circuit wiring: September 2013

Monday, September 30, 2013

Preamplifier For Soundcard Circuit

This circuit can be used for inductive pick-up elements and dynamic microphones Most soundcards have a ‘line’ input and one for an electret (condenser) microphone. To be able to connect an inductive tape-recorder head or a dynamic microphone, an add-on preamplifier is needed. Even in this day and age of integrated microelectronics, a transistorised circuit built from discrete part has a right of existence. The preamplifier described in this short article goes to show that it will be some time before discrete transistors are part of the silicon heritage. The preamplifier is suitable for use with a soundcard or the microphone input of a modem. As you will probably know, most sound-cards have input sockets for signals at line level (stereo), as well as one for a (mono) electret microphone.

For the applications we have in mind, connecting-up an inductive pick-up element or a dynamic microphone, both inputs are in principle suitable, provided the source signal is amplified as required. The author eventually chose the microphone input on the soundcard. Firstly, because the line inputs are usually occupied, and secondly, because the bias voltage supplied by the micro-phone input eliminates a separate power supply for the preamplifier. The microphone input of a soundcard will typically consist of a 3.5-mm jack socket in stereo version, although only one channel is available. The free contact is used by the soundcard to supply a bias voltage to the mono electret microphone. This voltage is accepted with thanks by the present preamplifier, and conveniently obviates an external (mains adaptor) power supply.

Circuit diagram:

Preamplifier For Soundcard Circuit Diagram

A classic design:

In true transistor-design fashion, the preamplifier consists of three stages. Capacitor C1 decouples the signal received from the microphone or pick-up element, and feeds it to the input of the first stage, a transistor in emitter configuration, biased to provide a current amplification of about 300 times. Together with the source impedance of the microphone or pick-up element, capacitors C2 and C3 form a low-pass filter which lightly reduces the bandwidth. In addition, the output low-pass, R2-C3, reduces the dynamic collector resistance at higher frequencies. In this way, the filter reduces the gain in the higher part of the frequency spectrum and so helps to eliminate any oscillation tendencies.

The first, high-gain, stage is terminated by T2. Unlike T1, this transistor does not add to the overall gain, because the output signal is taken from the emitter (common-collector circuit). T2 thus acts as an impedance converter, with C4 reducing any tendency to oscillation. The output stage around T3 is a common-emitter circuit again. In it, preset P1 determines the voltage amplification. T3 is biased by means of a direct-current feedback circuit based on components R7 and C5. To this is added an ‘overruling’ dc feedback path back to the input transistor, via R6. This measure guarantees good dc stability in the preamplifier. The circuit is small enough to be built on a piece of veroboard or stripboard, and yet remain reasonably compact.

To prevent interference from external sources, the completed board should be mounted in a properly screened (metal) enclosure, with the connections to the input source and the sound card made in screened cable. The preamplifier provides a frequency-linear response. In case the source signal is marked by frequency correction (e.g., RIAA), then a matching linearization circuit should be used if the relevant signals are used by the computer.

Source : www.extremecircuits.net

Sunday, September 29, 2013

Thrifty 2Hz Clock

CMOS circuits are known for their low current consumption. This is particularly important for battery-powered circuits. Unfortunately, oscillators often require quite a bit of current. We therefore propose this oscillator circuit that has a very low current consumption (about 3 µA). The circuit is powered from a type LM334Z current source. The current has been set with R4 to about 3 µA. This is sufficient to power IC1 and the oscillator circuit around X1. The oscillator generates, with the aid of a cheap watch crystal and a few surrounding parts, a signal that is subsequently applied to the divider in the 4060 and results in a frequency of 2 Hz at pin 3 (output Q13). The level of the output pulses is a lot lower than the nominal 5-V power supply voltage (IC1 is after all powered from a current source with very low current). That is why the signal on pin 3 of IC1 is amplified and inverted by T1. IC3a finally turns it into a proper square wave with acceptably steep edges.

Saturday, September 28, 2013

Temporarily Silencing A Smoke Detector

It provides a means of temporarily silencing a battery-powered smoke detector after you’ve burnt the toast, scorched the baked beans – or whatever! Unlike the earlier design, this more sophisticated version does not cause strange chirps and whistles to emanate from the smoke detector towards the end of the silenced period. It also flashes a LED and produces a series of short, unobtrusive tones from its inbuilt buzzer while it is active. A separate 9V (or 6V) battery is required to power the circuit, which is mounted remotely from the smoke alarm. Connection to the alarm is made via a 3-core data cable terminated in a 3.5mm stereo plug, while a matching switched socket is fitted to the alarm’s casing. In addition to the socket, only three other components are installed inside the smoke alarm.

These are Mosfet Q3, its 100W gate resistor and 15V zener diode ZD1. These parts can all be mounted on a small section of prototyping board or soldered point to point from the socket terminals. The Mosfet is wired in series with the smoke alarm’s negative battery lead and acts as a switch. As shown, the contacts of the socket must be wired so that the Mosfet drain-source connections are shorted out when the plug is removed, thus allowing immediate restoration of the smoke alarm to normal operation. When the silencer circuit is inactive, the reed relay (RLY1) is off, so battery power is disconnected from the circuit. An exception to this is Q3’s 4.7kO gate pull-up resistor, which is powered directly from the battery. This holds the Mosfet switch on, powering the smoke alarm from its on-board 9V battery.

Now consider what happens when the "silence" switch (S1) is pressed. This action applies battery power to the entire circuit through the switch contacts. At the same time, IC1 (which is wired as a monostable) is triggered by a brief pulse on its reset input (pin 2). This initiates the 555’s timing sequence, so its output (pin 3) immediately swings high, switching on Q1 and activating the relay. A second transistor (Q2) wired to IC1’s output also conducts, pulling Q3’s gate low and switching it off. As a result, the smoke alarm is disconnected from its 9V battery and all of the noise ceases instantly! When the relay is closed, an additional path exists from battery positive to the circuit’s power rail – so that when the switch is released, the circuit keeps running.

The circuit then continues to run for the duration of IC1’s timing period (over 8 minutes). The remaining two 555 timers (IC2 & IC3) are configured as astable multivibrators. IC2 is used exclusively to flash an indicator LED at a rate of about once per second. IC3 has a longer period, sounding a piezo buzzer briefly about once every 10.5 seconds. Use a 5V reed relay when the circuit is powered from a 6V battery and a 12V version when powered from 9V. Because of the high impedance and low leakage of the Mosfet’s gate, the silencer’s battery can be expected to last almost its shelf life – assuming that you don’t burn the toast too often!

Warning:

This circuit must not be used with mains-connected smoke detectors
Test your smoke detector and this silencer circuit regularly.

Friday, September 27, 2013

Low Voltage Cutout For 12V SLA Batteries

This simple circuit protects an SLA battery from over-discharge by disconnecting the load when the terminal voltage drops below a preset level. In operation, a sample of the battery voltage is derived from the 22kΩ resistor and 20kΩ trimpot divider. This is applied to the non-inverting input (pin 3) of IC1, where it is compared with a reference voltage on the inverting input (pin 2). When the sampled battery voltage falls below the reference voltage, IC1’s output (pin 1) swings towards ground, switching Mosfet Q2 off and disconnecting the load from the battery. The reference voltage is derived from a 4.7V zener diode (ZD1), which is connected to ground via the collector-emitter circuit of Q1 (ie, when Q1 is on).

However, when the op amp’s output is driven low, Q1 is switched off, causing the non-inverting input to rise towards the full battery voltage. This greatly reinforces the switching action, latching the circuit in the "off" state until the battery is recharged and the reset switch (S1) pressed. The Mosfet used for Q2 should be selected to suit the intended application. The circuit could also drive a relay simply by connecting the coil across the "load" terminals. As is usual practice, a diode should be connected across the relay coil to limit back-EMF spikes.

Thursday, September 26, 2013

Fuse Box BMW R1100S Diagram

Fuse Box BMW R1100S Diagram - Here are new post for Fuse Box BMW R1100S Diagram.

Fuse Box BMW R1100S Diagram

Fuse Panel Layout Diagram Parts: Instrument panel, horn, power socket, instrument panel, Fuel pump, Motronic, Heated handlebar grips, brake light , Rear light, parking light, number palte light, controller for fuel warning lamp or indicator damping.

Wednesday, September 25, 2013

Tiny Dew Sensor

Dew (condensed moisture) adversely affects the normal performance of sensitive electronic devices. A low-cost circuit described here can be used to switch off any gadget automatically in case of excessive humidity. At the heart of the circuit is an inexpensive (resistor type) dew sensor element. Although dew sensor elements are widely used in video cassette players and recorders, these may not be easily available in local market. However, the same can be procured from authorized service cent res of reputed companies. The author used the dew sensor for FUNAI VCP model No. V.I.P. 3000A (Part No: 6808-08-04, reference no. 336) in his prototype.

In practice, it is observed that all dew sensors available for video application possess the same electrical characteristics irrespective of their physical shape/size, and hence are interchangeable and can be used in this project. The circuit is basically a switching type circuit made with the help of a popular dual op-amp IC LM358N which is configured here as a comparator. (Note that only one half of the IC is used here.) Under normal conditions, resistance of the dew sensor is low (1 kilo-ohm or so) and thus the voltage at its non-inverting terminal (pin 3) is low compared to that at its inverting input (pin 2) terminal.

The corresponding output of the comparator (at pin 1) is accordingly low and thus nothing happens in the circuit. When humidity exceeds 80 per cent, the sensor resistance increases rapidly. As a result, the non-inverting pin becomes more positive than the inverting pin. This pushes up the output of IC1 to a high level. As a consequence, the LED inside the opto-coupler is energized. At the same time LED1 provides a visual indication. The opto-coupler can be suitably interfaced to any electronic device for switching purpose. Circuit comprising diode D1, resistors R8 and R6 and capacitor C1 forms a low-voltage, low-current power supply unit. This simple arrangement obviates the requirement for a bulky and expensive step-down transformer.

Tuesday, September 24, 2013

Dimmer Control Voltage Polarity Changer

Some older Strand dimmer units used a zero to -10V control signal, and the standard analogue control voltage is zero to +10V. This project allows the easy conversion from one standard to another. This is a very simple project, but may turn out to be a lifesaver for small theatre groups and the like. It has come to my attention that there are still a great many old Strand dimmers very much in use. The problem is that they are just too reliable, and wont go away ... but, they use a zero to -10V control signal, so are incompatible with the dimmer unit in these project pages, and with any new commercial analogue control console.

In addition, there are no doubt quite a few old lighting consoles that use this standard, which means that they cant drive modern dimmer packs. As it turns out, a simple opamp inverter will convert either standard to the other. This is shown in Figure 1.

Figure 1 - Dimmer Control Signal Inverter

There is really nothing to it. Use as many circuits as needed, and a simple power supply (such as that in Project 05) will drive as many of these inverters as are likely to be required in any lighting setup. The above circuit has two channels, and may be simply repeated as many times as you need to get the required number of channels. The 100 ohm resistors on each output are there to prevent the opamps from oscillating when supplying a capacitive load (such as a coax cable).

With an input of zero volts, the output will also be at zero volts. As the input increases (or decreases in the case of the -10V control) the output will change by exactly the same value, but in the opposite direction. Wiring is not critical, the 1458 opamps specified are very cheap (but more than capable of doing the job), and they can be built very simply on Veroboard or similar. Supplies should be bypassed to common (ground) with 10uF electrolytic caps.

Monday, September 23, 2013

Download 2012 GMC Terrain Owners Manual

This 2012 GMC Terrain owner Manual describes features that may or may not be on your specific vehicle either because they are options that you did not purchase or due to changes subsequent to the printing of this owner manual. Please refer to the purchase documentation relating to your specific vehicle to confirm each of the features found on your vehicle.

For vehicles first sold in Canada, substitute the name “General Motors of Canada Limited” for GMC Motor Division wherever it appears in this manual. Download 2012 GMC Terrain Owners Manual

Sunday, September 22, 2013

Non Contact Power Monitor circuit

Here is a simple non-contact AC power monitor for home appliances and laboratory equipment that should remain continuously switched-on. A fuse failure or power breakdown in the equipment going unnoticed may cause irreparable loss. The monitor sounds an alarm on detecting power failure to the equipment. The circuit is built around CMOS IC CD4011 utilising only a few components. NAND gates N1 and N2 of the IC are wired as an oscillator that drives a piezobuzzer directly. Resistors R2 and R3 and capacitor C2 are the oscillator components. The amplifier comprising transistors T1 and T2 disables the oscillator when mains power is available. In the standby mode, the base of T1 picks up 50Hz mains hum during the positive half cycles of AC and T1 conducts.

Circuit diagram:

Non-Contact Power Monitor circuit diagram

This provides base current to T2 and it also conducts, pulling the collector to ground potential. As the collectors of T1 and T2 are connected to pin 2 of NAND gate N1 of the oscillator, the oscillator gets disabled when the transistors conduct. Capacitor C1 prevents rise of the collector voltage of T2 again during the negative half cycles. When the power fails, the electrical field around the equipment’s wiring ceases and T1 and T2 turn off. Capacitor C1 starts charging via R1 and preset VR and when it gets sufficiently charged, the oscillator is enabled and the piezobuzzer produces a shrill tone. Resistor R1 protects T2 from short circuit if VR is adjusted to zero resistance.

The circuit can be easily assembled on a perforated/breadboard. Use a small plastic case to enclose the circuit and a telescopic antenna as aerial. A 9V battery can be used to power the circuit. Since the circuit draws only a few microamperes current in the standby mode, the battery will last several months. After assembling the circuit, take the aerial near the mains cable and adjust VR until the alarm stops to indicate the standby mode. The circuit can be placed on the equipment to be monitored close to the mains cable.

Saturday, September 21, 2013

1979 Jeep CJ Electrical Wiring Diagram

1979 Jeep CJ Elecrical Wiring Diagram

The part of 1979 Jeep CJ Electrical Wiring Diagram: accessory feed, air conditioner compressor, anti diesel solenoid, back up lamps, manual transmission, battery, boy, brake, cogar lighter, capacitor, chassis, marker & reflector, module assembly, neutral safety switch, oil lamp gauge, oil pressure sender, panel lamp, parking brake, park & signal lamp, resistor heater blower moor, splice, coil 6 cylinder, dimmer switch, distributor, electric choke, fuel gauges, fuel sender, ground fan lamp feed, headlamp, heater motor, ignition switch, horn relay, kick down, starting motor, stop lamp, tail & stop lamp, temperature gauge, temperature sender, windshield wiper, washer.

Friday, September 20, 2013

2003 Chevrolte Monte Carlo 3400 Wiring Diagram

2003 Chevrolet Monte Carlo 3400 Wiring Diagram

The Part of 1957-58 Dodge 4-Way Power Seat Wiring Diagram: compressor control, power
distribution, schematics, battery, ignition voltage, junction block, refrigerant pressure sensor, ctrl module, body ctrl module, compressor cluth, instrument panel lamp, fuse supply voltage,

Wednesday, September 11, 2013

Simpled Solar Powered Lithium Ion Battery Charger Circuit

The circuit below feeds a controlled current and voltage to a 3.6v lithium ion battery. The current is limited to 300ma and the voltage is limited to 4.2 volts. The circuit uses a LTC1734 IC from Linear Technology. No diode is needed between the circuit and a 6 volt solar panel. Some very nice 6 volt solar panels are available from www.plastecs.comTheir SP6-200-12 cranks out about 1 watt while the SP6-300-12 can produce about 2 watts. Assuming a 6 hour sunlit day, the 2 watt panel will pump about 1.8 amp-hours into a battery.

Tuesday, September 10, 2013

Current Controlled Boost LED Driver and Black Soldermasks

The MAX16834 is a neat little chip (its not the only one, there are plenty of others out there) that allows high efficiency designs for LED string driving. It provides a platform for a Buck or Boost converter design, as well as brightness adjustment via analog/PWM input pins, as well as a fault output (in case of open/short circuits for example) and also diverse other functionalities that can be quite useful.

Monday, September 9, 2013

Now Oyster Releases the First True Netflix for E books App

Now Oyster Releases the First True Netflix-for-E-books App. Netflix and Spotify have built multi-billion dollar enterprises by offering subscription services for film and music, respectively, but no company has actually made this form work for digital publications. Now, Oyster has disclosed its first try to change that.

Oyster, a New York-based startup, made headlines late last year when it broadcast lifting $3 million from Founders finance to construct out a service that would offer "unlimited access" to e-books. On Thursday, the startup commenced its e-reading app for iPhone, which is accessible on a first-come, first-served invitation-only cornerstone for now.

With the iPhone app, users get access to more than 100,000 ebooks from hundreds of publishers including Houghton Mifflin Harcourt, Melville House and one of the "big five" announcing houses, HarperCollins. Oyster will ascribe users $9.95 a month to read as numerous e-books as they like.

"People love accessing things when they desire it with one price," Eric Stromberg, co-founder of Oyster, said in an interview with Mashable. although, he believes a couple of obstacles have held back most startups from endeavouring to do the lone cost subscription form with e-books: "Any company that does this desires to be actually good at technology, at merchandise and on the joint venture side of things, and construction a centre area of know-how in each of those."

Another new ebook startup, is also trying to make the digital publication subscription notion work, but with a very distinct charge form. Rather than charge on flat monthly rate for unlimited reads, eReatah offers three tiered charges extending from $16.99 a month for two reads to $33.50 for four reads a month.

While the tiered pricing form could verify to be a better deal for publishers and authors, Stromberg states his group endeavoured to discover from living digital subscription services and put simultaneously a income model that "really places the rightsholders interest first and makes sense over decades." That said, the group is somewhat open to other charge structures in the future. "If we can provide a large experience kind of in a freemium form, well work in the direction of that," said Willem Van Lancker, one of the three co-founders.

The novelty of the subscription model for ebooks almost overshadows some of the more subtle but important changes Oyster is trying to make to the e-reading know-how. Like Netflix and Spotify, Oyster doesnt just provide easier get access to to content, but furthermore aspires to help users discover and share content. The publications are coordinated into genres similar to Netflix and every client has a social profile in the app and can pursue the reading undertaking of other users theyre connected to. There are furthermore constructed in choices to share books to Facebook, Twitter and even Instagram.

after that, Oyster made the interesting alternative to focus on the smartphone reading experience first, rather than tablets, where one might assume most persons do their long reading. The reasoning, according to the founders, is easy: many more people carry round smartphones than tablets. To make it work, though, Oysters group rethought the e-reading design: Users scroll through the text from peak to bottom rather than right to left, and they have more customizability over font kind and dimensions.

The two large-scale matters for Oyster are of course cost and selection. Oysters 100,000 books encompasses a pleasant variety of classics and up to date titles, but at launch its lacking numerous bestsellers and brand new releases. For the casual client, giving $120 a year for a service like this makes the most sense if you dont have to pay much more on top to read other issues not available to rent. In my own know-how, many of the publications I sought for — from well-known authors like Jonathan Lethem, George Saunders and Anthony Swofford — were unavailable. That may change if the service gets more traction amidst users and thus expanded leverage amidst publishers.

At $9.95 a month, Oyster is slightly more costly than Netflixs streaming-only option. That is a better worth proposition in the sense that you need only lease one ebook a month to at smallest shatter even, while you would need to watch multiple movies or display seasons a month on Netflix to come out ahead of usual rental charges in bricks-and-mortar video stores. Unfortunately, a Pew survey from last year discovered that just 27% of Americans read the matching of one or more publications per month — digital or physical — which proposes the $120/year could be seen as steep cost to pay for many.

For better or worse, the success or malfunction of Oyster may assist as the ultimate litmus check for whether digital apparatus boost the consumption of publications — in the way that they might with movies — or undermine it.

"You glimpse all the times someone says Im really enjoying shattering awful, its on Netflix, you have no apologise not to go at smallest give it a shot. We seem that same way with books," Stromberg says. With an get get access to to form, he states, "You spend less time conceiving about making a buy, less time conceiving about if you should read this publication and actually just start reading it. Thats ultimately the way youll be adept to notify you like it."