Pazzy

‘Valve sound’ is not just an anachronism: there are those who remain ardent lovers of the quality of sound produced by a valve amplifier. However, not everyone is inclined to splash out on an expensive valve output stage or complete amplifier with a comparatively low power output. Also, for all their aesthetic qualities, modern valve amplifiers burn up (in the full sense of the word!) quite a few watts even at normal listening volume, and so are not exactly environmentally harmless. This valve sound converter offers a cunning way out of this dilemma. It is a low cost unit that can be easily slipped into the audio chain at a suitable point and it only consumes a modest amount of energy. A valve sound converter can be constructed using a common-or-garden small-signal amplifier using a readily-available triode. Compared to using a pentode, this simplifies the circuit and, thanks to its less linear characteristic, offers even more valve sound. For stereo use a double triode is ideal. Beca...

This circuit is intended to signal, through a flashing LED, the exceeding of a fixed threshold in room noise, chosen from three fixed levels, namely 50, 70 & 85 dB. Two Op-amps provide the necessary circuit gain for sounds picked-up by a miniature electret microphone to drive a LED. With SW1 in the first position the circuit is off. Second, third and fourth positions power the circuit and set the input sensitivity threshold to 85, 70 & 50 dB respectively. Current drawing is 1mA with LED off and 12-15mA when the LED is steady on. Circuit diagram : Room Noise Detector Circuit diagram Parts List : R1____________10K 1/4W Resistor R2,R3_________22K 1/4W Resistors R4___________100K 1/4W Resistor R5,R9,R10_____56K 1/4W Resistors R6_____________5K6 1/4W Resistor R7___________560R 1/4W Resistor R8_____________2K2 1/4W Resistor R11____________1K 1/4W Resistor R12___________33K 1/4W Resistor R13__________330R 1/4W Resistor C1___________100nF 63V Polyester Capacitor C2____________10µF 25V ...

The MQ series of gas sensors use a small heater inside with an electro-chemical sensor. They are sensitive for a range of gasses and are used indoors at room temperature. The output is an analog signal and can be read with an analog input of the Arduino. The MQ-2 Gas Sensor module is useful for gas leakage detecting in home and industry. It can detect LPG, i-butane, propane, methane ,alcohol, hydrogen and smoke. Some modules have a built-in variable resistor to adjust the sensitivity of the sensor. [ ]

Here is a very simple   auto turn-off alarm with 8-minute delay circuit. This circuit uses a NE555 timer and CD4020B. When +12 Vdc is applied to the circuit, the output of IC2 is set low via C2, which turns on the relay, and IC1, a pulse generator. Auto Turn-Off Alarm With 8-Minute Delay Circuit Diagram:      IC1 pulses counter IC2. After 8192 clocks, IC2 output (pin 3) goes high, cuts off Q2, and completes the cycle.

This is a MicroChip Uninterruptible Power Supply (UPS) reference design with PIC17C43 microcontroller. The document is available to download from the end of this post. At times, power from a wall socket is neither clean nor uninterruptible. Many abnormalities such as blackouts, brownouts, spikes, surges, and noise can occur. Under the best conditions, power interruptions can be an inconvenience. At their worst, they can cause loss of data in computer systems or damage to electronic equipment. It is the function of an Uninterruptible Power Supply (UPS) to act as a buffer and provide clean, reliable power to vulnerable electronic equipment. The basic concept of a UPS is to store energy during normal operation (through battery charging) and release energy (through DC to AC conversion) during a power failure. UPS systems are traditionally designed using analog components. Today these systems can integrate a microcontroller with AC sine wave generation, offering the many benefits. The PI...

Build a low-cost and very simple Automotive Electronic Circuit Project of USB car charger circuit diagram. This USB car charger circuit adapter from car cigar socket project is a DC DC power converter that safely converts the 12V car battery voltage into stable 5V. This circuit can be used to supply power from a car cigar lighter socket to a portable device that require a 5 volts.  USB Car Charger Circuit Diagram: This circuit makes it possible to power/recharge any USB power-operated device, using in-dash board cigar lighter socket of your car. The DC supply available from the cigar lighter socket is fed to an adjustable, three-pin regulator LM317L (IC1). R1 and R2 resistors regulate the output of IC1 to steady 5V, which is available at the ‘A’ type female USB socket. Red LED1 indicates the output status and zener diode ZD1 acts as a protector against high voltage. As you can see in the circuit diagram, the circuit is very simple and requires just few common cheap components. Even...

iPhone 6 concept shows thinner handset with touch-sensitive home button and 12MP camera Created by Arthur Reis, a budding designer who aspires to join the ranks of Jony Ive and Shin Nishibori someday, 3D renderings of the iPhone 6 imagine a handset that looks largely identical to iPhone 5 (think: anodised aluminium casing with chamfered edges), but an impressive 20 per cent slimmer at just 6.1mm thick. The handset also features a 12-megapixel camera with an ‘iSight Pro’ sensor boasting an f/1.8 aperture and a ‘Magic TrackPad’ that replaces the physical home button with a touch-sensitive equivalent. As far as we’re concerned, this is one of the best iPhone concepts we’ve seen, principally because it doesn’t go crazy on novel or unrealistic features as most concepts do. Apple is always trying to make its handsets slimmer, so a more slender iPhone is within the realms of possibility. And with Samsung upping the ante with a 13-megapixel camera on the freshly launched Galaxy S4, we can cert...