Door Security Lock with Keypad

Hafiz Abdul Haseeb Tariq

Security is important everywhere. To secure things using the digits, keypads are used to take the input from the user. For this purpose, components that you need are:

Microcontroller: At89c51

Microcontroller At89c51

Keypad: cellular phone keypad (4×3)

Microcontroller At89c51 programming

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How to test KIA78R09PI

sir, May I know how to test “KIA78R09PI”. There is not output voltage
from the mentioned ic on the PCB of TV. and I can’t understand to
test it. please show some ideas to test it. hope lots of help comes.
thanks

 

Reply:

This is a 4 pins Voltage Regulator IC. It has an additional control pin and the signal usually coming from MCU IC to trigger the IC so that there will be output. If there is no signal to the control pin this means there will be no output. The first thing to check, the IC must have DC input first. You need to locate the datasheet in order find out the control pin. If there is an On signal (usually few volts) to the control pin and if the input dc voltage is presence and no output voltage then direct replace the IC. If the load has something shorted, it can also cause the output line voltage to drop. This also means you need to lift up the IC output pin and test. If still no output voltage then the IC indeed is faulty and need replacement

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ViewSonic LCD Monitor Went Off After Few Minutes

Dear sir,
One of the LCD ViewSonic VA1931WA-2, complaint was it went off after 3 to 5 minutes. I connected the VGA cable and power on, Viewsonic logo appeared but after 5 minutes power went off. The power LED also went off. I pressed the power switch but i didn’t work, I switched off the main power and connect again display will come, but after 3 to 4 minutes power went off again.

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New Elditest High Voltage Oscilloscope Probes

high voltage probes

Recently Cal Test Electronics introduced a new line of Elditest brand High Voltage Oscilloscope Probes. The line includes the following models:

  • CT2982B
  • CT4024
  • CT4025
  • CT4026
  • CT4028




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About IC Programmer In the Market

For the past weeks I’d been receiving a common question about IC programmer. The question was which one is the best and which programmer can be used to program my ICs? Actually there is no best programer in the market because programmers coming out to the market every now and then with better features and etc. Ok here is the answer for those who wanted to buy a programmer:

1) Make sure that programmer could support the IC part number that you want to program. Most of the programmer website will list out the IC part numbers. If the programmer could program many types of ICs( MCU, PIC, EEPROM, FLASH ROM and etc) then it will be good

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