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General Description: The BA3853BFS is a dual-channel electronic volume controller built around a low-noise, low-distortion VCA. It is suited for car-audio applications, and has performance that rivals mechanical-type volume controllers. In addition to volume control, the IC includes all functions required for controlling sound quality, to allow more compact designs with far fewer components. Circuit diagram: Dual-channel electronic volume controller Datasheet for BA3853: Download

The article will guide you on how to use NES controller in Atari 2600 or ZX Spectrum using an Arduino. Read through the entire article to have a better idea. An arduino and a few connectors are the only components involved here. Since the source code is small, any Arduino board can be utilized. The detailed list of components involved is mentioned below: Arduino DB-9 Male connectors – 2 nos DB-9 Female connector 5 Leds for the test dongle 5 resistors 330 Ohms 1/4 Watt for the test dongle Connecting wires The DB-9 female plus wires can be replaced by a used Atari Joystick cable if required. The NES cable also can be cut and connected to the arduino. But the wires should be identified without any confusion. The source code is compiled and uploaded to the Ardunio. IDE version 0.22 was used to develop the code. In order to observe the exact behavior of the circuit, a dongle has to be used before the circuit is conneced to the ATARI. Buttons on the NES controller are used to a...

The Maxim MAX 6665 (www.maxim-ic.com) provides a complete temperature-dependent fan controller. It can switch fans operating at voltages of up to 24 V and currents of up to 250 mA. The IC is available from the manufacturer in versions with preset threshold temperatures between +40 °C (MAX6665 ASA40) and +70 °C (MAX6665 ASA 70). The device’s hysteresis can be set by the user via the HYST input, which can be connected to +3.3 V, connected to ground, or left open. The following table shows the hysteresis values available: HYST = Hysteresis open = 1 °C ground = 4 °C +3.3V = 8 °C Circuit diagram: Fan Controller Circuit Diagram The other pins of the SO8 package are the FORCEON input and the status outputs WARN, OT and FANON. The test input FORCEON allows the fan to be run even below the threshold temperature. The open-drain output WARN goes low when the temperature rises more than 15 °C above the threshold temperature, while the open-drain output OT indicates when the temperature is mo...

My new home theatre receiver was getting rather hot in the close confines of its cabinet, with the temperature reaching over 40°C after only about 30 minutes of use. To help lower the temperature, I decided to install a fan in the cabinet. A 75mm hole was cut in the shelf under the receiver, and a 12V fan salvaged from an old computer power supply was mounted underneath. The fan was powered from a 12V DC plugpack. This did the job, keeping the temperature below 30°C even after prolonged use on a warm day. However, the fan was annoyingly loud when running at full speed. To reduce the noise level substantially, I built this fan speed controller with temperature feedback. The circuit was culled from variety of ideas found on various sites on the internet, with the final circuit designed from what was in the "junk box". Air temperature in the cabinet is sensed via an LM335 (TS1). It is glued to a piece of aluminium about 25mm square with instant glue, which is then attached to th...

This is yet another project born of necessity. It's a simple circuit, but does exactly what it's designed to do - dim LED lights or control the speed of 12V DC motors. The circuit uses PWM to regulate the effective or average current through the LED array, 12V incandescent lamp (such as a car headlight bulb) or DC motor. The only difference between the two modes of operation is the addition of a power diode for motor speed control, although a small diode should be used for dimmers too, in case long leads are used which will create an inductive back EMF when the MOSFET switches off. The photo shows what a completed board looks like. Dimensions are 53 x 37mm, so it's possible to install it into quite small spaces. The parts used are readily available, and many subsitiutions are available for both the MOSFET and power diode (the latter is only needed for motor speed control). The opamps should not be substituted, because the ones used were chosen for low power and their abilit...

This handy circuit can be used as a speed controller for a 12V motor rated up to 5A (continuous) or as a dimmer for a 12V halogen or standard incandescent lamp rated up to 50W. It varies the power to the load (motor or lamp) using pulse width modulation (PWM) at a pulse frequency of around 220Hz.  SILICON CHIP has produced a number of DC speed controllers over the years, the most recent being our high-power 24V 40A design featured in the March & April 2008 issues. Another very popular design is our 12V/24V 20A design featured in the June 1997 issue and we have also featured a number of reversible 12V designs.   Project Image :   12V Speed Controller/Dimmer Project Image For many applications though, most of these designs are over-kill and a much simpler circuit will suffice. Which is why we are presenting this basic design which uses a 7555 timer IC, a Mosfet and not much else. Being a simple design, it does not monitor motor back-EMF to provide improved speed regul...

An unconventional, scalable high efficiency 12V solar power system and battery charge controller with low voltage cutout to protect the battery. (ideal for systems of 50W or less). The most common solar charger consists of a Schottky diode to prevent the battery from draining into the PV panel and a shunt regulator that effectively short circuits the panel once the battery is fully charged. One problem with this approach is diode losses and the resulting heat. If a 50W 12V panel supplies 4A to the battery, the Schottky diode will drop about 0,4V across it dissipating about 1,6W of heat. This requires a heat sink and loses power to heat. The problem is that there is no way of reducing the volt drop, paralleling diodes may share current, but the 0,4V will still be there. The circuit uses a MOSFET in stead of the usual diode and the primary power loss is resistive. [ ]

Many bathrooms are fitted with a fan to vent  excess humidity while someone is showering. This fan can be connected to the light  switch, but then it runs even if you only want  to brush your teeth. A better solution is to  equip the fan with a humidity sensor. A disadvantage of this approach is that by the time  the humidity sensor switches on the fan, the  room is already too humid. Consequently, we decided to build a circuit  that operates by sensing the temperature of  the hot water line to the shower. The fan runs  as soon as the water line becomes hot. It continues to run for a few minutes after the line  cools down, so that you have considerably  fewer problems with humidity in the bathroom without having the fan run for no reason. Naturally, this is only possible if you can  fit a temperature sensor somewhere on the  hot water line and the line does not become  warm if hot water is used somewhere else. We use...

When you step out of your brightly-lit house  into the darkness, it takes a while for your  vision to adjust. A solution to this problem  is this outdoor light with automatic switch-off. As a bonus, it will also make it a little bit  easier to find the keyhole when returning  late at night. Often no mains neutral connection is avail-able at the point where the switch-off timer  is to be installed, which makes many circuit  arrangements impractical. However, the circuit here is designed to work in this situation. The design eschews bulky components such as transformers and the whole unit can  be built into a flush-mounted fitting. The circuit also features low quiescent current consumption. Outdoor Lighting Controller Circuit Diagram : The circuit is star ted by closing switch (or  pushbutton) S1. The lamp then immediately receives power via the bridge rectifier. The drop across diodes D5 to D10 is 4.2 V, which provides the power supply for t...

This project provides some lighting effect by the blinking pattern of the bulbs connected at its output. Up to 8 Bulbs can be connected in between connector CN2 to CN9 and AC power to control them should be connected at Connector CN10. DC Power should be applied at Connector CN11 in accordance with the polarity marked on this connector. Care should be taken while using this it as it contains Main Power on the board. [ ]

The SCC2 is a solar charge controller, it’s function is to regulate the power flowing from a photovoltaic panel into a rechargeable battery. It features easy setup with one potentiometer for the float voltage adjustment, an equalize function for periodic overcharging, and automatic temperature compensation for better charging over a range of temperatures. 10 Amp Solar Charge Controller Circuit Diagram With Parts List The goal of the circuit design was to make a charge controller with analog simplicity, high efficiency, and reliability. A medium power solar system can be built with a 12V solar panel up to 10 amps, the SCC2, and a lead acid or other rechargeable up to a few hundred amp hour capacity. The SCC2 can be operated at battery voltages other than 12V, it can work at 6V and 24V by changing a few parts. Operation at voltages between 6V and 24V is also possible. Specifications Maximum solar panel current: 10 Amps Night time battery drain current: approximately 1ma Nominal battery v...

Central heating systems that include under- floor heating of ten leave the extra pump used to pump the water through the under-floor pipes running continuously. The reason for this is that the central heating controller doesn’t have a separate control circuit and output for the under floor heating pump. Under-floor Heating Controller Circuit Diagram This circuit was designed to control the under- floor heating pump independently or via the switch in the living room thermostat. The design has been made very flexible and can be connected in four different ways: Temperature sensor 1 is connected to the inlet pipe of the under floor heating , Temperature sensor 2 is shor ted. The pump is turned on when the inlet pipe becomes warm enough. When the temperature of the inlet pipe drops below the trigger temperature the pump will continue to run for 20 minutes. Temperature sensor 1 is connected to the inlet pipe of the under floor heating , Temperature sensor 2 is connected to the outlet pip...

When you step out of your brightly-lit house into the darkness, it takes a while for your vision to adjust. A solution to this problem is this outdoor light with automatic switch-off. As a bonus, it will also make it a little bit easier to find the keyhole when returning late at night. Often no mains neutral connection is avail-able at the point where the switch-off timer is to be installed, which makes many circuit arrangements impractical. However, the circuit here is designed to work in this situation. The design eschews bulky components such as transformers and the whole unit can be built into a flush-mounted fitting. The circuit also features low quiescent current consumption. The circuit is star ted by closing switch (or pushbutton) S1. The lamp then immediately receives power via the bridge rectifier. The drop across diodes D5 to D10 is 4.2 V, which provides the power supply for the delay circuit itself, built around the CD4060 binary counter. When the switch is opened the l...

How to Build Outdoor Lighting Controller  Circuit. When you step out of your brightly-lit house  into the darkness, it takes a while for your  vision to adjust. A solution to this problem  is this outdoor light with automatic switch-off. As a bonus, it will also make it a little bit  easier to find the keyhole when returning  late at night. Often no mains neutral connection is avail-able at the point where the switch-off timer  is to be installed, which makes many circuit  arrangements impractical. However, the circuit here is designed to work in this situation. The design eschews bulky components such as transformers and the whole unit can  be built into a flush-mounted fitting. The circuit also features low quiescent current consumption. Outdoor Lighting Controller Circuit Diagram : The circuit is star ted by closing switch (or  pushbutton) S1. The lamp then immediately receives power via the bridge rectifier. The drop across diodes D5...

The fan runs continuously in many computers, it may not be necessary. A simple circuit controller can adjust the fan speed according to demand. This not only saves energy but also reduces s irritation fan noise. Only three components are required to enable the fan speed is controlled according to the cooling needs.  An adjustable voltage regulator that this circuit is the LM317 and two resistors form a voltage divider. One of the resistors is an NTC thermistor (temperature-sensitive resistor), while the other is a standard resistor.   Controller fan speeds using LM317 Circuit Diagram

IC Timer 555 has a basic PWM controller with pulse width control feature 0 .. 100% which is controlled using the R1, at the time of controlling the oscillator frequency relatively stabi so it may be used to build the Simple PWM controller. Frequency of Simple PWM controller 555 depending on the value of R1 and C1, values ​​shown R1 and C1 will form the output with a frequency of 170 to 200 Hz. Diode-diode used in the Simple PWM controller With this 555 can use a 1N4148. R2, R3 and C3 form a giver triger circuit beginning at the reset IC 555 for 2 seconds. If you want to use a series of Simple PWM controller 555 with the V + not +12 V, it does not matter to raise tilapia R2 where (V + * R2) / (R2 + R3) is about 2, because it limits the signal level reset is 0.5 .. 1V. If you do not do that, then signal the kickstart to get too close to the limit reset signal reception. PWM controller circuit Q output of 555 on the Simple PWM controller circuit 555 is used for driver PWM pulse, so that t...

Exhaustion fan is a very important element in kitchens. Here may be a easy circuit to manage kitchen fans by monitoring the ambient temperature. it's engineered round the renowned precision integrated temperature sensor chip LM35 (IC1). remainder of the circuit may be a non-traditional electromagnetic relay driver wired round the fashionable LED driver LM3914 (IC2). User will switch 3 presetted temperature levels employing a jumper/slide switch (JP1), that determines the warmth level to activate the relay and hence the electrical exhaustion fan wired through the relay contacts. It works off 12V DC power offer. Kitchen Exhaustion Fan Controller  Circuit Schematic Only one adjustment is needed during this kitchen Exhaustion fan controller circuit. when construction, set jumper purpose in its 1st position, ie base terminal of T1 is connected to pin thirteen of IC2 and alter the preset P1 fastidiously in order that relay RL1 is energised when ambient temperature level reaches close to ...

A partial solution to quietening noisy PCs can be to reduce the speed of internal cooling fans. Low-cost fan speed controllers are available, but they often employ inefficient, heat-generating linear regulators and contain no temperature feedback mechanism. This idea makes use of a readily available, cheap in-car mobile phone charger. The majority of these use common circuitry and require only minor modifications to operate as efficient fan speed controllers complete with temperature feedback. Most in-car chargers are based on the well-known MC34063 DC-DC switchmode IC. When used for charging mobile phones, the open-circuit output voltage is typically set to between 7V and 9V. This is achieved with a simple voltage divider across the output, the centre point of which connects to the feedback input (pin 5) of the MC34063. To make the output voltage var-iable with air temperature, first replace the upper resistor of the divider with a 4.7kΩ resistor in series with a 4.7kΩ trimpot. The lo...

Water reservoir automatic level control, Simple circuitry - 12V supply By means of a Relay, employed to drive a water pump, this circuit provides automatic level control of a water reservoir or well. The shorter steel rod is the "water high" sensor, whereas the longer is the "water low" sensor. When the water level is below both sensors, IC1C output (pin #10) is low; if the water becomes in contact with the longer sensor the output remains low until the shorter sensor is reached. At this point IC1C output goes high, Q1 conducts, the Relay is energized and the pump starts operating. Now, the water level begins to decrease and the shorter sensor will be no longer in contact with the water, but IC1C output will be hold high by the signal return to pin #5 of IC1B, so the pump will continue its operation. But when the water level falls below the longer sensor, IC1C output goes low and the pump will stop. SW1 is optional and was added to provide reverse operation. Switch...

Cheap Pump Controller Circuit diagram. This simple but effective circuit can be used to control water level in a container. The prototype is used to pump water out of a bucket that collects condensation from a home air-conditioning system. The design is based around a 555 timer (IC1). Although the timer in configured as a mono-stable, it lacks the usual timing capacitor from pin 6 to ground. Instead, a metal probe inserted in the water provides a current path to a second, grounded probe. When the water level in the container reaches a third ("high") probe, the trigger input (pin 3) is pulled low, switching the 555 output high and energizing the relay via transistor Q1. Cheap Pump Controller Circuit diagram:   Cheap Pump Controller Circuit Diagram Once the water level drops below the "low" probe, the threshold input (pin 6) swings high, switching the output (pin 3) low and the relay and pump off. The two 100kΩ pull-up resistors can be replaced with larger values if m...