Matt circuit

Description. This circuit is designed as per a request made by Mr Vinoth from India. His requirement was a 12V/5A DC fan motor controller . I think this circuit is sufficient for this purpose. Quad 2 input Schmitt trigger IC CD4093 is the heart of this circuit. Out of the four Schmitt triggers inside the 4093, U1a is wired as an oscillator with adjustable duty cycle. The U1b, U1c, U1d buffers the output of the oscillator to drive the switching MOSFET Q1.The MOSFET drives the DC motor according to the switching pulse obtained from the oscillator. When R1 is varied the duty cycle varies and so do the speed of the motor. Diode D3 acts as a freewheeling diode. Circuit diagram with Parts list. Notes. Assemble the circuit on a good quality PCB. IC U1 should be mounted on a holder. U1a, U1b, U1c, U1d are part of the same IC CD4093; so power supply is shown connected only once. The12V power supply for this circuit must be able to handle at least 5A. A heat sink is recommended for Q1.

The circuit shown below is of a DC motor driver circuit based on the IC TC4424 from Microchip. TC 4424 is a dual MOSFET driver that can be used in a variety of applications like SMPS, pulse transformer drivers, line drivers, motor drivers etc. The speed and of direction rotation of the motor depends on the logic levels of pin 2 and 4. The speed of rotation of the motor is proportional to the duty cycle of the PWM signal fed to pin 2. If the pin 4 is held at logic 0 the motor will run in the forward direction and if it is held at logic 1, then the motor will run in the reverse direction. In the circuit, resistors R1 and R2 are pull up resistors. D1 and D4 protect the IC chip from under voltages (negative back emf). D2 and D3 provide a safe path for the motors positive back emf to dissipate and safeguard the IC. Capacitors C1 and C2 reduce electrical noises. The circuit can be assembled on a Vero board. The circuit can be powered from anything between 10 to 18V DC depending on the voltag...

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.    Photo of Completed PWM Dimmer/Speed Control 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 ...

 Rolling Shutter Motor Control Circuit. An electrically operated rolling shutter usually has a standard control panel with a three-position switch: up, down and stop. If you would like to automate the opening and closing with a time controlled switch, a few additional wires will have to be connected. Typically, the controls are implemented as indicated in the schematic ‘Normal Situation’. If this is indeed the case, then you can see in ‘New Situation’ how the shutter can be automated with a timer. There is only one method to determine the actual schematic of your control circuit, and that is to open the control box and using an ohmmeter, pencil and paper to check out and draw the circuit. Make sure you turn the power off first though! Connect a 230-V relay (with both the contacts and the coil rated 230 VAC) to the timer.  Rolling Shutter Motor Control Circuit   The changeover switch between automatic and manual control needs to be rated 230 VAC as well and may not be a haz...

Electrical engines are a significant aspect of most large functions. They are used to make current that can be linked with a strength or to immediately petrol other systems. These engines are complicated items of professional systems and consequently it is not recommended for a individual who is not a certified fix individual to attempt to fix them. This transforms digital strength into technical strength. They come in a wide range of types and the type that you use will depend on what you need it for. The primary parts are the blades and the stator. The blades is the going aspect and the stator is the invitations aspect of it. These two items make the time frame for it. Most engines are attractive in characteristics. Both the blades and the stator generate a attractive area which makes a twisting, or demand on the powerplant base and makes the revolving of the powerplant. This is how it functions. Finding a reliable serviceman for your powerplant can be a complicated procedure. The cr...

Unipolar 4-Phase Stepper Motor Controller Board will help you control a Stepper Motor or 4 individual Solenoids. This circuit consisting of transistors that serve as current amplifier and also diode to prevent damaging back EMF, circuit uses Darlington transistors to provide high current capacity to unipolar stepper motor. Just provide sequence of pulse using Micro-Controller or descript circuit to roll out the unipolar motor. On board High Watt resistor to control the current, value of the resistor can be set as per your load current requirement. [ ]

Here are two simple 12V DC motor speed controllers that can be built for just a few dollars. They exploit the fact that the rotational speed of a DC motor is directly proportional to the mean value of its supply voltage. The first circuit shows how variable voltage speed control can be obtained via a potentiometer (VR1) and compound emitter follower (Q1 & Q2). With this arrangement, the motor’s DC voltage can be varied from 0V to about 12V. This type of circuit gives good speed control and self-regulation at medium to high speeds but very poor low-speed control and slow starts. The second circuit uses a switchmode technique to vary motor speed. 2 Basic Motor Speed Controllers Circuit Diagram Fig.1: a very simple motor speed controller based on a compound emitter follower (Q1 & Q2). Here a quad NOR gate (IC1) acts as a 50Hz astable multivibrator that generates a rectangular output. The mark-space ratio of the rectangular waveform is fully variable from 20:1 to 1:20 via potentio...

In first part we discussed about the detail of circuit, back EMF and Mosfet protection; and in second part we covered the display and menu, in this third and last part we will build and test our project.  The DC Motor Speed Controller is built on two PC boards: a main board, and a display  board. These are joined together via a 12-way flat ribbon cable, which plugs into a pin header on the main board.  The main board can be assembled first – see Fig.9. Start by checking the PC board for hairline cracks and for any visible shorts across the copper tracks, especially between the ground plane and any adjacent tracks. In addition, check the hole sizes for the larger hardware items by test fitting these parts into position. Making a link That done, begin by installing the 17 wire links. These must go in first, since some of them run underneath some components. To straighten the link wire, first clamp one end in a vice, then stretch it slightly by pulling on the other end with ...

This DC motor controller circuit shown in this schematic use the L620x motor driver . The L620x is a monolithic full bridge switching motor driver realized in the new Multipower-BCD technology which allows the integration of multiple, isolated DMOS power transistors plus mixed CMOS/bipolar control circuits and is available in many versions : L6201 /1PS/2/3 . L6203 DC Motor Controller Schematic All this motor driver circuits are identically , the differences between them is the total RMS current , which is up to : 1A for L6201 , 2A for L6202 and 4A for L6203 and L6201PS . If the device is combined with a current regulator like the L6506 , can be implemented a transconductance amplifier for speed control, as shown in this circuit schematic . In this configuration only half of the L6506 is used and the other half of the device may be used to control a second motor. The L6506 senses the voltage across the sense resistor RS to monitor the motor current: it compares the sensed voltage both t...

This motor starter protects single-phase motors against voltage fluctuations and overloading. Its salient feature is a soft on/off electronic switch for easy operation. The transformer steps down the AC voltage from 230V to 15V. Diodes D1 and D2 rectify the AC voltage to DC. The unregulated power supply is given to the protection circuit. In the protection circuit, transistor T1 is used to protect the motor from over-voltage. The over-voltage setting is done using preset VR1 such that T1 conducts when voltages goes beyond upper limit (say, 260V). When T1 conducts, it switches off T2. Transistor T2 works as the under-voltage protector. The under-voltage setting is done with the help of preset VR2 such that T2 stops conducting when voltage is below lower limit (say, 180V). Zener diodes ZD1 and ZD2 provide base bias to transistors T1 and T2, respectively. Transistors T3 and T4 are connected back to back to form an SCR configuration, which behaves as an ‘on’/‘off’ control.Switch S1 is use...

Here is a low-cost and simple wireless stepper motor controller using infrared signals. Using this circuit you can control the stepper motor from a distance of up to four metres. The circuit comprises transmitter and receiver sections. The communication between the transmitter and receiver sections is achieved through infrared signals. Fig. 1: Infrared transmitter In the transmitter section, timer NE555 ICs (IC1 and IC2) are configured as astable multivibrators with frequencies of around 1 Hz and 38 kHz, respectively. The output of IC1 is given to reset pin 4 of IC2, so the 38kHz carrier signal is modulated by 1Hz modulating signal. The modulated signal from pin 3 of IC2 is transmitted by the infrared LED.  Resistor R5 limits the current through the IR LED. The transmitted signal is sensed by IR receiver module TSOP1738 (IC6) of the receiver section and its output at pin 3 is used as clocks for dual flip-flop 74LS74 Ics (IC3 and IC4), which are configured as a ring counter. Fig. 2:...

Description. A simple DC motor controller circuit using NE555 is shown here. Many DC motor speed control circuits have been published here but this is the first one using NE555 timer IC. In addition to controlling the motors speed its direction of rotation can be also changed using this circuit. A PWM circuit based on timer NE555 is the heart of this circuit. NE555 is wired as an astable multivibrator whose duty cycle can be adjusted by varying the POT R1. The output of IC1 is coupled to the base of transistor Q1 which drives the motor according to the PWM signal available at its base. Higher the duty cycle the average voltage across motor will be high which results in higher motor speed and vice versa. Change of DC motor direction is attained using the DPDT switch S1 which on application just toggles the polarity applied to the motor. Circuit diagram of DC motor controller. DC motor controller using NE555 Notes. The circuit can be assembled on a Vero board or PCB. Use 12V DC for pow...