Showing posts with label control. Show all posts
Showing posts with label control. Show all posts
Saturday, November 1, 2014
TIP120 Simplified Motor Control
TIP120 Simplified Motor Control
bildr.org writes:
Up until now, we have talked about working with a lot of low-power devices. Sensors, LEDs, ICs, and the like are all capable of being powered directly from your Arduino, but as many awesome 5 and 3.3v components as there are, eventually you will find yourself holding a 12v solenoid, motor, or light and wondering “How the heck am I supposed to control this from my Arduino?” Well today we are going to talk about doing just that from a magical device know as a transistor, specifically the TIP120 Darlington Transistor.
Thursday, October 30, 2014
TDA8551 AF Amplifier With Digital Volume Control Diagram Circuit
The Philips Semiconductors TDA8551 is a small audio amplifier with an integrated volume control. When operated from +5 V, it delivers a nominal output power of more than one watt into 8 ohms. It can also be used over a supply voltage range of +2.7 to +5.5 V, with correspondingly reduced output power. The output volume can be adjusted from –60 dB to +20 dB in 64 steps, using a set of up and down push-buttons. The shared UP/DOWN input for the up and down switches has three states. If it is ‘floating’, which means that both of the switches are open, the volume remains unchanged. A pulse to earth decreases the volume by 1.25 dB, while a positive pulse increases the volume by 1.25 dB.
When the power is switched on, the internal counter takes on the –20 dB setting. An additional input (MODE) allows the amplifier to be switched from the operating state to the mute or standby state. If this input is held at the earth level, the amplifier is operational. If +5 V is applied to this pin, the TDA8551 enters the Standby mode, in which the current consumption drops from the typical operational level of 6mA to less than 10µA. Finally, the MODE input can be used as a mute input by applying a voltage of 1 t0 3.6 V to this input. This voltage can be provided by a connection to the SCR pin, which lies at half of the operating voltage and to which a filter capacitor is connected.
The loudspeaker is connected in a floating configuration between the two outputs of the bridge amplifier in the TDA8551. This provides the desired output power level, in spite of the low supply voltage. For headphone applications, which do not need as much output power, you can connect the headphone between earth and one of the outputs, via an electrolytic coupling capacitor. You can make a stereo headphone amplifier in this way, using two TDS8551 ICs. The TDA8551 is housed in a DIP8 package. The SMD version is the TDA8551T, in an SO8 package
When the power is switched on, the internal counter takes on the –20 dB setting. An additional input (MODE) allows the amplifier to be switched from the operating state to the mute or standby state. If this input is held at the earth level, the amplifier is operational. If +5 V is applied to this pin, the TDA8551 enters the Standby mode, in which the current consumption drops from the typical operational level of 6mA to less than 10µA. Finally, the MODE input can be used as a mute input by applying a voltage of 1 t0 3.6 V to this input. This voltage can be provided by a connection to the SCR pin, which lies at half of the operating voltage and to which a filter capacitor is connected.
The loudspeaker is connected in a floating configuration between the two outputs of the bridge amplifier in the TDA8551. This provides the desired output power level, in spite of the low supply voltage. For headphone applications, which do not need as much output power, you can connect the headphone between earth and one of the outputs, via an electrolytic coupling capacitor. You can make a stereo headphone amplifier in this way, using two TDS8551 ICs. The TDA8551 is housed in a DIP8 package. The SMD version is the TDA8551T, in an SO8 packageWednesday, October 22, 2014
DC fan control circuit for power amplifier
DC fan control circuit for power amplifier .Variable speed DC fan This series of works based on the input signal. Speed / fan rotation depending on size of the input signal coming from speaker lines. If there is no signal then the fan will spin slowly according to the setting VR1. Input supply can be taken directly from the main transformer power amplifier, 12V CT 12V, so no need to increase the transformer again.
This circuit has been tested and do not cause buzzing. correction: the lowest R: 560 ohm
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| Circuit Schematic Electronics | CSE |
This circuit has been tested and do not cause buzzing. correction: the lowest R: 560 ohm
Thursday, August 28, 2014
Open Loop Close Loop Speed control for induction motors
Open Loop Speed control for induction motors.
In the above block diagram the Open Loop Speed control for induction motors is shown.
The system consists of theRectifier, Filter, Three phase variable Frequency Inverter and induction motor.
The controlled rectifier converted the tree phase supply to a DC, the out put of the rectifier is a pulsing DC, there fore it is passes through the Filter, after the filter the DC voltage is feed to the variable frequency inverter ckt and the it supply to the induction.
There is no feed back in this system for the control purpose there it is called Open Loop control System.
Closed Loop Speed control for induction motors.
In the above block diagram the Close Loop Speed control for induction motors is shown.
The system consist of theRectifier, Filter, Three phase variable Frequency Inverter, Feed back system and induction motor.
The main operation of the Closed Loop Speed control for induction motor is same as of the Open Loop system, In this system simply a feed back system is introduce to control for control purpose.
Tuesday, August 26, 2014
3 Band Tone Control with LF351
3 Band Tone Control circuit uses an op-amp as an amplifier end. Tone Control circuit is a regulator of tone bass, midrange and treble or 3 band called because it can set the three tones. Filter circuit is applied to the series of "Tone Control 3 band" This type baxandal like the title of this article.
Results filtering regulator tone or tone control baxandal type is good, because there is no signal level is wasted directly into the ground. Range frequency tones generated from Tone Control 3 band was determined by the configuration of the R and C of the filter section baxandal. As an amplifier on Tone Control The set of three band use traditional IC LF351 has slewrate high and high input impedance. For more details, series 3 Band Tone Control as follows.
Figure Series 3 Band Tone Control
3 Band Tone Control circuit above using LF351 Op-Amp is used to strengthen the signal after filtering by the filter process baxandal. Level tone Bass, Midrange and Treble settings are determined by potensio R1, R2 and R3. Frequency filter in the circuit above baxandal to 50 Hz bass tone, tone Midrange 1 KHz and 10 KHz for Treble tone.
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