around  0,1%.  You can adjust the amplitude of  the output signal with P2 as required for the application. The  circuit is powered from a 9-V battery. Because of the low current  consumption  of  only  2 mA  the  circuit will provide many hours  of service.


Author :Ton Giesberts  - Copyright : Elektor Electronics
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Push-Bike Light Circuit Diagram

Automatic switch-on when it gets dark, 6V or 3V battery operation This design was primarily intended to allow automatic switch-on of push-bike lights when it gets dark. Obviously, it can be used for any other purpose involving one or more lamps to be switched on and off depending of light intensity. Power can be supplied by any type of battery suitable to be fitted in your bike and having a voltage in the 3 to 6 Volts range.

The Photo resistor R1 should be fitted into the box containing the complete circuit, but a hole should be made in a convenient side of the box to allow the light hitting the sensor. Trim R2 until the desired switching threshold is reached. The setup will require some experimenting, but it should not be difficult.
Circuit diagram:
Push-Bike Light Circuit Diagram
Push-Bike Light Circuit Diagram


Parts:
R1_____________Photo resistor (any type)
R2______________22K 1/2W Trimmer Cermet or Carbon type
R3_______________1K 1/4W Resistor
R4_______________2K7 1/4W Resistor
R5_____________330R 1/4W Resistor (See Notes)
R6_______________1R5 1W Resistor (See Notes)
D1____________1N4148 75V 150mA Diode
Q1_____________BC547 45V 200mA NPN Transistor
Q2_____________BD438 45V 4A PNP Transistor
LP1____________Filament Lamp(s) (See Notes)
SW1_____________SPST Toggle or Slider Switch
B1______________6V or 3V Battery (See Notes)


Notes:
  • In this circuit, the maximum current and voltage delivered to the lamp(s) are limited mainly by R6 (that can't be omitted if a clean and reliable switching is expected). Therefore, the Ohm's Law must be used to calculate the best voltage and current values of the bulbs.
  • For example: at 6V supply, one or more 6V bulbs having a total current drawing of 500mA can be used, but for a total current drawing of 1A, 4.5V bulbs must be chosen, as the voltage drop across R6 will become 1.5V. In this case, R6 should be a 2W type.
  • At 3V supply, R6 value can be lowered to 1 or 0.5 Ohm and the operating voltage of the bulbs should be chosen accordingly, by applying the Ohm's Law.
  • Example: Supply voltage = 3V, R6 = 1R, total current drawing 600mA. Choose 2.2V bulbs as the voltage drop caused by R6 will be 0.6V.
  • At 3V supply, R5 value must be changed to 100R.
  • Stand-by current is less than 500µA, provided R2 value after trimming is set at about 5K or higher: therefore, the power switch SW1 can be omitted. If R2 value is set below 5K the stand-by current will increase substantially. 

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Automatic Bicycle Light Circuit Diagram

T his  automatic  bicycle  light  makes cycling in the dark much  easier (although you still need  to pedal of course). The circuit  takes  the  ambient  light  level  into account and only turns on  the light when it becomes dark.  The light is turned off when no  cycling has taken place for over  a minute or if it becomes light  again. The biggest advantage of  this circuit is that it has no manual controls. This way you can  never ‘forget’ to turn the light  on or off. This makes it ideal for  children and those of a forgetful  disposition.

Bicycle Light Image :
Bicycle Image Proj


To detect when the bicycle is  used (in other words, when the  wheels turn), the circuit uses a  reed switch (S1), mounted on  the frame close to the wheel.  A small magnet is fixed to the  spokes (similar to that used with  most  bicycle  speedometers),  which  closes  the  reed  switch  once for every revolution of the  wheel. Whilst the wheel turns,  pulses are fed to the base of T1  via C1. This charges a small electrolytic capacitor (C2). When it is  dark enough and the LDR there-fore has a high resistance, T2  starts conducting and the lamp  is turned on. With every revolution of the wheel C2 is charged  up again. The charge in C2 ensures that T2  keeps conducting for about a minute after  the wheel stops turning. Almost any type of  light can be connected to the output of the  circuit.

Circuit diagram :
Automatic Bicycle-Light-Circuit-Diagram
Automatic Bicycle Light Circuit Diagram



Part List :
Resistors
R1 = 1MΩ (SMD 0805)
R2,R4 = 100kΩ (SMD 0805)
R3,R6 = 1kΩ (SMD 0805)
R5 = LDR e.g. FW150 Conrad Electronics # 183547
Capacitors
C1 = 1µF 16V (SMD 0805)
C2 = 10µF 16V (SMD chip type)
C3 = 100nF (SMD 0805)
Semiconductors
T1 = BC807 (SMD SOT23)
T2 = STS6NF20V (SMD SO8)
Miscellaneous
S1 = reed switch (not on board) +
2-way right angle pinheader
BT1 = 3–12V (see text)

With a supply voltage of 3V the quiescent  current when the reed switch is open is just  0.14 μA. When the magnet happens to be in  a position such that S1 is closed,  the current is 3 μA. In either case  there is no problem using batteries to supply the circuit. The  supply voltage can be anywhere  from 3 to 12 V, depending on the  type of lamp that is connected. Since it is likely that the circuit  will be mounted inside a bicycle light it is important to keep  an eye on its dimensions. The  board has therefore been kept  very compact and use has been made of SMD components. Most  of them come in an 0805 pack-age.  C2 comes in a so called  chip version. The board is single sided with the top also acting as the solder side.

PCB


The print outline for the LDR (R5)  isn’t exactly the same as that of  the  outline  of  the  LDR  mentioned  in  the  component  list.  The outline is more a general one  because there is quite a variety  of different LDR packages on the  market. It is therefore possible  to use another type of LDR, if for  example the light threshold isn’t  quite right. The LDR may also be  mounted on the other side of the  board, but that depends on how  the board is mounted inside the  light. For the MOSFET there are also many alternatives available, such as the FDS6064N3 made  by   Fairchild ,  the  SI4864 DY  made by  Vishay Siliconix , the IR F74 0 4 made by IR F or the NTMS 4N01R 2G  made by ONSEMI. The reed switch also  comes in many different shapes and sizes; some of them are even waterproof and come with the wires already attached.

For the supply connection and  the connection to the lamp you  can either use PCB pins or solder the wires directly onto the  board. The soldered ends of the  pins can be shortened slightly so that they  don’t stick out from the bottom of the board.  This reduces the chance of shorts with any metal parts of the light. Do take care when you use a dynamo  to  power the circuit the alternating voltage must first be rectified! The same applies to  hub dynamos, which often also output an  alternating voltage.

Please Note. Bicycle lighting is subject to legal restrictions, traffic laws and, additionally in  some countries, type approval.
 


Author : Ludwig Libertin (Austria) – Copyright : Elektor
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Car Head Lights Turn Off Circuit Diagram

This circuit when setup in a car automatically turns off the head light after a preset time after the ignition switch is turned off.So you can walk out easily from the dark garage in the light of your car.


Circuit diagram :
automatic-head-light-turn-off Circuit Diagram
Car Head Lights Turn Off  Circuit Diagram

When the ignition switched on first the voltage from battery is fed to the relay through diode D1.When the ignition switch is turned off it produces a negative going pulse at the pin 2 that triggers the timer. The output of the IC goes high for the time set by R1  .This makes the transistor Q1 to conduct to energize the relay to drive the headlight.After the set time the light goes off.With the value of components used you can make a setting from 10 S to 60 S.
Notes :
  • Assemble the circuit on a good quality PCB or common board.
  • Fit the potentiometer on somewhere on the dashboard so that  you can easily set the timing.
Source :circuitstoday
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Motorbike Alarm Circuit Diagram

This simple to build alarm can be fitted in bikes to protect them from being stolen. The tiny circuit can be hidden anywhere, without any complicated wiring. Virtually, it suits all bikes as long as they have a battery. It doesn't drain out the battery though as the standby current is zero. The hidden switch S1 can be a small push-to-on switch, or a reed switch with magnet, or any other similar simple arrangement. The circuit is designed around a couple of low-voltage MOSFETs configured as monostable timers. Motorbike key S2 is an ignition switch, while switch S3 is a tilt switch. Motorbike key S2 provides power supply to the gate of MOSFET T2, when turned on. 
When you turn ignition off using key S2, you have approximately 15 seconds to get off the bike; this function is performed by resistor R6 to discharge capacitor C3. Thereafter, if anyone attempts to get on the bike or move it, the alarm sounds for approximately15 seconds and also disconnects the ignition circuit. During parking, hidden switch S1 is normally open and does not allow triggering of mosfet T1. But when someone starts the motorbike through ignition switch S2, MOSFET T2 triggers through diode D1 and resistor R5. Relay RL1 (12V, 2C/O) energises to activate the alarm (built around IC1) as well as to disconnect the ignition coil from the circuit. Disconnection of the ignition coil prevents generation of spark from the spark plug. Usually, there is a wire running from the alternator to the ignition coil, which has to be routed through one of the N/C1 contacts of relay RL1 as shown in Fig.1 Fig.2 shows the pin configurations of SCR BT169, MOSFET BS170 and transistor BC548.
Circuit diagram :

Motorbike Alarm-Circuit-Diagram
 Motorbike Alarm Circuit Diagram

Motorbike Alarm-Pin Configurations :

Motorbike Alarm-Pin configurations
Pin configurations of BT169, BS170 and BC548
 
Also, on disconnection of the coil, sound generator IC UM3561 (IC1) gets power supply through N/O2 contact of relay RL1. This drives the darlington pair built around T3 and T4 to produce the siren sound through loudspeaker LS1.  To start the vehicle, both hidden switch S1 and ignition key S2 should be switched on. Otherwise, the alarm will start sounding. Switching on S1 triggers SCR1, which, in turn, triggers MOSFET T1. MOSFET T1 is configured to disable MOSFET T2 from functioning. As a result, MOSFET T2 does not trigger and relay RL1 remains de-energised, alarm deactivated and ignition coil connected to the circuit.  Connection to the ignition coil helps in generation of spark from the spark plug. Keeping hidden switch S1 accessible only to the owner prevents the bike from pillaging. Tilt switch S3 prevents attempt to move the vehicle without starting it. Glass-and metal-bodied versions of the switch offer bounce-free switching and quick break action even when tilted slowly. 
Unless otherwise stated, the angle by which the switch must be tilted to ensure the contact operation (operating angle), must be approximately 1.5 to 2 times the stated differential angle. The differential angle is the measure of the 'just closed' position to the 'just open' position. The tilt switch has characteristics like contacts make and break with vibration, return to the open state at rest, non-position sensitivity, inert gas and hermetic sealing for protection of contacts and tin-plated steel housing. If you find difficulty in getting the tilt switch, you may replace it with a reed switch (N/O) and a piece of magnet. The magnet and the reed switch should be mounted such that the contacts of the switch close when the bike stand is lifted up from rest.
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Mobile Car Stereo Player Circuit Diagram

Using a mobile phone while driving is dangerous. It is also against the law. However, you can use your mobile phone as a powerful music player with the help of a stereo power amplifier. This does away with the need of a sophisticated in-dash car music system. Most mobile phones have a music player that offers a number of features including preset/manual sound equalisers. They have standard 3.5mm stereo sockets that allow music to be played through standard stereo headphones/sound amplifiers. Nokia 2700 classic is an example. 

Circuit diagram :
Circuit of mobile car stereo player
Mobile Car Stereo Player Circuit Diagram
 
A car audio amplifier with 3.5mm socket can be designed and simply connected to the mobile phone output via a shielded cable with suitable connectors/jacks (readymade 3.5mm male-to-male connector cable is a good alternative). Fig. 1 shows the circuit of car stereo player. It is built around popular single-chip audio power amplifier TDA1554Q (IC1). The TDA1554Q is an integrated class-B power amplifier in a 17-lead single-in-line (SIL) plastic power package. 

IC TDA1554Q contains four 11W identical amplifiers with differential input stages (two inverting and two non-inverting) and can be used for single-ended or bridge applications. The gain of each amplifier is fixed at 20 dB. Here it is configured as two 22W stereo bridge amplifiers. The amplifier is powered from the 12V car battery through RCA socket J2. Diode D1 protects against wrong-polarity connection. LED1 indicates the power status. 

Stereo Jack :
3.5mm stereo socket and (b) 3.5mm
(a) 3.5mm stereo socket and (b) 3.5mm Stereo Jack
 
Connect stereo sound signal from the 3.5mm headset socket of the mobile phone to audio input socket J1. When you play the music from your mobile, IC1 amplifies the input. The output of IC1 is fed to speakers LS1 and LS2 fitted at a suitable place in your car. Electrolytic capacitor C5 connected between pin 4 of IC1 and GND improves the supply-voltage ripple rejection. Components R2 and C4 connected at mute/standby pin (pin 14) of IC1 eliminate the switch on/off plop. The circuit is quite compact. A good-quality heat-sink assembly is crucial for IC1. Fig. 2 shows the stereo socket and stereo jack. 

Proposed enclosure Proposed enclosure

Assemble the circuit on a general-purpose PCB and enclose in a suitable cabinet. Small dimensions of the power amplifier make it suitable for being enclosed in a plastic (ABS) case with vent holes. Signal input socket, speaker output terminals, on/off switch, indicator, fuse holder and power supply socket are best located on the front panel of the enclosure as shown in Fig. 3. 

Author : T.K. Hareendran
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Track Your Distance Through a Bicycle Odometer

Just like cars that measures the distance it can travel, you can also do it with your bicycles. We usually keep track of our mileage to see how far our strength can go but would it be of great use if we track it because we are maintaining a workout everyday considering the calories we are burning.

Hacks and Mods: Track Your Distance Through a Bicycle Odometer

If you want to make your own odometer, you will need a micro controller that generates pulse and a MOSFET that converts those voltage pulses. Just remember to check your batteries all the time.
The best way of burning calories is to move those muscles everyday! Set your bikes and your odometer! Burn fats!
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Lambda Probe Readout For Carburettor Tuning

A lambda probe (or oxygen sensor) can be found on the exhaust system of most cars running on unleaded fuel. Having reached its normal operating temperature (of about 600 degrees Celsius!) the lambda probe supplies an output voltage proportional to the amount of residual oxygen measured in the exhaust gas.

This information is indicative of, among others, the air/fuel ratio supplied by the carburetor(s) and hence the combustion efficiency. In modern car (and motorcycle) engines, this information is used to (electronically) adjust engine parameters like ignition timing and fuel injection. The indicator described here is intended for permanent installation on a motorcycle of which the air/fuel ratio needed to be watched, with the obvious aim engine power tuning after fitting a different set of carburetors. Apart from this obvious technical use the unit’s bright LEDs will no doubt attract the attention of curious motorcyclists.

Lambda Probe Readout For Carburettor Tuning

At the local junkyard a single-wire lambda probe may be salvaged from a wrecked car. Once a suitable nut has been found, the probe can screwed into the exhaust pipe of the motorcycle, at about 30 cm from the cylinders.  Since we’re talking of welding and drilling in an expensive (chrome-plated) exhaust pipe, you may find that actually fitting the probe is best left to specialists!  The starting point for the design of a suitable electronic indicator is that in the noble art of carburetor tuning an air/fuel ratio of 14.7 to 1 is generally considered ‘perfect’, the range covering 16.2 to 1 (‘lean’) to 11.7 to 1 (‘rich’). The perfect ratio typically corresponds to a probe output voltage of 0.45 V. 

 Referring to the circuit diagram, that is the input level at which 5 of the 10 LEDs will light, including the green one, D5. If one of the red LEDs lights, the mixture is definitely too rich. Note that in general it is better to have a mixture that is a little to rich than one that’s on the lean side, hence a yellow LED lights between the green LED and the first red one. Also note that the engine needs to be at its normal operating temperature before a meaningful indication is obtained.
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Hacking Car Wipers for Easy Control

How do you want to have your wipers become more intelligent? In this way, they could remember how frequent you need to use them. But of course, this will need the help of an ATmega8L microcontroller.

Hacks and Mods: Hacking Car Wipers for Easy Control

When you need to activate the wiper, you just press the button and it will run in one course. There is a 45 seconds waiting time that if you do not press the button, it will go on standby while telling itself that only one course is needed. The system will activate the wiper again if the button is pressed before 45 seconds. The good thing is that it will remember the interval when you pressed the button. Click here to visit the project page.

Hacks and Mods: Hacking Car Wipers for Easy Control
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Car Reverse Horn Circuit Diagram

Most of people have there own vehicles.so I suppose this circuit will be very useful circuit for them.This circuit is a car reverse horn.If you can build your own circuit for your car I think that is great.Here I have used common Music generator IC UM 66.The out put voltage of UM66 is not enough to make a good car reverse horn so by using two transistors (BC148 and BEL187)I have increased it.


Car Reverse Horn Circuit Diagram




Note

# This circuit operates with 12V power supply
# Build this circuit on a PCB to get good results
# use 8ohm speaker.
# Use only push to on switch.


 Source by
Free circuits4u
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OBD Vehicle Protection Circuit Diagram

vehicle immobilisers are fitted as standard to modern cars and heavy goods vehicles. Anti-theft mechanisms have become more sophisticated but so have the methods employed by crooks. Nowadays once the thief has gained access to a vehicle they will most likely use an electronic deactivation tool which seeks to disable the immobiliser, once this has been accomplished a blank transponder key/card can be used to start the engine. In many cases communication with the immobiliser is made using the OBD-II diagnostic connector.

Although the OBD-II protocol itself does not support the immobiliser, the vehicle manufacturer is free to use the interface as neces-sary for communication, either the standard OBD-II signals or unused pins in the OBD-II connector (i.e. those undefined in the OBD-II standard). Using one of these pathways the immobiliser can usually be electronically disabled. 

OBD Vehicle Protection Circuit Diagram
OBD-Vehicle-Protection-Circuit Diagram

This may be unsettling news for owners of expensive vehicles but when professional car-thieves call, armed with the latest OBD-II hacking equipment this simple low-cost low-tech solution may be all that you need. The idea is ver y simple: if all connections to the OBD-II connector are disconnected there is no possibility for any equipment, no matter how sophisticated to gain access via the vehicle’s wiring. 

The OBD-II connector is usually locate d underneath the dashboard on the passenger side; once its wiring loom has been identified a switch can be inserted in line with the wires. The switch should be hidden away some-where that is not obvious. In normal opera-tion you will be protected if the vehicle is run with the wires to the socket disconnected. Make sure however that you throw the switch reconnecting the socket before you next take the vehicle along to a garage for servicing or fault diagnosis. 

The diagram shows the ISO K and ISO L wires switched. To cover all bases it is wise for every wire to the socket is made switchable except the two earth connections on pins 4 and 5 and the supply voltage on pin 16. Almost ever y vehicle manufacturer has their own method of vehicle immobilisation, by disconnecting every wire it ensures that no communication is possible (even over the CAN bus). Now the innermost workings of your vehicle will be safe from prying eyes. When a hacker plugs in a deactivation tool it will power up as normal but probably report something like ‘protocol unrecognised’ when any communication with the OBD port is attempted. 




Author : Florian Schäffer - Copyright: Elektor
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Lights Control for Model Cars Circuit Diagram

The author gave his partner a radio controlled (RC) model car as a gif t. She found it a lot of fun, but thought that adding realistic lights would be a definite improvement. So the author went back to his shed, plugged in his soldering iron, and set to work equipping the car with realistic indicators, headlights, tail lights and brake lights.

Lights Control for Model Cars Circuit Diagram
Lights Control for Model Cars Circuit Diagram

The basic idea was to tap into the signal from the radio control receiver and, with a bit of help from a microcontroller, simulate indicators using flashing yellow LEDs and brake lights using red LEDs. Further red LEDs are used for the tail lights, and white LEDs for the headlights. Connectors JP4 and JP5 (channel 0) are wired in parallel, as are JP6 and JP7 (channel 1), allowing the circuit to be inserted into the servo control cables for the steering and drive motor respectively. The ATtiny45 micro-controller takes power from the radio receiver via diode D1. T1 and T2 buffer the servo signals to protect IC1’s inputs from damage. 
IC1 analyses the PWM servo signals and gen-erates suitable outputs to switch the LEDs via the driver transistors. T3 drives the two left indicators (yellow), T4 the two right indica-tors, and T5 the brake LEDs (red). The red tail lights (JP2-8 and JP2-8) and the white head-lights (JP2-9 and JP2-10) are lit continuously. The brake lights are driven with a full 20 mA, so that they are noticeably brighter than the tail lights, which only receive 5 mA. If you wish to combine the functions of tail light and brake light, saving t wo red LEDs, sim-ply connect pin 10 of JP2 to pin 14 and pin 12 to pin 16. Then connect the two combined brake/tail LEDs either at JP2-5 and JP2-6 or at JP2-7 and JP2-8.

JP3 is provided to allow the use of a separate lighting supply. This can either be connected to an additional four-cell battery pack or to the main supply for the drive motor. The val-ues given for resistors R8 to R17 are suitable for use with a 4.8 V supply. JP2 can take the form of a 2x10 header.

As usual the sof t ware is available as a free download from the Elektor web pages accom-panying this article[1], and ready-programmed microcontrollers are also available. The microcontroller must be taught what servo signals correspond to left and right turns, and to full throttle and full braking. First connect the fin-ished circuit to the radio control electronics in the car, making sure everything is switched of f. Fit jumper JP1 to enable configuration mode, switch on the radio control transmit-ter, set all proportional controls to their cen-tre positions, and then switch on the receiver. The indicator LEDs should first flash on both sides. Then the car will indicate left for 3 s: during this time quickly turn the steering on the radio control transmitter fully to the left and the throt tle to full reverse (maximum braking).

Hold the controls in this position until the car starts to indicate right. Then set the controls to their opposite extremes and hold them there until both sides flash again. Now, if the car has an internal combustion engine (and so cannot go in reverse), keep the throttle control on full; if the car has an electric motor, set the throttle to full reverse. Hold this position while both sides are flashing. Configuration is now complete and JP1 can be removed. If you make a mistake during the configuration process, start again from the beginning.
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Simple Wireless Auto Tachometer Circuit Diagram

Anyone performing their own automobile tune-ups knows how important it is to know your engines speed. With this tachometer, you can measure your engines speed without any connections or annoying timing lights. 
  
Wireless Auto Tachometer Circuit Diagram

New Wireless Auto Tachometer
PC board layout and parts placement 

New Wireless Auto Tachometer


  1. Calibrate the unit as folows:
    1. Set up this circuit:
      This is the setup for calibrating the Tach
    2. Turn on the Tach and allow a few minutes for temperature stabilization.
    3. Set S2 to 4 cylinders and adjust R5 for a meter indication of 180 (1800 rpm).
    4. Set S2 to 6 cylinders and adjust R6 for a meter indication of 120 (1200 rpm).
    5. Set S2 to 8 cylinders and adjust R7 for a meter indication of 90 (900 rpm).
  2. To use the Tach, turn it on and let it sit for one minute to allow for temperature stabilization. Extend the antenna, select the right number of cylinders and hold the unit over the engine. If the reading is erratic or the needle jumps around, move the antenna closer to the ignition coil or spark plug wires.
  3. The unit draws power from the car battery. If it is connected backwards, it will not work, but it won't be damaged.
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Rear Fog Lamp For Vintage Cars Circuit Diagram

According to current legislation in many countries, vintage cars must also be fitted with a fog lamp at the rear. In modern cars, there is a bit of circuitry associated with the fog lamp switch to prevent the fog lamp from going on when the lights are switched on if the driver forgot to switch it off after the last patch of fog cleared up. The circuit described here extends that technology back in time. The circuit is built around a dual JK flip-flop (type 4027). T3 acts as an emitter follower, and it only supplies power to the circuit when the lights are switched on.

For safety reasons, the supply voltage is tapped off from the number plate lamp (L2), because it is on even if you accidentally drive with only the parking lights on. The wire that leads to the number plate lamp usually originates at the fuse box. As the states of the outputs of IC1a and IC1b are arbitrary when power is switched on, the reset inputs are briefly set high by the combination of C1, R1 and T1 when the lights are switched on (ignition switch on). That causes both Q outputs (pins 1 and 15) to go low. IC1a and IC1b are wired in toggle mode (J and K high).

The Set inputs are tied to ground (inactive). The driver uses pushbutton switch S1 to generate a clock pulse that causes the outputs of the flip-flops to toggle. The debouncing circuit formed by C2, R4 and T2 is essential for obtaining a clean clock pulse, and thus for reliable operation of the circuit. C1 and C2 should preferably be tantalum capacitors. The Q output of IC1b directly drives LED D1 (a low-current type, and yellow according to the regulations). The Q output of IC1a energises relay Re1 via T4 and thus applies power to the rear fog lamp L1.

Rear Fog Lamp For Vintage Cars Circuit Diagram




Free-wheeling diode D2 protects T4 against inductive voltage spikes that occur when the relay is de-energised. In older-model cars, the charging voltage of the generator or alternator is governed by a mechanical voltage regulator. These regulators are less reliable than the electronic versions used in modern cars. For that reason, a Zener diode voltage-limiter circuit (D3 and R9) is included to keep the voltage at the emitter of T3 below 15 V and thus prevent the 4027 from being destroyed by an excessively high voltage.

The supply voltage for the circuit is tapped off from the fuse box. An accessory terminal is usually present there. Check to make sure it is fed from the ignition switch. The pushbutton switch must be a momentary-contact type (not a latching type). Ensure that the pushbutton and LED have a good ground connection. Fit the LED close to the button.

The following ‘Bosch codes’ are used in the schematic:
  • 15 = +12 V from ignition switch
  • 58K = number plate lamp
  • 86 = relay coil power (+) IN
  • 85 = relay coil power OUT
  • 30 = relay contact (+) IN
  • 87 = relay contact OUT
Author: Eric Vanderseypen - Copyright: Elektor Electronics Magazine

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Rear Light After Glow Circuit Diagram

This article is of interest only to readers whose bicycle lights are powered by a dynamo. The laws on bicycle lights in the United Kingdom are stricter than in other countries and a dynamo is, therefore, a rarity in this country. From the point of view of traffic safety it is advisable (in UK obligatory) for cyclists to have the rear lamp of their bicycle to light even when they are at standstill. In principle, it is not very difficult to modify the existing rear light with afterglow: all this needs is a large enough energy reservoir. Since the after-glow is required for short periods of time only, a battery is not required: a large value capacitor, say, 1 F, is quite sufficient.

As the circuit diagram shows, in the present circuit, the normal rear light bulb is replaced by two series-connected bright LEDs, D2 and D3. These are clearly visible with a current of only 6 mA (compared with 50 mA of the bulb). The current is set with series resistor R1. The LEDs are shunted by the 1 F capacitor, C1. Since the working voltage of this component is only 5.5 V, it is, in spite of its high value, physically small. An effective regulator is needed to limit the dynamo voltage adequately. Normal regulators cannot be used here, since they do not work at low voltages. Moreover, such a device would discharge the capacitor when the cycle is at standstill.

 Rear Light After Glow Circuit Diagram

Simple Rear Light After Glow Circuit Diagram

Fortunately, there is a low-drop type that meets the present requirements nicely: the Type LP2950CZ5.0. Of course, the dynamo output voltage needs to be rectified before it can be applied to the regulator. In the present circuit, this is effected by half-wave rectifier D1 and buffer capacitor C2. Diode D1 is a Schottky type to keep any losses low – important for this application, because the ground connection via the bicycle frame usually causes some losses as well. The value of buffer capacitor has been chosen well above requirements to ensure that C1 is charged during the negative half cycles of the dynamo voltage.
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New Honda Gold wing Gl1100 Wiring Diagram Electrical System Harness

 Honda Gold wing Gl1100 Wiring Diagram Electrical System Harness . This is a new  Honda Gold wing Gl1100 Wiring Diagram Electrical System Harness .

Here Is The Wiring Diagram For The Trailer Lights.



Polaris Trail Boss 330 Magneto Wiring Harness Circuit Schematic


Volkswagen Cabriolet Cruise Control Wiring Schematic.


Honda Prelude Wiring Harness Routing And Ground Location 88.


 Sourced By : Circuitsstream
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