PC817 High Density Mounting Type Photocoupler

An optical isolator is known as a device which enables transmission of an electric signal by making use of the signals induced by light. The theory behind this is that coupling needs to be done between the insulation of input and output of a circuit board or a single wire which makes use of these principles. The basic purpose of any kind of optical isolator or a photo coupler is to make sure that any high changing voltages do not damage the components. This is done via carefully designed and manufactured photo couplers which are sold by a couple of different electronics manufacturers out there. Most known manufacturer of photo couplers is Sharp. If you’re interested in upgrading your circuitry with a device like this, you will need to do some proper researching first. Since this is a component which is intended to protect your devices, it’s important to know exact specifications of the photo coupler you’re looking for. Fortunately, this is no problem since there are plenty of datasheets specific to PC817 photo couplers which you can get for free online and get all the information you need. For starters, you can visit HQEW.net ’s official website where you might find some decent information on how can you order their products, but it’s more important for you to test your circuits first to know what numbers need to be matched and to what extent. Tolerances are very important here and this research will help you save cost on future purchases.

Recharge a 9V NiMh battery with a Solar Panel / Constant Current Generator LM317LZ

 
If you enjoyed the previous post solar-powered Arduino board, you should keep reading this one as well to improve your solar power generator. In fact, with that setup the 9V battery would decay too soon: A NiMh (Nichel – metal hydroxide) battery must be recharged with a constant current generator, a solar panel alone is not.

In order to do so, we can assemble a quite simple circuit using the following components:

    LM317M or LM317LZ
    A 200Ohm trimmer
    10Ohm resistance
    A LED to check if the current is actually flowing

The core of this circuit is the integrated three-terminal adjustable linear voltage regulator LM317. The ‘adj’ pin is a control terminal that is used to adjust the output current. So, the trick is to use a variable resistor (in our case, a trimmer with a small resistance put in front of it) to set the current at a definite value.

With an input DC voltage of max 24V, and the resistances shown in the diagram, one can obtain an output current of:

I_out = 1.2/(10 + R_trim) [A]

This current must be less than 1/10 of the battery output, e.g. for a 750mAh battery the output current must be less than 75mA. As usual, it is customary to insert a capacitor (100uF should be ok) in parallel at the input node to smooth out fast-varying voltages.

The CA3046 was pure simplicity

When you learn about making things like amplifiers in EE class, you learn about how important it is to have matched pairs of transistors. Symmetry tends to be just as important in electronic circuits as it is in plant life: pairs of tubes supply and remove fluids from a plant leaf much the same way electrons flow through paired transistors in an amplifier. Optimal behaviour occurs when these sides respond in a balanced, symmetrical manner (in the most common cases.)

The more closely you can match the behaviour of these 2 transistors, the more symmetrical the circuit becomes. So, someone got the bright idea — what if we put more than one transistor on the same piece of silicon? Thus, the integrated circuit was born: not with the goal of putting computers on chips (or anything digital, for that matter), but with the idea of making the performance of a circuit uniform.

The earliest ICs only had simple transistors on them. The CA3046 was pure simplicity: 5 matched NPN type BJT transistors on the same chip. You could continue to build circuits the way you were used to — with resistors and capacitors on the circuit board or prototype board — and simply replace the transistors in there with matched transistors, formed from the same piece of silicon. Presto, your circuit sounded a lot better. If you went high volume, you could have your circuit burned into its own integrated circuit; many opamps (the building block of modern analog circuit design) were designed this way. Or you could create a printed circuit board, and go that way — the sort you might have seen in just about every consumer electronics product in the 1970s and 1980s.

The CA3046 (and its strange partner, the CA3096: 3 NPN, 2PNP in a single chip) helped us ring in an age of harmony. Matched pair transistors were essential to building harmonic circuits that were pleasing to the ear. The original Moog “transistor ladder” design required hand matching of transistors; were the CA3046 available then, Moogs probably would have been a lot cheaper (had they not already become a “fad”)  .

Later I had a few missed starts trying to make circuits: a failed design for a video game emulator cartridge that was already halfway into production nearly bankrupted me, and I lost heart. I put away my skills for many, many years, always thinking that i could fall back on it if I really needed to. Now I see it’s a skill I’ve neglected for far too long, and one that can enrich my life if I only take the time to apply it artfully. 

Best DC power supply 3Amp LM317T

There is the high quality power supply to provide high current 3A. And still adjust voltage in steps from 3V, 6V, 9V, 12V. adjust voltage is continuous 1.25V to 20V. Using LM317T and 2N3055 are main parts so easy to made and cheap.

Friends would known the power supply as well. Because you must use in various circuit experiment. It originally had a small supply current, when found projects that uses lot of current. Such as an audio amplifier circuit so provide current is not enough.
This project can help you. Because of provide high current 3A. And still adjust voltage in steps from 3V, 6V, 9V, 12V. adjust voltage is continuous. And you do not have to worry. This creates a simple and economical. If interested, please read on.

How it works
In the circuit below can be seen that, when opening switch S1 is current through the transformer. To convert from 220V AC to 18V, then through diode bridge rectifier BD1. But is a DC supply that still not smooth. Then, a filter capacitor C1 serves electricity, out of BD1 to be more smooth with the LED1 to show that power is supplied to already.
When the filter current is smooth on one order. The current will through the regulator circuit that the main components are IC1(LM317T) and Q1(2N3055).
-IC1 is the regulator IC number : LM317T.
-Q1 is power transistor NPN type number : 2N3055.

Before the DC volt through IC1 would have C2 served filter noise off. When we adjust the variable resistor VR1 or rotary switches S3 twist choose it. Will cause changes the voltage at the ADJ pin and OUT pin of IC1. Which will be resulting the voltage drop across the base pin and the emitter pin of transistor Q1 changes. Makes the voltage on the connector is changed accordingly. And before the voltage is applied to current C3 filter to smooth again.
Detail see in circuit image.

12V Low side and High side PWM Motor/Light Controller IRFZ48N

 

 

Here these two schematics are variations on addition PWM circuit that I designed. The diagrams are for 12V operation alone and there are aerial ancillary (common ground) and low ancillary (common +12V) versions. The low ancillary adaptation of the ambit uses an N Channel FET, the aerial ancillary adaptation of the circuit uses a P Channel FET. N Channel accessories tend to handle added accepted than P Channel devices, they are additionally beneath expensive. The aerial ancillary adaptation of the ambit is advantageous back one ancillary of the bulk has to be grounded.

This Circuit can about-face a adequately aerial bulk of current, an IRFZ34N MOSFET can handle over 35 Amps if affiliated to a able calefaction sink. Higher ability FETs, such as the IRFZ48N or IRF1010Z can be commissioned if alike beyond currents are required. It is additionally accessible to affix assorted FETs in alongside for alike added accepted capacity. Always use thermally conductive grease amid the FET and the calefaction sink, and bethink that the calefaction bore is electrically live.

Inductive endless (motors) may crave appropriate affliction back they can accomplish ample voltage spikes that can accident the MOSFET. Replacing the 1N4002 with a fast accretion diode may advice blot the about-face voltage bang back active an anterior bulk such as a motor. If you use these circuits for abstracts with electric vehicles, be abiding to install a ambit breaker in alternation with the battery, the ambit breaker should be accessible to ability by the driver. This is abnormally important due to the actuality that back MOSFETs fail, they generally abbreviate out, abrogation the motor on at abounding speed.

Note that the pwm ascendancy has an adverse aftereffect on these two circuits, the low ancillary adaptation is on with a aerial pin 7 achievement voltage and the aerial ancillary adaptation is on with a low output.

The inductor on the aboideau ancillary of the ability MOSFET transistor can be a ferrite bean or a few turns of wire captivated about a 10 ohm, 1/4W resistor. The purpose of this allotment is to anticipate RF oscillations from occurring in the MOSFET circuitry.

Remote Control by using RF remote control Encoder and Decoder PT2272

RF Modules are used wireless transfer data and low cost application . This makes them suitable for remote control applications, as in where you need to control some machines or robots without getting in touch with them (may be due to various reasons like safety, etc). Now depending upon the type of application, the RF module is chosen. For short range wireless control applications, an RF Transmitter-Receiver Module of frequency 315 MHz is the most suitable type. This RF modules are works with PT2262(encoder) and PT2272(decoder) as remote control.


Specification:

Frequency: 315Mhz
Modulation: ASK
Transmitter input voltage: 3-12V
Transmitter(RF-TX-315) and Receiver(RF-RX-315)

Range in open space(Standard Conditions) : 100 Meters

PT2262

Is a remote control encoder paired with PT2272 utilizing CMOS Technology. It encodes data and address pins into a serial coded waveform suitable for or IR modulation. PT2262 has a maximum of 12 bits of tri-state address pins providing to 531,441 (or 312) address codes; thereby, drastically reducing any code collision and unauthorized code scanning possibilities.

 

PT2272

Remote Control Decoder PT2272 is a remote control decoder paired with PT2262 utilizing CMOS Technology. It has 12 bits of tri-state address pins providing a maximum of 531,441 (or 312) address codes; thereby, drastically reducing any code collision and unauthorized code scanning possibilities. This IC has Latch or Momentary output type.

VENDOR chip data sources offer PDF | IPSec and NAT compatibility analysis and solutions

Network security protocol IPSec (IP Security) and TLP181 datasheet and Network Address Translation NAT (Network Address Translation) has been widely used, but if the words run together, will encounter many problems. From the perspective of IP, NAT to the IPs were revised lower, to the IP protocol, it is a departure; and TLP181 price and from the application point of view, network managers have to deal with the problem of network addresses, NAT allows the user to take a variety of ways to their own network and TLP181 suppliers and the host of the external public network hiding is a good tool, now, whether large or small and medium enterprises are in use. And NAT, like, IPSec: is also a good tool, he can safely allow users to connect through the Internet to a remote terminal. However, the IPSec protocol architecture itself and the lack of support for IPSec, NAT devices, when the IPSec and NAT will be running with a lot of problems. To solve the problem of coexistence between the two, it is necessary for IPSec and NAT have a certain understanding.

NO-NC SSR Plastic Box ICL7107CPL

This was a Fire Retardant Plastic Box which was made for the SSR I/O Stackable Modules. DC Control for an AC Load. Usually it is to control another Big Three phase contactor; Pneumatic or Steam Valve, Solenoids-Motors. When Mounted at the end of the PCB it offers over 2kV Isolation from the Digital Circuits. The Output 230V signals NO-NC, can control Light Loads like the Coil of a Big 230V Relay also called contactor.

NO NC SSR Box

20N60      ICL7107CPL       SSM2164        2SC2625

It could be Mounted on a PCB by soldering or a Plugin Base. It is better to have Crimped connections or Terminals. A very good quality spring Loaded Socket may also work but it has to be rated for many operations. Things like Nickle Alloy Plated, Beryllium Copper were the Materials Jargon. A contact resistance in the Terminals, a mismatch of alloys, electrochemical reactions, Corrosive Fumes, Brine or High Humidity can build a Loose connection into a Dangerous Sparking Contact.

Not only the Functionality of the SSR will be affected in a Sparking Contact, but a Risk of a Fire Developing. When Inflammable Materials or Volatile Liquids are Present Nearby, the risk is even greater. Read More – Solid State Relays SSR

Accelerometer, Arduino and Processing - MMA7260Q

Accelerometers can measure acceleration and tilt (angle). They are used in many devices nowadays such as Mobile phones (iPhone), Gaming consoles and gadgets (Nintendo Wii), Navigation (GPS navigators, Airplanes), and etc. In physical computing accelerometers are used to measure device’s position relative to the ground.  A simple Accelerometers can measure acceleration along one axis. Here, a simple program is presented that interfaces a 3-axis MMA7260Q accelerometer from Sparkfun to an Arduino board.

Use a MMA7260Q “triple Axis Accelerometer Breakout board” from Sparkfun. Connect the board as shown below to an Arduino board:

Be careful while making connections to your Arduino, not to misconnect the Negative and Positive supply.

Download the code for Processing and Arduino in a zip package . Unzip and upload the code provided for the Arduino to your Arduino board. Then run the code provided for Processing. Press ‘X’, ‘Y’, ‘Z’ key on your keyboard to see the real time graph for the corresponding axis on your screen.

The Arduino code sends three consecutive bytes by serial baudrate of 9600. On the computer side the processing program gets the data and translates the bytes (each byte for one axis[X,Y,Z]) into a graph representation.

Diagram Block IC TDA7377

The TDA7377 is a new technology class AB car radio amplifier able to work either in DUAL BRIDGE or QUAD SINGLE ENDED configuration.



The exclusive fully complementary structure of the output stage and the internally fixed gain guarantees the highest possible power performances with extremely reduced component count. The on-board clip detector simplifies gain compression operation. The fault diagnostics makes it possible to detect mistakes during car radio set assembly and wiring in the car.

The stand-by can be easily activated by means of a CMOS level applied to pin 7 through a RC filter. Under stand-by condition the device is turned off completely (supply current = 1µA typ.; output attenuation= 80dB min.). Every ON/OFF operation is virtually pop free. Furthemore, at turn-on the device stays in muting condition for a time determined by the value assigned to the SVR capacitor.

While in muting the device outputs becomes insensitive to any kinds of signal that may be present at the input terminals. In other words every transient coming from previous stages produces no unplesantacoustic effect to the speakers.

Voltage Comparator Circuit with MOSFET - CA3140

I would like to present the voltage comparator circuit ,you can bring this circuit to apply with your project that concern in voltage checking or comparison.
This circuit provides an indication if has the input voltage differs from the two defined limits, V1 and V2 voltage source. We can adjustable limit and made to trigger from the adjustable “window”.

As to the amplifiers to the CA3140 MOSFET is used in circuit. They are used to benefit, as they have very little influence and can counteract the tension for change near 0 volts.

If a second operational amplifier is used as LF351 and CA741, will require a zero transverse force control.

This is only a predetermined 10k contact between pins 1 and 5, the wiper connected to the negative supply voltage and the pin of the fourth operational amplifier With this circuit, both operational amplifier, the LED when the input voltage out of range, 1N4148 diodes both “Y” to the exit door. The input voltage to be monitored is supplied through a 10K series resistor to the inputs of the two amplifiers operational amplifiers. If the input voltage exceeds the threshold value V1 and CA3140, the output voltage swing almost completely and turn off the LED. Similarly, if the input voltage is lower than the limit defined by V 2, then this is the operational amplifier moves to the Vcc and light the LED.

When PWM is turned on - IRFP450

During the ON time of the cycle, the MOSFET turns on and starts conducting. Since inductor poses no resistance to DC current, large current flows through the MOSFET. This large current then becomes constant at some point during the ON time of the cycle. Due to the property of inductor, the energy is stored in its magnetic field around it.

During the OFF time of the cycle, MOSFET turns off and no conduction can take place. Due to the property of inductor it blocks any change in current. Because of this, the energy stored in its magnetic field is released. This creates high current. But since the MOSFET is turned off, the large current flows through the diode and charges the capacitor.

When the whole process is done fast enough, we are able to achieve a large voltage at the output.

In this experiment, I have used an old inductor from switch mode power supply that I found in the computer’s monitor. So I don’t know the value, but it is definitely greater than 200uH. IRFP450 MOSFET (HEXFET as they call it) can carry 14 amperes of current, and has a very very low drain to source resistance. The reason for using such a large MOSFET is, it does’t heat up. If you use a MOSFET with large drain to source resistance, you are going to get a lot of heat, this increases the possibility of destroying the transistor (I already destroyed like 4 expensive MOSFETs)

MOSFETs are very sensitive to heat and over voltage, so please take care that you do no exceed the specifications. My advice would be to obtain MOSFETs from old power supplies. You can also get a good number of high voltage fast response diodes from those old circuits.

I suggest you to build this circuit and try out different values of inductor and PWM. Here is a small arduino code used for generating PWM with On time of 50 uS and OFF time of 15 uS.

When this PWM configuration is used with my circuit it can yeild upto 394 V. I did not go beyond that, because the capacitors I have used are limited to 400V and so is the diode. So it is better to be safe below the range.

A CL Version 2N7000

The CL version shows the basic ideas but the LTspiceIV version runs much faster and it is far easiler to see the detail of the waveforms concerned.

There are some minor differences between the LTspiceIV and CL versions to do with the availability of models: namely the CL version uses the 2N7000 MOSFET which has a somewhat different SOA compared to the 2N7002 used in LTspice.
 

Two Wire Arduino Knight Rider PCF8574

This tutorial shows how to interface eight LEDs to an Arduino using only two Arduino pins. This is made possible by using a PCF8574 I/O expander IC. A “Knight Rider” display is shown on the LEDs.

The suggested sequence of building the circuit is:

    Insert the PCF8574 IC
    Make power and ground connections to the IC
    Connect pin 1, 2 and 3 of the IC (U1) to ground
    Insert capacitor C1 (100n) and wire it between power (5V) and ground (GND)
    Insert the eight LEDs with anodes (longer pin) on the left
    Connect resistors R1 to R8 between the LED anodes and the top breadboard rail (5V)
    Wire the cathode of each LED to the correct pins on the IC
    Connect R9 and R10
    Connect the two wires from Arduino pins A4 and A5 to the IC
    Connect the Arduino 5V to the top breadboard rail and GND to the bottom breadboard rail

You may have noticed that the breadboard circuit swaps the position of the LEDs and resistors from the circuit diagram – e.g. R1 and D1 swap positions. This will make no difference to how the circuit operates. It has only been done to simplify the breadboard circuit.

Is the bc337 and 2n4401 similar enough to use each other?

For many applications, yes. 
The BC337 comes in different gain grades, but the 2N4401 is about in the middle of the middle grade. The 4401 is a bit faster, but has a bit lower voltage and lower max current rating. But if you operate it with under 40 volts collector to emitter and with a collector current no higher than 100 mA, they should both work well in most circuits. 
Note that you have to reverse the flat side orientation to get the leads to have the same definitions.

60kHz PIC Function Generator - LF353

  This project is based on the Function Generator described on Mondo Technology web site. I just did very slight changes and fixed some obvious typos in schematic. The code is rewritten for the Microchip MPLAB IDE syntax.

    Device features

        Frequency range: 11Hz – 60KHz
        Digital frequency adjustment with 3 different steps
        Signal forms: sine, triangle, square, pulses, burst, sweep, noise
        Output range: ±15V for sine and triangle, 0-5V for others
        Sync output for pulses

    The device is powered from 12VAC which provides a sufficiently high (over 18V) DC voltage needed for a normal operation of 78L15 and 79L15. The 12V power supplies are replaced with 15V ones. This is done in order to LF353 Op-amp could output the full range of signals to a 1K load. By using a ±12V supply this resistor must be at least 3K.
 

Types of Serial EEPROM Chips - 93C46

There are several types of Serial EEPROMs, but most of them fall into either a 2-wire or 3-wire interface category. Usually, the 3-wire devices require an addition wire (beyond the 3 for data transfer) for each chip to be used. The 2-wire interface, called I2C or IIC or "I squared C" uses only two wires, regardless of how many chips are attached. I2C is a trademard of Philips. The three wire interfaces include SPI and Microwire, which is a trademark ofNational Semiconductor.

As the pressure on engineers to make products smaller has grown, semiconductor manufacturers have introduced several new interfaces, usually aimed at lower a product's size and cost... and undoubtedly many more will appear in the future.
As a practical matter, the code offered below only works with the Microwire 3 Wire interface, and is specifically intended to work with the 93C46, which is a standard part available from a variety of distributors.

What is an FM transmitter?

An Fm transmitter is a circuit/device to transmit audio signals to an fm radio receiver through air (wirelessly). The input (audio)to an fm transmitter can be fed using a microphone or the output of your music player to be transmitted, and the signal which you transmit can be received using an FM radio, the advantages of FM TRANSMITTERS ARE many:

1.You may transmit audio to another room/floor of your house without using any wires!

2.You may transmit your own voice if you used an electret microphone in the circuit

3.You don’t need to build a receiver to receive the ransmitting audio as any standard fm radio can be used to receive your voice/audio and many..!

building the circuit
this circuit can transmit audio to a distance of around 50 meters if you used 2n3904 transistor and boost the supply voltage to 6V, and 1Km(1 kilometer) if used S8050 transistor with 9V supply!

BS170 - is used for the QRP rig PA

The 2N7000 PA was described in my blog message sometime ago. The BS170 by Fairchild can be also used for QRP rig PA. It is N-Channel Enhancement Mode FET. The Maximum Power Dissipation Pd is 830mW, therefore it can be suitable for QRP rig PA. The transmitter section of ADC-40 is the dual BS170 and it generates about 4watts with 13.8V power supply. The small heatsink is required to use BS170s for PA because it will be hot and drops the power. The PFR-3A is the triple BS170 for PA and generates 5 Watts with 12V power supply.

An integrated circuit MAX232

The MAX232 is an integrated circuit, first created by Maxim Integrated Products, that converts signals from an RS-232 serial port to signals suitable for use in TTL compatible digital logic circuits. The MAX232 is a dual driver/receiver and typically converts the RX, TX, CTS and RTS signals.

The drivers provide RS-232 voltage level outputs (approx. ± 7.5 V) from a single + 5 V supply via on-chip charge pumps and external capacitors. This makes it useful for implementing RS-232 in devices that otherwise do not need any voltages outside the 0 V to + 5 V range, as power supply design does not need to be made more complicated just for driving the RS-232 in this case.

The receivers reduce RS-232 inputs (which may be as high as ± 25 V), to standard 5 V TTL levels. These receivers have a typical threshold of 1.3 V, and a typical hysteresis of 0.5 V.

The later MAX232A is backwards compatible with the original MAX232 but may operate at higher baud rates and can use smaller external capacitors – 0.1 μF in place of the 1.0 μF capacitors used with the original device.

The newer MAX3232 is also backwards compatible, but operates at a broader voltage range, from 3 to 5.5 V. 

Pin to pin compatible: ICL232, ST232, ADM232, HIN232.