D/A conversion, SC HR-04, AT89S52

[RAHUL_KUMAR]

D/A conversion , SC HR-04 , AT89S52

uController - AT89s52
ultrasonic sensor - SC HR-04
DAC sensor - MCP4921 (D/A conversion using SPI)

The complete module was working fine in normal condition.

PROBLEM ARISES when the system is applied in its respected application area.
the sensor is attached to the torch of welding machine ,which measure correct distance and its corresponding voltage UNLESS the welding machine is on .

during POWER ON of welding machine or when it start functioning ,..the sensor stops working.

what would be the probable reason?

 

[baileychic]

Re: D/A conversion , SC HR-04 , AT89S52

Power supply is dipping when welding machine is powered and also while welding is being done. Welding machine draws more power from mains. If you have a incandescand bulb connected to mains supply where welding transformer is connected then you can observe that when welding is being done the light dims due to voltage dip. If you are not powering the sensor from a regulated 5V supply then you have to use a regulated power supply of 5V and at the input of the regulator use a 10000uF capacitor. See if this works.

What is the voltage rating of the power supply transformer ? The LM7805 regulator input should be min 3V above its output that is input should be min 8V for it to work properly. If this voltage is dipping while welding then you might need to change the transformer to say 0-15V transformer and also add the 10000uF Capacitor.

 

[KlausST]

Re: D/A conversion , SC HR-04 , AT89S52

Hi,

other probably issues:
* the welding process may send out ultarasonic sound that affects SC HR-04 operation.
* the welding process may couase a huge amount of EMI noise that affects the operation of the sensor.

Klaus