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.