Matt circuit

A TMOS power FET , Q1 , and LM393 comparator provide a high efficiency rectifier circuit. When Va exceeds Vb1 U1's output becomes high and Q1 conducts. Conversely, when Vb exceeds Va1, the comparator output becomes low and Q1 does not conduct. The Forward drop is determined by Q1's on resistance and current I. The MTH40N05 has an ON resistance of 0.028 Ω ; for I = 10 A , the forward drop is less than 0.3V .Typically , the best Schottky diodes do not even begin conducting below a few hundred mV.

Low power amplifier with based on the IC (intregated circuit) TA7140 manufactered by TOSHIBA , its have original output power is 0,15 Watts, and the schematic diagram is monolithic power amplifier.Though the amplifier circuit has a low output , but the maximum voltage large enough to 30 volts. Part List : Resistor     = 100R Capacitors = 4u7F , 33uF , 100uF , 1000nF , 4700nF , 47uF IC              = TA7140P Technical information : Max. Voltage = 30 V Min. Voltage = 5 V Max. Output = 1 W RL                =  150 Ohm

This is simple and Low-cost circuit diagram project of simple power mosfet inverter circuit. This inverter can deliver .high-voltage ac or de, with a rectifier and filter, up to several hundred volts. Low- Cost Power Mosfet Inverter Circuit Diagram: The secondary and primary of T1-a 12.6 to 440 V power transformer, respectively-are reversed; e.g., the primary becomes the secondary and the secondary becomes the primary. Transistors Q1 and Q2 can be any power FET. Note: Be sure to heat sink Q1 and Q2. Capacitors C1 and C2 are used as spike suppressors.

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. 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 more sensitivity is required (eg, if the 555 doesn’t trigger)....

This is stereo audio amplifier with based on ICTDA2824S , Minimum voltage require 3 volts and maximum voltage 17 volts . Maximum output power 2 X 2 Watt , its low power amplifier. Output impedance  4 ohm. see schematic audio below :

The circuit described here protects your electrical appliances like AC motors from damage due to low voltage at power-on. It remains standby without giving power to the load after power resumes. The load can be switched on only manually. This prevents damage to the device if it is 'on' when power resumes. unregulated power supply is derived from a 12V-0-12V, 300mA step-down transformer and rectifying diodes D2 and D3. The rectified DC is made ripple-free using capacitor C3. An audio/video indicator (piezobuzzer and LED3) is provided along with the power supply for power resumption. When power is switched on, capacitor C4 charges through the piezobuzzer and LED3, making both of them active. The piezobuzzer beeps and LED3 glows for a few seconds. When capacitor C4 is fully charged, the cathode of the LED becomes high inhibiting further flow of current through the buzzer. When the power is off, capacitor C4 discharges through resistor R9. The circuit uses IC CA3140 (IC1) as a volt...

This simple dual digital dice is based on three low-cost ICs, a few transistors and a handful of LEDs. IC1a & IC1b operate as an oscillator with a frequency of about 4kHz and this clocks IC2. The frequency of oscillation is not critical - it simply needs to be high enough to prevent cheating. IC2 and IC3 are 4516 binary counters, configured to count in binary from 1-6. A power-on reset is not required here since, if the initial state is outside the correct range, the counters will count into the correct range after a few clock pulses. Let's first consider how IC2 operates. When the counter reaches "7" (ie, 111), the AND gate formed by diodes D1 & D2 and the 47kO resistor applies a high to the PE pin (pin 1). Circuit diagram: Low-Cost Dual Digital Dice Circuit Diagram This presets the counter to 1 (ie, 001) and so PE goes low again. The counter then increments in the normal manner until it reaches "7" again. Counter IC3 operates in the same manner except ...

This is simple project of 500W Low Cost 12V to 220V Inverter Circuit Diagram. Note : This Circuit is using high voltage that is lethal. Please take appropriate precautions. Using this circuit you can convert the 12V dc in to the 220V Ac. In this circuit 4047 is use to generate the square wave of 50hz and amplify the current and then amplify the voltage by using the step transformer. How to calculate transformer rating. 500W Low Cost 12V to 220V Inverter Circuit Diagram . The basic formula is P=VI and between input output of the transformer we have Power input = Power output For example if we want a 220W output at 220V then we need 1A at the output. Then at the input we must have at least 18.3V at 12V because: 12V*18.3 = 220v*1 So you have to wind the step up transformer 12v to 220v but input winding must be capable to bear 20A.

Here is simple and low-cost phone calling detector and nbsp electronic circuit Project. This electronic circuit using by powered 1.5V cell. Low-Cost Calling Detector Circuit Diagram: This circuit was designed to detect when a call is incoming in a cellular phone (even when the calling tone of the device is switched-off) by means of a flashing LED. The device must be placed a few centimeters from the cellular phone, so its sensor coil L1 can detect the field emitted by the phone receiver during an incoming call. The signal detected by the sensor coil is amplified by transistor Q1 and drives the monostable input pin of IC1. The IC's output voltage is doubled by C2 & D2 in order to drive the high-efficiency ultra-bright LED at a suitable peak-voltage. Notes: Stand-by current drawing is less than 200µA, therefore a power on/off switch is unnecessary. Sensitivity of this circuit depends on the sensor coil type. L1 can be made by winding 130 to 150 turns of 0.2 mm. enameled wire on a...

The circuit is a MOSFET based linear voltage regulator with a voltage drop of as low as 60 mV at 1 ampere. Drop of a fewer millivolts is possible with better MOSFETs having lower  RDS(on)  resistance. The circuit in Fig.1 uses 15V-0-15V secondary output from a step-down transformer and employs an n-channel MOSFET IRF540 to get the regulated 12V output from DC input, which could be as low as 12.06V. The gate drive voltage required for the MOSFET is generated using a voltage doubler circuit consisting of diodes D1 and D2 and capacitors C1 and C4. To turn the MOSFET fully on, the gate terminal should be around 10V above the source terminal which is connected to the output here. The voltage doubler feeds this voltage to the gate through resistor R1. Adjustable shunt regulator TL431 (IC2) is used here as an error amplifier, and it dynamically adjusts the gate voltage to maintain the regulation at the output. Circuit Fig.1 With adequate heatsink for the MOSFET, the circuit can provide up...

Circuit diagram: LOW NOISE STEREO PREAMPLIFIER TDA7334 Datasheet for TDA7334: Download

Do you still remember the H1N1 outbreak in Asia? The manifestations are usually flu-like symptoms which includes fever, cough and colds. The best way to detect fever when people are arriving from the affected areas was to use a thermal camera. These were widely used in Asian countries especially on airports but not all can afford one because it’s very expensive. We can all agree that this is the greatest deal ever! A thermo-cam which costs around 100$, now there is no reason it can’t be bought by even poor countries to help prevent the spread of the disease. Credit must be given to inventions like this because it’s really a big help.

This is a simple Battery Switch With Low-Dropout Regulator Circuit Diagram. In the form of the LT1579 Linear Technology (www.linear-tech.com) has produced a practical battery switch with an integrated low-dropout regulator. In contrast to previous devices no diodes are required. The circuit is available in a 3.3 V version (LT1579CS8-3.3) and in a 5 V version (LT1579CS8-5), both in SO8 SMD packages. There is also an adjustable version and versions in an SO16 package which offer a greater range of control and drive signals. The main battery, whose terminal voltage must be at least 0.4 V higher than the desired output voltage, is connected to pin IN1. The backup battery is connected to pin IN2. The regulated output OUT can deliver a current of up to 300 mA. The LDO regulator part of the IC includes a pass transistor for the main input voltage IN1 and another for the backup battery on IN2. The IC will switch over to the backup battery when it detects that the pass transistor for the main ...

Basic Low Power AM transmitter This transmitter is basic but allows transmission of audio to an AM radio. It consists of an RF oscillator operating in the AM broadcast band, together with a modulator stage, which mixes the incoming audio and the RF. A signal appears on the output, which has an AM component that can be picked up on a nearby AM radio receiver. Basic Low Power AM transmitter The transmitter consists of oscillator stage Q1 and modulator/buffer stage Q2. Q1 is biased via R1, R2, and R3. L1, C3, and C4 form the tank circuit with feedback network C3-C4 providing feedback to the emitter of Q1. RF voltage at the junction of C3 and L1 drives buffer/modulator stage Q2. Q2 is biased by base current produced by RF rectification in the base emitter junction of Q2. C6 is an RF and AF bypass capacitor. C9, C10, and L2 form the tank circuit for the collector of Q2. RF is taken from the junction of C9 and C10 and fed to a short-wire...

Small and portable unit, Useful for old men and old women This low-cost, general-purpose electronic hearing aid works off 3V DC (2x1.5V battery). The circuit can be easily assembled on a veroboard. For easy assembling and maintenance, use an 8-pin DIP IC socket for TDA2822M. Circuit Diagrams:   A Low Cost hearing Aid Circuit Parts: P1 = 10K R1 = 2.2K R2 = 330K R3 = 680R R4 = 33R R5 = 100R R6 = 4.7R R7 = 4.7R R8 = 220R C1 = 0.01uF-10V C2 = 100nF-63V C3 = 47uF-10V C4 = 10uF-10V C5 = 0.01uF-10V C6 = 100uF-10V C7 = 100nF-63V C8 = 100nF-63V D1 = Red LED Q1 = BC547 IC1 = TDA2822M EP1 = Mono Earphone 32R SW1 = On-Off Switch Circuit Operation: In this circuit, transistor Q1 and associated components form the audio signal preamplifier for the acoustic signals picked up by the condenser microphone and converted into corresponding electrical signals. Resistor R5 and capacitor C3 decouple the power supply of the preamplifier stage. Resistor R1 biases the internal circuit of the low-voltage co...

This project details the design of a very low dropout adjustable power supply. A good power supply is essential to electronic projects. While there are many existing designs for adjustable power supplies, this one makes improvements that make it more useful for hobby designs MIC2941 regulator has guaranteed 1.25A output Low dropout, only 40mV - 400mV compared to 1.25V - 2.0V for LM317. This means you can use a wider range of output voltages including generating 3.3V from as low as 3.7V (such as 3 AA's or a lithium ion battery)! Short circuit and overheating protection Input diode to protect circuitry from negative voltages or AC power supplies. 2.1mm DC jack and terminal connector for voltage inputs Two indicator LEDs for high and low voltages Output selection switch to select from 3.3v, 5v and Adjustable On-board potentiometer for adjusting voltage from 1.25V up to within 0.5V of the input voltage. (20V max) On/Off switch for entire board

In the form of the LT1579 Linear Technology (www.linear-tech.com) has produced a practical battery switch with an integrated low-dropout regulator. In contrast to previous devices no diodes are required. The circuit is available in a 3.3 V version (LT1579CS8-3.3) and in a 5 V version (LT1579CS8-5), both in SO8 SMD packages. There is also an adjustable version and versions in an SO16 package which offer a greater range of control and drive signals. The main battery, whose terminal voltage must be at least 0.4 V higher than the desired output voltage, is connected to pin IN1. The backup battery is connected to pin IN2. The regulated output OUT can deliver a current of up to 300 mA. The LDO regulator part of the IC includes a pass transistor for the main input voltage IN1 and another for the backup battery on IN2.  Battery Switch With Low-Dropout Regulator circuit Diagram The IC will switch over to the backup battery when it detects that the pass transistor for the main voltage input ...

How to build a simple and low cost 1.5v to 9v DC Converter Circuit. This inverter circuit will convert 1.5v to 9v to take the place of those expensive 9v batteries.The input voltage for this inverter can be from 1.5 volts , up to 4.5 volts . 1.5v to 9v DC Converter Circuit Diagram: When no current is being drawn from the output the current is less than 10mA. This inverter circuit is very simple requiring few components , but it can be used only for projects that require low current . The L1 coil must have 60 turns on a 10 mm ferrite slug 15 mm long , using a 0.25 mm diameter enameled wire .

Battery-Powered portable unit, Suitable for all type Televisions Using this low-cost project one can reproduce audio from TV without disturbing others. It does not use any wire connection between TV and Loud Speaker. In place of a pair of wires, it uses invisible infra-red light to transmit audio signals from TV to Loud speakers, Without using any lens a range of up to 6 meters is possible. Range can be extended by using lenses and reflectors with IR sensors comprising transmitters and receivers. Transmitter's operation: IR transmitter uses two-stage transistor amplifier to drive two series-connected IR LEDs. An audio output transformer (T1) is used (in reverse) to couple audio output from TV to the IR transmitter. Transistors Q1 and Q2 amplify the audio signals received from TV through the audio transformer. Low impedance output windings (lower gauge or thicker wires) are used for connection to TV side while high-impedance windings are connected to IR transmitter. This IR transmit...