Hey guys, we have been given this project to do for an assignment this semester. It is a digital panel meter which can display a unipolar voltage between 0 and 30V DC.
The info on the project as well as a schematic diagram are included in this post.
This is the problem that i am having:
When the two ICs are removed from their holders, if i put 7V DC into the circuit, the output voltage from the 78M05CT regulator is exactly 5 volts which is normal but when i plug back in the ICs (well the one that causes this problem in particular is the CA3162E.) the voltage falls to 3.2 VOlts. I am not sure if i was supposed to do this but i increased the supply voltage to say 12 volts (my lecturer did say that this was safe enough) and then the output voltage from the regulator started pulsing around 4 volts. The current meter on my power supply was also pulsing in time with this. The Leds were also flashing in the same fashion with garbage outputs. I have checked the wiring maybe 5 times now and cant seem to figure out whats going on.
Can anyone hazard a guess as to why the regulator's voltage is dropping like this? When the output voltage falls the current meter is still saying that there is very little current out so i dont think there is a short? (unless the regulator has an inbuilt short circuit protection?
The info on the project as well as a schematic diagram are included in this post.
This is the problem that i am having:
When the two ICs are removed from their holders, if i put 7V DC into the circuit, the output voltage from the 78M05CT regulator is exactly 5 volts which is normal but when i plug back in the ICs (well the one that causes this problem in particular is the CA3162E.) the voltage falls to 3.2 VOlts. I am not sure if i was supposed to do this but i increased the supply voltage to say 12 volts (my lecturer did say that this was safe enough) and then the output voltage from the regulator started pulsing around 4 volts. The current meter on my power supply was also pulsing in time with this. The Leds were also flashing in the same fashion with garbage outputs. I have checked the wiring maybe 5 times now and cant seem to figure out whats going on.
Can anyone hazard a guess as to why the regulator's voltage is dropping like this? When the output voltage falls the current meter is still saying that there is very little current out so i dont think there is a short? (unless the regulator has an inbuilt short circuit protection?
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