The inverter failure-tolerant control of single-phase sine wave is studied BTA16-600B

The failure-tolerant control purpose lies in directing against different trouble sources and symptoms, take the corresponding fault-tolerant processing measure, compensate for trouble, dispel or repair automatically, in order to guarantee the apparatus continues safe reliability service, or regard sacrificing characteristic losses as the cost, guarantee the apparatus finishes its basic function within stipulated time. If you want to adopt failure-tolerant control, have structure or redundancy functionally in the real-time analysis system at first. Find through analyzing, as to the inverter circuit of single-phase full-bridge, in fact the structural redundancy exists. Can regard the whole-bridge circuit as the superposing of two pieces of half bridge converter, if can be after the gas switching tube trouble of the power of a bridge arm of the inverter of the full-bridge, blockade this bridge arm, reconstruct the characteristic of certain holding circuit as the half bridge converter of the whole-bridge circuit, realize failure-tolerant control. Fig. 1 is the equivalent electrical circuit that the circuit reconstructs after full-bridge circuit topology with fault-tolerant capability and first, two bridge arm switch troubles.

In Fig. 1a, divides into two the electric capacity C1 as half bridge converter of the direct-flow Filtering capacitance in the whole-bridge circuit, C2, links the first bridge arm middle point A with two electric capacity middle points o with the bidirectional thyristor VTr1, the bidirectional thyristor VTr2 links the second bridge arm middle point B with point o, forms full-bridge circuit topology with fault-tolerant capability in this way.
Normal working hour, VTr1, VTr2 is the off state, the circuit equivalent is the normal full-bridge inverter circuit. After the trigger impulse takes place and lose the trouble in the power tube VM1, adopt the fault-tolerant control strategy to close the power tube VM3 of the same bridge arm, touch off VTr2 to turn on at the same time, VTr1 keeps off, the whole-bridge circuit is reconstructed as the half bridge converter, the circuit equivalent, in order to pursue 1b at this moment. After the trigger impulse takes place and lose the trouble in the power tube VM2, adopt the fault-tolerant control strategy to close the power tube VM4 of the same bridge arm, touch off VTr1 to turn on at the same time, VTr2 keeps off, the whole-bridge circuit is reconstructed as the half bridge converter, the circuit equivalent, in order to pursue 1c at this moment. The original control device should carry on corresponding adjustment according to the change of the control objective after the circuit is reconstructed, in order to guarantee the characteristic maintains at the acceptable range.
Sum up the fault-tolerant control strategy as follows, suppose VMi i =1,2,3,4The trigger impulse is lost. The whole fault-tolerant control process can be divided into the following several step: Judge the switch position of the trouble in fault detection and diagnostic circuitry; Blockade the trigger impulse of power switch on VMi and the same bridge arm in control unit, touch off the bidirectional thyristor which connects this bridge arm; The control unit changes the controller parameter, it is topological after make it adapt to reconstructing.
On the foundation of analyzing in the principle and artificial experiment, have designed and made a low-powered experimental provision. The experimental parameter is: Switching frequency fs =10 kHz; Export the filtering inductance L =1 mH; Filtering capacitance C of the output =20 F; Input the Filtering capacitance C1 =C2 =1 000 F; Direct-flow input voltage Uin =48 V. All power switches adopt the power MOSFET of the Model IRF650A, the output voltage adopts the voltage to isolate the man of great talent AD202 to measure after partial pressure. The output current measures and adopts the electric current transducer of Hall of Model CSB6-50A. The sense resistor of electric current of elementary straight flow side adopts 4 times 0. The resistance of 3 / 2 W is connected in parallel. Input the filtering resistance and is formed by two pieces of 1 000 F electric capacity, o some connect A, B bipunctate with VTr2 by VTr1. The bidirectional thyristor chooses BTA16-600B, drive and choose the bidirectional thyristor to drive special purpose chip MOC3 021. The main control chip of the circuit adopts the Model TMS302LF2407A DSP, is finished implementation of failure diagnosis and fault-tolerant tactics by it.
Experimental analogy VM1 is on the appointed phase place 90 degrees, 170 degrees, 270 degrees The trigger impulse takes place to lose the trouble, after the testing signal is judged by DSP trouble diagnostic element, carry out the fault-tolerant control procedure, blockades VM2 trigger impulse, touches off VTr1, it is 2 fold to change the given sine wave uref.

Water towers water level controller circuit PC817

IC2 can use a variety of 555 time base integrated circuits. IC3 is the infrared receiver decoder CX20106A. IC4 can use 4N25, 4N26, PC817 and other optocoupler. Part of the infrared receiver can purchase finished infrared receiver components or integrated infrared receiver,it’s easy to produce and improve reliability. VD1, VD2 and VD3 ​​can use infrared transmitter and receiver diodes of TVremote control. J chooses to use ​​a new selection of memory self-locking relay,the shape of this relay is same as the general replay, the difference is that the pullis not required to maintain current,justwhen pulling and releasingit requires a certain pulse drive power, then the mechanical structure maintains locked state.

motor controller for R/C models LL4148

The complete circuit diagram of the motor control is shown in Figure 1. The schematic includes all components for unidirectional as well as bidirectional use. The desired version is chosen before building the circuit. Your choice therefore determines the components used. The circuit has been kept as compact as possible. The result: a motor control weighing less than 25grammes.

Resistors:
R1 = 4kOhm, SMD
R2 = 100Ohm, SMD
R3 = 470Ohm, SMD
R4,R6 = 100kOhm, SMD
R5 = 10Ohm SMD
R7 = NTC, 100kOhm
R8 = 1kOhm, SMD
R9 = 10kOhm, SMD

Capacitors:
C1,C2 = 15pF, SMD
C3,C5 = 100nF, SMD
C4 = 10nF, SMD
C6 = 47µF 10V SMD

Semiconductors:
D1 = LL4148*
D2 = MBR2045CT*
T1 = BC517
T2,T3,T4 = BUZ11
T5 = IRF9530
IC1 = PIC16C84 (order code 966510-1)
IC2 = L4940V5
IC3 = PC827

Miscellaneous:
K1 = 10-way pinheader
X1 = 4MHz quartz crystal
Printed circuit board and programmed PIC (IC1): set order code 960095-C
PIC also available separately: order code 966510-1

3.2 The 8255 a PI/O - Chip 82C55A

The 82C55A is a high performance CMOS version of the industry standard 8255A . It is a general purpose programmable I/O device which may be used with many different microprocessors. There are 24 I/O pins which may be individually programmed in 2 groups of 12 and used in 3 major modes of operation. The high performance and industry standard configuration of the 82C55A make it compatible with the 80C86, 80C88 and other microprocessors. Static CMOS circuit design ensures low operating power. TTL compatibility over the full military temperature range and bus hold circuitry eliminate the need for pull-up resistors.

 The device comprises three 8 bit ports whereby port c can be sub-divided into two 4 bit groups. Each of these three ports is addressed by A0 and A1 . With it's read, write, the chip select and data signals it looks and behaves like a tiny ROM or a RAM with only three bytes.

    To switch between 'RAM-' and 'ROM-mode' the 8255 has a mode register where three working modes can be selected. The mode register is selected when A0 and A1 are set to high (+5V).

    The three modes are:

    Mode 0: basic input / output
    Mode 1: strobed input / output
    Mode 2: bi-directional bus

For our purpose only mode 0 was interesting, but the device may be switched into each with the setup supplied in this document.
To work with the three ports they must first be initialized. This is done by writing the proper control word into the control register. Figure 11a shows the definition of the control word. While bit D2, D5, D6 and D7 define mode 0..2 the bits D0, D1, D3 and D4 define the settings of the ports to input- or output-mode. In other words you need to 'program' or switch the 82C55 every time you want to change a port data flow direction.
If 'all input mode' in mode 0 is requested the control word would be 10011011bin = 9Bhex = 155dec. If 'all output mode' in mode 0 shall be selected the control word would be 10000000bin = 80hex = 128dec.

3A/800V 50KHz Power Switch KA5L0380R

The Fairchild Power Switch (FPS) KA5L0380R product family is specially designed for an off-line SMPS with minimal external components. The Fairchild Power Switch (FPS) consist of high voltage power SenseFET and current mode PWM IC. Included PWM Controller integrates the fixed frequency Oscillator the under voltage lock-out, the leading edge blanking, the optimized Gate turn-on/turn-off driver, the thermal shutdown protection, the over voltage protection, and the temperature compensated precision current sources for the loop compensation and the fault protection circuitry. Compared to Discrete MOSFET and PWM Controller or RCC solution, a Fairchild Power Switch (FPS) CAN reduce total component count, design size, weight and at the same time increase efficiency, productivity, and system reliability. It has a basic platform well suited for cost-effective design in either a flyback converter or a forward converter.

DC Voltage Doubler - 74HC132

74HC132
This is a cheap DC Voltage Doubler Circuit diagram, which requires a few components and will deliver 10V from a 5V power supply. If the oscillator must be built from a non-functional gate then is required 2 more components: R1 and C3.
The most important parameters of this voltage doubler circuit are given in the table below. Note that because of the IC tolerances these data may have some differences.

L7812CV Positive voltage regulators

The L7812CV is a three-terminal positive regulator. It is available in TO-220, TO-220FP, TO-220FM, TO-3 and D2PAK packages and several fixed output voltages, making it useful in a wide range of applications. The L7812CV can provide local on-card regulation, eliminating the distribution problems associated with single point regulation. The L7812CV employs internal current limiting, thermal shut-down and safe area protection, making it essentially indestructible. If adequate heat sinking is provided, the L7812CV can deliver over 1A output current. Although designed primarily as fixed voltage regulators, the L7812CV can be used with external components to obtain adjustable voltage and currents.

TL494CN SMPS Controller

The TL494CN is a pulse-width-modulation control circuit. It incorporates all the functions required in the construction of a pulse-width-modulation (PWM) control circuit on a single chip. Designed primarily for power-supply control, the TL494CN offers the flexibility to tailor the power-supply control circuitry to a specific application. The TL494CN contains two error amplifiers, an on-chip adjustable oscillator, a dead-time control (DTC) comparator, a pulse-steering control flip-flop, a 5-V, 5%-precision regulator, and output-control circuits. It provides for push-pull or single-ended output operation, which can be selected through the output-control function.

TL494CN absolute maximum ratings: (1)VCC Supply voltage: 41 V MAX; (2)VI Amplifier input voltage: VCC + 0.3 V max; (3)VO Collector output voltage: 41 V max; (4)IO Collector output current: 250 mA max; (5)θJA Package thermal impedance:D package: 73℃/W max; DB package℃/W max: 82; N package 67 ℃/W max; NS package: 64℃/W max; PW package: 108℃/W max; (6)Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds: 260 ℃ max; (7)Tstg, Storage temperature range: –65 to 150 ℃.

TL494CN features: (1)Complete PWM Power-Control Circuitry; (2)Uncommitted Outputs for 200-mA Sink or Source Current; (3)Output Control Selects Single-Ended or Push-Pull Operation; (4)Internal Circuitry Prohibits Double Pulse at Either Output; (5)Variable Dead Time Provides Control Over Total Range; (6)Internal Regulator Provides a Stable 5-V Reference Supply With 5% Tolerance; (7)Circuit Architecture Allows Easy Synchronization.

SPS250A power supply 2SC2625

A SMPS I take on trips I forgot is NOT auto voltage sensing on input and was still set to 110V after recent US trip.

Pretty obviously the power transistors got fried and rather than junk it I thought I should fix it

This is dealing with mains voltage so do not do this unless you know what you are doing as the voltages are lethal.

It took a bit of digging to find the circuit diagram (thought it was on the pdf that came with it), still haven't found it exactly but this is very similar except mine appears to run the fan full all the time instead of having a fan control board on the lower right here.


These power supplies are widely in use and all are called SPS250A in the name and are all made in China under various names... so if yours has SPS250A in the name and looks like mine then chances are it is the same but no responsibility if it is not, use information at own peril (and this is running at mains voltage which can kill so do not do this without a healthy respect for high voltages).

The two NPN power transistors 2SC2625 were removed still attached to their heatsink.


Note all the common mode filtering on the input side (top right corner).
Mine has had the right hand transistor crater and the other is short circuit between the pins.

Anyway suffice to say power supply can be easily repaired.

I hear that it might make sense to replace the 2Sc2625 10A versions with 2Sc3220 which are 15A versions but I would source them in HQEW.net  .

Car Audio Amplifier TDA1557Q TDA1553Q

This stereo audio amplifier is for car purpose and can deliver up to 2 x 22W using a single TDA1557Q or TDA1553Q IC from Philips.