Mutchus

In most cases where you want to control an AC load, a triac or SCRs will be used. However, it is not easy to drive a triac or SCR. The drive requirement for the triac or SCR makes it sometimes difficult to control it as we want. One thing is that we can not turn the triac or SCR on or off as we desire, because once we turn it on, it latches and stays on until the next zero crossing or until current stops flowing through it. Also, driving a triac with reference to MT1 (or A1) is not as straightforward as we would want. However, a MOSFET can be controlled as we want. Set the gate high (with a sufficient voltage) and current can flow from drain to source. Set the gate low and current can no longer flow. Convenient! However, a MOSFET can only be used to control DC loads since it is a unidirectional switch - current flow can be controlled when it is flowing from drain to source, but can not be controlled from source to drain. So, certainly it can not be used to control AC loads. Right? Well...

This is the Simple 300mA DC to AC converter Circuit Diagram. This circuit was used to provide battery backup to a device that had an AC (output)wall transformer. Due to the quasi sine-wave output and imprecise 60Hz output frequency, some devices might not work pro perly. Peak output is the DC input voltage minus about 20 ohms drop. Use bigger output MOSFETS for more current output.[link]  Simple 300mA DC to AC converter Circuit Diagram    

his is the  DC to AC Inverter Circuit Diagram. This DC to AC inverter circuit work based on unstable multi vibrator does. In this circuit, IC CD4047 is chosen as a heart of unstable multivibrator, because this IC type gives a complementary output that has opposite phase to another ( pin 10 and 11 as seen in Figure 1), and has 50 % duty cycle that satisfy to generate a pulse for inverter.   DC to AC Inverter Circuit Diagram Sourced By: www.circuitsproject.com

This AC mains-operated bistable  switch turns on or turns off a  device using a miniature neon  lamp and a few discrete components.  This switch can be used for control pan-els, appliances and lighting controls.  A push-to-on switch is used to  light up the neon lamp. The light emit-ted by the neon lamp, in turn, enables  the switching action of the circuit. Use  of a 555 timer wired for bistable operation makes the circuit act as a bistable  switch. Circuit diagram : AC Mains Bistable Switch Circuit Diagram The neon lamp (NL1) and the  push-to-on switch (S1) are directly connected to 230V AC mains. The 12V DC  supply for timer 555 (IC1) is derived  from 230V AC mains through capacitive dropper C1, resistor R1 and a 12V  zener diode. IC1 works as a flip-flop  circuit, with the signal at its output  pin 3 toggling every time it receives a  pulse at its pins 2 and 6. The operation of the circuit is simple. When you press switch S1 momentarily, the neon lamp glows, making  phototran...

This circuit will allow you to turn on any piece of equipment that operates on 115 volts ac. The receiver circuit is based on the Radio Shack infrared receiver module (MOD), part number 276-137. It is also available from some of the other sources listed on my s page. The MOD accepts a 40khz IR signal that is modulated at 4 khz. Circuit Diagram When a signal is received the MOD will go low. The sensitivity of the MOD is set by different values for R1 and C1. The values for R1 may need to be as high as 10,000 ohms and for C1 40uf. This will prevent the unit from turning on under normal lighting conditions. You will need to experiment with the values that work best for you. The output of the 4013 chip a flip flop toggles on and off with the reception of a IR pulse. The output of the 4013 turns on the MOC optical coupler which in turn switches on the triac and supplies power to the AC load.

This inverter circuit can convert 12 volt DC voltage into AC voltage of 220 volts with a Modified Sine waveform or better known as the “Modified Sine Wave Inverter”. This inverter circuit has a modified sine wave output, so it has a better power efficiency than an inverter with square wave inverter type. Inverter circuit “Modified Sine Wave” is simple enough to be made, this inverter circuit built using the IC LM555 astable multivibrator, jonhson STP36No6L counter CD4017 and MOSFET as a power inverter. And a complete range of components to make a list Modified Sine Wave inverter can be seen in the following figure. DC 12V to AC 220V Modified Sine Wave Inverter Circuit Diagram  Above the inverter circuit comprises a square wave generator (IC LM555) with a working frequency of 200Hz is used as a clock input johnson counter IC CD4017 as a modifier to be used as a square wave signal so that the output MOSFET drivers STP36N06L transformers form a modified sine wave. Step-up transformer ...

How to build varying brightness AC bulb circuit.  In this circuit, an SCR is used to slowly vary the intensity of a 120 volt light bulb by controlling the time that the AC line voltage is applied to the lamp during each half cycle. Varying brightness AC Bulb Circuit Diagram: Caution: The circuit is directly connected to the AC power line and should be placed inside an enclosure that will prevent direct contact with any of the components. To avoid electrical shock, do not touch any part of the circuit while it is connected to the AC power line. A 2K, 10 watt power resistor is used to drop the line voltage down to 9 volts DC. This resistor will dissipate about 7 watts and needs some ventilation. Operation: A couple NPN transistors are used to detect the beginning of each half cycle and trigger a delay timer which in turn triggers the SCR at the end of the delay time. The delay time is established by a current source which is controlled by a 4017 decade counter. The first count (pin 3...

AC means Alternating Current and DC means Direct Current. AC and DC are also used when referring to voltages and electrical signals which are not currents! For example: a 12V AC power supply has an alternating voltage (which will make an alternating current flow). An electrical signal is a voltage or current which conveys information, usually it means a voltage. The term can be used for any voltage or current in a circuit. AC from a power supply This shape is called a  sine wave .   This triangular signal is AC because it changes between positive (+) and negative (-). Alternating Current (AC) Alternating Current (AC) flows one way, then the other way, continually reversing direction. An AC voltage is continually changing between positive (+) and negative (-). The rate of changing direction is called the  frequency  of the AC and it is measured in  hertz (Hz)  which is the number of forwards-backwards  cycles per second . M...