LM393N integrated Circuits (ICs)

A TMOS power FET, Q1, and an LM393N comparator provide a high-efficiency rectifter circuit. When VA exceeds VB, U1's output becomes high and Q1 conducts. Conversely, when VB exceeds VA, the comparator output becomes low and Q1 does not conduct.

The forward drop is determined by Q1's on resistance and current I. The MTH40N05 has an on resistance of 0.028 Ω; for I = 10 A, the forward drop is less than 0.3 V. Typically, the best Schottky diodes do not even begin conducting below a few hundred mV.

pulse signal interfaces EPC1PC8

The pulse signal examined is a driving signal of the power, used in the propulsion power to support, the drive current is usually several mA to several numerous mA, adopt the open-collector gate OC The form is exported, it is usually 12 – 30 V signal. For compatible many kinds of signal levels, and can isolate power type signal and ordinary base band level signal, realize better electromagnetic compatibility, this system adopts the photoelectric coupler as signal isolation and interface device of level switch.

TLP121 is the photoelectric coupler that Toshiba produced, isolates impedance as M grade, its drive current of forward direction IF Maximum 20 mA, rear end switch open and make time ‘s s grade, can respond to the request that the error in emasurement of this system pair is not greater than 1 ms. The input interface resistance is set as the adjustable resistance, can adapt to different input voltages.

The pulse signal interface circuit is shown as in Fig Straight line and loop of pulse signal are connected to the forward end 1, 3 pins of TLP121 in Fig of the photosensitive resister ,Rear end 4, 6 pins of TLP121 in Fig Adopt 5V power in the board to pull upward, sends and deals with FPGA to the interface after having a facelift through the Schmidt circuit 74HC14. When the pulse signal is effective, photosensitive resister forward end have electric current flow through, interface circuit export the intersection of high level and ” the 1 ” ; When pulse signal invalid, interface circuit export the intersection of low level and ” the 0 ” .

interface treatment FPGA

Because need to gauge pulse signals of No. 80, it is unable to meet concurrent processing’s demands to adopt the one-chip computer, so choose FPGA and finish the impulse sampling function. Interface deal with FPGA adopt the intersection of Altera and FLEX10K50 of Company, working primary frequency is 6 MHz, the storage chip adopts EPC1PC8.
Its main function has three parts: Frequency demultiplication timer, sampled data buffer, peripheral control logic. FPGA carries on the frequency demultiplication to the main clock, forms cycle as the clock signal of 1 ms. FPGA every ms finishes running side by side and gathers the pulse signals of No. 80 once, leaves the data in the register, send out the interrupt signal to the one-chip computer at the same time, notify the one-chip computer and initiate the data to move, and the time counter within the one-chip computer increases by oneself. The sampled data buffers the module and is used for latching the pulse signals of No. 80 to the internal register at the same time, the one-chip computers every ms all read once. Peripheral control logic is used in the decipher of every control signal of periphery of the one-chip computer, including control register, every chip control the signal interpretation, and the realization of other auxiliary functions.

INA128, Adding -9V offset with reference pin BAV99

There is a bipolar (-10V/+10V) ADC on my circuit. And want to measure 0V to 5V signal with high empedance circuitry. To not loose ADC resolution I want to add a negative offset in INA128 circuit without using second amplifier. (0V to 5V  input;  -9V to 8.5V output) Theroticaly and experimentaly (using TINA-TI)  applying -9V to INA128 reference input solve my problem. Input and output voltage seems to be within specified limits but what about internal node voltages.

According to my calculation; when input is 5V and output is 8.5V,  A2 output node should be 11.25V.  But it seems difficult the reach this level with 12V supply. (Is it RRO)

Could you please clearify and make me sure for these ?

1.) Reference input is just intended for applying small offset nulling voltages or can I use it to apply higher offset ?

2. ) Using -9V offset is adequate for INA128 ? If yes how does it effect the CMRR ?

3.) Using 15V positive supply for INA128 allows me to apply -9V offset to reference pin if 12V supply is not enough?
a

( Diodes are BAV199 but not found in TINA-TI library so I used BAV99 instead. )

MAX202CSE TRANSMITTER/RECEIVER

   

 MAX202CSE IL00 RS-232 TRANSMITTER/RECEIVER —TOP VIEW— 1 2 C1+ V+ C1+ 1 VCC 16 3 C1_ 4 6 C2+ V_ V+ 2 15 GND 5 C2_ C1_ 3 14 T1 OUT 11 14 T1 T1 10 7 T2 T2 C2+ 4 13 R1 IN 13 12 R1 R1 C2_ 5 12 R1 OUT 8 9 R2 R2 V_ 6 11 T1 IN R1, 2 : RECEIVER 1, 2 T1, 2 : TRANSMITTER 1, 2 T2 OUT 7 10 T2 IN R2 IN 8 9 R2 OUT +5 V 0.1 µF 0.1 µF INPUT 6.3 V + + 16 1 + 2 +10 V +5V to +10V 0.1 µF VOLTAGE DOUBLER 3 + 4 _10 V +10V to _10V 0.1 µF VOLTAGE INVERTER 6 0.1 µF 5 +16 V +5 V 400 K 11 14 T1 +5 V TTL/CMOS RS-232 INPUTS OUTPUTS 400 K 10 7 T2 12 13 R1 5 K TTL/CMOS RS-232 OUTPUTS INPUTS 9 8 R2 5 K 15

Schematics LM358 Op Amp

In this schematic, a piezo is the sensor. Piezos generate voltage when physically bent or deformed, the the foltage is in the millivolt range. The direction that the piezo is deformed determines the polarity: bend it one way, get a positive voltage. Bend it the other way, get a negative voltage.

In this circuit, the piezo is put through a full-wave rectifier bridge (the four diodes) to make its voltage always positive. The output of the bridge is sent into one of the LM358's amplifiers that's configured as a voltage summing amp. The output of that amp is then fed into the other amp on the LM358 that's configured as a DC voltage gain amp. The output from the second amp is approximately 0.2 - 3.0 V DC.

Epson Lx300 Printer Repair service-No Energy And Cannot Print -Max232ic Defective MAX232CWE

Cleansing with the thinner answer and utilized new solder solved the intermittent no strength issue. In this report, I would like you to know that not all strength difficulties should be brought on by main elements burnt. A free connections, dry joints, resistor wide open circuit, substantial esr ohms in electrolytic capacitor could result in intermittent no energy or no energy at all.

Troubleshooting with the appropriate tactics and using a excellent procedure would typically solve digital faults very easily. Yet another factor that I want to discuss with you is that the electrical power board is making use of a dual image coupler (optoisolator) NEC PS2561-two ic. There are two separate optoisolator ic built into one solitary bundle. If you have the ECG Philips master replacement guide e-book, you could discover out the interior diagram of this type of ic. After you identify the pinouts, you really could check it with your analog multimeter.

Often there are far more than handful of troubles that you want to fix. In the previously mentioned case, right after energy up the printer, it cannot print at all. It seems like there was no sign coming into the CPU IC. The printer self test operates completely ok. For your data, if this sort of problems transpires in other model of printer, the troubleshooting strategy is the same. I will very first seem at the conversation chip or buffer chip. In this printer, the primary suspect was the Maxim Max232cwe multi channel RS232 Transceivers ic.

Solder the ic out was not a dilemma in this smd kind ic. Right after the substitution with a new ic the printer functions wonderfully. Keep in mind, regardless of whether you are troubleshooting the Epson lx 300 printer or any other product, very first verify the printer cable and then the communication or buffer ic.

As you may possibly currently know, a rigid borescope is the finest option for you if you are searching for an affordable device that can look at inside of tight enclosed locations that could be achieved through a straight line. However, are you acquainted with the diverse parts and products which these devices use in order Epson Lx300 Printer Restore-No Electrical power And Can’t Print -Max232ic Faulty to give you with these high quality images? This article will search for to describe these diverse components to you in quick so you can far better recognize how these remarkable machines operate.

Initial of all, it makes use of an optical lens in purchase to transmit their pictures from one particular conclude of the insertion tube to the other, from the region you are inspecting straight to your eye. Even so, the object should initial be lit up ample so you are able to see it. The check is for viewing your results, the light-weight supply allows you to see in darkish locations, and the video clip digital camera will report your findings so you can Epson Lx300 Printer Repair-No Power And Can’t Print -Max232ic Defective view them afterwards. This also helps make it considerably How a Standard Rigid Borescope is Made less difficult to look at your findings with other individuals at the identical time.

Mono Power Amplifier A1015, BD140 ,TIP2955

Mono Power Amplifier - A1015, BD140 ,TIP2955 Circuit Diagram


Typically audio amplifier stereo amplifier to a two amplifier. And if a mono amplifier is a single speaker. However this circuit command be present extended to the mono two loudspeaker.But not a equivalence or else serialization access.This makes it needless impedance of the speaker has altered.But will remain to utilize the spokeswoman as a replacement for of the resistance - Collection Peter (RC) of the transistor.The circuit can be alive prolonged to 2 loudspeaker itself.

What time raising the power supply circuit and the audio to input. the audio sign coupling to through the C1 and R1 to increase with the Q1.Which Q1 serves like the Regional Pre amp amplifier to power up to a one point.already conveyance it to Q2.Which Q2 is connected to emitter follower circuit.be active as a driver amplifier intimate section from the pre amp section provides added power to drive the Q3 perform. and Q3 motivation provide while a Regional Power amp amplifier output to the spokeswoman.The opinion of the audio intimate through the VR1 and R2 to enter the pin B of Q2.To control the stability of working instead of well brought-up.This circuit is an output of 40 milliwatts watts of distortion of the gesture rate is by the side of 0.1 percent.And frequency response from 15 Hz - 200 kHz.

GP2D12 distance sensor 1N5819

During 250 ms, sensor is configured as a light sensor (powered), C1 charges through D1 up to SENSOR+ voltage. Low drop regulator U1 generates a 5V regulated supply. Q1 is blocked by D2 (D2 maintains base to a voltage higher or equal to its emitter voltage), so GP2D12 is not powered. Q3 is non-conducting too, preventing current flow through D3/R5/Q2. So the only significant current diverted from C1 charging is through R1 (less than 2 mA), and at the end of this phase C1 is fully charged.

During the following 50 ms, sensor is configured as a touch sensor (passive). SENSOR+ is now only pulled up to +5V through 10Kohm (inside RCX), insufficient to block Q1. Q1 and Q3 are then conducting, and GP2D12 is powered. Q2, mounted as an emitter follower, buffers GP2D12 output and its value is available to RCX through D3 and R5.



Sample code to read sensor:

    SetSensor(SENSOR_1,SENSOR_LIGHT);
    
    Wait(25);
    
    SetSensor(SENSOR_1,SENSOR_TOUCH);
    
    Wait(5);
    
    SetSensorMode(SENSOR_1,SENSOR_MODE_RAW);
    
    distance=SENSOR_1;
    
    SetSensor(SENSOR_1,SENSOR_LIGHT); //Enable C1 charge as soon as possible



Component selection

    D1 prevents destroying the sensor in case of reverse connexion. I didn't use the full bridge rectifier used in Lego sensor that enables sensors to work when connected backwards (number of needed diodes jumps from 3 to 8 !). I considered that someone able to build this sensor is also able to connect it in the right way... For those who want it, here is the diagram with full bridge rectifier.
    I used 1 Amp. Shottky diode 1N5819 for D1, inexpensive and readily available. Its low forward drop foltage is less than 0.1V for the current that flow through it, this enables to charge C1 to the highest voltage possible.
    C1 stores energy that will be used during measure phase, it must provide 5V at the end of this stage. Assuming typical values for GP2D12 (I=35mA, conversion time=50ms) and an initial 7.5V across C1, its value is C = I * dT / dV = 35 * 50 / (7.5-5) = 700 µF. Small margin with 1000 µF...
    U1 is a low drop out 5V regulator in TO92 case. I used a Telcom/Microchip TC55RP5000, but other regulators will probably work, such as STMicroelectronics L4931-50. Standard regulators such as 78L05 will NOT work because they require more than 7V at input to get a 5V output. Take care with some low drop regulators such as LM2931 that require more than 25 mA when powered at 1V. With RCX current limitation, this hog eats all energy. (I was caught with this one...)
    Q1 switches power on and off for GP2D12. At 35 mA current, I originally used a plain-vanilla BC548. My sensor began to work with it, but exhibited strange behavior. Looking to GP2D12 power supply I then discovered 2V dips ! I then looked at GP2D12 consumption and discovered that it was pulsed (220mA pulses 1/8th of time, supperposed to a 8mA constant current. See oscilloscope captures here). At such a current, BC548 has a low gain, and since I couldn't lower base resistor R1 (main current drain during capacitor charge) I used a high performance Zetex transistor, ZTX718 that offers high gain at high current (other similar devices can work!).
    C2 stabilizes U1 and helps absorb peaks of current. A low ESR version would be better (see "grass" on 5V output when GP2D12 works).

Extending the MAX6959 LED Display-Driver Keyscan from 8-Keys to 12-Keys BAV70

The circuit is shown in the image. Each key requires a dual diode (such as the low-cost common-cathode BAV70 in SOT-23), which pulls both INPUT1 and INPUT2 low when the switch is pressed.

 Each of the four extension keys is wired to simulate a dual key press for the two keys on each of the four LED cathode drive outputs, DIG0/SEG0 through DIG3/SEG3. With this connection, each key pair is always scanned and debounced at the same time. Extra keys that simulate a dual key press of keys scanned by different LED cathode drive outputs will be unreliable. Because the keyscan is performed sequentially, two keys at a time, the extra key could miss the debounce cycle for one LED cathode drive, yet be correctly debounced by the other. This dual key press would then appear as two sequential key presses, not as a dual key press. This wouldn't happen with the recommended connection scheme because each key pair representing a dual key is debounced together.

User Interface - Lcd Driver Based On The HT1621 Controller

Application Note Abstract This Application Note describes implementation of a liquid crystal Display (LCD) driver based on the widely available HOLTEK HT1621 LCD Controller Methods and algorithms of Display control are described and an API library is provided. The LCD used in this example was a customer’s custom part. The proposed algorithms CAN be easily adapted to any custom LCD panel connected to the controller. Introduction LCDs are widely used as data Display devices in embedded systems. Among the features that have made LCDs popular are low price, low power dissipation, lightweight, durability, reliability, and broad support by dedicated ICs for Communication with Microcontrollers A good example of an LCD Driver is the Hitachi character LCD Driver HD44780, the industry standard. This dot-matrix LCD Controller is supported by PSoC APIs. It is useful in applications that permit alphanumeric data Display However, specialized Displays are often needed. Specialized Displays keep end- product prices low, simplify the Interface between the Microcontroller and LCD Driver and decrease weight and size parameters. Examples of specialized Displays include Clocks calculators, telephones, and home and industrial appliances. This implementation is based on one of these dedicated drivers, the HT1621. This Application Note addresses the proposed implementation in two parts: ƒ General Description ƒ LCD Driver Implementation General Description The HT1621 driver is a 128-segment (32x4), multi-functional LCD Driver with memory mapping. The software configuration feature of HT1621 makes it suitable for many LCD applications, including LCD modules and Display subsystems. Only three or four connections are required for interfacing between the host controller and the HT1621. A structural schematic of the Display system is shown in Figure 1. This structure requires few external components and uses only three Interface connections. The system consists of the PSoC, HT1621 controller, and an LCD panel. The HT1621 besides its primary function as an LCD controller, has peripherals including the watchdog Timer time base generator and the Tone frequency generator. For more information about these features, refer to the HT1621 data sheet. Note that the controller has an on-chip RC Oscillator (256 kHz) for controlling the LCD and peripherals. This General Description focuses on the components and functions of the HT1621 driver that relate directly to the LCD: ƒ Display Memory RAM ƒ LCD Driver in HT1621 ƒ Command Format ƒ Interfacing with HT1621

Using DS3902 in Low Cost Optical Modules and Serial EEPROM AT24C02

The two variable resistors in DS3902 are used to set bias and modulation currents. The settings are done through I2C* interface. Some modules may require additional EEPROM. This is typically used for serial ID information, and new modules may need to include this feature. DS3902 has programmable address, therefore connecting it to a single I2C bus line (with other devices) without any additional components.

Figure 2 shows connection details for using DS3902 and a serial EEPROM (ATmel AT24C02) on a common I2C interface. Also Figure 2 illustrates connections to a laser driver.

 The DS3902's default address is A2h (Add_sel = 0). If an address different from A2h is required, Add_sel will be pulled high. Register 00h content is the device address when Add_sel = 1. In the above schematic AT24C02 is configured for A0h address, (A0 = A1 = A2 = 0).

The WP (write-protect) pin connects to ground using a link, allowing R/W access to memory locations. Once the memory is programmed, the WP pin can be pulled high through LK1, to prevent accidental write. DS3902 has S/W protection scheme, whereby access to memory is only possible with password.

The choice of laser driver depends on the specific application and there are a number of Maxim laser drivers to choose from.

MMBT3904 NPN switching transistor

The MMBT3904 is a NPN General Purpose Amplifier. This device is designed as a general purpose amplifier and switch. The useful dynamic range extends to 100 mA as a switch and to 100 MHz as an amplifier.

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Absolute maximum ratings: (1)Collector-Emitter Voltage: 40 V; (2)Collector-Base Voltage: 60 V; (3)Emitter-Base Voltage: 6.0 V; (4)Collector Current - Continuous: 200 mA; (5)Operating and Storage Junction Temperature Range: -55 to +150 ℃.

Features: (1)Collector-Emitter Breakdown Voltage: 40 V at IC = 1.0 mA, IB = 0; (2)Collector-Base Breakdown Voltage: 60 V at IC = 10 μA, IE = 0; (3)Emitter-Base Breakdown Voltage: 6.0 V at IE = 10 μA, IC = 0; (4)Collector Cutoff Current: 50 nA at VCE = 30 V, VEB = 3V.

CA3046 VCA

Using discrete transistors from a transistor array, this circuit avoids an OTA altogether. It uses one transistor as a Gilbert multiplier to predistort the signal, so that a larger signal can be fed into the circuit. The circuit is based on the one described in Modulus issue 5, that was provided by Chris Crosskey.
I have modfied it with a trimmer to adjust the DC offset and adjusted the input sensitivity and output gain to give some headroom and unity gain. This VCA has a linear response. A diode has been added on the control input, to block out negative voltages, which cause DC on the output. Because of the diode, the control caracreristics is unlinear below 1 volt.
The predistortion really works in this circuit. The distortion stays low up to a point where it suddenly increases dramatically. With the chosen resistor values, that point is well above normal signal levels.
Noise figures for this circuit is comparable to the SSM2024 and the LM13600 but signal bleedthrough is not as good. On the other hand, CV bleedthrough is lower than the LM13600, with proper trimming.


CA3046

LM317T Variable Voltage Regulator

The LM317T is a adjustable 3 terminal positive voltage regulator capable of supplying in excess of 1.5 amps over an output range of 1.25 to 37 volts. The device also has built in current limiting and thermal shutdown which makes it essentially blow-out proof.

Output voltage is set by two resistors R1 and R2 connected as shown below. The voltage across R1 is a constant 1.25 volts and the adjustment terminal current is less than 100uA. The output voltage can be closely approximated from Vout=1.25 * (1+(R2/R1)) which ignores the adjustment terminal current but will be close if the current through R1 and R2 is many times greater. A minimum load of about 10mA is required, so the value for R1 can be selected to drop 1.25 volts at 10mA or 120 ohms. Something less than 120 ohms can be used to insure the minimum current is greater than 10mA. The example below shows a LM317 used as 13.6 volt regulator. The 988 ohm resistor for R2 can be obtained with a standard 910 and 75 ohm in series.

When power is shut off to the regulator the output voltage should fall faster than the input. In case it doesn't, a diode can be connected across the input/output terminals to protect the regulator from possible reverse voltages. A 1uF tantalum or 25uF electrolytic capacitor across the output improves transient response and a small 0.1uF tantalum capacitor is recommended across the input if the regulator is located an appreciable distance from the power supply filter. The power transformer should be large enough so that the regulator input voltage remains 3 volts above the output at full load, or 16.6 volts for a 13.6 volt output.

Wideband Sense & Heater Control ADC muxing 74HC4052

 The dual 4 to 1 line mux U4 (74HC4052) allows two groups of four signals to be sensed by the microcontroller's two ADC input lines ADC0 and ADC1.

Wideband signals Vsx5, Ih, Vsx1, IpSense, DACV & Cal (VGND) voltages are sensed as well as H- via filtering provided by R112 and C103. also shown here is the H+ sense signal but it is not selected by the mux, but rather passed directly to the microcontroller via filter components R111 and C102.

Analogue user channel 1 USR1 (see Y5 connector input below) is also sensed by this mux.

Variable Frequency PWM Circuit IRFP064N

R1,R6,R11 = 10K
R2,R9 = 1K8
R3 = 100 ohm
R4,R8 = 1K
R5 = 22K
R7 = 1M
*R10 = 0.003 ohm
R12 = 3K9
R13 = 100K
R14 = 10 ohm/1 Watt
P1 = 20K (Frequency adjust)
P2 = 10K (Duty Cycle)
P3 = 1K (Current Limiting)
C1 = 1000uF, 64V
C2 = 10nF, polyester
C3 = 100uF, 64V
C4 = 22nF
C5 = 47uF, 35V
D1,D2 = 1N4004
U1 = LM7810, volt regulator
U2 = LM324, Op-amp
Q1 = IRFP064N , IRFZ44, etc. MOSFet

FM Stereo decoder using TDA7388

A very simple with a compact design FM stereo decoder schematic circuit can be designed using the TDA7388 IC manufactured by ST Microelectronics .
The TDA7338 is a monolithic integrated stereo decoder with noise blanking for FM car radio applications.
With the used BICMOS technique, the 19KHz Notch Filter, the PLL Filter and Phase Filter is realized on the chip with a Switched Capacitor concept.
The TDA7338 stereo decoder contains all necessary functions for processing the MPX signal.
The only external component needed for the PLL is the ceramic resonator for the oscillator which runs at 456kHz.

The pilot detector output is designed as an open collector output, therefore an external pull up resistor is needed. To force the decoder to "MONO" Pin 19 has to be clamped to a voltage below 0.8V.
Selecting VCO-OFF (Pin 7 to GND) the VCO is switched off and the SB and HCC are disabled.
This TDA7338 receiver circuit needs to be powered by a 9 volts DC power supply .

Flyback converter VIPER12A

Hi,
I've been trying to come up with a really small design that will take mains line voltage in the range of 90-250 volt a/c - 50/60 Hz and output
5 / 3.3volt at < 500mA.

I don't want to use a big transformer+linear regulator because of the size !

I've seen implementations like Microchip AN954, (capacitive and resistive PSU):



Then I located the ViPer family of devices from ST, specifically the VIPER12A which can handle a bulk and flyback configurations.
It provides some sort of protection and I like them, they come in DIP package and most important I can source them in my town !

From the app note "AN1484":
The circuit is a standard Flyback converter with secondary current and voltage regulation driving the VIPer12A feedback pin through an optocoupler.

This is the design I was looking for !, it's small, safe and it's been used all over the world but I know nothing about them  :o,
I feel I'm going through the rabbit hole and things get complicated every step of the way.
First and most important it's very hard to find the correct flyback transformer, the two vendors I found don't have a sales webpage they work only
through distributors, and even then I'm not sure about the stock.

The MC44603P 750w power problems 20N60

burn the IGBT control

IGBT with a 20N60

Anyboday can help?

Thank you!

74HC14D Hex inverting Schmitt trigger

The 74HC14D is a hex inverting schmitt trigger. The 74HC14D is a high-speed Si-gate CMOS device and are pin compatible with low power Schottky TTL (LSTTL). They are specified in compliance with JEDEC standard no. 7A. The 74HC14D provides six inverting buffers with Schmitt-trigger action. They are capable of transforming slowly changing input signals into sharply defined, jitter-free output signals.

74HC14D absolute maximum ratings: (1)VCC supply voltage: -0.5 +7 V; (2)IIK input diode current VI < -0.5 V or VI > VCC + 0.5 V: ±20 mA; (3)IOK output diode current VO < -0.5 V or VO > VCC + 0.5 V: ±20 mA; (4)IO output source or sink current: -0.5 V < VO < VCC + 0.5 V - ±25 mA; (5)ICC; IGND VCC or GND current: - 50 mA; (6)Tstg storage temperature: -65 +150℃.

74HC14D features: (1)Complies with JEDEC standard no. 7A; (2)ESD protection: HBM EIA/JESD22-A114-A exceeds 2000 V; MM EIA/JESD22-A115-A exceeds 200 V; (3)Specified from -40 to +85℃ and -40 to +125℃.