use 8952 to control ac loads

[shafee001]

please can you make any suggestion to solve my problem
i built a program that lets 8952 to control ac loads, using uln2003 to drive 12 volt relays , that relays connected to ac loads.
when ac loads connected the circuit halt (some times)

waiting for reply,
thanks

 

[mondunno]

hi, nice situation.

just tell me whether u've connected the relay properly(dun connect the load, instead check working of relay)

the power on reset of the controller board would be triggering more resets when u have connected the circuit. so just connect a bypass capacitor(100uf+) across the VCC (5V)

or if u have connected the uln2003 all wrong.
one test, dont connect the uln to VCC(leave it open). rather just connect the relay coil with one end to 12 volts the other end to uln.

tell me if u've problem with working of this circuit. do reply if u dint get the circuit right and working.
all the best

 

[shafee001]

hi mondunno
i tried so
but nothing changed
do you have any other suggestions
thanks

 

[zhanhualiu]

Carefully check the VCC and GND for MCU,they should be seperately connected to power supply with VCC&GND of relay driver(uln2003),and the GND for oscillation crystal should be seperately connected too.