Diagram Plus guide

1999-2000 Porsche 911 Carrera Electrical Wiring DiagramThe Part of 1999-2000 Porsche 911 Carrera Electrical Wiring Diagram: Porsche stability management., tiptronic,sun roof, convertible top drive, sensor overturn,  engine fuel ignition system, alarm system, ground points, cruise control, airbag, radio, telephone circuit, spoiler extend, interior monitoring, radio remote control, anti drive off lock, antilock brake system, power supply, parking assistant, central locking system, motronic, electronic...

An amplifier to drive low to medium impedance headphones built using discrete components. Both halves of the circuit are identical. Both inputs have a dc path to ground via the input 47k control which should be a dual log type potentiometer. The balance control is a single 47k linear potentiometer, which at center adjustment prevents even attenuation to both left and right input signals. If the balance control is moved towards the left side, the left input track has less resistance than the right...

First, we want to explain how such a controller works and what’s involved. A bipolar motor has two windings, and thus four leads. Each winding can carry a positive current, a negative current or no current. This is indicated in Table 1 by a ‘+’, a ‘–‘ or a blank. A binary counter (IC1) receives clock pulses, in response to which it counts up or down (corresponding to the motor turning to the left or the right). The counter increments on the positive edge of the pulse applied to the clock input if...

In contrast to an ordinary voltmeter, the input of an oscilloscope generally has one side (GND) connected to ground via the mains lead. In certain situations this can be very problematic. When the measuring probe is connected to a circuit that is also connected to ground, there is a chance that a short is introduced in the circuit. That the circuit, and hence the measurement, is affected by this is the least of your problems. If you were taking measurements from high current or high voltage (valve...

Three LEDs signal bumper-barrier distance, Infra-red operation, indoor useThis circuit 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...

Many modern circuits tend to work from a single supply voltage of 3V. But often they need a virtual earth at half the supply voltage for efficient operation. The splitter shown in the diagram bisects the supply voltage with a high-resistance potential divider, R1-R2, and buffers the resulting 1.5 V line with an op amp. Since the op amp used is not a fast type, the output is decoupled by capacitive divider C2-C3. This ensures that the impedance of the virtual earth point remains low over a wide frequency...

My current vehicle, a Pajero, was modified for dual fuel - ie, petrol and gas. However, its necessary to run the vehicle on petrol at regular intervals to stop the injectors from clogging up. This simple circuit allows the vehicle to be started using petrol and then automatically switches it to gas when the speed exceeds 45km/h and the brake pedal is pressed. Alternatively, the vehicle may be run on petrol simply by switching the existing petrol/gas switch to petrol. You can also start the vehicle...

How often does it happen that you close down Windows and then forget to turn off the computer? This circuit does that automatically. After Windows is shut down there is a ‘click’ a second later and the PC is disconnected from the mains. Surprisingly enough, this switch fits in some older computer cases. If the circuit doesn’t fit then it will have to be housed in a separate enclosure. That is why a supply voltage of 5 V was selected. This voltage can be obtained from a USB port when the circuit...

Voice manipulation device specially intended for props, 9V Battery operationAlthough this kind of voice effect can be obtained by means of some audio computer programs, a few correspondents required a stand-alone device, featuring microphone input and line or loudspeaker outputs. This design fulfills these requirements by means of a variable gain microphone preamplifier built around IC1A, a variable steep Wien-bridge pass-band filter centered at about 1KHz provided by IC1B and an audio amplifier...

It is all too often necessary to augment the power supply of an existing electronic circuit because exactly the voltage that you need is missing. The circuit presented here may provide a solution in a number of cases, since it can be used to convert a single-ended supply voltage into a balanced set of supply voltages. That’s not so remarkable by itself, but the special feature of this circuit is that this is accomplished without using difficult to obtain, exotic ICs. All of the components used in...

The treble control works in a similar manner as the bass control elsewhere in this site, but contains several modifications, of course. One of these is the series network C1-C2– R1– R1 1. The d.c. operating point of IC3 is set with resistors R12 and R13. To ensure that these resistors do not (adversely) affect the control characteristics, they are coupled to the junction of R9 and R1 0. In this way they only affect the low-frequency noise and the load of the opamp. Their value of 10 kΩ is a reasonable...

This circuit optimizes the operation of a solar hot water system. When the water in the solar collector is hotter than the storage tank, the pump runs. The circuit comprises two LM335Z temperature sensors, a comparator and Mosfet. Sensor 1 connects to the solar collector panel while Sensor 2 connects to the hot water panel. Each sensor includes a trimpot to allow adjustment of the output level. In practice, VR1 and VR2 are adjusted so that both Sensor 1 and Sensor 2 have the same output voltage...

The electronic dog repellent circuit diagram below is a high output ultrasonic transmitter which is primarily intended to act as a dog and cat repeller, which can be used individuals to act as a deterrent against some animals. It should NOT be relied upon as a defence against aggressive dogs but it may help distract them or encourage them to go away and do not consider this as an electronic pest repeller. The ultrasonic dog repellant uses a standard 555 timer IC1 set up as an oscillator using a...

This simple circuit can be used to program the PIC16F84 and similar "flash memory" type parts. It uses a cheap 555 timer IC to generate the programming voltage from a +5V rail, allowing the circuit to be powered from a computer’s USB port. The 555 timer (IC1) is configured as a free-running oscillator, with a frequency of about 6.5kHz. The output of the timer drives four 100nF capacitors and 1N4148 diodes wir-ed in a Cockroft-Walton voltage multiplier configuration.The output of the multiplier is...

This circuit ensures that you will never again forget to switch on the lights of your car. As soon as the engine is running, the dipped beams and the sidelights are automatically switched on. The circuit also causes the dipped beams to be extinguished as soon as the main beams are switched on. As you can see from the schematic diagram, no special components are needed. When the engine is running, the alternator will generate a voltage of more than 14 V. Diode D1 reduces this voltage by 5.6 V and...

Can be fitted into a packet of cigarettes, Also suitable as Fuzz-box This small amplifier was intended to be used in conjunction with an electric guitar to do some low power monitoring, mainly for practice, either via an incorporated small loudspeaker or headphones. The complete circuit, loudspeaker, batteries, input and output jacks can be encased in a small box having the dimensions of a packet of cigarettes, or it could be fitted also into a real packet of cigarettes like some ready-made units...

By configuring a comparator and a transistor to control the oscillator in a charge pump circuit, you enable the pump to generate a regulated output of in principle any desired value. Charge pump ICs can either invert or double an input voltage (for example, 3 V to –3 V or 3 V to 6 V). The charge pump itself does not regulate the output voltage and one running off 3 V is not normally capable of generating intermediate output voltage levels like 5 V. However, by adding a comparator and a reference...

Can be fitted into a packet of cigarettes Also suitable as Fuzz-box This small amplifier was intended to be used in conjunction with an electric guitar to do some low power monitoring, mainly for practice, either via an incorporated small loudspeaker or headphones. The complete circuit, loudspeaker, batteries, input and output jacks can be encased in a small box having the dimensions of a packet of cigarettes, or it could be fitted also into a real packet of cigarettes like some ready-made units...

A timed Bell/Siren Cut-Off. It’s designed to be used with the usual types of normally-closed input devices such as – magnetic reed contacts – micro switches – foil tape – and PI...

LEDs are used more and more in motor vehicles, replacing the standard incandescent lamps because they are more energy efficient and have a much longer life expectancy. In this article we describe a simple LED tail light that has been specifically designed for motorcycles, scooters and mopeds. There appears to be a significant need among motorcyclists for rear lights with LEDs, as evidenced by the many messages on this topic that turn up in various internet forums. The circuits that accompany these...