can a ANDgate ic 7403 can able to switch the uln2803 input to produce output to actuate a 12v relay?

 

What 74xx series are you talking about?
74HC03, 7403 (actual), 74S03, 74LS03?

What is the current requirement of the relay, or the coil resistance?

ULN2803's should be able to be driven directly by TTL.
However, the maximum practical sink current is about 350mA; above that, Vce gets to be rather high, and the IC will heat up.

 

can a ANDgate ic 7403 can able to switch the uln2803 input to produce output to actuate a 12v relay?

The 7403 is an open collector chip, so a ~1K pull-up is all you should need.

 

Come to think of it, if it satisfies your logic state, and if it's a low current relay, the 7403 can drive (Current Sink) a relay directly when the output is in the logic Lo state.

 

Sometimes I get the feeling that AAC gets stuck somewhere in the 'Space/Time Continuum'. I really don't like parroting other members as done here, but when I posted 'both' of my posts no one had replied as yet. Now my posts are last in the list.