Power supplies control

Short Overview of Switching Power Supply Control... 

Some power supply control ICs have synchronization inputs for this purpose. For those ICs which have an oscillator, but not a synchronization pin, the circuit in Figure 3-55 can be used. The frequency on the IC must be set lower than the synchronization signal. The sync signal causes the oscillator to prematurely time-out. 

Selecting the SMPS controller IC. The important factors within this application that affect the choice of switching power supply controller IC are MOSFET driver needed (totem-pole driver), single-ended output, 50 percent duty cycle limit desired, and current-mode control desired. The popular industry choice that meets these needs is the UC3845B. 

One of the outstanding features of fluid power systems is that force, generated by the power supply, controlled and directed by suitable valving, and transported by lines, can be converted with ease to almost any kind of mechanical motion. Either linear or rotary motion can be obtained by using a suitable actuating device. 

The process is carried out in an air-tight chamber—originally a simple bell jar and now normally in commercial production purpose-built plant some metres in diameter and length. The chamber is fitted with the necessary pumping system, work holder, source holder, power supply, control equipment, and gauges. It is possible for an experienced operator to control the process with the precision necessary but for routine production to a specified standard automatic control is regarded as essential. 

For bench testing the general performance of an electrolyzer, construct a power supply controller. This will allow you to vary the current and voltage input to the electrolyzer and test its performance and characteristics. You can also measure and compare exact input in terms of current and voltage, and the output in terms of volume of gas and so on. 

Sanjaya Maniktala is back with a new installment of his popular power supply design column. The question he asks is how to make up for the erratic quality of the 3842 and 3844 switching power supply controllers now on the market. An adjustment of the RC components in the hysteresis loop allowed a power supply company to safely utilize the batch lot of jittery components they were stuck with — some 50,000 of them. 

Category II Equipment of primary importance, but redundant or can be easily inspected or repaired (e.g. electric power supply, control rods). 

Fig. 2 (a) Multi-wafer anodizer right, protective cover removed to show ancillaries) and power supply/control rack left), (b) wafer racks in etch tank pSiMedica Ltd)... 

Step 3 In reviewing critical equipment and resources consider all necessary measures to manage the incident, ie drainage, firewater management, power supply, control centres, communications etc. Consider the requirements to deal with the more likely scenarios, not just the high impact-low probability events. Assess what the likely level of damage would be to vulnerable equipment and resources, in terms of Table f 9 ... 

In general, an X-ray generator consists of a metal target (anode), an electron gun (cathode), a vacuum chamber with an X-ray window, and a power supply/controller. X-rays are generated by the electrons accelerated from the... 

The EU contains capacitor battery (CB), current source (CS), accumulator (Ac), controlled by CS, impulse former (IF),power supply (PS), two comparators (Cpl,Cp2),... 

Fig. 1 shows the block diagram of the vibrometer, in which the most sensible to small phase variations interferometric scheme is employed. It consists of the microwave and the display units. The display unit consists of the power supply 1, controller 2 of the phase modulator 3, microprocessor unit 9 and low-frequency amplifier 10. The microwave unit contains the electromechanical phase modulator 3, a solid-state microwave oscillator 4, an attenuator 5, a bidirectional coupler 6, a horn antenna 7 and a microwave detector 11. The horn antenna is used for transmitting the microwave and receiving the reflected signal, which is mixed with the reference signal in the bidirectional coupler. In the reference channel the electromechanical phase modulator is used to provide automatic calibration of the instrument. To adjust the antenna beam to the object under test, the microwave unit is placed on the platform which can be shifted in vertical and horizontal planes. 

The HILL-SCAN 30XX boards can be used in different PCs. Desktop- and tower-PCs as well suited for laboratory uses. For in-field inspections rugged notebooks and portable PCs are advantageous. A typical portable system is shown in Fig. 2 (USPC 3010), used in MUSE (Mobile Ultrasonic Equipment). This portable PC not only contains the boards for ultrasonic testing but also a controller with power supply for stepper motors, so that a manipulator can be connected directly. The MUSE system is enlarged with a water circulation system which enables a local immersion technique" for in-field inspections. A typical result is shown in Fig. 3, which presents a D-scan of a CFRP- component in RTM-techniques. The defect area caused by an impact is clearly indicated. The manipulator is described in [3]. 

In addition to the controlling computer the system contains only a small control unit - PSP-4 (weight approx. 5 kg.) which among other system components includes a motor control system integrated closely with the PS-4 ultrasonic system. For communication between the PSP-4 control unit and the robot as well as robot power supply is used a single cable less than 10 mm. in diameter. 

The electronic block, which includes block of the analysis and registration and control system engines, and block of the source-receiver of acoustic oscillations are universal for any installations of this type. As the source-receiver of acoustic oscillations the ultrasonic flow detector is usually use. It s, as a rule, the serial devices for example y/f2-12. The electronic block contains the microprocessor device or PC, device of the power supply and management of engines... 

Power Supplies and Controls. Induction heating furnace loads rarely can be connected directiy to the user s electric power distribution system. If the load is to operate at the supply frequency, a transformer is used to provide the proper load voltage as weU as isolation from the supply system. Adjustment of the load voltage can be achieved by means of a tapped transformer or by use of a solid-state switch. The low power factor of an induction load can be corrected by installing a capacitor bank in the primary or secondary circuit. 

Some induction heating furnaces must operate at frequencies higher than the supply frequency. Formerly, rotating motor alternator frequency converters were used. Now the avadabdity of high speed, high power sdicon controlled rectifiers for use in frequency converters has made rotary converters obsolete. Modem units operate at higher efficiency, cost less, require less factory space, and coordinate readdy with process controls (2). 

Hydraulic power supply This actuates brakes and also feeds the yawing and pitch control (if they are also hydraulically operated). 

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