Showing posts with label a. Show all posts
Showing posts with label a. Show all posts

Testing A FT245RL Chip with Software

Friday, September 26, 2014 | Labels: , , , , , | 0 comments |
Chips FT245RL testing, checking for the program. It can set the output and input signals to the findings and submit. It is thus possible to enable or disable the 8 channels, for a 8-channel input. It all started a long time ago. Once, when I learned that the computer can be sent off signals that you can manage yourself, immediately began to take interest in the way they can do. It was somewhere in ~ 2002. After browsing the internet and found some examples of how the device can be connected to an LPT Port,.

Testing A FT245RL Chip with Software

Since that time almost all computers have an LPT port, its all gone well. In the LPT port connected LEDs managed a program written by someone that has been written as to support in the MS-DOS. It certainly was not a pleasant appearance, ease of operation ... Was only possible to manage such a procedure, a combination of ... as was intended by its creator. Therefore, once thought myself why can not I create and manage the program as he wants. So began an interest in computer programming and bonding with their devices. [Link]
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A Li Ion Battery Charger with Load Sharing MCP73837

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Batteries often serve as the main energy source for portable electronic devices. Although they depend on batteries, portable consumer electronic products, such as GPS devices and multi-media players, often consume energy directly from an ac-dc wall adapter or accessory power adapter (or “Auto Adapter”) when the battery is low or the device is in a stationary mode. Due to their cost effectiveness over their useful life, rechargeable batteries are often used for the power source of the portable electronic device.


Designing A Li-Ion Battery Charger with Load Sharing - MCP73837

 
Attributes such as “relatively high energy density” and “maintenance free” make Lithium-Ion (Li-Ion) batteries popular in the portable consumer electronic products. Refer to the application note, AN1088, “Selecting the Right Battery System For cost Sensitive Portable Applications While maintaining Excellent Quality” (DS01088) for characteristics of Li-Ion batteries. Some examples of how to properly design with Li-Ion batteries will be discussed in this application note. [Link]
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Build a Telephone Record Control Circuit Diagram

Tuesday, September 23, 2014 | Labels: , , , , , , | 0 comments |
This simple Telephone Record Control Circuit Diagram will allow you to connect any tape recorder that has a mic and remote input to a phone line and automatically record both sides of a conversation when ever the phone is in use. You will need to take a couple of voltage readings before connecting the circuit. First determine the polarity of your phone line and connect it to the circuit as shown and then determine the polarity of the remote input and connect it to the circuit.

Circuit operation is as follows. When the phone is on hook the voltage across the phone line is about 48volts dc. When the phone is off hook the voltage will drop to below 10volts dc. When the line voltage is at 48volts the FET is off which causes Q2 and Q3 to be off. When the phone is picked up the FET turns on along with Q2 and Q3 which turns your recorder on. The tape recorder must be in the record mode at all times. As you can see the power source for the circuit is the phone line. 

Telephone Record Control Circuit Diagram

Telephone Record Control Circuit Diagram
 
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Build a Wideband UHF Amplifier Circuit Diagram

Friday, September 19, 2014 | Labels: , , , , , , | 0 comments |
This is the simple wide band UHF amplifier with high-performance fetes. The amplifier circuit is designed for 225 MHz center frequency, 1 dB bandwidth of 50 MHz, low input VSWR in a 75-ohm system, and 24 dB gain Three stages of U310 FETs are used in a straight forward design.


Wide-band UHF Amplifier Circuit Diagram


Wideband UHF Amplifier Circuit Diagram

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Build a PC Based Timer Circuit Diagram

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Timers are very useful both for industrial applications and household appliances. Here is a PC-based timer that can be used for controlling the appliances for up to 18 hours. For control, the timer uses a simple program and interface circuit. It is very cost-effective and efficient for those who have a PC at workplace or home. The tolerance is ±1 second.

The circuit for interfacing the PC’s parallel port with the load is very simple. It uses only one IC MCT2E, which isolates the PC and the relay driver circuits. The IC prevents the PC from any short circuit that may occur in the relay driver circuit or appliance. The glowing of LED1 indicates that the appliance is turned on. Transistor BC548 is used as the relay driver.

The program code is written in ‘C’ language and compiled using ‘Turbo C’ compiler. When the program is run, it prompts the user to input the time duration in seconds or minutes to control the appliance. After entering the required timing, press any key from the keyboard.

Suppose you input the total duration as ‘x’ minutes, of which ‘on’ and ‘off’ durations are ‘y’ and ‘z’ minutes, respectively. The program will repeat the on-off cycle for x/(y+z) number of times. After completion of the total time, to repeat the cycle, you will have to reset the time in the program to activate the circuit.

PC-Based Timer Circuit Diagram

PC-Based Timer Circuit Diagram


The program uses two bytes for storing integer type data. So when input is given in terms of seconds or minutes, it can hold 216–1=65,535 seconds or 18 hours at the maximum. The sleep() function in the program is used to hold the appliance in ‘on’ or ‘off’ condition for the ‘on’ and ‘off’ periods as entered by the user against prompts. The sound() function is used to give a beep during ‘on’ condition of the appliance.

EFY note. The source code and executable file of this program have been included in this month’s EFY-CD.

Sourced By: EFY Author Akshy

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Lock Down USB Ports via a PIC Based Smart Card Reader

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What i am making here is a USB lock with smartcard key. The idea is that a phonecard reader made with a PIC micro will be able to store a number of different phonecards into memory. Whenever one of these cards is inserted into the slot, it will activate a 4-ports USB On/Off switch. If the card is removed, the USB ports will be de-activated. [Link]

Lock Down USB Ports via a PIC-Based Smart Card Reader
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Build a Power Pulse Using by LM350 and NE555 Circuit Diagram

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This is a Simple Power Pulse Using by LM350 and NE555 Circuit Diagram. This circuit can use to drive lamp,power LED,DC motor etc. Adjust R5 for output amplitude.Adjust R1 for output power .

Power Pulse Circuit Diagram

Power Pulse Circuit Diagram


The LM350 is adjustable 3-terminal positive voltage regulators is capable of supplying in excess of 3A over a 1.2V to 33V output range.This circuit requires 5-15V power supply.
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Build a Fast Breaker Circuit Diagram

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This is the simple and Fast Breaker Circuit Diagram. This 115 Vac, electronic circuit breaker uses the low drive power, low on resistance and fast turn off of the TMOS MTM15N50. The trip point is adjustable, LED fault indication is provided and battery power provides complete circuit isolation. The two `circuit breaker` terminals are across one leg of a full wave diode bridge consisting of D1-D4. Normally, Q1 is turned ON so that the circuit breaker looks like a very low resistance. 

 Fast Electronic Breaker Circuit Diagram



One input to comparator Ul is a fraction of the internal battery voltage and the other input is the drop across zeners D6 and D7 and the voltage drop across R1. If excessive current is drawn, the voltage drop across Rl increases beyond the comparator threshold (determined by the setting of R6), U1 output goes low, Q1 turns OFF, and the circuit breaker `opens.` When this occurs, the LED fault indicator is illuminated.
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Testing the Photovoltaic Effect with a Transistor

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Most photovoltaic cells are made of silicon chip above which there resides a very thin layer of noble metal through which around 1% of photon particles enter the material and activates electron flow. Here I’m showing how to make one simple solar panel using transistor. [Link]

Testing the Photovoltaic Effect with a Transistor
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Build a 32W Amplifier Circuit Diagram Using by TDA2050V

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Build a 32W Amplifier Circuit Diagram Using by TDA2050V. This is a simple circuit diagram, 32w per channel stereo power amplifier made using the TDA2050V monolithic integrated circuit.

32W Amplifier Circuit Diagram 

32W Amplifier Circuit Diagram


Notes:

This circuit is for a 32 Watt stereo audio power amplifier using the TDA20501. With a dual 22 Volt supply this amplifier can deliver 32W into 8 ohm loudspeakers. Moreover, the TDA 2050 delivers typically 50W music power into 4 ohm load over 1 sec at VS= 22.5V and f = 1KHz. The amplifier is cased as a Pentawatt package see pinout below:

TDA2050V

This is a power amplifier and requires 200mV RMS for full output. Voltage gain is 30.5dB with resistor values shown. Closed loop gain is set by Ratio R1/R2. Increase R2 for less gain and vice versa. Power bandwidth is 20Hz to 80KHz. R3, C3 and R6, C11 form a zobel network to prevent high frequency instability.

The speaker is direct coupled, therefore no expensive large value electrolytics are needed and the bass will be crisp and clean. It is advisable to place fuses in the power supply (not shown).

Parts List:

R1,R4,R5,R8______22k 1/4W Resistor
R2,R7__________680R 1/4W Resistor
R3,R6___________2.2R 1/4W Resistor
C1,C10___________1u NP 25V Capacitor
C2,C12__________22u 63V Electrolytic
C3,C11_________0.47u 400V Polyester
C4,C7,C8,C9_____100n 400V Polyester
C5,C6,C13,C14___220u 63V Electrolytic
U1,U2__________TDA2050V 32W Audio Power Amp
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