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8051 / 8052
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H Bridge Circuit
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4 Band Resistor
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Stepper Motor Circuits
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Power Control Circuits
Motor Control Circuits
One instance of loudness control circuit
Figure 1-89 is an example of loudness control circuit. Potentiometer from the ground 30% of the total resistance at the tap. When the slide arm when screwed to the tap position
2 -Y- connection automatic three-speed motor acceleration control circuit
Figure 3-118 automatic acceleration control circuit. It uses the male contactor time relay, the motor starts automatically from a low speed by the speed the transition to high-
Forward and reverse speed control circuit can be integrated with a brake function
Figure 3173 is a mechanical braking, dynamic braking, reverse braking function wound rotor induction motor speed can be positive and negative control circuit. Figure, KI, to st
Using current quick break and overcurrent protection circuit overcurrent relay a sensor
Figure 4-52 (a) for the two-phase wiring, DC operation; Figure 4r52 (b) for the two-phase current differential wiring, AC operation.
Digital Voice Recorder/Playback (UM5100)
This Circuit is based on the UM5100 which can record speech into a digital memory and then play it back. The device is designed to be used directly with static RAM's up to 256K bits, or with EPROM 's or ROM's for playback only. High quality voice reproduction is possible and note that it is not a "computer voice", it is the original speaker's...
Remote control Encoder M145026B-1
This encoder can generate up to 19,683 codes from 9 address lines by detecting 1,0, or open circuit. To initiate the transmit sequence, pin 14 should be pulsed low. The encoder will now output on pin 15 a data stream representing the condition on each of the address/data pins in turn and then repeat the operation, so that two complete identical...
Reversing motor drive dc control
This is a positioning servo drive featuring adjustment of balance, gain, and deadband. In addition to control from a dc signal, mechanical input can be fed into the balance control, or that control could be replaced by a pair of resistance transducers for control by light or by temperature.
Dc servo bipolar control
This circuit accepts bipolar control inputs of Â± 5 V and provides a phase-chopped output to a dc load (such as a servo motor) of the same polarity as the input. The rms voltage of the output is closely proportional to the control input voltage. N-channel and p-channel TMOS devices', Ql and Q2, are connected in anti-series to form a...
The relay operates a certain time, td, after power is applied to it, and then it operates for a length of time, tc. The SCR fires when the voltage on Ci reaches VA. This operates the relay, which stays activated until the current charging C2 drops below the dropout current. To keep the relay in its activated position indefinitely (tc =00),...
Phase Control Circuit
The most elementary application is a half-wave control circuit. The thyristor is acting both as a power control device and as a rectifier, providing variable power to the load !luring the positive half cycle and no power to the load during the negative half cycle. The circuit is designed to be a two terminal control which can be inserted in...
12-24V Impulse control dimmer
This circuit is intended for use with motors, lamps,heatings etc. Continuously from nearly zero up to maximum capacity (5-95%). Almost lossfree control by means of this impulse control. Nearly total turning moment of motors. The transistior T3 must absolutely be fastened on a heatsink with minimum dimentions of approximate 100x100x5mm. The...
Single chip pump controller
This circuit controls the level of a tank using a bang-bang controlled electrical pump. The actual level of liquid is measured by a capacitive level-meter. The first inverter performs as a capacitance to frequency converter. It is a Schmitt oscillator and its frequency output decreases as the capacitance increases. The second inverter is a...
Speed regulator for dc motors
A four thyristor controlled bridge is used for operation in two quadrants of the torque-speed characteristics. In the trigger circuits the usual pulse transformers were replaced by self biased circuits which minimize gate power consumption and increase noise immunity. Electrical isolation is guaranteed by the use of optocouplers. The trigger...
Three-phase ac motor driver 2
By varying either Rl or R2, the oscillator frequency can be adjusted over a narrow range. The R3/R4 ratio sets the second amplifier's gain to compensate for signal attenuation occurring in the phase shifters. The circuits can be driven from an external source, such as a pulse or square wave, setting the gain of the left-hand amplifier to a level...
Tachometer feedback control
The system utilizes the H21A1 and a chopper disc to provide superior speed regulation when the dynamic characteristics of the motor system and the feedback system are matched to provide stability. The tachometer feedback system illustrated was designed around specific motor/load combinations and may require modification to prevent hunting or...
Integrated solid state relay
A complete zero-voltage switch solid-state relay contains an input circuit, an output circuit, and the power thyristor. The circuit illustrates a triac power thyristor with snubber circuit and GE-MOVRII Vans tor transient over-voltage protection. The 22 ohm resistor shunts di/dt currents, passing through the bridge diode capacitances, from the...
Triac relay-contact protection
This circuit can be used to prevent relay contact arcing for loads up to 50 amperes. There is some delay between the time a relay coil is energized and the time the contacts close. There is also a delay between the time the coil is de-energized and the time the contacts open. For the relay used in this circuit both times are about 15 ms. The...
Capacitor Cl and body capacitance (C2>of the operator form the voltage divider from the hot side of the ac line to ground. The voltage across Cl is determined by the ratio of Cl to C2. The higher voltage is developed across the smaller capacitor. When no one is close to the touch button, C2 is smaller than Cl. When a hand is brought close to the...
High-torque motor speed control
A bridge circuit consisting of two SCRs and two silicon rectifiers furnishes full-wave power to the motor. Diodes, D3 and D5, supply dc to the trigger circuit through dropping resistors, Rl. Phase delay of SCR firing is obtained by charging C2 through resistors R3 and R4 from the voltage level established by the zener diode, D8. When C2 charges...
AC motor brake
A shot of direct current will instantly stop any ac power tool motor. Switch Si is a center-off, one side spring return. With Si on, ac will be fed to the motor and the motor will run. To brake the motor, simply press Si down and a quick shot of dc will instantly stop it. The switch returns to the center off position when released
Universal-motor speed control
Simple half-wave motor speed control is effective for use with small universal (ac/dc) motors. Maximum current capability 2 amps RMS. Because speed-dependent feedback is provided, the control gives excellent torque characteristics to the motor, even at low rotational speeds
Motor speed control
Universal motors and shade d-pole induction motors can be easily controlled with a full-wave Triac speed controller. Q1 combines both the triac and diac trigger diodes in the same case. The motor used for the load must be limited to 6 amperes maximum. Triac Ql must be provided with a heat sink
Model train speed control
Virtually any NPN small signal transistor may be used in place of the BC 108 shown. Likewise any suitable NPN power transistor can be used in place of the 2N3055. The output transistor must be mounted on a suitable heat-sink. Short circuit protection may be provided by wiring a 12 volt 12 watt bulb in series with the output
DC motor speed control
The circuit uses a 4011 CMOS NAND gate, a pair of diodes and an NPN power transistor to provide a variable duty-cycle dc source. Adjusting the speed control varies the average voltage applied to the motor. The peak voltage, however, is not changed. This pulse power is effective at very low speeds, constantly kicking the motor along
Universal motor control
When the time delay expires, SCRl conducts and removes the gate signal from SCR2, which stops the motor. Both the time delay and motor speed are adjustable by potentiometers R2 and R3. If heavier motor loads are anticipated, use the larger C30B SCR in place of the GE-X1 for SCR2
Direction and speed control
This circuit operates like the one shown in Fig, 57-4, The only differences are that the field is placed across the rectified supply and the armature is placed in the SCR bridge. Thus the field current is unidirectionali)ut armature current is reversible; consequently the motor"s direction of rotation is reversible
Universal motor speed control
The resistor capacitor network R1-R2-C1 provides a ramp-type reference voltage superimposed on top of a dc voltage adjustable with the speed-setting potentiometer R2. This reference voltage appearing at the wiper of R2 is balanced against the residual counter emf of the motor through the SCR gate. As the motor slows down due to heavy loading,...
Power tool torque control
As the speed of an electric drill is decreased by loading, its torque also drops. A compensating speed control like this one puts the oomph back into the motor. When the drill slows down, a back voltage developed across the motorâ€”in series with the SCR cathode and gateâ€”decreases. The SCR gate voltage therefore increases relatively as the...
The circuit is built around the LM567 tone decoder IC that requires about 100 millivolts at its operating frequency. The frequency is set by a 10 K variable resistor and can be between 700 and 1500 He
Remote on-off switch
This circuit provides power control without running line-voltage switch leads. The primary of a 6-volt filament transformer is connected between the gate and one of the main terminals of a triac. The secondary is connected to the remote switch through ordinary low-voltage line. With switch open, transformer blocks gate current, prevents the...
Audio operated relay
Ql and Q2 are general purpose transistors. The 10 K input pot is adjusted to a point just short of where Ql turns on as indicated by K pulling in. K is any 5 V reed relay. With the values shown for R (100 K) and C (47 Âµf), timing values from 5 to slightly over 5 seconds can be achieved
Sound-modulated light source
This circuit modulates a light beam with voice or music from the output of an amplifier. If the 10 K pot is adjusted to slightly less than the Vbe of the transistor, the circuit forms a peak detector
Ultrasonic distance finder circuit
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is measured. There are three main categories of distance measurement methods in use: a) By...
Simple Metal detector circuit with CD4030
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to find something potentially valuable, hidden a few centimeters below the soil. So many...
Fully automatic watering circuit for flower pots
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This circuit comes as a solution to this problem. Depending on humidity of the pot at...
Simple deep searching metal detector circuit
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the circuit of this metal detector, it is possible to detect a metal coin in depth of 90 to...
Sub-Harmonic Bass Converter for Electric Guitars
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound, such as filtering or distortion. Instead, a frequency division system produces outputs...
Echo Depth Sounding Sonar for Boats
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the calibration of the rope. This arrangement still exists in some yachts. The big...
100W HiFi Audio Amplifier Circuit
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power supply must be symmetrical so that no electrolytic capacitors are needed at the outlet....
Plant-Pot Water Level Indicator Circuit
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower. The circuit of the device is shown in Figure 2. The water detection is made from the bottom...
Analogue Sound Preasure dB-Meter Circuit
The best human ear can capture sounds from 20Hz to 20KHz. These limits are known to be the broadest that can exist. Normally the normal limits range from 100Hz to about 13KHz and depend on the age and health of the individual. We for our measurements and to have a good accuracy we will get the limits of 20Hz to 20KHz. A sound to be heard does...
Digital Signal Integrity
Interconnection and Timing of Digital Circuits
CMOS Circuits Tutorial