can a computer circuit run on a AC current?i am not talking of first converting it to dc and then using it?

Question

what happens when you pass ac through a transistor.why or why not
please give a reason

Answer 1

Yes, you could easily design and build a computer which used AC- but it would also complicate it at the same time and you probably wouldn't gain much (which is why they aren't used).

Most of the previous replies firstly assume that semiconductors only work in DC. This isn't quite true. Silicon Controller Rectifiers (SCRs) and Triacs are used in AC as switches eg in a light dimmer switch. Transistors could also be used in back to back or push-pull configurations to create the necesssary AC switching capability.

However, instead of using 0v and +V as 0 and 1 we could have a tristate system of -V, 0V and +V representing 0,1 and 2. So this computer would be tristate and based on power 3 not binary. Aside from the base all the other standard logic could be created.

However, it wouldn't be worth it as the extra circuitry to sense the voltages would complicate it and use up more semiconductors on the chip, so that the gain in going to base 3 would be negated by the need for extra circuitry. In addition, in for example hard drives, etc. it's much better and easier to sense if a field is +/- than to also have to find a zero option, so that they would probably still run as binary even in a base 3 system.

However, earlier analog computers did effectively use AC where the outputs from the op amps used in the computers went positive and negative.

I'm also sure I read a research article where -V/0V/+V were being used in a digital design, but I can't find a reference so I might have dreamt it!

New radical computer designs using quantum phenomena however do rely on having more than two states to effectively multiply the speed (see reference or just do a search for quantum computer).

Answer 2

don't believe all u read in here, some electric circuits can work directly with AC eg electric fans and electric motors etc. anyway a computer circuit cannot work with AC because it is not designed to work with it ie the CPU and all other components on the board are designed with DC power in mind, if u passed direct AC u'll end up blowing up the board and maybe recieving a little electric shock too. as for transistor and AC passage, it depend on the kind of transistor, it might try to magnify the AC or attempt to straighten it up to DC

Answer 3

Not easily. A computer works binary. Base 2. On or off. Zero or one.

AC will not pass through a transistor, a PNP would only pass the positive side of AC while a NPN would only pass the negative, so it would be switching off and on at the frequency of the AC voltage. You could of course then wire that pulse to a capacitor to smooth it, and have it control a relay, but you would lose any speed and increase expense.

Answer 4

A computer has a power supply inside that is designed to convert line voltage (120V) to required DC voltages. The mother board on the computer requires several DC voltages to work. If you sent AC voltages to the mother board the computer would NOT work. A transistor would either amplify the AC, or convert it to DC depending on how you hooked it up.

Answer 5

why not do an experiment to find out
first try reversing the dc supply and see what happens, this will give you a clue as to the behaviour with ac
(I assume you intend to first reduce the ac voltage to something suitable)
Your question shows an inquiring mind,
which doesn't just do something because that is the way it is
always done

Answer 6

I suppose one could design a computer using motors and relays that ran on AC. You can't pass AC through a NPN or PNP transistor because the diodes only allow current in one direction.

Answer 7

NO. Since transistors operate on DC it will work only may be 30% of the time. 50% positive cycle and less 20% to stay above operating voltage. ( approx)

Answer 8

All electronic circuits need DC power supply like we breath air.

Answer 9

computer circuits utilize logic highs (e.g +5 v) and logic lows (e.g. 0v) . If you used alternating currents, even it you stepped them down to a lower voltage, you would have to rectify( convert to dc) them in order to have the Integrated components to work properly.

Answer 10

All electronic circuits use dc.